chore(release): v1.0.50 (#1359)

Emit structured validation, API, network, file, and internal error envelopes for Doc shortcuts so users and agents can recover from failed document workflows using stable type, subtype, param, and code fields.

Add Doc domain errscontract and golangci guards to prevent legacy envelope and common helper regressions.

.golangci.yml

@@ -57,6 +57,14 @@ linters:
       - path: internal/vfs/
         linters:
           - forbidigo
+      # internal/gen build-time generators (standalone `package main` run via
+      # go:generate) are not shortcut runtime code — no ctx/runtime/framework —
+      # so the shortcut forbidigo bans don't apply. Going "compliant" is also
+      # impossible here: a structured error return needs os.Exit (also banned),
+      # and the vfs.Xxx() alternative is blocked by depguard shortcuts-no-vfs.
+      - path: shortcuts/.*/internal/gen/
+        linters:
+          - forbidigo
       # shortcuts-no-raw-http is shortcuts-only; internal/ wraps raw HTTP
       # for the client / credential layer.
       - path-except: shortcuts/
@@ -65,10 +73,23 @@ linters:
           - forbidigo
       # errs-typed-only enforced on paths already migrated to errs.NewXxxError.
       # Add a path when its migration is complete.
-      - path-except: (internal/auth/|internal/errcompat/|internal/errclass/|internal/client/|internal/cmdutil/factory\.go|cmd/auth/|cmd/config/|cmd/service/|shortcuts/common/mcp_client\.go|shortcuts/calendar/helpers\.go)
+      - path-except: (internal/auth/|internal/errcompat/|internal/errclass/|internal/client/|internal/cmdutil/factory\.go|cmd/auth/|cmd/config/|cmd/service/|shortcuts/common/mcp_client\.go|shortcuts/base/|shortcuts/calendar/|shortcuts/contact/|shortcuts/doc/|shortcuts/drive/|shortcuts/im/|shortcuts/mail/|shortcuts/minutes/|shortcuts/okr/|shortcuts/task/|shortcuts/vc/|shortcuts/whiteboard/|internal/event/consume/|cmd/event/|events/|shortcuts/event/)
         text: errs-typed-only
         linters:
           - forbidigo
+      # errs-no-bare-wrap enforced on paths fully migrated to typed final
+      # errors. Scoped separately from errs-typed-only because cmd/auth/,
+      # cmd/config/ still have residual fmt.Errorf and must not be caught.
+      - path-except: (shortcuts/base/|shortcuts/calendar/|shortcuts/contact/|shortcuts/doc/|shortcuts/drive/|shortcuts/im/|shortcuts/mail/|shortcuts/minutes/|shortcuts/okr/|shortcuts/task/|shortcuts/vc/|shortcuts/whiteboard/|shortcuts/common/mcp_client\.go|cmd/event/|events/|shortcuts/event/)
+        text: errs-no-bare-wrap
+        linters:
+          - forbidigo
+      # errs-no-legacy-helper enforced on domains whose shared validation/save
+      # helpers have migrated to typed final errors.
+      - path-except: (shortcuts/base/|shortcuts/calendar/|shortcuts/contact/|shortcuts/doc/|shortcuts/drive/|shortcuts/im/|shortcuts/mail/|shortcuts/minutes/|shortcuts/okr/|shortcuts/task/|shortcuts/vc/|shortcuts/whiteboard/|cmd/event/|events/|shortcuts/event/)
+        text: errs-no-legacy-helper
+        linters:
+          - forbidigo
 
   settings:
     depguard:
@@ -94,6 +115,21 @@ linters:
           msg: >-
             [errs-typed-only] use errs.NewXxxError(...) builder
             (see errs/types.go).
+        # ── legacy shared error helpers banned on migrated domains ──
+        # These helpers emit legacy output.Err* / bare error shapes or drop
+        # typed metadata such as Param/Cause. Migrated domains must use typed
+        # common replacements or local typed helpers instead.
+        - pattern: (common\.FlagErrorf|common\.RejectDangerousChars|common\.WrapInputStatError|common\.WrapSaveErrorByCategory)\b
+          msg: >-
+            [errs-no-legacy-helper] these shared helpers emit legacy or
+            metadata-poor error shapes. Use typed common replacements, typed
+            errs.NewXxxError builders, or domain-local typed helpers.
+        # ── bare error wraps banned on fully-typed paths ──
+        - pattern: (fmt\.Errorf|errors\.New)\b
+          msg: >-
+            [errs-no-bare-wrap] final errors must be typed (errs.NewXxxError);
+            wrap a cause with .WithCause(err). Genuine intermediate wraps:
+            //nolint:forbidigo with a reason.
         # ── http: shortcuts must not construct raw HTTP requests ──
         # Bans request / client construction; constants (http.MethodPost,
         # http.StatusOK) and pure helpers (http.StatusText, http.Header) are

AGENTS.md

@@ -75,7 +75,31 @@ The one rule to internalize: **every error message you write will be parsed by a
 
 ### Structured errors in commands
 
-`RunE` functions must return `output.Errorf` / `output.ErrWithHint` — never bare `fmt.Errorf`. AI agents parse stderr as JSON; bare errors break this contract.
+Command-facing failures must be typed `errs.*` errors — never the legacy `output.Err*` helpers and never a final bare `fmt.Errorf`. AI agents parse the stderr envelope's `type` / `subtype` / `param` / `hint` fields to decide their next action; the full taxonomy lives in `errs/ERROR_CONTRACT.md`.
+
+Picking a constructor:
+
+| Failure | Constructor |
+|---------|-------------|
+| User flag/arg fails validation | `errs.NewValidationError(errs.SubtypeInvalidArgument, ...).WithParam("--flag")` |
+| Valid request, wrong system state | `errs.NewValidationError(errs.SubtypeFailedPrecondition, ...).WithHint(...)` |
+| Lark API returned `code != 0` | `runtime.CallAPITyped` (shortcuts) / `errclass.BuildAPIError` (raw responses) — never hand-build |
+| Network / transport failure | `errs.NewNetworkError(errs.SubtypeNetworkTransport, ...)` |
+| Local file I/O failure | `errs.NewInternalError(errs.SubtypeFileIO, ...)` — validate the path first (`validate.SafeInputPath` / `SafeOutputPath`) and use `vfs.*` |
+| Unclassified lower-layer error as final | `errs.NewInternalError(errs.SubtypeUnknown, ...).WithCause(err)` |
+| Lower layer already returned a typed error | pass it through unchanged — re-wrapping downgrades its classification |
+
+Signatures that are easy to guess wrong:
+
+- `runtime.CallAPITyped(method, url string, params map[string]interface{}, data interface{}) (map[string]interface{}, error)` — it performs the HTTP request itself and classifies `code != 0` into a typed error; just return the error it gives you.
+- Typed pass-through check: `if _, ok := errs.ProblemOf(err); ok { return err }` — `ProblemOf` returns `(*errs.Problem, bool)`, not a nilable pointer.
+- `.WithParam` exists only on `*errs.ValidationError`. `InternalError` / `NetworkError` have no param field — file or endpoint context goes in the message or `.WithHint(...)`.
+
+`forbidigo` + `lint/errscontract` reject the legacy `output.Err*` helpers, bare final `fmt.Errorf` / `errors.New`, and legacy envelope literals on migrated paths. Beyond what lint catches, three authoring conventions apply:
+
+- Preserve the underlying error with `.WithCause(err)` so `errors.Is` / `errors.Unwrap` keep working.
+- `param` names only the user input that actually failed. Recovery guidance goes in `.WithHint(...)`; machine-readable recovery fields (`missing_scopes`, `log_id`) carry server/system ground truth only — never caller-side guesses.
+- Error-path tests assert typed metadata via `errs.ProblemOf` (`category` / `subtype` / `param`) and cause preservation, not message substrings alone.
 
 ### stdout is data, stderr is everything else
 

CHANGELOG.md

@@ -2,6 +2,146 @@
 
 All notable changes to this project will be documented in this file.
 
+## [v1.0.50] - 2026-06-09
+
+### Features
+
+- **doc**: Emit typed error envelopes across the doc domain (#1346)
+- **event**: Emit typed error envelopes across the event domain (#1289)
+- **contact**: Emit typed error envelopes across the contact domain (#1287)
+- **sheets**: Guard `+csv-put --csv` against a path passed without `@` (#1337)
+- **cli**: Adjust agent timeout hint output conditions (#1328)
+
+### Bug Fixes
+
+- **drive**: Add `@file`/stdin support to `+add-comment --content` (#1343)
+- **slides**: Build create URL locally instead of drive metas call (#1329)
+- **cli**: Clarify `--block-id` supports comma-separated batch delete in help text (#1336)
+
+### Documentation
+
+- **doc**: Replace append with `block_insert_after` in skeleton workflow guidance (#1340)
+- **doc**: Document `<folder-manager>` resource block (#1168)
+- **drive**: Add drive comment location guidance (#1258)
+
+## [v1.0.49] - 2026-06-08
+
+### Features
+
+- **events**: Add whiteboard event domain with per-board subscription (#1265)
+- **im**: Support feed group (#1102)
+- **im**: Add feed shortcut create, list, and remove shortcuts (#1273)
+- **im**: Format feed group error handling (#1308)
+- **im**: Return typed error envelopes across the im domain (#1230)
+- **base**: Emit typed error envelopes across the base domain (#1248)
+- **calendar**: Emit typed error envelopes across the calendar domain (#1232)
+- **task**: Emit typed error envelopes across the task domain (#1231)
+- **okr,whiteboard**: Emit typed error envelopes across both domains (#1236)
+- **minutes,vc**: Emit typed error envelopes across both domains (#1234)
+- **markdown**: Harden create upload failures (#1325)
+- **drive**: Harden inspect shortcut failures (#1324)
+- **slides**: Add IconPark lookup for Lark slides (#1123)
+- **doc**: Remove docs v1 API (#1291)
+- **cli**: Add `skills` command to read embedded skill content (#1318)
+- **cli**: Fetch official skills index (#1301)
+- **shared**: Document relative-path-only file arguments (#1319)
+- **scopes**: Clear `recommend.allow` scope auto-approve overrides (#1272)
+- **shortcuts**: Check shortcut example commands against the live CLI tree (#1244)
+
+### Bug Fixes
+
+- **events**: Keep bounded event consume runs alive after stdin EOF (#1285)
+- **drive**: Use docs secure label read scope (#1281)
+
+### Documentation
+
+- **approval**: Restructure skill with intent table and scope boundaries (#1307)
+- **skills**: Tighten drive and markdown guardrails (#1326)
+- **skills**: Optimize calendar, vc, and minutes skill guidance (#1269)
+- **markdown**: Add markdown domain template (#1293)
+- **markdown**: Improve lark-markdown skill guidance (#1279)
+- **doc**: Improve lark-doc skill guidance (#1283)
+- **wiki**: Optimize skill guidance and routing boundaries (#1275)
+- **slides**: Tighten routing/boundary and reconcile in-slide whiteboard (#1169)
+
+## [v1.0.48] - 2026-06-04
+
+### Features
+
+- **mail**: Preserve mailbox context in `+triage` output for public mailboxes (#1238)
+- **contact**: Add contact skill domain guidance (#1144)
+
+### Bug Fixes
+
+- **skills**: Use JSON skills list during update (#1251)
+
+### Documentation
+
+- **drive**: Refine lark-drive knowledge organize workflow (#1253)
+- **vc-agent**: Require explicit leave request (#1260)
+- **slides**: Add whiteboard element documentation and improve slide guidance (#1029)
+
+## [v1.0.47] - 2026-06-03
+
+### Features
+
+- **sheets**: Add spec-driven shortcut package with backward-compatible wrapper (#1220)
+- **base**: Add base block shortcuts (#1044)
+- **im**: Complete card message format (#1198)
+- **im**: Improve markdown guidance for messages (#1237)
+- **vc**: Forward invite call-id on meeting join (#1243)
+- **drive**: Emit typed error envelopes across the drive domain (#1205)
+- **common**: Emit typed validation errors from shared shortcut pre-checks (#1242)
+- **mail**: Validate `message_ids` in `+messages` before batch get (#1202)
+- **wiki**: Support `appid` member type (#1235)
+- **cli**: Add `--json` flag as no-op alias for `--format json` (#1104)
+- **config**: Validate credentials after `config init` (#1151)
+
+### Bug Fixes
+
+- **skills**: Recover empty fallback for skills to update (#1233)
+
+## [v1.0.46] - 2026-06-02
+
+### Features
+
+- **im**: Add card message format support (#1218)
+- **im**: Resolve markdown blank-line formatting inconsistency in post messages (#1216)
+- **vc**: Inline transcript from artifacts API and add keywords (#1206)
+- **transport**: Add proxy plugin mode for CLI HTTP transport (#1181)
+- **agent**: Increase agent trace max length to 1024 (#1211)
+- **shortcuts**: Unconditionally inject `--format` flag for all shortcuts (#1156)
+
+### Bug Fixes
+
+- **cli**: Remove FLAGS section from root `--help` (#1226)
+- **cli**: Stop root `--help` listing per-command flags as global (#1223)
+
+### Refactor
+
+- **transport**: Own all HTTP transport in `internal/transport`, fix util layering inversion (#1213)
+
+### Documentation
+
+- **base**: Optimize base skill references (#1171)
+- **drive**: Add Lark Drive knowledge organization workflow (#1028)
+
+## [v1.0.45] - 2026-06-01
+
+### Features
+
+- **errors**: Add typed envelope contract for auth-domain errors (#1135)
+- **platform**: Support multiple policy rules per plugin (#1182)
+
+### Bug Fixes
+
+- **vc**: Add domain boundaries and enrich `+notes` (#1172)
+- **whiteboard**: Fix whiteboard skill (#1180)
+
+### Refactor
+
+- **auth**: Update login hint and split-flow docs (#1201)
+
 ## [v1.0.44] - 2026-05-29
 
 ### Features
@@ -948,6 +1088,12 @@ Bundled AI agent skills for intelligent assistance:
 - Bilingual documentation (English & Chinese).
 - CI/CD pipelines: linting, testing, coverage reporting, and automated releases.
 
+[v1.0.50]: https://github.com/larksuite/cli/releases/tag/v1.0.50
+[v1.0.49]: https://github.com/larksuite/cli/releases/tag/v1.0.49
+[v1.0.48]: https://github.com/larksuite/cli/releases/tag/v1.0.48
+[v1.0.47]: https://github.com/larksuite/cli/releases/tag/v1.0.47
+[v1.0.46]: https://github.com/larksuite/cli/releases/tag/v1.0.46
+[v1.0.45]: https://github.com/larksuite/cli/releases/tag/v1.0.45
 [v1.0.44]: https://github.com/larksuite/cli/releases/tag/v1.0.44
 [v1.0.43]: https://github.com/larksuite/cli/releases/tag/v1.0.43
 [v1.0.42]: https://github.com/larksuite/cli/releases/tag/v1.0.42

cmd/api/api.go

@@ -90,6 +90,7 @@ func NewCmdApiWithContext(ctx context.Context, f *cmdutil.Factory, runF func(*AP
 	cmd.Flags().IntVar(&opts.PageLimit, "page-limit", 10, "max pages to fetch with --page-all (0 = unlimited)")
 	cmd.Flags().IntVar(&opts.PageDelay, "page-delay", 200, "delay in ms between pages")
 	cmd.Flags().StringVar(&opts.Format, "format", "json", "output format: json|ndjson|table|csv")
+	cmd.Flags().Bool("json", false, "shorthand for --format json")
 	cmd.Flags().StringVarP(&opts.JqExpr, "jq", "q", "", "jq expression to filter JSON output")
 	cmd.Flags().BoolVar(&opts.DryRun, "dry-run", false, "print request without executing")
 	cmd.Flags().StringVar(&opts.File, "file", "", "file to upload as multipart/form-data ([field=]path, supports - for stdin)")

cmd/api/api_test.go

@@ -718,3 +718,23 @@ func TestApiCmd_PermissionError_DerivesFirstClassFields(t *testing.T) {
 		t.Errorf("LogID = %q, want %q", pe.LogID, "20260527-test-log")
 	}
 }
+
+func TestApiCmd_JsonFlag_Accepted(t *testing.T) {
+	f, _, _, _ := cmdutil.TestFactory(t, &core.CliConfig{
+		AppID: "test-app", AppSecret: "test-secret", Brand: core.BrandFeishu,
+	})
+
+	var gotOpts *APIOptions
+	cmd := NewCmdApi(f, func(opts *APIOptions) error {
+		gotOpts = opts
+		return nil
+	})
+	cmd.SetArgs([]string{"GET", "/open-apis/test", "--json"})
+	err := cmd.Execute()
+	if err != nil {
+		t.Fatalf("--json should be accepted without error, got: %v", err)
+	}
+	if gotOpts.Method != "GET" {
+		t.Errorf("expected method GET, got %s", gotOpts.Method)
+	}
+}

cmd/auth/login.go

@@ -296,10 +296,11 @@ func authLoginRun(opts *LoginOptions) error {
 	}
 
 	// Step 2: Show user code and verification URL.
-	// Both branches surface AgentTimeoutHint, but on different channels:
-	// JSON mode embeds it as a structured field (so an agent that captures
-	// stdout into a JSON parser sees it without stream-mixing surprises),
-	// text mode prints to stderr (alongside the URL prompt).
+	// JSON mode embeds AgentTimeoutHint as a structured field so agents that
+	// capture stdout into a JSON parser see it without stream-mixing surprises.
+	// Text mode prints the hint to stderr only when running under a non-TTY
+	// (i.e. piped / agent harness), since humans reading a terminal don't need
+	// the agent-oriented instructions.
 	if opts.JSON {
 		data := map[string]interface{}{
 			"event":                     "device_authorization",
@@ -317,7 +318,9 @@ func authLoginRun(opts *LoginOptions) error {
 	} else {
 		fmt.Fprintf(f.IOStreams.ErrOut, msg.OpenURL)
 		fmt.Fprintf(f.IOStreams.ErrOut, "  %s\n\n", authResp.VerificationUriComplete)
-		fmt.Fprintln(f.IOStreams.ErrOut, msg.AgentTimeoutHint)
+		if f.IOStreams != nil && !f.IOStreams.IsTerminal {
+			fmt.Fprintln(f.IOStreams.ErrOut, msg.AgentTimeoutHint)
+		}
 	}
 
 	// Step 3: Poll for token
@@ -404,10 +407,11 @@ func authLoginPollDeviceCode(opts *LoginOptions, config *core.CliConfig, msg *lo
 			fmt.Fprintf(f.IOStreams.ErrOut, "[lark-cli] [WARN] auth login: failed to remove cached requested scopes: %v\n", err)
 		}
 	}
-	// Skip the stderr hint in JSON mode — the --no-wait call that issued the
-	// device_code already returned the hint as a JSON field, and writing
-	// text to stderr would pollute consumers that combine streams via 2>&1.
-	if !opts.JSON {
+	// Skip the stderr hint in JSON mode (the --no-wait call that issued
+	// the device_code already surfaced it as a JSON field), and also skip it
+	// when running on an interactive terminal — the agent-oriented
+	// instructions only matter for piped / harness environments.
+	if !opts.JSON && f.IOStreams != nil && !f.IOStreams.IsTerminal {
 		fmt.Fprintln(f.IOStreams.ErrOut, msg.AgentTimeoutHint)
 	}
 	log(msg.WaitingAuth)

cmd/build.go

@@ -6,6 +6,7 @@ package cmd
 import (
 	"context"
 	"io"
+	"io/fs"
 
 	"github.com/larksuite/cli/cmd/api"
 	"github.com/larksuite/cli/cmd/auth"
@@ -16,6 +17,7 @@ import (
 	"github.com/larksuite/cli/cmd/profile"
 	"github.com/larksuite/cli/cmd/schema"
 	"github.com/larksuite/cli/cmd/service"
+	"github.com/larksuite/cli/cmd/skill"
 	cmdupdate "github.com/larksuite/cli/cmd/update"
 	_ "github.com/larksuite/cli/events"
 	"github.com/larksuite/cli/internal/build"
@@ -51,6 +53,18 @@ func WithKeychain(kc keychain.KeychainAccess) BuildOption {
 	}
 }
 
+// embeddedSkillContent is the skill tree wired into cmdutil.Factory.SkillContent
+// at build time. It is registered by the repo-root package main's init via
+// SetEmbeddedSkillContent — it cannot be threaded through main.go without
+// breaking the single-file preview build (see skills_embed.go). nil in builds
+// that embed no skills; the `skills` commands then return a typed internal error.
+var embeddedSkillContent fs.FS
+
+// SetEmbeddedSkillContent registers the embedded skill tree. Called from the
+// repo-root package main's init; a wrapper main can call it before Execute to
+// supply its own skill content.
+func SetEmbeddedSkillContent(fsys fs.FS) { embeddedSkillContent = fsys }
+
 // HideProfile sets the visibility policy for the root-level --profile flag.
 // When hide is true the flag stays registered (so existing invocations still
 // parse) but is omitted from help and shell completion. Typically called as
@@ -103,6 +117,7 @@ func buildInternal(ctx context.Context, inv cmdutil.InvocationContext, opts ...B
 	if cfg.keychain != nil {
 		f.Keychain = cfg.keychain
 	}
+	f.SkillContent = embeddedSkillContent
 	rootCmd := &cobra.Command{
 		Use:     "lark-cli",
 		Short:   "Lark/Feishu CLI — OAuth authorization, UAT management, API calls",
@@ -117,6 +132,13 @@ func buildInternal(ctx context.Context, inv cmdutil.InvocationContext, opts ...B
 
 	installTipsHelpFunc(rootCmd)
 	rootCmd.SilenceErrors = true
+	// SilenceUsage as a static field (not only in PersistentPreRun) so it also
+	// covers flag-parse errors, which fail before PreRun runs — otherwise cobra
+	// dumps usage instead of our structured error. SetFlagErrorFunc on root is
+	// inherited by every subcommand, turning unknown-flag errors into a
+	// structured "did you mean" envelope.
+	rootCmd.SilenceUsage = true
+	rootCmd.SetFlagErrorFunc(flagDidYouMean)
 
 	RegisterGlobalFlags(rootCmd.PersistentFlags(), &cfg.globals)
 	rootCmd.PersistentPreRun = func(cmd *cobra.Command, args []string) {
@@ -133,6 +155,7 @@ func buildInternal(ctx context.Context, inv cmdutil.InvocationContext, opts ...B
 	rootCmd.AddCommand(completion.NewCmdCompletion(f))
 	rootCmd.AddCommand(cmdupdate.NewCmdUpdate(f))
 	rootCmd.AddCommand(cmdevent.NewCmdEvents(f))
+	rootCmd.AddCommand(skill.NewCmdSkill(f))
 	service.RegisterServiceCommandsWithContext(ctx, rootCmd, f)
 	shortcuts.RegisterShortcutsWithContext(ctx, rootCmd, f)
 

cmd/cmdexample_catalog_test.go

@@ -0,0 +1,160 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package cmd_test
+
+import (
+	"sort"
+	"strings"
+)
+
+// universalFlags are accepted by every command (cobra auto-injects help; the
+// root injects version). They are never reported as unknown.
+var universalFlags = map[string]bool{"--help": true, "-h": true, "--version": true}
+
+// catalog is the source-of-truth command catalog: command path -> accepted flag
+// tokens. A path is the command words WITHOUT the "lark-cli" root prefix, e.g.
+// "contact +search-user". The root command is the empty path "".
+type catalog struct {
+	flagsByPath map[string]map[string]bool
+	group       map[string]bool // paths that are parent groups (have subcommands)
+	sorted      []string        // cached sorted paths for suggestCommand; invalidated on addCommand
+}
+
+func newCatalog() *catalog {
+	return &catalog{
+		flagsByPath: map[string]map[string]bool{},
+		group:       map[string]bool{},
+	}
+}
+
+// setGroup records whether path is a parent group (has subcommands). Leftover
+// words after a group node are unknown subcommands; after a leaf they are
+// positionals (e.g. "api GET /path").
+func (c *catalog) setGroup(path string, isGroup bool) {
+	if isGroup {
+		c.group[path] = true
+	}
+}
+
+func (c *catalog) isGroup(path string) bool { return c.group[path] }
+
+// addCommand registers a command path and the flags it accepts. Repeated calls
+// for the same path union the flag sets. flags are full tokens ("--query", "-q").
+func (c *catalog) addCommand(path string, flags []string) {
+	set := c.flagsByPath[path]
+	if set == nil {
+		set = map[string]bool{}
+		c.flagsByPath[path] = set
+	}
+	for _, f := range flags {
+		set[f] = true
+	}
+	c.sorted = nil // invalidate cached suggestion list
+}
+
+func (c *catalog) hasCommand(path string) bool {
+	_, ok := c.flagsByPath[path]
+	return ok
+}
+
+// hasFlag reports whether flag is accepted by command path (universal flags
+// always pass).
+func (c *catalog) hasFlag(path, flag string) bool {
+	if universalFlags[flag] {
+		return true
+	}
+	set := c.flagsByPath[path]
+	return set[flag]
+}
+
+// longestPrefix returns the longest known command path that is a prefix of
+// words, plus how many words it consumed. This separates real subcommands from
+// trailing positionals (e.g. "api GET /path" resolves to "api"). When words is
+// empty it falls back to the root command. ok=false means not even the first
+// word names a command.
+func (c *catalog) longestPrefix(words []string) (path string, n int, ok bool) {
+	if len(words) == 0 {
+		if c.hasCommand("") {
+			return "", 0, true
+		}
+		return "", 0, false
+	}
+	for i := len(words); i >= 1; i-- {
+		cand := strings.Join(words[:i], " ")
+		if c.hasCommand(cand) {
+			return cand, i, true
+		}
+	}
+	return "", 0, false
+}
+
+// paths returns all known command paths, sorted.
+func (c *catalog) paths() []string {
+	out := make([]string, 0, len(c.flagsByPath))
+	for p := range c.flagsByPath {
+		out = append(out, p)
+	}
+	sort.Strings(out)
+	return out
+}
+
+// suggestCommand returns the known command path closest to want (small edit
+// distance), for error hints. Returns "" when nothing is reasonably close.
+func (c *catalog) suggestCommand(want string) string {
+	if c.sorted == nil {
+		c.sorted = c.paths() // built once after the catalog is fully populated
+	}
+	return closest(want, c.sorted)
+}
+
+// suggestFlag returns the flag of path closest to flag, for error hints.
+func (c *catalog) suggestFlag(path, flag string) string {
+	set := c.flagsByPath[path]
+	cands := make([]string, 0, len(set))
+	for f := range set {
+		cands = append(cands, f)
+	}
+	sort.Strings(cands)
+	return closest(flag, cands)
+}
+
+// closest returns the candidate with the smallest Levenshtein distance to want,
+// but only if that distance is within a tolerance scaled to want's length
+// (avoids absurd suggestions).
+func closest(want string, cands []string) string {
+	best := ""
+	bestD := 1 << 30
+	for _, cand := range cands {
+		d := levenshtein(want, cand)
+		if d < bestD {
+			bestD, best = d, cand
+		}
+	}
+	tol := len(want)/2 + 1
+	if bestD > tol {
+		return ""
+	}
+	return best
+}
+
+func levenshtein(a, b string) int {
+	ra, rb := []rune(a), []rune(b)
+	prev := make([]int, len(rb)+1)
+	for j := range prev {
+		prev[j] = j
+	}
+	for i := 1; i <= len(ra); i++ {
+		cur := make([]int, len(rb)+1)
+		cur[0] = i
+		for j := 1; j <= len(rb); j++ {
+			cost := 1
+			if ra[i-1] == rb[j-1] {
+				cost = 0
+			}
+			cur[j] = min(prev[j]+1, cur[j-1]+1, prev[j-1]+cost)
+		}
+		prev = cur
+	}
+	return prev[len(rb)]
+}

cmd/cmdexample_check_test.go

@@ -0,0 +1,60 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package cmd_test
+
+import "strings"
+
+// Finding kinds.
+const (
+	unknownCommand = "unknown_command"
+	unknownFlag    = "unknown_flag"
+)
+
+// finding is a single mismatch between an example command reference and the
+// catalog.
+type finding struct {
+	line    int
+	raw     string
+	kind    string // unknownCommand | unknownFlag
+	path    string // resolved command path (unknownFlag) or attempted path (unknownCommand)
+	flag    string // offending flag (unknownFlag only)
+	suggest string // nearest known command/flag, "" if none close
+}
+
+// checkRefs validates refs against cat and returns all mismatches in order.
+func checkRefs(cat *catalog, refs []ref) []finding {
+	var out []finding
+	for _, r := range refs {
+		path, n, ok := cat.longestPrefix(r.words)
+		if !ok {
+			attempted := strings.Join(r.words, " ")
+			out = append(out, finding{
+				line: r.line, raw: r.raw, kind: unknownCommand,
+				path: attempted, suggest: cat.suggestCommand(attempted),
+			})
+			continue
+		}
+		// Leftover words after a group node are an unknown subcommand (e.g. a
+		// mistyped method like "batch_modify_message"). After a leaf they are
+		// positionals (e.g. "api GET /path"), so only groups trigger this.
+		if n < len(r.words) && cat.isGroup(path) {
+			attempted := strings.Join(r.words, " ")
+			out = append(out, finding{
+				line: r.line, raw: r.raw, kind: unknownCommand,
+				path: attempted, suggest: cat.suggestCommand(attempted),
+			})
+			continue
+		}
+		for _, f := range r.flags {
+			if cat.hasFlag(path, f) {
+				continue
+			}
+			out = append(out, finding{
+				line: r.line, raw: r.raw, kind: unknownFlag,
+				path: path, flag: f, suggest: cat.suggestFlag(path, f),
+			})
+		}
+	}
+	return out
+}

cmd/cmdexample_parse_test.go

@@ -0,0 +1,222 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package cmd_test
+
+import (
+	"regexp"
+	"strings"
+)
+
+// ref is one lark-cli command reference extracted from a shortcut example.
+type ref struct {
+	line  int      // 1-based line number (the line where the command starts)
+	raw   string   // reconstructed command text, for error display
+	words []string // command words before the first flag (subcommand candidates)
+	flags []string // flag tokens used, e.g. "--query", "-q"
+}
+
+const cliToken = "lark-cli"
+
+// subcommandStart guards against false positives from prose: a real command's
+// first word is ASCII (a service name or a +shortcut). A token starting with
+// CJK / punctuation is treated as narration, not a command.
+var subcommandStart = regexp.MustCompile(`^[A-Za-z+]`)
+
+// shellStops are standalone tokens that terminate a command (pipes, redirects,
+// separators). Separators glued to a token (`get;`, `foo|`) are handled inline.
+var shellStops = map[string]bool{
+	"|": true, "||": true, "&&": true, "&": true, ";": true,
+	">": true, ">>": true, "<": true, "2>": true, "2>&1": true,
+}
+
+// wordTrailPunct is sentence / CJK punctuation that can cling to a command word
+// in prose ("auth login." / "auth login，"); stripped so the word still resolves
+// instead of being dropped as an unknown command or non-ASCII narration.
+const wordTrailPunct = `.,;:!?"')]}，。、；：！？）】」』`
+
+// parseRefs extracts every lark-cli command reference from text (a shortcut's
+// Tips line, which may embed an "Example: lark-cli ..." command). It is
+// deliberately format-agnostic: it keys on the "lark-cli" token whether it sits
+// in a ```bash fence, an inline `code` span, or bare prose. Backslash
+// line-continuations are joined first so a multi-line invocation is parsed as
+// one command; inline-code backticks and trailing # comments terminate it.
+func parseRefs(content string) []ref {
+	var refs []ref
+	lines := strings.Split(content, "\n")
+	for i := 0; i < len(lines); i++ {
+		lineNo := i + 1
+		logical := lines[i]
+		// Shell line continuation: a trailing backslash joins the next physical
+		// line. Without this, flags on the continuation lines of a multi-line
+		// `lark-cli ... \` example are never seen by the checker.
+		for endsWithBackslash(logical) && i+1 < len(lines) {
+			logical = strings.TrimRight(logical, " \t")
+			logical = logical[:len(logical)-1] // drop the trailing backslash
+			i++
+			logical += " " + lines[i]
+		}
+		refs = append(refs, parseLine(logical, lineNo)...)
+	}
+	return refs
+}
+
+func endsWithBackslash(s string) bool {
+	return strings.HasSuffix(strings.TrimRight(s, " \t"), `\`)
+}
+
+func parseLine(line string, lineNo int) []ref {
+	var refs []ref
+	rest := line
+	for {
+		idx := strings.Index(rest, cliToken)
+		if idx < 0 {
+			break
+		}
+		after := rest[idx+len(cliToken):]
+		beforeOK := idx == 0 || isBoundary(rest[idx-1])
+		afterOK := after == "" || isBoundary(after[0])
+		if beforeOK && afterOK {
+			if words, flags, raw, ok := parseCmd(after); ok {
+				refs = append(refs, ref{line: lineNo, raw: cliToken + raw, words: words, flags: flags})
+			}
+		}
+		rest = after
+	}
+	return refs
+}
+
+// parseCmd tokenizes the text following "lark-cli" into leading command words
+// (the subcommand path, up to the first flag) and flag tokens. It stops at a
+// shell separator (standalone or glued), an inline-code backtick, a comment, or
+// a placeholder/prose word. ok=false filters out non-commands.
+func parseCmd(after string) (words, flags []string, raw string, ok bool) {
+	// An inline code span ends at the next backtick; a command never spans one.
+	if i := strings.IndexByte(after, '`'); i >= 0 {
+		after = after[:i]
+	}
+	// Drop $(...) command substitutions so flags belonging to the inner command
+	// (e.g. `--data "$(jq -n --arg x ...)"`) are not mistaken for lark-cli flags.
+	after = stripCmdSubst(after)
+
+	var kept []string
+	inFlags := false
+	for _, orig := range strings.Fields(after) {
+		tok := orig
+		if shellStops[tok] || strings.HasPrefix(tok, "#") {
+			break
+		}
+		// A shell separator glued to a token ends the command mid-token
+		// ("get;", "foo|next"): keep the part before it, handle it, then stop.
+		stop := false
+		if i := strings.IndexAny(tok, ";|"); i >= 0 {
+			tok, stop = tok[:i], true
+		}
+		switch {
+		case tok == "" || tok == "-":
+			// empty (after a glued separator) or a bare stdin marker — skip
+		case strings.HasPrefix(tok, "-"):
+			if f := normalizeFlag(tok); f != "" {
+				inFlags = true
+				flags = append(flags, f)
+				kept = append(kept, tok)
+			}
+		case inFlags:
+			// positional / flag value after the first flag — not a command word
+			kept = append(kept, tok)
+		default:
+			// Command-path word. ASCII placeholder markers (<x>, [x], {x|y},
+			// +<verb>, ...) end the command — checked on the RAW token so the
+			// trailing-punct stripping below cannot erase a "..." ellipsis
+			// ("base +..." must stay a placeholder, not become "+").
+			if strings.ContainsAny(tok, "<>[]{}|") || strings.Contains(tok, "...") {
+				stop = true
+				break
+			}
+			// Strip trailing sentence/CJK punctuation so "login." / "login，"
+			// resolve to "login"; non-ASCII narration ends the command.
+			w := strings.TrimRight(tok, wordTrailPunct)
+			if w == "" || hasNonASCII(w) {
+				stop = true
+				break
+			}
+			words = append(words, w)
+			kept = append(kept, tok)
+		}
+		if stop {
+			break
+		}
+	}
+	if len(kept) > 0 {
+		raw = " " + strings.Join(kept, " ")
+	}
+	// Keep root-only refs ("lark-cli --help") and refs whose first word looks
+	// like a subcommand; drop prose ("lark-cli 就能搞定 ...").
+	if len(words) == 0 {
+		return words, flags, raw, len(flags) > 0
+	}
+	if !subcommandStart.MatchString(words[0]) {
+		return nil, nil, "", false
+	}
+	return words, flags, raw, true
+}
+
+// stripCmdSubst removes $(...) command substitutions (including nested ones)
+// from s, leaving the surrounding text intact. Backtick substitutions are
+// already handled upstream (a command never spans a backtick).
+func stripCmdSubst(s string) string {
+	var b strings.Builder
+	depth := 0
+	for i := 0; i < len(s); i++ {
+		if depth == 0 && i+1 < len(s) && s[i] == '$' && s[i+1] == '(' {
+			depth = 1
+			i++ // skip '('
+			continue
+		}
+		if depth > 0 {
+			switch s[i] {
+			case '(':
+				depth++
+			case ')':
+				depth--
+			}
+			continue
+		}
+		b.WriteByte(s[i])
+	}
+	return b.String()
+}
+
+// isPlaceholderOrProse reports whether a command word is a doc placeholder
+// (<resource>, [flags], {a|b}, +<verb>, ...) or narration (CJK / other
+// non-ASCII), rather than a literal command token.
+func isPlaceholderOrProse(w string) bool {
+	if hasNonASCII(w) {
+		return true
+	}
+	return strings.ContainsAny(w, "<>[]{}|") || strings.Contains(w, "...")
+}
+
+func hasNonASCII(s string) bool {
+	return strings.IndexFunc(s, func(r rune) bool { return r > 127 }) >= 0
+}
+
+// flagShape matches the leading flag token, stripping any trailing junk such as
+// a "=value" suffix or punctuation that bled in from the surrounding markdown
+// ("--help\"", "--help;", "--params={}"). The underscore is allowed because
+// real flags use it ("--input_format", "--output_as"). Returns "" for non-flags.
+var flagShape = regexp.MustCompile(`^--?[A-Za-z][A-Za-z0-9_-]*`)
+
+// normalizeFlag extracts the canonical flag token from tok, or "" if tok is not
+// a real flag (e.g. a shell-string fragment like "-草稿'").
+func normalizeFlag(tok string) string {
+	return flagShape.FindString(tok)
+}
+
+func isBoundary(b byte) bool {
+	switch b {
+	case ' ', '\t', '`', '(', ')', '\'', '"', '*':
+		return true
+	}
+	return false
+}

cmd/cmdexample_test.go

@@ -0,0 +1,113 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+// This file and its cmdexample_*_test.go siblings implement a test-only check:
+// the example commands embedded in shortcut definitions (the "Example: lark-cli
+// ..." lines in each shortcut's Tips, shown in --help) must match the real
+// command tree. It lives entirely in _test.go files (package cmd_test) so it
+// ships in no binary and is not importable by product code; the truth source is
+// cmd.Build, the same tree the binary uses, so the check cannot drift.
+//
+// It runs in the standard unit-test CI job (go test ./cmd/...). A mismatch — an
+// example using a renamed command or an unaccepted flag — fails that job.
+
+package cmd_test
+
+import (
+	"context"
+	"sort"
+	"strings"
+	"testing"
+
+	"github.com/larksuite/cli/cmd"
+	"github.com/larksuite/cli/internal/cmdutil"
+	"github.com/larksuite/cli/shortcuts"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+)
+
+// TestShortcutExampleCommands checks the example commands embedded in every
+// shortcut's Tips against the live command tree. A shortcut that defines no
+// example is simply skipped.
+//
+// Because the examples and the command definitions live in the same Go code,
+// this is a self-consistency check: any mismatch (an example using a renamed
+// command or a flag the command doesn't accept) is a bug to fix at the source.
+// It runs over all shortcuts — no baseline, no diff — since a wrong example is
+// always a defect, never acceptable "pre-existing drift".
+func TestShortcutExampleCommands(t *testing.T) {
+	// Reproducibility: use the embedded API metadata (not a developer's stale
+	// ~/.lark-cli remote cache, which can miss commands) and an empty config
+	// dir so local strict mode / plugins / policy cannot reshape the tree.
+	// t.Setenv auto-restores after the test, so other cmd tests are unaffected.
+	t.Setenv("LARKSUITE_CLI_REMOTE_META", "off")
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+
+	cat := buildCmdExampleCatalog()
+
+	type located struct {
+		shortcut string
+		f        finding
+	}
+	var findings []located
+	for _, sc := range shortcuts.AllShortcuts() {
+		var refs []ref
+		for _, tip := range sc.Tips {
+			refs = append(refs, parseRefs(tip)...)
+		}
+		label := strings.TrimSpace(sc.Service + " " + sc.Command)
+		for _, f := range checkRefs(cat, refs) {
+			findings = append(findings, located{shortcut: label, f: f})
+		}
+	}
+
+	if len(findings) == 0 {
+		return
+	}
+	sort.Slice(findings, func(i, j int) bool { return findings[i].shortcut < findings[j].shortcut })
+	for _, lf := range findings {
+		hint := ""
+		if lf.f.suggest != "" {
+			hint = "  (did you mean " + lf.f.suggest + "?)"
+		}
+		if lf.f.kind == unknownFlag {
+			t.Errorf("shortcut %q example uses unknown flag %s on %q%s\n      %s",
+				lf.shortcut, lf.f.flag, lf.f.path, hint, strings.TrimSpace(lf.f.raw))
+		} else {
+			t.Errorf("shortcut %q example uses unknown command %q%s\n      %s",
+				lf.shortcut, lf.f.path, hint, strings.TrimSpace(lf.f.raw))
+		}
+	}
+	t.Fatalf("%d shortcut example command(s) don't match the real CLI — "+
+		"fix the Example in the shortcut definition.", len(findings))
+}
+
+// buildCmdExampleCatalog walks the live cobra command tree and records every
+// command path (minus the "lark-cli" root prefix) with its accepted flags and
+// whether it is a parent group. This is the same Build() the binary uses, so
+// the catalog can never drift from the real commands.
+func buildCmdExampleCatalog() *catalog {
+	root := cmd.Build(context.Background(), cmdutil.InvocationContext{})
+	cat := newCatalog()
+	var walk func(c *cobra.Command)
+	walk = func(c *cobra.Command) {
+		path := strings.TrimSpace(strings.TrimPrefix(c.CommandPath(), "lark-cli"))
+		var flags []string
+		add := func(fl *pflag.Flag) {
+			flags = append(flags, "--"+fl.Name)
+			if fl.Shorthand != "" {
+				flags = append(flags, "-"+fl.Shorthand)
+			}
+		}
+		c.Flags().VisitAll(add)
+		c.InheritedFlags().VisitAll(add)
+		c.PersistentFlags().VisitAll(add) // root's own persistent flags (e.g. --profile)
+		cat.addCommand(path, flags)
+		cat.setGroup(path, c.HasSubCommands())
+		for _, sub := range c.Commands() {
+			walk(sub)
+		}
+	}
+	walk(root)
+	return cat
+}

cmd/cmdexample_units_test.go

@@ -0,0 +1,233 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package cmd_test
+
+import (
+	"strings"
+	"testing"
+)
+
+func testCatalog() *catalog {
+	c := newCatalog()
+	c.addCommand("", []string{"--profile"}) // root
+	c.setGroup("", true)
+	c.addCommand("contact", []string{"--profile"})
+	c.setGroup("contact", true)
+	c.addCommand("contact +search-user", []string{"--query", "--as", "--format", "-q"})
+	c.addCommand("api", []string{"--params", "--data", "--as"}) // leaf (no subcommands)
+	c.addCommand("mail", nil)
+	c.setGroup("mail", true)
+	c.addCommand("mail user_mailbox.messages", []string{"--profile"})
+	c.setGroup("mail user_mailbox.messages", true)
+	c.addCommand("mail user_mailbox.messages batch_modify", []string{"--params", "--data"})
+	return c
+}
+
+func TestCmdExampleCatalogHasCommandAndFlag(t *testing.T) {
+	c := testCatalog()
+	if !c.hasCommand("contact +search-user") {
+		t.Fatal("expected contact +search-user to exist")
+	}
+	if c.hasCommand("contact +nope") {
+		t.Fatal("did not expect contact +nope")
+	}
+	if !c.hasFlag("contact +search-user", "--query") {
+		t.Fatal("--query should be valid")
+	}
+	if c.hasFlag("contact +search-user", "--nope") {
+		t.Fatal("--nope should be invalid")
+	}
+	// universal flags pass on any command
+	for _, f := range []string{"--help", "-h", "--version"} {
+		if !c.hasFlag("contact +search-user", f) {
+			t.Fatalf("universal flag %s should pass", f)
+		}
+	}
+}
+
+func TestCmdExampleLongestPrefix(t *testing.T) {
+	c := testCatalog()
+	tests := []struct {
+		words  []string
+		want   string
+		wantN  int
+		wantOK bool
+	}{
+		{[]string{"contact", "+search-user"}, "contact +search-user", 2, true},
+		{[]string{"api", "GET", "/open-apis/x"}, "api", 1, true}, // trailing positionals
+		{[]string{"nope"}, "", 0, false},
+		{nil, "", 0, true}, // empty -> root
+	}
+	for _, tt := range tests {
+		got, n, ok := c.longestPrefix(tt.words)
+		if got != tt.want || n != tt.wantN || ok != tt.wantOK {
+			t.Errorf("longestPrefix(%v) = (%q,%d,%v), want (%q,%d,%v)",
+				tt.words, got, n, ok, tt.want, tt.wantN, tt.wantOK)
+		}
+	}
+}
+
+func refWordsOf(refs []ref) [][]string {
+	var out [][]string
+	for _, r := range refs {
+		out = append(out, r.words)
+	}
+	return out
+}
+
+func TestCmdExampleParseRefsExtractsCommands(t *testing.T) {
+	content := strings.Join([]string{
+		"运行 `lark-cli contact +search-user --query 张三` 搜索", // inline code
+		"```bash",
+		"lark-cli api GET /open-apis/x --params '{}'", // bash block
+		"```",
+		"用 lark-cli mail user_mailbox.messages batch_modify 即可", // bare prose command
+		"npx foo | lark-cli api GET /y",                         // after a pipe
+	}, "\n")
+	refs := parseRefs(content)
+	if len(refs) != 4 {
+		t.Fatalf("expected 4 refs, got %d: %v", len(refs), refWordsOf(refs))
+	}
+	if got := refs[0]; strings.Join(got.words, " ") != "contact +search-user" ||
+		len(got.flags) != 1 || got.flags[0] != "--query" {
+		t.Errorf("ref0 = %+v", got)
+	}
+	if got := refs[1]; strings.Join(got.words, " ") != "api GET /open-apis/x" {
+		t.Errorf("ref1 words = %v", got.words)
+	}
+}
+
+func TestCmdExampleParseRefsFiltersPlaceholdersAndProse(t *testing.T) {
+	// A line whose first word is prose yields no command at all.
+	if refs := parseRefs("lark-cli 就能搞定这件事"); len(refs) != 0 {
+		t.Errorf("prose-first line should yield 0 refs, got %v", refWordsOf(refs))
+	}
+	// Syntax templates / trailing prose may leave a real leading word ("mail"),
+	// but no placeholder or CJK token may leak into the command words — that is
+	// what prevents false positives like an "<resource>" unknown-command report.
+	for _, line := range []string{
+		"lark-cli mail <resource> <method> [flags]",
+		"lark-cli apps +<verb> [flags]",
+		"lark-cli base +...",
+		"lark-cli mail 写信场景下的格式说明",
+	} {
+		for _, r := range parseRefs(line) {
+			for _, w := range r.words {
+				if isPlaceholderOrProse(w) {
+					t.Errorf("%q: placeholder/prose token %q leaked into words %v", line, w, r.words)
+				}
+			}
+		}
+	}
+}
+
+func TestCmdExampleParseRefsStripsTrailingJunk(t *testing.T) {
+	// frontmatter-style quoted value: the trailing quote must not bleed into the flag
+	refs := parseRefs(`cliHelp: "lark-cli contact --help"`)
+	if len(refs) != 1 {
+		t.Fatalf("expected 1 ref, got %d", len(refs))
+	}
+	if len(refs[0].flags) != 1 || refs[0].flags[0] != "--help" {
+		t.Errorf("expected flag --help, got %v", refs[0].flags)
+	}
+	// bare "-" (stdin marker) and "=value" suffix
+	refs = parseRefs("lark-cli api GET /x --params={} --data -")
+	if len(refs) != 1 {
+		t.Fatalf("expected 1 ref, got %d", len(refs))
+	}
+	flags := strings.Join(refs[0].flags, " ")
+	if flags != "--params --data" {
+		t.Errorf("expected '--params --data', got %q", flags)
+	}
+}
+
+func TestCmdExampleCheck(t *testing.T) {
+	c := testCatalog()
+	tests := []struct {
+		name     string
+		r        ref
+		wantKind string // "" = no finding
+		wantPath string
+	}{
+		{"valid shortcut", ref{words: []string{"contact", "+search-user"}, flags: []string{"--query"}}, "", ""},
+		{"valid leaf positional", ref{words: []string{"api", "GET", "/x"}}, "", ""},
+		{"unknown top command", ref{words: []string{"nope"}}, unknownCommand, "nope"},
+		{"group leftover = unknown subcommand",
+			ref{words: []string{"mail", "user_mailbox.messages", "batch_modify_message"}},
+			unknownCommand, "mail user_mailbox.messages batch_modify_message"},
+		{"unknown flag", ref{words: []string{"contact", "+search-user"}, flags: []string{"--nope"}}, unknownFlag, "contact +search-user"},
+		{"universal flag ok", ref{words: []string{"contact", "+search-user"}, flags: []string{"--help"}}, "", ""},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			fs := checkRefs(c, []ref{tt.r})
+			if tt.wantKind == "" {
+				if len(fs) != 0 {
+					t.Fatalf("expected no finding, got %+v", fs)
+				}
+				return
+			}
+			if len(fs) != 1 {
+				t.Fatalf("expected 1 finding, got %d: %+v", len(fs), fs)
+			}
+			if fs[0].kind != tt.wantKind || fs[0].path != tt.wantPath {
+				t.Errorf("got kind=%s path=%q, want kind=%s path=%q", fs[0].kind, fs[0].path, tt.wantKind, tt.wantPath)
+			}
+		})
+	}
+}
+
+func TestCmdExampleCheckSuggestsNearest(t *testing.T) {
+	c := testCatalog()
+	fs := checkRefs(c, []ref{{words: []string{"mail", "user_mailbox.messages", "batch_modify_message"}}})
+	if len(fs) != 1 || fs[0].suggest != "mail user_mailbox.messages batch_modify" {
+		t.Fatalf("expected suggestion 'mail user_mailbox.messages batch_modify', got %+v", fs)
+	}
+}
+
+// TestCmdExampleParseRefsRobustness covers the parser edge cases hardened after
+// review: backslash continuation, underscore flags, $(...) substitution, glued
+// separators, trailing punctuation, and the "..." placeholder.
+func TestCmdExampleParseRefsRobustness(t *testing.T) {
+	cases := []struct {
+		name, content, wantWords, wantFlags string
+		wantRefs                            int
+	}{
+		{"backslash continuation joins flags",
+			"lark-cli contact +search-user \\\n  --query foo \\\n  --as user",
+			"contact +search-user", "--query --as", 1},
+		{"underscore flag not truncated",
+			"lark-cli whiteboard +update --input_format mermaid",
+			"whiteboard +update", "--input_format", 1},
+		{"command-substitution flags ignored",
+			`lark-cli slides x create --data "$(jq -n --arg c '{}')" --as user`,
+			"slides x create", "--data --as", 1},
+		{"glued separator truncates",
+			"lark-cli auth login; echo done",
+			"auth login", "", 1},
+		{"trailing CJK punctuation stripped",
+			"用 lark-cli auth login。",
+			"auth login", "", 1},
+		{"ellipsis placeholder stays placeholder",
+			"lark-cli base +...",
+			"base", "", 1},
+	}
+	for _, tt := range cases {
+		t.Run(tt.name, func(t *testing.T) {
+			refs := parseRefs(tt.content)
+			if len(refs) != tt.wantRefs {
+				t.Fatalf("refs=%d want %d: %v", len(refs), tt.wantRefs, refWordsOf(refs))
+			}
+			if tt.wantRefs == 0 {
+				return
+			}
+			if got := strings.Join(refs[0].words, " "); got != tt.wantWords {
+				t.Errorf("words=%q want %q", got, tt.wantWords)
+			}
+			if got := strings.Join(refs[0].flags, " "); got != tt.wantFlags {
+				t.Errorf("flags=%q want %q", got, tt.wantFlags)
+			}
+		})
+	}
+}

cmd/config/init.go

@@ -341,6 +341,9 @@ func configInitRun(opts *ConfigInitOptions) error {
 		output.PrintSuccess(f.IOStreams.ErrOut, fmt.Sprintf("Configuration saved to %s", core.GetConfigPath()))
 		printLangPreferenceConfirmation(opts)
 		output.PrintJson(f.IOStreams.Out, map[string]interface{}{"appId": opts.AppID, "appSecret": "****", "brand": brand})
+		if err := runProbe(opts.Ctx, f, opts.AppID, opts.appSecret, brand); err != nil {
+			return err
+		}
 		return nil
 	}
 
@@ -380,6 +383,9 @@ func configInitRun(opts *ConfigInitOptions) error {
 		}
 		printLangPreferenceConfirmation(opts)
 		output.PrintJson(f.IOStreams.Out, map[string]interface{}{"appId": result.AppID, "appSecret": "****", "brand": result.Brand})
+		if err := runProbe(opts.Ctx, f, result.AppID, result.AppSecret, result.Brand); err != nil {
+			return err
+		}
 		return nil
 	}
 
@@ -419,6 +425,11 @@ func configInitRun(opts *ConfigInitOptions) error {
 			output.PrintSuccess(f.IOStreams.ErrOut, fmt.Sprintf(msg.ConfigSaved, result.AppID))
 		}
 		printLangPreferenceConfirmation(opts)
+		if result.AppSecret != "" {
+			if err := runProbe(opts.Ctx, f, result.AppID, result.AppSecret, result.Brand); err != nil {
+				return err
+			}
+		}
 		return nil
 	}
 
@@ -507,5 +518,10 @@ func configInitRun(opts *ConfigInitOptions) error {
 	}
 	output.PrintSuccess(f.IOStreams.ErrOut, fmt.Sprintf("Configuration saved to %s", core.GetConfigPath()))
 	printLangPreferenceConfirmation(opts)
+	if appSecretInput != "" {
+		if err := runProbe(opts.Ctx, f, resolvedAppId, appSecretInput, parseBrand(resolvedBrand)); err != nil {
+			return err
+		}
+	}
 	return nil
 }

cmd/config/init_interactive.go

@@ -6,7 +6,6 @@ package config
 import (
 	"context"
 	"fmt"
-	"net/http"
 
 	"github.com/charmbracelet/huh"
 	"github.com/larksuite/cli/internal/build"
@@ -17,6 +16,7 @@ import (
 	"github.com/larksuite/cli/internal/cmdutil"
 	"github.com/larksuite/cli/internal/core"
 	"github.com/larksuite/cli/internal/output"
+	"github.com/larksuite/cli/internal/transport"
 )
 
 // configInitResult holds the result of the interactive config init flow.
@@ -177,7 +177,9 @@ func runCreateAppFlow(ctx context.Context, f *cmdutil.Factory, brandOverride cor
 	}
 
 	// Step 1: Request app registration (begin)
-	httpClient := &http.Client{}
+	// Use the shared proxy-plugin-aware transport so registration traffic is not
+	// a bypass of proxy plugin mode.
+	httpClient := transport.NewHTTPClient(0)
 	authResp, err := larkauth.RequestAppRegistration(httpClient, larkBrand, f.IOStreams.ErrOut)
 	if err != nil {
 		return nil, errs.NewConfigError(errs.SubtypeInvalidClient, "app registration failed: %v", err).WithCause(err)

cmd/config/init_probe.go

@@ -0,0 +1,91 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package config
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/larksuite/cli/errs"
+	"github.com/larksuite/cli/internal/build"
+	"github.com/larksuite/cli/internal/cmdutil"
+	"github.com/larksuite/cli/internal/core"
+	"github.com/larksuite/cli/internal/credential"
+)
+
+// probeTimeout is the total wall-clock budget for the credential probe step
+// (covering both TAT acquisition and the subsequent probe request).
+const probeTimeout = 3 * time.Second
+
+// runProbe runs a best-effort credential validation after config init has
+// persisted the App ID and App Secret. It returns a non-nil error only for a
+// deterministic credential-rejection signal; every other outcome returns nil
+// so that valid configurations and transient/upstream noise never block the
+// command.
+//
+// The function performs up to two HTTP calls in series, bounded by
+// probeTimeout:
+//
+//  1. A TAT request using the just-saved credentials. credential.FetchTAT
+//     returns a typed errs.* error (via the shared classifyTATResponseCode)
+//     only when the server deterministically rejected the credentials — a
+//     non-zero TAT body code, classified as CategoryConfig / SubtypeInvalidClient
+//     (10003 / 10014) or whatever codemeta maps. That typed error is propagated
+//     so the root dispatcher renders the canonical envelope and `config init`
+//     exits non-zero — identical to how every other token-resolving command
+//     reports the same bad credentials. Ambiguous failures (transport errors,
+//     HTTP non-200, JSON parse errors, timeouts) come back as raw untyped
+//     errors and are swallowed (return nil), so valid configurations are never
+//     disturbed by upstream noise. errs.IsTyped is the discriminator.
+//
+//  2. If TAT succeeded, a POST to the probe endpoint is fired. The outcome of
+//     that call (success, server error, timeout, parse failure) is always
+//     ignored — return nil regardless.
+func runProbe(parent context.Context, factory *cmdutil.Factory, appID, appSecret string, brand core.LarkBrand) error {
+	if factory == nil {
+		return nil
+	}
+	httpClient, err := factory.HttpClient()
+	if err != nil {
+		return nil
+	}
+
+	ctx, cancel := context.WithTimeout(parent, probeTimeout)
+	defer cancel()
+
+	token, err := credential.FetchTAT(ctx, httpClient, brand, appID, appSecret)
+	if err != nil {
+		// A typed error from FetchTAT is a deterministic credential rejection
+		// (classifyTATResponseCode). Propagate it so config init exits with the
+		// same envelope the rest of the CLI uses for bad credentials. Untyped
+		// errors are ambiguous (transport / HTTP / parse / timeout) — stay
+		// silent and let the command succeed.
+		if errs.IsTyped(err) {
+			return err
+		}
+		return nil
+	}
+
+	// TAT succeeded — fire the probe call. Any outcome is ignored.
+	url := core.ResolveEndpoints(brand).Open + "/open-apis/application/v6/larksuite_cli_app/probe"
+	body := []byte(fmt.Sprintf(`{"from":"lark-cli/%s"}`, build.Version))
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
+	if err != nil {
+		return nil
+	}
+	req.Header.Set("Authorization", "Bearer "+token)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return nil
+	}
+	defer resp.Body.Close()
+	_, _ = io.Copy(io.Discard, resp.Body)
+	return nil
+}

cmd/config/init_probe_test.go

@@ -0,0 +1,288 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package config
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/larksuite/cli/errs"
+	"github.com/larksuite/cli/internal/build"
+	"github.com/larksuite/cli/internal/cmdutil"
+	"github.com/larksuite/cli/internal/core"
+)
+
+// fakeRT routes requests to per-path handlers and records what it saw.
+type fakeRT struct {
+	tatHandler   func(req *http.Request) (*http.Response, error)
+	probeHandler func(req *http.Request) (*http.Response, error)
+	tatCalls     int
+	probeCalls   int
+	probeReq     *http.Request
+	probeBody    string
+}
+
+func (f *fakeRT) RoundTrip(req *http.Request) (*http.Response, error) {
+	switch {
+	case strings.HasSuffix(req.URL.Path, "/auth/v3/tenant_access_token/internal"):
+		f.tatCalls++
+		if f.tatHandler == nil {
+			return jsonResp(200, `{"code":0,"tenant_access_token":"t-ok"}`), nil
+		}
+		return f.tatHandler(req)
+	case strings.HasSuffix(req.URL.Path, "/application/v6/larksuite_cli_app/probe"):
+		f.probeCalls++
+		f.probeReq = req
+		if req.Body != nil {
+			b, _ := io.ReadAll(req.Body)
+			f.probeBody = string(b)
+		}
+		if f.probeHandler == nil {
+			return jsonResp(200, `{"code":0,"data":{},"msg":"success"}`), nil
+		}
+		return f.probeHandler(req)
+	}
+	return nil, errors.New("unexpected URL: " + req.URL.String())
+}
+
+func jsonResp(code int, body string) *http.Response {
+	return &http.Response{
+		StatusCode: code,
+		Body:       io.NopCloser(strings.NewReader(body)),
+		Header:     make(http.Header),
+	}
+}
+
+// fakeFactory builds a test Factory whose HttpClient is overridden to use
+// the caller-supplied RoundTripper.
+//
+// Wired through cmdutil.TestFactory(t, nil) so the canonical IOStreams,
+// Credential, Keychain and FileIO wiring is in place (per repo test-factory
+// guidance). The HttpClient is then swapped to our stub so we can drive
+// exact HTTP responses for the probe. Config-dir isolation is set up via
+// t.Setenv(LARKSUITE_CLI_CONFIG_DIR, t.TempDir()) so any incidental config
+// touch lands in a temp dir rather than the developer's real config.
+//
+// The returned buffer is the Factory's stderr. runProbe never writes to
+// stderr (it propagates a typed error or stays silent), so every test asserts
+// this buffer stays empty as an invariant.
+func fakeFactory(t *testing.T, rt http.RoundTripper) (*cmdutil.Factory, *bytes.Buffer) {
+	t.Helper()
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+	f, _, errBuf, _ := cmdutil.TestFactory(t, nil)
+	f.HttpClient = func() (*http.Client, error) {
+		return &http.Client{Transport: rt}, nil
+	}
+	return f, errBuf
+}
+
+// assertConfigRejection asserts runProbe propagated a deterministic credential
+// rejection: a *errs.ConfigError (CategoryConfig / SubtypeInvalidClient) with
+// the expected upstream code. This is the same typed error every other
+// token-resolving command returns for the same bad credentials, and nothing is
+// written to stderr (the root dispatcher renders the envelope).
+func assertConfigRejection(t *testing.T, err error, errBuf *bytes.Buffer, wantCode int) {
+	t.Helper()
+	if err == nil {
+		t.Fatalf("expected *errs.ConfigError (code %d), got nil", wantCode)
+	}
+	var cfgErr *errs.ConfigError
+	if !errors.As(err, &cfgErr) {
+		t.Fatalf("expected *errs.ConfigError, got %T: %v", err, err)
+	}
+	if cfgErr.Category != errs.CategoryConfig {
+		t.Errorf("Category = %q, want %q", cfgErr.Category, errs.CategoryConfig)
+	}
+	if cfgErr.Subtype != errs.SubtypeInvalidClient {
+		t.Errorf("Subtype = %q, want %q", cfgErr.Subtype, errs.SubtypeInvalidClient)
+	}
+	if cfgErr.Code != wantCode {
+		t.Errorf("Code = %d, want %d", cfgErr.Code, wantCode)
+	}
+	if errBuf.Len() != 0 {
+		t.Errorf("runProbe must not write to stderr, got: %q", errBuf.String())
+	}
+}
+
+// assertSilent asserts runProbe stayed quiet: no propagated error and nothing
+// written to stderr. Used for every ambiguous (non-credential) outcome.
+func assertSilent(t *testing.T, err error, errBuf *bytes.Buffer) {
+	t.Helper()
+	if err != nil {
+		t.Errorf("expected nil (silent), got error: %v", err)
+	}
+	if errBuf.Len() != 0 {
+		t.Errorf("expected no stderr output, got: %q", errBuf.String())
+	}
+}
+
+// 10003 (bad / non-existent app_id) → ConfigError/InvalidClient, propagated.
+func TestRunProbe_TATCode10003_ReturnsConfigError(t *testing.T) {
+	rt := &fakeRT{
+		tatHandler: func(req *http.Request) (*http.Response, error) {
+			return jsonResp(200, `{"code":10003,"msg":"invalid param"}`), nil
+		},
+	}
+	f, errBuf := fakeFactory(t, rt)
+
+	err := runProbe(context.Background(), f, "cli_x", "secret_y", core.BrandFeishu)
+
+	if rt.probeCalls != 0 {
+		t.Error("probe endpoint must not be called when TAT fails")
+	}
+	assertConfigRejection(t, err, errBuf, 10003)
+}
+
+// 10014 (real app_id + wrong secret) → ConfigError/InvalidClient via codemeta —
+// the most common real-world rejection, propagated.
+func TestRunProbe_TATCode10014_ReturnsConfigError(t *testing.T) {
+	rt := &fakeRT{
+		tatHandler: func(req *http.Request) (*http.Response, error) {
+			return jsonResp(200, `{"code":10014,"msg":"app secret invalid"}`), nil
+		},
+	}
+	f, errBuf := fakeFactory(t, rt)
+	assertConfigRejection(t, runProbe(context.Background(), f, "cli_x", "secret_y", core.BrandFeishu), errBuf, 10014)
+}
+
+// Any non-zero body code is a deterministic rejection and propagates (typed).
+// An unrecognized code falls back to *errs.APIError via BuildAPIError — still
+// typed, so the probe still surfaces it rather than swallowing.
+func TestRunProbe_TATUnknownBodyCode_Propagates(t *testing.T) {
+	rt := &fakeRT{
+		tatHandler: func(req *http.Request) (*http.Response, error) {
+			return jsonResp(200, `{"code":99999,"msg":"future-unknown"}`), nil
+		},
+	}
+	f, errBuf := fakeFactory(t, rt)
+	err := runProbe(context.Background(), f, "cli_x", "secret_y", core.BrandFeishu)
+	if err == nil || !errs.IsTyped(err) {
+		t.Fatalf("expected a propagated typed error, got %T: %v", err, err)
+	}
+	if errBuf.Len() != 0 {
+		t.Errorf("runProbe must not write to stderr, got: %q", errBuf.String())
+	}
+}
+
+// Non-200 HTTP at the TAT endpoint is ambiguous (not a payload credential
+// rejection) → silent, exit 0.
+func TestRunProbe_TATHTTPNon200_Silent(t *testing.T) {
+	for _, code := range []int{401, 403, 500} {
+		rt := &fakeRT{
+			tatHandler: func(req *http.Request) (*http.Response, error) {
+				return jsonResp(code, `nope`), nil
+			},
+		}
+		f, errBuf := fakeFactory(t, rt)
+		assertSilent(t, runProbe(context.Background(), f, "cli_x", "secret_y", core.BrandFeishu), errBuf)
+	}
+}
+
+func TestRunProbe_TATTransportError_Silent(t *testing.T) {
+	rt := &fakeRT{
+		tatHandler: func(req *http.Request) (*http.Response, error) {
+			return nil, errors.New("network down")
+		},
+	}
+	f, errBuf := fakeFactory(t, rt)
+	assertSilent(t, runProbe(context.Background(), f, "cli_x", "secret_y", core.BrandFeishu), errBuf)
+}
+
+func TestRunProbe_TATSuccess_ProbeFails_Silent(t *testing.T) {
+	rt := &fakeRT{
+		probeHandler: func(req *http.Request) (*http.Response, error) {
+			return jsonResp(500, `server error`), nil
+		},
+	}
+	f, errBuf := fakeFactory(t, rt)
+	err := runProbe(context.Background(), f, "cli_x", "secret_y", core.BrandFeishu)
+	if rt.probeCalls != 1 {
+		t.Errorf("probe should be called once, got %d", rt.probeCalls)
+	}
+	assertSilent(t, err, errBuf)
+}
+
+func TestRunProbe_TATSuccess_ProbeOK_Silent(t *testing.T) {
+	rt := &fakeRT{}
+	f, errBuf := fakeFactory(t, rt)
+	err := runProbe(context.Background(), f, "cli_x", "secret_y", core.BrandFeishu)
+	if rt.tatCalls != 1 || rt.probeCalls != 1 {
+		t.Errorf("expected 1/1 calls, got tat=%d probe=%d", rt.tatCalls, rt.probeCalls)
+	}
+	assertSilent(t, err, errBuf)
+}
+
+func TestRunProbe_ProbeRequestShape(t *testing.T) {
+	rt := &fakeRT{}
+	f, _ := fakeFactory(t, rt)
+	if err := runProbe(context.Background(), f, "cli_x", "secret_y", core.BrandFeishu); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if rt.probeReq == nil {
+		t.Fatal("probe request not captured")
+	}
+	if rt.probeReq.Method != http.MethodPost {
+		t.Errorf("probe method = %s, want POST", rt.probeReq.Method)
+	}
+	if got := rt.probeReq.URL.String(); got != "https://open.feishu.cn/open-apis/application/v6/larksuite_cli_app/probe" {
+		t.Errorf("probe URL = %s", got)
+	}
+	if got := rt.probeReq.Header.Get("Authorization"); got != "Bearer t-ok" {
+		t.Errorf("Authorization = %q, want Bearer t-ok", got)
+	}
+	if !strings.Contains(rt.probeBody, `"from":"lark-cli/`+build.Version+`"`) {
+		t.Errorf("probe body missing from field: %s", rt.probeBody)
+	}
+}
+
+func TestRunProbe_LarkBrand_HostRoutedCorrectly(t *testing.T) {
+	rt := &fakeRT{}
+	f, _ := fakeFactory(t, rt)
+	if err := runProbe(context.Background(), f, "cli_x", "secret_y", core.BrandLark); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if rt.probeReq == nil {
+		t.Fatal("probe request not captured")
+	}
+	if !strings.Contains(rt.probeReq.URL.Host, "larksuite.com") {
+		t.Errorf("probe host = %s, want larksuite.com", rt.probeReq.URL.Host)
+	}
+}
+
+func TestRunProbe_HTTPClientError_Silent(t *testing.T) {
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+	f, _, errBuf, _ := cmdutil.TestFactory(t, nil)
+	f.HttpClient = func() (*http.Client, error) {
+		return nil, errors.New("client init failed")
+	}
+	assertSilent(t, runProbe(context.Background(), f, "cli_x", "secret_y", core.BrandFeishu), errBuf)
+}
+
+func TestRunProbe_TimeoutHonored(t *testing.T) {
+	rt := &fakeRT{
+		tatHandler: func(req *http.Request) (*http.Response, error) {
+			<-req.Context().Done()
+			return nil, req.Context().Err()
+		},
+	}
+	f, errBuf := fakeFactory(t, rt)
+
+	start := time.Now()
+	err := runProbe(context.Background(), f, "cli_x", "secret_y", core.BrandFeishu)
+	elapsed := time.Since(start)
+
+	if elapsed > 4*time.Second {
+		t.Errorf("runProbe took %v, expected <= ~3s", elapsed)
+	}
+	// A timeout is an ambiguous failure (context deadline → untyped), so it
+	// must stay silent and not block.
+	assertSilent(t, err, errBuf)
+}

cmd/doctor/doctor.go

@@ -19,6 +19,7 @@ import (
 	"github.com/larksuite/cli/internal/core"
 	"github.com/larksuite/cli/internal/identitydiag"
 	"github.com/larksuite/cli/internal/output"
+	"github.com/larksuite/cli/internal/transport"
 	"github.com/larksuite/cli/internal/update"
 )
 
@@ -152,7 +153,9 @@ func networkChecks(ctx context.Context, opts *DoctorOptions, ep core.Endpoints)
 		}
 	}
 
-	httpClient := &http.Client{}
+	// Use the shared proxy-plugin-aware transport so connectivity checks reflect
+	// the real egress path (and are blocked when proxy plugin fails closed).
+	httpClient := transport.NewHTTPClient(0)
 	mcpURL := ep.MCP + "/mcp"
 
 	type probeResult struct {

cmd/event/bus.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/cmdutil"
 	"github.com/larksuite/cli/internal/core"
 	"github.com/larksuite/cli/internal/event"
@@ -38,7 +39,8 @@ func NewCmdBus(f *cmdutil.Factory) *cobra.Command {
 
 			logger, err := bus.SetupBusLogger(eventsDir)
 			if err != nil {
-				return err
+				return errs.NewInternalError(errs.SubtypeFileIO,
+					"set up bus logger: %s", err).WithCause(err)
 			}
 
 			tr := transport.New()
@@ -58,7 +60,14 @@ func NewCmdBus(f *cmdutil.Factory) *cobra.Command {
 				}
 			}()
 
-			return b.Run(ctx)
+			if err := b.Run(ctx); err != nil {
+				if _, ok := errs.ProblemOf(err); ok {
+					return err
+				}
+				return errs.NewInternalError(errs.SubtypeUnknown,
+					"event bus daemon exited: %s", err).WithCause(err)
+			}
+			return nil
 		},
 	}
 

cmd/event/bus_test.go

@@ -0,0 +1,45 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package event
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/larksuite/cli/errs"
+	"github.com/larksuite/cli/internal/cmdutil"
+	"github.com/larksuite/cli/internal/core"
+)
+
+// The hidden `event _bus` daemon command must exit with a typed file_io error
+// when its log directory cannot be created (the error is only visible in the
+// forked process's captured stderr / bus.log).
+func TestBusCommandLoggerSetupFailureIsTypedFileIO(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
+	// Block the events/ root with a regular file so MkdirAll fails.
+	if err := os.WriteFile(filepath.Join(dir, "events"), []byte("x"), 0600); err != nil {
+		t.Fatal(err)
+	}
+
+	f, _, _, _ := cmdutil.TestFactory(t, &core.CliConfig{
+		AppID: "cli_bus_test", AppSecret: "secret", Brand: core.BrandFeishu,
+	})
+	cmd := NewCmdBus(f)
+	cmd.SetArgs([]string{})
+
+	err := cmd.Execute()
+	if err == nil {
+		t.Fatal("expected logger setup error")
+	}
+	p, ok := errs.ProblemOf(err)
+	if !ok {
+		t.Fatalf("expected typed errs error, got %T: %v", err, err)
+	}
+	if p.Category != errs.CategoryInternal || p.Subtype != errs.SubtypeFileIO {
+		t.Errorf("problem = %s/%s, want %s/%s", p.Category, p.Subtype,
+			errs.CategoryInternal, errs.SubtypeFileIO)
+	}
+}

cmd/event/consume.go

@@ -16,6 +16,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/appmeta"
 	"github.com/larksuite/cli/internal/auth"
 	"github.com/larksuite/cli/internal/cmdutil"
@@ -64,8 +65,8 @@ Use 'event schema <EventKey>' for parameter details.`,
 	cmd.Flags().StringVar(&o.jqExpr, "jq", "", "JQ expression to filter output")
 	cmd.Flags().BoolVar(&o.quiet, "quiet", false, "Suppress informational messages on stderr")
 	cmd.Flags().StringVar(&o.outputDir, "output-dir", "", "Write each event as a file in this directory (relative paths only; absolute paths and ~ are rejected to prevent path traversal)")
-	cmd.Flags().IntVar(&o.maxEvents, "max-events", 0, "Exit after N successful emits (0 = unlimited). Multi-worker EventKeys may emit up to workers-1 past N before all workers stop.")
-	cmd.Flags().DurationVar(&o.timeout, "timeout", 0, "Exit after DURATION (e.g. 30s, 2m). 0 = no timeout. Timeout is a normal exit (code 0; stderr 'reason: timeout').")
+	cmd.Flags().IntVar(&o.maxEvents, "max-events", 0, "Exit after N successful emits (0 = unlimited). Multi-worker EventKeys may emit up to workers-1 past N before all workers stop. Bounded runs ignore stdin EOF.")
+	cmd.Flags().DurationVar(&o.timeout, "timeout", 0, "Exit after DURATION (e.g. 30s, 2m). 0 = no timeout. Timeout is a normal exit (code 0; stderr 'reason: timeout'). Bounded runs ignore stdin EOF.")
 	cmd.Flags().String("as", "auto", "identity type: user | bot | auto (must match EventKey's declared AuthTypes)")
 	_ = cmd.RegisterFlagCompletionFunc("as", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
 		return []string{"user", "bot", "auto"}, cobra.ShellCompDirectiveNoFileComp
@@ -101,11 +102,10 @@ func runConsume(cmd *cobra.Command, f *cmdutil.Factory, eventKey string, o consu
 
 	if o.jqExpr != "" {
 		if err := output.ValidateJqExpression(o.jqExpr); err != nil {
-			return output.ErrWithHint(
-				output.ExitValidation, "validation",
-				err.Error(),
-				fmt.Sprintf("see `lark-cli event consume --help` EXAMPLES for common patterns, or `lark-cli event schema %s` for valid field paths", eventKey),
-			)
+			return errs.NewValidationError(errs.SubtypeInvalidArgument, "%s", err).
+				WithParam("--jq").
+				WithCause(err).
+				WithHint("see `lark-cli event consume --help` EXAMPLES for common patterns, or `lark-cli event schema %s` for valid field paths", eventKey)
 		}
 	}
 
@@ -184,8 +184,9 @@ func runConsume(cmd *cobra.Command, f *cmdutil.Factory, eventKey string, o consu
 		errOut = io.Discard
 	}
 
-	// Non-TTY only: stdin EOF is shutdown for subprocess callers; in TTY Ctrl-D must not exit.
-	if !f.IOStreams.IsTerminal {
+	// Non-TTY unbounded consumers use stdin EOF as shutdown for subprocess callers.
+	// Bounded runs already have --max-events/--timeout as their lifecycle control.
+	if shouldWatchStdinEOF(f.IOStreams.IsTerminal, o.maxEvents, o.timeout) {
 		watchStdinEOF(os.Stdin, cancel, errOut)
 	}
 
@@ -260,12 +261,12 @@ func preflightScopes(ctx context.Context, pf *preflightCtx) error {
 	if len(missing) == 0 {
 		return nil
 	}
-	return output.ErrWithHint(
-		output.ExitAuth, "auth",
-		fmt.Sprintf("missing required scopes for EventKey %s (as %s): %s",
-			pf.eventKey, pf.identity, strings.Join(missing, ", ")),
-		scopeRemediationHint(pf.identity, missing, pf.appID, pf.brand),
-	)
+	return errs.NewPermissionError(errs.SubtypeMissingScope,
+		"missing required scopes for EventKey %s (as %s): %s",
+		pf.eventKey, pf.identity, strings.Join(missing, ", ")).
+		WithIdentity(string(pf.identity)).
+		WithMissingScopes(missing...).
+		WithHint("%s", scopeRemediationHint(pf.identity, missing, pf.appID, pf.brand))
 }
 
 // scopeRemediationHint returns an identity-appropriate fix for missing scopes.
@@ -300,23 +301,27 @@ func preflightEventTypes(pf *preflightCtx) error {
 	if len(missing) == 0 {
 		return nil
 	}
-	return output.ErrWithHint(
-		output.ExitValidation, "validation",
-		fmt.Sprintf("EventKey %s requires event types not subscribed in console: %s",
-			pf.keyDef.Key, strings.Join(missing, ", ")),
-		fmt.Sprintf("subscribe these events and publish a new app version at: %s",
-			consoleEventSubscriptionURL(pf.brand, pf.appID)),
-	)
+	return errs.NewValidationError(errs.SubtypeFailedPrecondition,
+		"EventKey %s requires event types not subscribed in console: %s",
+		pf.keyDef.Key, strings.Join(missing, ", ")).
+		WithHint("subscribe these events and publish a new app version at: %s",
+			consoleEventSubscriptionURL(pf.brand, pf.appID))
 }
 
 // sanitizeOutputDir rejects absolute/parent-escaping paths and ~ (SafeOutputPath treats it as a literal dir name).
 func sanitizeOutputDir(dir string) (string, error) {
 	if strings.HasPrefix(dir, "~") {
-		return "", output.ErrValidation("%s; use a relative path like ./output instead", errOutputDirTilde)
+		return "", errs.NewValidationError(errs.SubtypeInvalidArgument,
+			"%s; use a relative path like ./output instead", errOutputDirTilde).
+			WithParam("--output-dir").
+			WithCause(errOutputDirTilde)
 	}
 	safe, err := validate.SafeOutputPath(dir)
 	if err != nil {
-		return "", output.ErrValidation("%s %q: %s", errOutputDirUnsafe, dir, err)
+		return "", errs.NewValidationError(errs.SubtypeInvalidArgument,
+			"%s %q: %s", errOutputDirUnsafe, dir, err).
+			WithParam("--output-dir").
+			WithCause(errOutputDirUnsafe)
 	}
 	return safe, nil
 }
@@ -328,18 +333,21 @@ func resolveTenantToken(ctx context.Context, f *cmdutil.Factory, appID string) (
 	}
 	result, err := f.Credential.ResolveToken(ctx, credential.NewTokenSpec(core.AsBot, appID))
 	if err != nil {
-		return "", output.ErrAuth("resolve tenant access token: %s", err)
+		if _, ok := errs.ProblemOf(err); ok {
+			return "", err
+		}
+		return "", errs.NewAuthenticationError(errs.SubtypeTokenMissing,
+			"resolve tenant access token: %s", err).WithCause(err)
 	}
 	if result == nil || result.Token == "" {
-		return "", output.ErrWithHint(
-			output.ExitAuth, "auth",
-			fmt.Sprintf("no tenant access token available for app %s", appID),
-			"Check that app_secret is configured (lark-cli config show) and try 'lark-cli auth login'.",
-		)
+		return "", errs.NewAuthenticationError(errs.SubtypeTokenMissing,
+			"no tenant access token available for app %s", appID).
+			WithHint("Check that app_secret is configured (lark-cli config show) and try 'lark-cli auth login'.")
 	}
 	return result.Token, nil
 }
 
+// Sentinels for errors.Is checks; call sites wrap them as typed ValidationError causes.
 var (
 	errInvalidParamFormat = errors.New("invalid --param format")
 	errOutputDirTilde     = errors.New("--output-dir does not support ~ expansion")
@@ -351,7 +359,10 @@ func parseParams(raw []string) (map[string]string, error) {
 	for _, kv := range raw {
 		k, v, ok := strings.Cut(kv, "=")
 		if !ok || k == "" {
-			return nil, output.ErrValidation("%s %q: expected key=value", errInvalidParamFormat, kv)
+			return nil, errs.NewValidationError(errs.SubtypeInvalidArgument,
+				"%s %q: expected key=value", errInvalidParamFormat, kv).
+				WithParam("--param").
+				WithCause(errInvalidParamFormat)
 		}
 		m[k] = v
 	}
@@ -370,3 +381,8 @@ func watchStdinEOF(r io.Reader, cancel context.CancelFunc, errOut io.Writer) {
 		cancel()
 	}()
 }
+
+// shouldWatchStdinEOF gates the stdin-EOF shutdown watcher: non-TTY unbounded runs only (<= 0 mirrors downstream's >0-is-bounded semantics, so negative bounds stay unbounded).
+func shouldWatchStdinEOF(isTerminal bool, maxEvents int, timeout time.Duration) bool {
+	return !isTerminal && maxEvents <= 0 && timeout <= 0
+}

cmd/event/consume_stdin_test.go

@@ -61,3 +61,70 @@ func TestWatchStdinEOF_DiagnosticMessage(t *testing.T) {
 		t.Fatal("watchStdinEOF did not cancel within 1s of EOF")
 	}
 }
+
+func TestShouldWatchStdinEOF(t *testing.T) {
+	tests := []struct {
+		name       string
+		isTerminal bool
+		maxEvents  int
+		timeout    time.Duration
+		want       bool
+	}{
+		{
+			name:       "terminal",
+			isTerminal: true,
+			want:       false,
+		},
+		{
+			name: "non terminal unbounded",
+			want: true,
+		},
+		{
+			name:      "non terminal negative max events is unbounded",
+			maxEvents: -1,
+			want:      true,
+		},
+		{
+			name:    "non terminal negative timeout is unbounded",
+			timeout: -1 * time.Second,
+			want:    true,
+		},
+		{
+			name:      "non terminal max events bounded",
+			maxEvents: 1,
+			want:      false,
+		},
+		{
+			name:    "non terminal timeout bounded",
+			timeout: 10 * time.Minute,
+			want:    false,
+		},
+		{
+			name:      "non terminal both bounds positive",
+			maxEvents: 1,
+			timeout:   10 * time.Minute,
+			want:      false,
+		},
+		{
+			name:      "non terminal bounded max events with negative timeout",
+			maxEvents: 1,
+			timeout:   -1 * time.Second,
+			want:      false,
+		},
+		{
+			name:      "non terminal bounded timeout with negative max events",
+			maxEvents: -1,
+			timeout:   10 * time.Minute,
+			want:      false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := shouldWatchStdinEOF(tt.isTerminal, tt.maxEvents, tt.timeout)
+			if got != tt.want {
+				t.Fatalf("shouldWatchStdinEOF() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

cmd/event/consume_test.go

@@ -4,9 +4,14 @@
 package event
 
 import (
+	"context"
 	"errors"
 	"strings"
 	"testing"
+
+	"github.com/larksuite/cli/errs"
+	"github.com/larksuite/cli/internal/cmdutil"
+	"github.com/larksuite/cli/internal/credential"
 )
 
 func TestParseParams(t *testing.T) {
@@ -73,6 +78,7 @@ func TestParseParams(t *testing.T) {
 				if tc.wantEcho != "" && !strings.Contains(err.Error(), tc.wantEcho) {
 					t.Errorf("err %q should echo %q so user sees the bad input", err.Error(), tc.wantEcho)
 				}
+				assertInvalidArgumentParam(t, err, "--param")
 				return
 			}
 			if err != nil {
@@ -90,6 +96,77 @@ func TestParseParams(t *testing.T) {
 	}
 }
 
+// emptyTokenResolver resolves to a result that carries no token.
+type emptyTokenResolver struct{}
+
+func (emptyTokenResolver) ResolveToken(_ context.Context, _ credential.TokenSpec) (*credential.TokenResult, error) {
+	return &credential.TokenResult{}, nil
+}
+
+// failingTokenResolver fails outright with an untyped error.
+type failingTokenResolver struct{}
+
+func (failingTokenResolver) ResolveToken(_ context.Context, _ credential.TokenSpec) (*credential.TokenResult, error) {
+	return nil, errors.New("backend unavailable")
+}
+
+func factoryWithResolver(r credential.DefaultTokenResolver) *cmdutil.Factory {
+	return &cmdutil.Factory{Credential: credential.NewCredentialProvider(nil, nil, r, nil)}
+}
+
+func TestResolveTenantToken_EmptyTokenResult(t *testing.T) {
+	_, err := resolveTenantToken(context.Background(), factoryWithResolver(emptyTokenResolver{}), "cli_x")
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	p, ok := errs.ProblemOf(err)
+	if !ok {
+		t.Fatalf("expected typed errs error, got %T: %v", err, err)
+	}
+	if p.Category != errs.CategoryAuthentication || p.Subtype != errs.SubtypeTokenMissing {
+		t.Errorf("problem = %s/%s, want %s/%s", p.Category, p.Subtype,
+			errs.CategoryAuthentication, errs.SubtypeTokenMissing)
+	}
+	var malformed *credential.MalformedTokenResultError
+	if !errors.As(err, &malformed) {
+		t.Error("empty-token failure should preserve the credential-layer cause")
+	}
+}
+
+func TestResolveTenantToken_ResolverFailure(t *testing.T) {
+	_, err := resolveTenantToken(context.Background(), factoryWithResolver(failingTokenResolver{}), "cli_x")
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	p, ok := errs.ProblemOf(err)
+	if !ok {
+		t.Fatalf("expected typed errs error, got %T: %v", err, err)
+	}
+	if p.Category != errs.CategoryAuthentication || p.Subtype != errs.SubtypeTokenMissing {
+		t.Errorf("problem = %s/%s, want %s/%s", p.Category, p.Subtype,
+			errs.CategoryAuthentication, errs.SubtypeTokenMissing)
+	}
+	if errors.Unwrap(err) == nil {
+		t.Error("resolver failure should preserve its cause")
+	}
+}
+
+// assertInvalidArgumentParam verifies err is a typed validation error with
+// subtype invalid_argument naming the given flag in its param field.
+func assertInvalidArgumentParam(t *testing.T, err error, param string) {
+	t.Helper()
+	var ve *errs.ValidationError
+	if !errors.As(err, &ve) {
+		t.Fatalf("expected *errs.ValidationError, got %T: %v", err, err)
+	}
+	if ve.Subtype != errs.SubtypeInvalidArgument {
+		t.Errorf("subtype = %s, want %s", ve.Subtype, errs.SubtypeInvalidArgument)
+	}
+	if ve.Param != param {
+		t.Errorf("param = %q, want %q", ve.Param, param)
+	}
+}
+
 func TestSanitizeOutputDir(t *testing.T) {
 	cases := []struct {
 		name       string
@@ -130,6 +207,7 @@ func TestSanitizeOutputDir(t *testing.T) {
 				if !errors.Is(err, tc.wantSentry) {
 					t.Fatalf("want errors.Is(err, %v), got %q", tc.wantSentry, err.Error())
 				}
+				assertInvalidArgumentParam(t, err, "--output-dir")
 				return
 			}
 			if err != nil {

cmd/event/preflight_test.go

@@ -8,10 +8,10 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/appmeta"
 	"github.com/larksuite/cli/internal/core"
 	eventlib "github.com/larksuite/cli/internal/event"
-	"github.com/larksuite/cli/internal/output"
 )
 
 func newPreflightCtx(appID string, brand core.LarkBrand, identity core.Identity, keyDef *eventlib.KeyDefinition, appVer *appmeta.AppVersion) *preflightCtx {
@@ -89,19 +89,17 @@ func TestPreflightEventTypes_MissingBlocks(t *testing.T) {
 	if !strings.Contains(err.Error(), "mail.user_mailbox.event.message_read_v1") {
 		t.Errorf("error should name the missing event type, got: %v", err)
 	}
-	var exit *output.ExitError
-	if !errors.As(err, &exit) {
-		t.Fatalf("expected output.ExitError, got %T: %v", err, err)
+	p, ok := errs.ProblemOf(err)
+	if !ok {
+		t.Fatalf("expected typed errs error, got %T: %v", err, err)
 	}
-	if exit.Code != output.ExitValidation {
-		t.Errorf("ExitCode = %d, want ExitValidation (%d)", exit.Code, output.ExitValidation)
-	}
-	if exit.Detail == nil {
-		t.Fatal("expected Detail with hint")
+	if p.Category != errs.CategoryValidation || p.Subtype != errs.SubtypeFailedPrecondition {
+		t.Errorf("problem = %s/%s, want %s/%s", p.Category, p.Subtype,
+			errs.CategoryValidation, errs.SubtypeFailedPrecondition)
 	}
 	wantURL := "https://open.feishu.cn/app/cli_XXXXXXXXXXXXXXXX/event"
-	if !strings.Contains(exit.Detail.Hint, wantURL) {
-		t.Errorf("hint missing subscription URL %q\ngot: %s", wantURL, exit.Detail.Hint)
+	if !strings.Contains(p.Hint, wantURL) {
+		t.Errorf("hint missing subscription URL %q\ngot: %s", wantURL, p.Hint)
 	}
 }
 
@@ -145,17 +143,19 @@ func TestPreflightScopes_Bot_MissingBlocks(t *testing.T) {
 	if !strings.Contains(err.Error(), "im:message.group_at_msg") {
 		t.Errorf("error should name missing scope, got: %v", err)
 	}
-	var exit *output.ExitError
-	if !errors.As(err, &exit) {
-		t.Fatalf("expected output.ExitError, got %T: %v", err, err)
+	var permErr *errs.PermissionError
+	if !errors.As(err, &permErr) {
+		t.Fatalf("expected *errs.PermissionError, got %T: %v", err, err)
 	}
-	if exit.Code != output.ExitAuth {
-		t.Errorf("ExitCode = %d, want ExitAuth (%d)", exit.Code, output.ExitAuth)
+	if permErr.Category != errs.CategoryAuthorization || permErr.Subtype != errs.SubtypeMissingScope {
+		t.Errorf("problem = %s/%s, want %s/%s", permErr.Category, permErr.Subtype,
+			errs.CategoryAuthorization, errs.SubtypeMissingScope)
 	}
-	if exit.Detail == nil {
-		t.Fatal("expected Detail with hint, got nil Detail")
+	wantMissing := []string{"im:message.group_at_msg"}
+	if len(permErr.MissingScopes) != 1 || permErr.MissingScopes[0] != wantMissing[0] {
+		t.Errorf("MissingScopes = %v, want %v", permErr.MissingScopes, wantMissing)
 	}
-	hint := exit.Detail.Hint
+	hint := permErr.Hint
 	wantSubstrings := []string{
 		"https://open.feishu.cn/app/cli_x/auth?q=",
 		"im:message.group_at_msg",

cmd/event/runtime.go

@@ -6,8 +6,8 @@ package event
 import (
 	"context"
 	"encoding/json"
-	"fmt"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/client"
 	"github.com/larksuite/cli/internal/core"
 )
@@ -26,7 +26,11 @@ func (r *consumeRuntime) CallAPI(ctx context.Context, method, path string, body
 		As:     r.accessIdentity,
 	})
 	if err != nil {
-		return nil, err
+		if _, ok := errs.ProblemOf(err); ok {
+			return nil, err
+		}
+		return nil, errs.NewNetworkError(errs.SubtypeNetworkTransport,
+			"api %s %s: %s", method, path, err).WithCause(err)
 	}
 	// Non-JSON HTTP errors (gateway text/plain 404 etc.) skip OAPI envelope parsing.
 	ct := resp.Header.Get("Content-Type")
@@ -36,11 +40,20 @@ func (r *consumeRuntime) CallAPI(ctx context.Context, method, path string, body
 		if len(body) > maxBodyEcho {
 			body = body[:maxBodyEcho] + "…(truncated)"
 		}
-		return nil, fmt.Errorf("api %s %s returned %d: %s", method, path, resp.StatusCode, body)
+		if resp.StatusCode >= 500 {
+			return nil, errs.NewNetworkError(errs.SubtypeNetworkServer,
+				"api %s %s returned %d: %s", method, path, resp.StatusCode, body).WithRetryable()
+		}
+		return nil, errs.NewInternalError(errs.SubtypeInvalidResponse,
+			"api %s %s returned %d: %s", method, path, resp.StatusCode, body)
 	}
 	result, err := client.ParseJSONResponse(resp)
 	if err != nil {
-		return nil, err
+		if _, ok := errs.ProblemOf(err); ok {
+			return nil, err
+		}
+		return nil, errs.NewInternalError(errs.SubtypeInvalidResponse,
+			"api %s %s: %s", method, path, err).WithCause(err)
 	}
 	if apiErr := r.client.CheckResponse(result, r.accessIdentity); apiErr != nil {
 		return json.RawMessage(resp.RawBody), apiErr

cmd/event/runtime_test.go

@@ -0,0 +1,147 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package event
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+
+	lark "github.com/larksuite/oapi-sdk-go/v3"
+	larkcore "github.com/larksuite/oapi-sdk-go/v3/core"
+
+	"github.com/larksuite/cli/errs"
+	"github.com/larksuite/cli/internal/client"
+	"github.com/larksuite/cli/internal/core"
+	"github.com/larksuite/cli/internal/credential"
+)
+
+// staticTokenResolver always returns a fixed token without any HTTP calls.
+type staticTokenResolver struct{}
+
+func (s *staticTokenResolver) ResolveToken(_ context.Context, _ credential.TokenSpec) (*credential.TokenResult, error) {
+	return &credential.TokenResult{Token: "test-token"}, nil
+}
+
+// stubRoundTripper intercepts every outgoing request with a canned response.
+type stubRoundTripper struct {
+	respond func(*http.Request) (*http.Response, error)
+}
+
+func (s stubRoundTripper) RoundTrip(r *http.Request) (*http.Response, error) { return s.respond(r) }
+
+func newTestConsumeRuntime(rt http.RoundTripper) *consumeRuntime {
+	sdk := lark.NewClient("test-app", "test-secret",
+		lark.WithEnableTokenCache(false),
+		lark.WithLogLevel(larkcore.LogLevelError),
+		lark.WithHttpClient(&http.Client{Transport: rt}),
+	)
+	return &consumeRuntime{
+		client: &client.APIClient{
+			SDK:        sdk,
+			ErrOut:     io.Discard,
+			Credential: credential.NewCredentialProvider(nil, nil, &staticTokenResolver{}, nil),
+			Config:     &core.CliConfig{AppID: "test-app", AppSecret: "test-secret", Brand: core.BrandFeishu},
+		},
+		accessIdentity: core.AsBot,
+	}
+}
+
+func stubResponse(status int, contentType, body string) func(*http.Request) (*http.Response, error) {
+	return func(r *http.Request) (*http.Response, error) {
+		return &http.Response{
+			StatusCode: status,
+			Header:     http.Header{"Content-Type": []string{contentType}},
+			Body:       io.NopCloser(strings.NewReader(body)),
+			Request:    r,
+		}, nil
+	}
+}
+
+func requireCallAPIProblem(t *testing.T, err error, category errs.Category, subtype errs.Subtype) {
+	t.Helper()
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	p, ok := errs.ProblemOf(err)
+	if !ok {
+		t.Fatalf("expected typed errs error, got %T: %v", err, err)
+	}
+	if p.Category != category || p.Subtype != subtype {
+		t.Fatalf("problem = %s/%s, want %s/%s", p.Category, p.Subtype, category, subtype)
+	}
+}
+
+func TestConsumeRuntimeCallAPI_NonJSONHTTPError(t *testing.T) {
+	r := newTestConsumeRuntime(stubRoundTripper{respond: stubResponse(http.StatusNotFound, "text/plain", "gone")})
+	_, err := r.CallAPI(context.Background(), "GET", "/open-apis/event/v1/connection", nil)
+	requireCallAPIProblem(t, err, errs.CategoryInternal, errs.SubtypeInvalidResponse)
+	if !strings.Contains(err.Error(), "returned 404") {
+		t.Errorf("error should echo the HTTP status, got: %v", err)
+	}
+}
+
+func TestConsumeRuntimeCallAPI_NonJSONHTTPErrorTruncatesLongBody(t *testing.T) {
+	long := strings.Repeat("x", 300)
+	r := newTestConsumeRuntime(stubRoundTripper{respond: stubResponse(http.StatusBadGateway, "text/html", long)})
+	_, err := r.CallAPI(context.Background(), "GET", "/open-apis/event/v1/connection", nil)
+	requireCallAPIProblem(t, err, errs.CategoryNetwork, errs.SubtypeNetworkServer)
+	p, _ := errs.ProblemOf(err)
+	if !p.Retryable {
+		t.Fatal("5xx non-JSON response should be marked retryable")
+	}
+	if !strings.Contains(err.Error(), "…(truncated)") {
+		t.Errorf("long body should be truncated in the message, got: %v", err)
+	}
+}
+
+func TestConsumeRuntimeCallAPI_UnparsableJSONBody(t *testing.T) {
+	r := newTestConsumeRuntime(stubRoundTripper{respond: stubResponse(http.StatusOK, "application/json", "{not json")})
+	_, err := r.CallAPI(context.Background(), "GET", "/open-apis/event/v1/connection", nil)
+	requireCallAPIProblem(t, err, errs.CategoryInternal, errs.SubtypeInvalidResponse)
+}
+
+func TestConsumeRuntimeCallAPI_TransportFailure(t *testing.T) {
+	r := newTestConsumeRuntime(stubRoundTripper{respond: func(*http.Request) (*http.Response, error) {
+		return nil, errors.New("connection refused")
+	}})
+	_, err := r.CallAPI(context.Background(), "GET", "/open-apis/event/v1/connection", nil)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	p, ok := errs.ProblemOf(err)
+	if !ok {
+		t.Fatalf("expected typed errs error, got %T: %v", err, err)
+	}
+	if p.Category != errs.CategoryNetwork {
+		t.Fatalf("category = %s, want %s", p.Category, errs.CategoryNetwork)
+	}
+}
+
+func TestConsumeRuntimeCallAPI_EnvelopeErrorIsTyped(t *testing.T) {
+	r := newTestConsumeRuntime(stubRoundTripper{respond: stubResponse(http.StatusOK, "application/json",
+		`{"code":99991663,"msg":"app not found"}`)})
+	_, err := r.CallAPI(context.Background(), "GET", "/open-apis/event/v1/connection", nil)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if _, ok := errs.ProblemOf(err); !ok {
+		t.Fatalf("envelope error should be typed via BuildAPIError, got %T: %v", err, err)
+	}
+}
+
+func TestConsumeRuntimeCallAPI_Success(t *testing.T) {
+	r := newTestConsumeRuntime(stubRoundTripper{respond: stubResponse(http.StatusOK, "application/json",
+		`{"code":0,"data":{"ok":true}}`)})
+	raw, err := r.CallAPI(context.Background(), "GET", "/open-apis/event/v1/connection", nil)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if !strings.Contains(string(raw), `"code":0`) {
+		t.Errorf("raw body should pass through, got: %s", raw)
+	}
+}

cmd/event/schema.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/cmdutil"
 	eventlib "github.com/larksuite/cli/internal/event"
 	"github.com/larksuite/cli/internal/event/schemas"
@@ -39,12 +40,14 @@ func resolveSchemaJSON(def *eventlib.KeyDefinition) (json.RawMessage, []string,
 	if len(def.Schema.FieldOverrides) > 0 {
 		var parsed map[string]interface{}
 		if err := json.Unmarshal(base, &parsed); err != nil {
-			return nil, nil, err
+			return nil, nil, errs.NewInternalError(errs.SubtypeUnknown,
+				"parse base schema for field overrides: %s", err).WithCause(err)
 		}
 		orphans := schemas.ApplyFieldOverrides(parsed, def.Schema.FieldOverrides)
 		out, err := json.Marshal(parsed)
 		if err != nil {
-			return nil, nil, err
+			return nil, nil, errs.NewInternalError(errs.SubtypeUnknown,
+				"serialize schema with field overrides: %s", err).WithCause(err)
 		}
 		return out, orphans, nil
 	}
@@ -73,7 +76,7 @@ func renderSpec(s *eventlib.SchemaSpec) (json.RawMessage, error) {
 		copy(buf, s.Raw)
 		return buf, nil
 	}
-	return nil, fmt.Errorf("schemaSpec has neither Type nor Raw")
+	return nil, errs.NewInternalError(errs.SubtypeUnknown, "schemaSpec has neither Type nor Raw")
 }
 
 func NewCmdSchema(f *cmdutil.Factory) *cobra.Command {
@@ -165,7 +168,7 @@ func runSchema(f *cmdutil.Factory, key string, asJSON bool) error {
 
 	resolved, _, err := resolveSchemaJSON(def)
 	if err != nil {
-		return output.Errorf(output.ExitInternal, "internal", "resolve schema: %v", err)
+		return err
 	}
 	if resolved != nil {
 		fmt.Fprintf(out, "\nOutput Schema:\n")

cmd/event/schema_test.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/cmdutil"
 	"github.com/larksuite/cli/internal/core"
 	eventlib "github.com/larksuite/cli/internal/event"
@@ -129,3 +130,38 @@ func TestResolveSchemaJSON_CustomWithOverlay(t *testing.T) {
 		t.Errorf("overlay format = %v, want open_id", got)
 	}
 }
+
+func TestRenderSpec_EmptySpecIsTypedInternalError(t *testing.T) {
+	_, err := renderSpec(&eventlib.SchemaSpec{})
+	if err == nil {
+		t.Fatal("expected error for spec with neither Type nor Raw")
+	}
+	p, ok := errs.ProblemOf(err)
+	if !ok {
+		t.Fatalf("expected typed errs error, got %T: %v", err, err)
+	}
+	if p.Category != errs.CategoryInternal {
+		t.Errorf("category = %s, want %s", p.Category, errs.CategoryInternal)
+	}
+}
+
+func TestResolveSchemaJSON_InvalidBaseWithOverridesIsTypedInternalError(t *testing.T) {
+	def := &eventlib.KeyDefinition{
+		Key: "synthetic.invalid.base",
+		Schema: eventlib.SchemaDef{
+			Custom:         &eventlib.SchemaSpec{Raw: json.RawMessage("{not json")},
+			FieldOverrides: map[string]schemas.FieldMeta{"x": {}},
+		},
+	}
+	_, _, err := resolveSchemaJSON(def)
+	if err == nil {
+		t.Fatal("expected error for unparsable base schema")
+	}
+	p, ok := errs.ProblemOf(err)
+	if !ok {
+		t.Fatalf("expected typed errs error, got %T: %v", err, err)
+	}
+	if p.Category != errs.CategoryInternal {
+		t.Errorf("category = %s, want %s", p.Category, errs.CategoryInternal)
+	}
+}

cmd/event/suggestions.go

@@ -8,8 +8,9 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/larksuite/cli/errs"
 	eventlib "github.com/larksuite/cli/internal/event"
-	"github.com/larksuite/cli/internal/output"
+	"github.com/larksuite/cli/internal/suggest"
 )
 
 const maxSuggestions = 3
@@ -28,7 +29,7 @@ func suggestEventKeys(input string) []string {
 			hits = append(hits, match{def.Key, 0})
 			continue
 		}
-		if d := levenshtein(input, def.Key); d <= threshold {
+		if d := suggest.Levenshtein(input, def.Key); d <= threshold {
 			hits = append(hits, match{def.Key, d})
 		}
 	}
@@ -63,40 +64,6 @@ func unknownEventKeyErr(key string) error {
 	if guesses := suggestEventKeys(key); len(guesses) > 0 {
 		msg += " — did you mean " + formatSuggestions(guesses) + "?"
 	}
-	return output.ErrWithHint(
-		output.ExitValidation, "validation",
-		msg,
-		"Run 'lark-cli event list' to see available keys.",
-	)
-}
-
-// levenshtein computes classic edit distance (two-row DP).
-func levenshtein(a, b string) int {
-	if a == b {
-		return 0
-	}
-	ra, rb := []rune(a), []rune(b)
-	if len(ra) == 0 {
-		return len(rb)
-	}
-	if len(rb) == 0 {
-		return len(ra)
-	}
-	prev := make([]int, len(rb)+1)
-	curr := make([]int, len(rb)+1)
-	for j := range prev {
-		prev[j] = j
-	}
-	for i := 1; i <= len(ra); i++ {
-		curr[0] = i
-		for j := 1; j <= len(rb); j++ {
-			cost := 1
-			if ra[i-1] == rb[j-1] {
-				cost = 0
-			}
-			curr[j] = min(prev[j]+1, curr[j-1]+1, prev[j-1]+cost)
-		}
-		prev, curr = curr, prev
-	}
-	return prev[len(rb)]
+	return errs.NewValidationError(errs.SubtypeInvalidArgument, "%s", msg).
+		WithHint("Run 'lark-cli event list' to see available keys.")
 }

cmd/event/suggestions_test.go

@@ -10,27 +10,6 @@ import (
 	_ "github.com/larksuite/cli/events"
 )
 
-func TestLevenshtein(t *testing.T) {
-	cases := []struct {
-		a, b string
-		want int
-	}{
-		{"", "", 0},
-		{"a", "", 1},
-		{"", "abc", 3},
-		{"kitten", "kitten", 0},
-		{"kitten", "sitten", 1},
-		{"kitten", "sitting", 3},
-		{"飞书", "飞书", 0},
-		{"飞书", "飞s", 1},
-	}
-	for _, tc := range cases {
-		if got := levenshtein(tc.a, tc.b); got != tc.want {
-			t.Errorf("levenshtein(%q,%q) = %d, want %d", tc.a, tc.b, got, tc.want)
-		}
-	}
-}
-
 func TestSuggestEventKeys(t *testing.T) {
 	cases := []struct {
 		name              string

cmd/flag_suggest_test.go

@@ -0,0 +1,70 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package cmd
+
+import (
+	"errors"
+	"slices"
+	"strings"
+	"testing"
+
+	"github.com/larksuite/cli/internal/output"
+	"github.com/spf13/cobra"
+)
+
+func TestUnknownFlagName(t *testing.T) {
+	cases := []struct {
+		in   string
+		name string
+		ok   bool
+	}{
+		{"unknown flag: --query", "query", true},
+		{"unknown flag: --with-styles", "with-styles", true},
+		{"unknown shorthand flag: 'z' in -z", "", false},
+		{"flag needs an argument: --find", "", false},
+		{`invalid argument "x" for "--count"`, "", false},
+	}
+	for _, c := range cases {
+		name, ok := unknownFlagName(errors.New(c.in))
+		if name != c.name || ok != c.ok {
+			t.Errorf("unknownFlagName(%q) = (%q,%v), want (%q,%v)", c.in, name, ok, c.name, c.ok)
+		}
+	}
+}
+
+func TestFlagDidYouMean_UnknownFlagSuggestsAndListsValid(t *testing.T) {
+	c := &cobra.Command{Use: "demo"}
+	c.Flags().String("range", "", "")
+	c.Flags().String("find", "", "")
+	c.Flags().Bool("dry-run", false, "")
+
+	err := flagDidYouMean(c, errors.New("unknown flag: --rang")) // typo of --range
+	var exitErr *output.ExitError
+	if !errors.As(err, &exitErr) {
+		t.Fatalf("expected *output.ExitError, got %T", err)
+	}
+	if exitErr.Detail.Type != "unknown_flag" {
+		t.Errorf("type = %q, want unknown_flag", exitErr.Detail.Type)
+	}
+	if !strings.Contains(exitErr.Detail.Hint, "--range") {
+		t.Errorf("hint should suggest --range, got %q", exitErr.Detail.Hint)
+	}
+	detail, _ := exitErr.Detail.Detail.(map[string]any)
+	valid, _ := detail["valid_flags"].([]string)
+	if !slices.Contains(valid, "find") || !slices.Contains(valid, "range") {
+		t.Errorf("valid_flags should list find & range, got %v", valid)
+	}
+}
+
+func TestFlagDidYouMean_OtherErrorStaysGeneric(t *testing.T) {
+	c := &cobra.Command{Use: "demo"}
+	err := flagDidYouMean(c, errors.New("flag needs an argument: --find"))
+	var exitErr *output.ExitError
+	if !errors.As(err, &exitErr) {
+		t.Fatalf("expected *output.ExitError, got %T", err)
+	}
+	if exitErr.Detail.Type != "flag_error" {
+		t.Errorf("type = %q, want flag_error (non-unknown-flag errors stay generic)", exitErr.Detail.Type)
+	}
+}

cmd/notice_test.go

@@ -0,0 +1,61 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package cmd
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/larksuite/cli/internal/deprecation"
+)
+
+// composePendingNotice must surface a deprecated-command alias under the
+// "deprecated_command" key, with the migration target and a skill-update hint,
+// so the JSON "_notice" envelope reaches users who run pre-refactor commands
+// without ever reading --help.
+func TestComposePendingNoticeDeprecatedCommand(t *testing.T) {
+	t.Cleanup(func() { deprecation.SetPending(nil) })
+
+	deprecation.SetPending(&deprecation.Notice{
+		Command:     "+read",
+		Replacement: "+cells-get",
+		Skill:       "lark-sheets",
+	})
+
+	got := composePendingNotice()
+	if got == nil {
+		t.Fatal("composePendingNotice() = nil, want deprecated_command entry")
+	}
+	entry, ok := got["deprecated_command"].(map[string]interface{})
+	if !ok {
+		t.Fatalf("missing deprecated_command key: %#v", got)
+	}
+	if entry["command"] != "+read" {
+		t.Errorf("command = %v, want +read", entry["command"])
+	}
+	if entry["replacement"] != "+cells-get" {
+		t.Errorf("replacement = %v, want +cells-get", entry["replacement"])
+	}
+	if entry["skill"] != "lark-sheets" {
+		t.Errorf("skill = %v, want lark-sheets", entry["skill"])
+	}
+	if msg, _ := entry["message"].(string); !strings.Contains(msg, "update your lark-sheets skill") {
+		t.Errorf("message missing skill-update hint: %q", msg)
+	}
+}
+
+// With nothing pending, the provider returns nil so no "_notice" field is
+// emitted on a clean run.
+func TestComposePendingNoticeEmpty(t *testing.T) {
+	t.Cleanup(func() { deprecation.SetPending(nil) })
+	deprecation.SetPending(nil)
+
+	if got := composePendingNotice(); got != nil {
+		// update/skills pending are process-global; only assert the absence of
+		// our own key to stay robust against unrelated pending state.
+		if _, ok := got["deprecated_command"]; ok {
+			t.Fatalf("deprecated_command present after clear: %#v", got)
+		}
+	}
+}

cmd/root.go

@@ -18,14 +18,17 @@ import (
 	"github.com/larksuite/cli/internal/cmdpolicy"
 	"github.com/larksuite/cli/internal/cmdutil"
 	"github.com/larksuite/cli/internal/core"
+	"github.com/larksuite/cli/internal/deprecation"
 	"github.com/larksuite/cli/internal/errclass"
 	"github.com/larksuite/cli/internal/errcompat"
 	"github.com/larksuite/cli/internal/hook"
 	"github.com/larksuite/cli/internal/output"
 	"github.com/larksuite/cli/internal/registry"
 	"github.com/larksuite/cli/internal/skillscheck"
+	"github.com/larksuite/cli/internal/suggest"
 	"github.com/larksuite/cli/internal/update"
 	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
 )
 
 const rootLong = `lark-cli — Lark/Feishu CLI tool.
@@ -48,20 +51,6 @@ EXAMPLES:
     # Generic API call
     lark-cli api GET /open-apis/calendar/v4/calendars
 
-FLAGS:
-    --params <json>       URL/query parameters JSON
-    --data <json>         request body JSON (POST/PATCH/PUT/DELETE)
-    --as <type>           identity type: user | bot
-    --format <fmt>        output format: json (default) | ndjson | table | csv | pretty
-    --page-all            automatically paginate through all pages
-    --page-size <N>       page size (0 = use API default)
-    --page-limit <N>      max pages to fetch with --page-all (default: 10, 0 for unlimited)
-    --page-delay <MS>     delay in ms between pages (default: 200, only with --page-all)
-    -o, --output <path>   output file path for binary responses
-    --jq <expr>           jq expression to filter JSON output
-    -q <expr>             shorthand for --jq
-    --dry-run             print request without executing
-
 AI AGENT SKILLS:
     lark-cli pairs with AI agent skills (Claude Code, etc.) that
     teach the agent Lark API patterns, best practices, and workflows.
@@ -83,7 +72,15 @@ COMMUNITY:
 More help: lark-cli <command> --help`
 
 // Execute runs the root command and returns the process exit code.
+// rawInvocationArgs holds os.Args[1:] captured at Execute() entry. cobra's
+// UnknownFlags whitelist (installUnknownSubcommandGuard) swallows unknown flags
+// before they reach a group's RunE, so unknownSubcommandRunE re-derives them
+// from here. It stays nil in unit tests that invoke a RunE directly with
+// explicit args — correct, since those don't exercise the whitelist path.
+var rawInvocationArgs []string
+
 func Execute() int {
+	rawInvocationArgs = os.Args[1:]
 	inv, err := BootstrapInvocationContext(os.Args[1:])
 	if err != nil {
 		fmt.Fprintln(os.Stderr, "Error:", err)
@@ -147,29 +144,49 @@ func setupNotices() {
 	skillscheck.Init(build.Version)
 
 	// Composed notice provider — emits keys only when each pending is set.
-	output.PendingNotice = func() map[string]interface{} {
-		notice := map[string]interface{}{}
-		if info := update.GetPending(); info != nil {
-			notice["update"] = map[string]interface{}{
-				"current": info.Current,
-				"latest":  info.Latest,
-				"message": info.Message(),
-				"command": "lark-cli update",
-			}
+	output.PendingNotice = composePendingNotice
+}
+
+// composePendingNotice merges all process-level pending notices (available
+// update, skills/binary drift, deprecated-command alias) into the map surfaced
+// as the JSON "_notice" envelope field. Returns nil when nothing is pending.
+// Extracted from Execute so the composition is unit-testable.
+func composePendingNotice() map[string]interface{} {
+	notice := map[string]interface{}{}
+	if info := update.GetPending(); info != nil {
+		notice["update"] = map[string]interface{}{
+			"current": info.Current,
+			"latest":  info.Latest,
+			"message": info.Message(),
+			"command": "lark-cli update",
 		}
-		if stale := skillscheck.GetPending(); stale != nil {
-			notice["skills"] = map[string]interface{}{
-				"current": stale.Current,
-				"target":  stale.Target,
-				"message": stale.Message(),
-				"command": "lark-cli update",
-			}
-		}
-		if len(notice) == 0 {
-			return nil
-		}
-		return notice
 	}
+	if stale := skillscheck.GetPending(); stale != nil {
+		notice["skills"] = map[string]interface{}{
+			"current": stale.Current,
+			"target":  stale.Target,
+			"message": stale.Message(),
+			"command": "lark-cli update",
+		}
+	}
+	if dep := deprecation.GetPending(); dep != nil {
+		entry := map[string]interface{}{
+			"command": dep.Command,
+			"message": dep.Message(),
+			"action":  "lark-cli update",
+		}
+		if dep.Replacement != "" {
+			entry["replacement"] = dep.Replacement
+		}
+		if dep.Skill != "" {
+			entry["skill"] = dep.Skill
+		}
+		notice["deprecated_command"] = entry
+	}
+	if len(notice) == 0 {
+		return nil
+	}
+	return notice
 }
 
 // isCompletionCommand returns true if args indicate a shell completion request.
@@ -255,6 +272,13 @@ func handleRootError(f *cmdutil.Factory, err error) int {
 		return typedExit
 	}
 
+	// Partial-failure (batch / multi-status): the ok:false result envelope is
+	// already on stdout; set the exit code and write nothing to stderr.
+	var pfErr *output.PartialFailureError
+	if errors.As(err, &pfErr) {
+		return pfErr.Code
+	}
+
 	if exitErr := asExitError(err); exitErr != nil {
 		if !exitErr.Raw {
 			// Raw errors (e.g. from `api` command via output.MarkRaw)
@@ -267,6 +291,19 @@ func handleRootError(f *cmdutil.Factory, err error) int {
 		return exitErr.Code
 	}
 
+	// A backward-compat alias records its deprecation notice in PreRunE, which
+	// runs before cobra's required-flag validation — but a missing required flag
+	// fails before RunE and lands here, where the bare "Error:" line would drop
+	// the notice. When a deprecation is pending, route through the structured
+	// envelope so the migration hint still reaches the caller; all other errors
+	// keep the existing plain output.
+	if deprecation.GetPending() != nil {
+		output.WriteErrorEnvelope(errOut, &output.ExitError{
+			Code:   1,
+			Detail: &output.ErrDetail{Type: "validation", Message: err.Error()},
+		}, string(f.ResolvedIdentity))
+		return 1
+	}
 	fmt.Fprintln(errOut, "Error:", err)
 	return 1
 }
@@ -308,6 +345,12 @@ func asExitError(err error) *output.ExitError {
 func installUnknownSubcommandGuard(cmd *cobra.Command) {
 	if cmd.HasSubCommands() && cmd.Run == nil && cmd.RunE == nil {
 		cmd.RunE = unknownSubcommandRunE
+		// Route an unknown subcommand to unknownSubcommandRunE even when flags
+		// are also present (e.g. `sheets +cells-find --url ...`). A pure group
+		// consumes no flags itself, so unknown flags belong to the (missing)
+		// subcommand; whitelisting them here prevents cobra from erroring on the
+		// flag first and printing usage instead of our structured suggestion.
+		cmd.FParseErrWhitelist.UnknownFlags = true
 		if cmd.Annotations == nil {
 			cmd.Annotations = map[string]string{}
 		}
@@ -327,14 +370,89 @@ func installUnknownSubcommandGuard(cmd *cobra.Command) {
 // they have moved to the typed surface.
 func unknownSubcommandRunE(cmd *cobra.Command, args []string) error {
 	if len(args) == 0 {
-		return cmd.Help()
+		// A bare group (e.g. `sheets`), or one carrying only group-valid flags
+		// like the global --profile, legitimately prints help. But a flag that
+		// belongs to a (missing) subcommand is a user error: the guard's
+		// FParseErrWhitelist swallows such flags and leaves args empty, so without
+		// the checks below they would silently fall through to help + exit 0 —
+		// letting an agent mistake a malformed call (`im --format json`,
+		// `sheets --badflag`) for success. Recover the swallowed tokens from the
+		// raw invocation and fail structured instead.
+		flags := flagTokensInArgs(rawInvocationArgs)
+		if len(flags) == 0 {
+			return cmd.Help()
+		}
+		if unknown := unknownFlagTokens(cmd, rawInvocationArgs); len(unknown) > 0 {
+			return &output.ExitError{
+				Code: output.ExitValidation,
+				Detail: &output.ErrDetail{
+					Type:    "unknown_flag",
+					Message: fmt.Sprintf("unknown flag %s before a subcommand for %q", strings.Join(unknown, ", "), cmd.CommandPath()),
+					Hint:    fmt.Sprintf("flags belong to a subcommand; run `%s --help` to list subcommands and their flags", cmd.CommandPath()),
+					Detail: map[string]any{
+						// Keep the same detail keys as flagDidYouMean's unknown_flag
+						// so a consumer keyed on Type can read a stable shape. The
+						// subcommand isn't resolved here, so suggestions/valid_flags
+						// have no meaningful universe to draw from — emit empty
+						// rather than the group's own (misleading) flags. unknown is
+						// the back-compat singular field; unknown_flags carries the
+						// full list when more than one flag was supplied.
+						"unknown":       strings.Join(unknown, ", "),
+						"unknown_flags": unknown,
+						"command_path":  cmd.CommandPath(),
+						"suggestions":   []string{},
+						"valid_flags":   []string{},
+					},
+				},
+			}
+		}
+		// The remaining flags are all defined somewhere in the tree. Those valid
+		// on the group itself or inherited (e.g. the global --profile) do not
+		// require a subcommand, so a bare group carrying only those still prints
+		// help. Anything left belongs to a subcommand that was omitted
+		// (e.g. `im --format json`): distinct from unknown_flag — the flags are
+		// real, the subcommand is what's missing.
+		misplaced := subcommandOnlyFlagTokens(cmd, rawInvocationArgs)
+		if len(misplaced) == 0 {
+			return cmd.Help()
+		}
+		return &output.ExitError{
+			Code: output.ExitValidation,
+			Detail: &output.ErrDetail{
+				Type:    "missing_subcommand",
+				Message: fmt.Sprintf("missing subcommand for %q; flag %s belongs to a subcommand, not the group", cmd.CommandPath(), strings.Join(misplaced, ", ")),
+				Hint:    fmt.Sprintf("run `%s --help` to list subcommands and their flags", cmd.CommandPath()),
+				Detail: map[string]any{
+					"command_path": cmd.CommandPath(),
+					"flags":        misplaced,
+					"suggestions":  []string{},
+				},
+			},
+		}
 	}
 	unknown := args[0]
-	available := availableSubcommandNames(cmd)
+	available, deprecated := availableSubcommandNames(cmd)
+	// Rank suggestions across both current and deprecated names so a mistyped
+	// legacy command (e.g. +raed → +read) still resolves; the alias stays
+	// runnable and self-flags via the _notice on execution.
+	suggestions := suggest.Closest(unknown, append(append([]string{}, available...), deprecated...), 6)
 	msg := fmt.Sprintf("unknown subcommand %q for %q", unknown, cmd.CommandPath())
 	hint := fmt.Sprintf("run `%s --help` to see available subcommands", cmd.CommandPath())
-	if len(available) > 0 {
-		hint = fmt.Sprintf("available subcommands: %s", strings.Join(available, ", "))
+	if len(suggestions) > 0 {
+		hint = fmt.Sprintf("did you mean one of: %s? (run `%s --help` for the full list)",
+			strings.Join(suggestions, ", "), cmd.CommandPath())
+	}
+	detail := map[string]any{
+		"unknown":      unknown,
+		"command_path": cmd.CommandPath(),
+		"suggestions":  suggestions,
+		"available":    available,
+	}
+	// Only services with backward-compat aliases (currently sheets) carry a
+	// deprecated bucket; omit the key elsewhere so every other service's
+	// envelope is unchanged.
+	if len(deprecated) > 0 {
+		detail["deprecated"] = deprecated
 	}
 	return &output.ExitError{
 		Code: output.ExitValidation,
@@ -342,17 +460,114 @@ func unknownSubcommandRunE(cmd *cobra.Command, args []string) error {
 			Type:    "unknown_subcommand",
 			Message: msg,
 			Hint:    hint,
-			Detail: map[string]any{
-				"unknown":      unknown,
-				"command_path": cmd.CommandPath(),
-				"available":    available,
-			},
+			Detail:  detail,
 		},
 	}
 }
 
-func availableSubcommandNames(cmd *cobra.Command) []string {
-	subs := make([]string, 0, len(cmd.Commands()))
+// flagTokensInArgs returns the flag-like tokens (-x, --foo, --foo=bar) in
+// rawArgs, stopping at the "--" positional terminator. Whether a flag is
+// defined is not considered (see unknownFlagTokens for that). A pure group
+// with any flag token but no subcommand is a user error — a pure group
+// consumes no flags of its own, so the flag must belong to a subcommand — so
+// the caller fails structured instead of falling through to help.
+func flagTokensInArgs(rawArgs []string) []string {
+	var toks []string
+	for _, a := range rawArgs {
+		if a == "--" {
+			break // everything after -- is positional
+		}
+		if len(a) < 2 || a[0] != '-' {
+			continue
+		}
+		toks = append(toks, a)
+	}
+	return toks
+}
+
+// unknownFlagTokens returns the flag tokens in rawArgs that cmd does not define
+// (on itself, inherited, or any direct subcommand). installUnknownSubcommandGuard
+// whitelists unknown flags on pure groups so a mistyped subcommand still reaches
+// the suggestion path; the side effect is that flags before a subcommand are
+// swallowed. This recovers the genuinely-unknown ones so the caller can name
+// them in a "did you mean" envelope.
+func unknownFlagTokens(cmd *cobra.Command, rawArgs []string) []string {
+	var unknown []string
+	for _, a := range flagTokensInArgs(rawArgs) {
+		name := strings.SplitN(strings.TrimLeft(a, "-"), "=", 2)[0]
+		if name != "" && !flagDefinedInTree(cmd, name) {
+			unknown = append(unknown, a)
+		}
+	}
+	return unknown
+}
+
+// flagKnownOnGroup reports whether name is a flag defined on cmd itself or
+// inherited (a global persistent flag like --profile) — i.e. valid on the bare
+// group and therefore not requiring a subcommand.
+func flagKnownOnGroup(cmd *cobra.Command, name string) bool {
+	short := len(name) == 1
+	lookup := func(fs *pflag.FlagSet) bool {
+		if short {
+			return fs.ShorthandLookup(name) != nil
+		}
+		return fs.Lookup(name) != nil
+	}
+	return lookup(cmd.Flags()) || lookup(cmd.InheritedFlags())
+}
+
+// subcommandOnlyFlagTokens returns the flag tokens in rawArgs that are valid on
+// a subcommand of cmd but not on cmd itself/inherited — flags supplied while
+// omitting the subcommand they belong to (`im --format json`). Global flags
+// valid on the bare group (e.g. --profile) are excluded so
+// `lark-cli --profile p im` still prints help rather than erroring.
+func subcommandOnlyFlagTokens(cmd *cobra.Command, rawArgs []string) []string {
+	var misplaced []string
+	for _, a := range flagTokensInArgs(rawArgs) {
+		name := strings.SplitN(strings.TrimLeft(a, "-"), "=", 2)[0]
+		if name == "" || flagKnownOnGroup(cmd, name) {
+			continue
+		}
+		if flagDefinedInTree(cmd, name) {
+			misplaced = append(misplaced, a)
+		}
+	}
+	return misplaced
+}
+
+// flagDefinedInTree reports whether name is defined on cmd, its inherited
+// (persistent) flags, or any direct subcommand. The subcommand case covers a
+// user who merely omitted the subcommand — e.g. `sheets --format json`, where
+// --format is injected on every leaf shortcut, not on the group — so only a
+// genuinely unknown flag like `sheets --badflag` is reported.
+func flagDefinedInTree(cmd *cobra.Command, name string) bool {
+	short := len(name) == 1
+	known := func(c *cobra.Command, inherited bool) bool {
+		fs := c.Flags()
+		if inherited {
+			fs = c.InheritedFlags()
+		}
+		if short {
+			return fs.ShorthandLookup(name) != nil
+		}
+		return fs.Lookup(name) != nil
+	}
+	if known(cmd, false) || known(cmd, true) {
+		return true
+	}
+	for _, c := range cmd.Commands() {
+		if known(c, false) {
+			return true
+		}
+	}
+	return false
+}
+
+// availableSubcommandNames returns the invokable subcommand names of cmd, split
+// into current commands and backward-compatibility aliases (those tagged into
+// the deprecated cobra group via cmdutil.DeprecatedGroupID). Both slices are
+// sorted; hidden commands plus help/completion are omitted.
+func availableSubcommandNames(cmd *cobra.Command) (available, deprecated []string) {
 	for _, c := range cmd.Commands() {
 		if c.Hidden || !c.IsAvailableCommand() {
 			continue
@@ -361,10 +576,95 @@ func availableSubcommandNames(cmd *cobra.Command) []string {
 		if name == "help" || name == "completion" {
 			continue
 		}
-		subs = append(subs, name)
+		if cmdutil.IsDeprecatedCommand(c) {
+			deprecated = append(deprecated, name)
+		} else {
+			available = append(available, name)
+		}
 	}
-	sort.Strings(subs)
-	return subs
+	sort.Strings(available)
+	sort.Strings(deprecated)
+	return available, deprecated
+}
+
+// flagDidYouMean is the root FlagErrorFunc (inherited by all subcommands). It
+// converts cobra's flag-parse errors into the structured ErrorEnvelope: an
+// unknown flag gets a focused "did you mean" hint plus the full valid-flag list
+// in detail (so agents recover even when the typo is semantic, e.g. --query vs
+// --find, where edit distance alone finds nothing). Other flag errors stay
+// structured but generic.
+func flagDidYouMean(c *cobra.Command, ferr error) error {
+	name, isUnknown := unknownFlagName(ferr)
+	if !isUnknown {
+		return &output.ExitError{
+			Code: output.ExitValidation,
+			Detail: &output.ErrDetail{
+				Type:    "flag_error",
+				Message: ferr.Error(),
+				Hint:    fmt.Sprintf("run `%s --help` for valid flags", c.CommandPath()),
+			},
+		}
+	}
+	valid := visibleFlagNames(c)
+	suggestions := suggest.Closest(name, valid, 3)
+	hint := fmt.Sprintf("run `%s --help` to see valid flags", c.CommandPath())
+	if len(suggestions) > 0 {
+		for i := range suggestions {
+			suggestions[i] = "--" + suggestions[i]
+		}
+		hint = fmt.Sprintf("did you mean %s? (run `%s --help` for all flags)",
+			strings.Join(suggestions, ", "), c.CommandPath())
+	}
+	return &output.ExitError{
+		Code: output.ExitValidation,
+		Detail: &output.ErrDetail{
+			Type:    "unknown_flag",
+			Message: fmt.Sprintf("unknown flag %q for %q", "--"+name, c.CommandPath()),
+			Hint:    hint,
+			Detail: map[string]any{
+				"unknown":      "--" + name,
+				"command_path": c.CommandPath(),
+				"suggestions":  suggestions,
+				"valid_flags":  valid,
+			},
+		},
+	}
+}
+
+// unknownFlagName extracts the offending long-flag name from cobra's flag-parse
+// error text ("unknown flag: --query" → "query"). Returns ok=false for anything
+// else (missing argument, invalid value, unknown shorthand) so the caller keeps
+// those structured but generic — hallucinated flags are essentially always long.
+//
+// CONTRACT: this matches cobra's English wording "unknown flag: --" (go.mod
+// pins github.com/spf13/cobra). If cobra rewords this or gains i18n the match
+// silently fails and unknown flags degrade to a generic flag_error — re-verify
+// this prefix when bumping cobra.
+func unknownFlagName(err error) (string, bool) {
+	const p = "unknown flag: --"
+	msg := err.Error()
+	i := strings.Index(msg, p)
+	if i < 0 {
+		return "", false
+	}
+	rest := msg[i+len(p):]
+	if j := strings.IndexAny(rest, " \t"); j >= 0 {
+		rest = rest[:j]
+	}
+	return rest, true
+}
+
+// visibleFlagNames lists the non-hidden flag names of c (for suggestions and
+// the valid_flags detail).
+func visibleFlagNames(c *cobra.Command) []string {
+	var names []string
+	c.Flags().VisitAll(func(f *pflag.Flag) {
+		if !f.Hidden {
+			names = append(names, f.Name)
+		}
+	})
+	sort.Strings(names)
+	return names
 }
 
 // installTipsHelpFunc wraps the default help function to append a TIPS section

cmd/root_integration_test.go

@@ -377,9 +377,9 @@ func TestIntegration_Shortcut_BusinessError_OutputsEnvelope(t *testing.T) {
 		OK:       false,
 		Identity: "bot",
 		Error: &output.ErrDetail{
-			Type:    "api_error",
+			Type:    "api",
 			Code:    230002,
-			Message: "HTTP 400: Bot/User can NOT be out of the chat.",
+			Message: "Bot/User can NOT be out of the chat.",
 		},
 	})
 }

cmd/root_test.go

@@ -21,6 +21,7 @@ import (
 	internalauth "github.com/larksuite/cli/internal/auth"
 	"github.com/larksuite/cli/internal/cmdutil"
 	"github.com/larksuite/cli/internal/core"
+	"github.com/larksuite/cli/internal/deprecation"
 	"github.com/larksuite/cli/internal/output"
 	"github.com/larksuite/cli/internal/registry"
 )
@@ -268,6 +269,54 @@ func (f *failingWriter) Write(p []byte) (int, error) {
 	return len(p), nil
 }
 
+// TestHandleRootError_DeprecatedAliasMissingFlagStructured pins issue #4: a
+// backward-compat alias that fails on a cobra-level required flag (which
+// short-circuits before RunE) still routes through the structured envelope,
+// because OnInvoke records the deprecation in PreRunE and the legacy fallback
+// switches to WriteErrorEnvelope when a deprecation is pending — so the
+// migration notice is no longer dropped on the plain "Error:" line.
+func TestHandleRootError_DeprecatedAliasMissingFlagStructured(t *testing.T) {
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+	t.Cleanup(func() { deprecation.SetPending(nil) })
+
+	f, _, _, _ := cmdutil.TestFactory(t, nil)
+	errOut := &bytes.Buffer{}
+	f.IOStreams.ErrOut = errOut
+
+	deprecation.SetPending(&deprecation.Notice{
+		Command: "+write", Replacement: "+cells-set", Skill: "lark-sheets",
+	})
+	// The bare error shape cobra's ValidateRequiredFlags produces: neither typed
+	// nor an *output.ExitError, so it reaches the legacy fallback.
+	handleRootError(f, fmt.Errorf(`required flag(s) %q not set`, "values"))
+
+	out := errOut.String()
+	if strings.HasPrefix(strings.TrimSpace(out), "Error:") {
+		t.Fatalf("deprecation pending: want a structured envelope, got a plain Error: line:\n%s", out)
+	}
+	if !strings.Contains(out, `"message"`) || !strings.Contains(out, "values") {
+		t.Errorf("expected a JSON error envelope carrying the failure message; got:\n%s", out)
+	}
+}
+
+// TestHandleRootError_NoDeprecationKeepsPlainError pins the other half: with no
+// deprecation pending, the legacy fallback stays a plain "Error:" line, so the
+// fix does not reshape every unrecognized cobra error.
+func TestHandleRootError_NoDeprecationKeepsPlainError(t *testing.T) {
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+	t.Cleanup(func() { deprecation.SetPending(nil) })
+	deprecation.SetPending(nil)
+
+	f, _, _, _ := cmdutil.TestFactory(t, nil)
+	errOut := &bytes.Buffer{}
+	f.IOStreams.ErrOut = errOut
+
+	handleRootError(f, fmt.Errorf(`required flag(s) %q not set`, "values"))
+	if !strings.HasPrefix(errOut.String(), "Error:") {
+		t.Errorf("no deprecation pending: want a plain 'Error:' line, got:\n%s", errOut.String())
+	}
+}
+
 // TestHandleRootError_PartialWritePreservesExitCode pins that when the
 // stderr write fails mid-envelope, handleRootError still returns the typed
 // exit code (ExitAuth=3 for AuthenticationError), not fall through to the

cmd/service/service.go

@@ -180,6 +180,7 @@ func NewCmdServiceMethodWithContext(ctx context.Context, f *cmdutil.Factory, spe
 	cmd.Flags().IntVar(&opts.PageLimit, "page-limit", 10, "max pages to fetch with --page-all (0 = unlimited)")
 	cmd.Flags().IntVar(&opts.PageDelay, "page-delay", 200, "delay in ms between pages")
 	cmd.Flags().StringVar(&opts.Format, "format", "json", "output format: json|ndjson|table|csv")
+	cmd.Flags().Bool("json", false, "shorthand for --format json")
 	cmd.Flags().StringVarP(&opts.JqExpr, "jq", "q", "", "jq expression to filter JSON output")
 	cmd.Flags().BoolVar(&opts.DryRun, "dry-run", false, "print request without executing")
 	if risk == "high-risk-write" {

cmd/service/service_test.go

@@ -765,3 +765,22 @@ func TestDetectFileFields(t *testing.T) {
 		})
 	}
 }
+
+func TestServiceMethod_JsonFlag_Accepted(t *testing.T) {
+	f, _, _, _ := cmdutil.TestFactory(t, testConfig)
+
+	var captured *ServiceMethodOptions
+	cmd := NewCmdServiceMethod(f, driveSpec(),
+		map[string]interface{}{"description": "desc", "httpMethod": "GET"}, "list", "files",
+		func(opts *ServiceMethodOptions) error {
+			captured = opts
+			return nil
+		})
+	cmd.SetArgs([]string{"--json"})
+	if err := cmd.Execute(); err != nil {
+		t.Fatalf("--json should be accepted without error, got: %v", err)
+	}
+	if captured == nil {
+		t.Fatal("expected runF to be called")
+	}
+}

cmd/skill/skill.go

@@ -0,0 +1,183 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+// Package skill implements the `lark-cli skills` command group, which serves
+// binary-embedded skill content to AI agents. The package is "skill"; the
+// user-facing verb is "skills".
+package skill
+
+import (
+	"fmt"
+
+	"github.com/larksuite/cli/errs"
+	"github.com/larksuite/cli/internal/cmdutil"
+	"github.com/larksuite/cli/internal/output"
+	"github.com/larksuite/cli/internal/skillcontent"
+	"github.com/spf13/cobra"
+)
+
+func newReader(f *cmdutil.Factory) (*skillcontent.Reader, error) {
+	if f.SkillContent == nil {
+		return nil, errs.NewInternalError(errs.SubtypeFileIO,
+			"skill content not embedded in this build")
+	}
+	return skillcontent.New(f.SkillContent), nil
+}
+
+type readEnvelope struct {
+	Skill    string `json:"skill"`
+	Path     string `json:"path"`
+	Content  string `json:"content"`
+	Guidance string `json:"guidance,omitempty"`
+}
+
+type listEnvelope struct {
+	OK     bool                     `json:"ok"`
+	Skills []skillcontent.SkillInfo `json:"skills"`
+	Count  int                      `json:"count"`
+}
+
+type listPathEnvelope struct {
+	OK      bool                    `json:"ok"`
+	Path    string                  `json:"path"`
+	Entries []skillcontent.DirEntry `json:"entries"`
+	Count   int                     `json:"count"`
+}
+
+func NewCmdSkill(f *cmdutil.Factory) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "skills",
+		Short: "Read embedded skill content (list / read)",
+		Long: "Read agent-readable skill content (SKILL.md and reference files) embedded in " +
+			"the CLI binary at build time, so it stays in sync with the CLI version. " +
+			"Machine resources such as assets/ and scripts/ are not embedded.",
+	}
+	// Risk is set on each leaf (GetRisk does not walk parents); the group has none.
+	cmdutil.DisableAuthCheck(cmd)
+	cmd.AddCommand(newListCmd(f), newReadCmd(f))
+	return cmd
+}
+
+func newListCmd(f *cmdutil.Factory) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "list [name[/path]]",
+		Short: "List skills, or list one layer under a skill path (like ls)",
+		Example: `  lark-cli skills list                      # all skills: name, description, version
+  lark-cli skills list lark-doc             # one layer under a skill (like ls)
+  lark-cli skills list lark-doc/references  # one layer under a subdirectory`,
+		Args: cobra.ArbitraryArgs,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if len(args) > 1 {
+				return errs.NewValidationError(errs.SubtypeInvalidArgument,
+					"list takes at most 1 argument: [name[/path]]").
+					WithHint("run 'lark-cli skills list --help'")
+			}
+			r, err := newReader(f)
+			if err != nil {
+				return err
+			}
+			if len(args) == 0 {
+				skills, err := r.List()
+				if err != nil {
+					return err
+				}
+				output.PrintJson(f.IOStreams.Out, listEnvelope{OK: true, Skills: skills, Count: len(skills)})
+				return nil
+			}
+			entries, listed, err := r.ListPath(args[0])
+			if err != nil {
+				return err
+			}
+			output.PrintJson(f.IOStreams.Out, listPathEnvelope{OK: true, Path: listed, Entries: entries, Count: len(entries)})
+			return nil
+		},
+	}
+	// --json is a no-op (list is always JSON), accepted only to stay symmetric with read.
+	cmd.Flags().Bool("json", false, "no-op (list output is always JSON)")
+	cmdutil.SetRisk(cmd, "read")
+	cmdutil.DisableAuthCheck(cmd)
+	return cmd
+}
+
+func newReadCmd(f *cmdutil.Factory) *cobra.Command {
+	var asJSON bool
+	cmd := &cobra.Command{
+		Use:   "read <name>[/<path>] [path]",
+		Short: "Print a skill's SKILL.md, or a file under the skill (raw markdown by default)",
+		Example: `  lark-cli skills read lark-doc                             # the skill's SKILL.md
+  lark-cli skills read lark-doc references/lark-doc-fetch.md  # a file under the skill
+  lark-cli skills read lark-doc/references/lark-doc-fetch.md  # same, slash form
+  lark-cli skills read lark-doc --json                      # JSON envelope`,
+		Args: cobra.ArbitraryArgs,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			name, relpath, err := parseReadTarget(args)
+			if err != nil {
+				return err
+			}
+			r, err := newReader(f)
+			if err != nil {
+				return err
+			}
+
+			var content []byte
+			var pathOut string
+			if relpath == "" {
+				content, err = r.ReadSkill(name)
+				pathOut = "SKILL.md"
+			} else {
+				content, pathOut, err = r.ReadReference(name, relpath)
+			}
+			if err != nil {
+				return err
+			}
+
+			isMain := pathOut == "SKILL.md"
+			if asJSON {
+				env := readEnvelope{Skill: name, Path: pathOut, Content: string(content)}
+				if isMain {
+					env.Guidance = readGuidance(name)
+				}
+				output.PrintJson(f.IOStreams.Out, env)
+				return nil
+			}
+			// Raw stdout stays byte-identical to the file; guidance goes to stderr.
+			if _, err := f.IOStreams.Out.Write(content); err != nil {
+				return errs.NewInternalError(errs.SubtypeFileIO, "failed to write output: %v", err)
+			}
+			if isMain {
+				fmt.Fprintln(f.IOStreams.ErrOut, readGuidance(name))
+			}
+			return nil
+		},
+	}
+	cmd.Flags().BoolVar(&asJSON, "json", false, "output as a JSON envelope instead of raw markdown")
+	cmdutil.SetRisk(cmd, "read")
+	cmdutil.DisableAuthCheck(cmd)
+	return cmd
+}
+
+// parseReadTarget maps 1-or-2 positional args to (name, relpath); a lone
+// "<a>/<b>" splits on the first '/', and relpath "" reads the main SKILL.md.
+func parseReadTarget(args []string) (name, relpath string, err error) {
+	switch len(args) {
+	case 1:
+		name, relpath = skillcontent.SplitArg(args[0])
+		return name, relpath, nil
+	case 2:
+		return args[0], args[1], nil
+	default:
+		return "", "", errs.NewValidationError(errs.SubtypeInvalidArgument,
+			"read requires 1 or 2 arguments: <name>[/<path>] [path]").
+			WithHint("run 'lark-cli skills read --help'")
+	}
+}
+
+// readGuidance routes cross-skill "../lark-foo/..." references back through
+// `skills read lark-foo/...`: the path guard rejects a literal "../", so the
+// relative form must be rewritten.
+func readGuidance(name string) string {
+	return fmt.Sprintf("> Tip: read this skill's own files (e.g. `references/...`) with "+
+		"`lark-cli skills read %s <relative-path>` to keep them in sync with this CLI version. "+
+		"A reference to another skill (`../lark-foo/...`) uses the same command with the "+
+		"leading `../` removed: `lark-cli skills read lark-foo/...`.", name)
+}

cmd/skill/skill_test.go

@@ -0,0 +1,306 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package skill
+
+import (
+	"encoding/json"
+	"io"
+	"io/fs"
+	"strings"
+	"testing"
+	"testing/fstest"
+
+	"github.com/larksuite/cli/internal/cmdutil"
+)
+
+// calFS is the default single-skill content tree for these tests. The embedded
+// FS is now injected through the Factory (no package global), so tests pass it
+// explicitly to run() — nothing is shared, so they are safe under -parallel.
+func calFS() fstest.MapFS {
+	return fstest.MapFS{
+		"lark-calendar/SKILL.md":             {Data: []byte("---\nname: lark-calendar\nversion: 1.0.0\ndescription: \"Cal\"\nmetadata:\n  cliHelp: \"lark-cli calendar --help\"\n---\nbody")},
+		"lark-calendar/references/agenda.md": {Data: []byte("# Agenda")},
+	}
+}
+
+// run executes the skills command tree against the given content FS (may be nil
+// to exercise the not-embedded path) and returns stdout/stderr/err.
+func run(t *testing.T, fsys fs.FS, args ...string) (stdout, stderr string, err error) {
+	t.Helper()
+	// Isolate CLI config state so tests never read/write the real config dir
+	// (repo convention).
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+	f, out, errOut, _ := cmdutil.TestFactory(t, nil)
+	f.SkillContent = fsys
+	cmd := NewCmdSkill(f)
+	cmd.SetOut(io.Discard)
+	cmd.SetErr(io.Discard)
+	cmd.SetArgs(args)
+	err = cmd.Execute()
+	return out.String(), errOut.String(), err
+}
+
+func TestSkillList(t *testing.T) {
+	stdout, _, err := run(t, calFS(), "list")
+	if err != nil {
+		t.Fatalf("list error: %v", err)
+	}
+	var got struct {
+		OK     bool             `json:"ok"`
+		Skills []map[string]any `json:"skills"`
+		Count  int              `json:"count"`
+	}
+	if e := json.Unmarshal([]byte(stdout), &got); e != nil {
+		t.Fatalf("invalid JSON: %v\n%s", e, stdout)
+	}
+	// "ok" is an explicit success marker (the list envelope is a typed struct;
+	// no automatic _notice attaches).
+	if !got.OK {
+		t.Error("expected ok=true in list envelope")
+	}
+	if got.Count != 1 || len(got.Skills) != 1 {
+		t.Fatalf("count: got %d", got.Count)
+	}
+	if got.Skills[0]["name"] != "lark-calendar" {
+		t.Errorf("name: got %v", got.Skills[0]["name"])
+	}
+	// Top-level list carries version + metadata, not a references list.
+	if _, ok := got.Skills[0]["references"]; ok {
+		t.Error("top-level list must not include references")
+	}
+	if got.Skills[0]["version"] != "1.0.0" {
+		t.Errorf("version: got %v, want 1.0.0", got.Skills[0]["version"])
+	}
+	if _, ok := got.Skills[0]["metadata"]; !ok {
+		t.Error("expected metadata in list entry")
+	}
+}
+
+func TestSkillListJSONFlagAccepted(t *testing.T) {
+	// `list --json` must be accepted (no-op), not rejected as an unknown flag,
+	// so it stays symmetric with read --json.
+	stdout, _, err := run(t, calFS(), "list", "--json")
+	if err != nil {
+		t.Fatalf("list --json error: %v", err)
+	}
+	var got struct {
+		OK    bool `json:"ok"`
+		Count int  `json:"count"`
+	}
+	if e := json.Unmarshal([]byte(stdout), &got); e != nil {
+		t.Fatalf("invalid JSON: %v\n%s", e, stdout)
+	}
+	if !got.OK || got.Count != 1 {
+		t.Errorf("envelope: %+v", got)
+	}
+}
+
+func TestSkillListPath(t *testing.T) {
+	stdout, _, err := run(t, calFS(), "list", "lark-calendar")
+	if err != nil {
+		t.Fatalf("list <name> error: %v", err)
+	}
+	var got struct {
+		OK      bool   `json:"ok"`
+		Path    string `json:"path"`
+		Entries []struct {
+			Path  string `json:"path"`
+			IsDir bool   `json:"is_dir"`
+		} `json:"entries"`
+		Count int `json:"count"`
+	}
+	if e := json.Unmarshal([]byte(stdout), &got); e != nil {
+		t.Fatalf("invalid JSON: %v\n%s", e, stdout)
+	}
+	if !got.OK || got.Path != "lark-calendar" {
+		t.Errorf("envelope: %+v", got)
+	}
+	// One layer under the skill root: SKILL.md (file) + references (dir).
+	if got.Count != 2 || len(got.Entries) != 2 {
+		t.Fatalf("entries: got %+v", got.Entries)
+	}
+	if got.Entries[0].Path != "lark-calendar/SKILL.md" || got.Entries[0].IsDir {
+		t.Errorf("entry[0]: got %+v", got.Entries[0])
+	}
+	if got.Entries[1].Path != "lark-calendar/references" || !got.Entries[1].IsDir {
+		t.Errorf("entry[1]: got %+v", got.Entries[1])
+	}
+}
+
+func TestSkillListPathUnknown(t *testing.T) {
+	_, _, err := run(t, calFS(), "list", "no-such-skill")
+	if err == nil || !strings.Contains(err.Error(), "unknown skill") {
+		t.Fatalf("expected 'unknown skill' error, got %v", err)
+	}
+}
+
+func TestSkillListPathTraversal(t *testing.T) {
+	stdout, _, err := run(t, calFS(), "list", "lark-calendar/../../etc")
+	if err == nil || !strings.Contains(err.Error(), "invalid path") {
+		t.Fatalf("expected 'invalid path' error, got %v", err)
+	}
+	if stdout != "" {
+		t.Errorf("stdout must be empty on rejection, got %q", stdout)
+	}
+}
+
+func TestSkillListTooManyArgs(t *testing.T) {
+	_, _, err := run(t, calFS(), "list", "a", "b")
+	if err == nil || !strings.Contains(err.Error(), "at most 1 argument") {
+		t.Fatalf("expected 'at most 1 argument' error, got %v", err)
+	}
+}
+
+// TestSkillListSkipsDirWithoutSKILLmd proves a top-level dir lacking SKILL.md is
+// omitted from the catalog (no blank entry).
+func TestSkillListSkipsDirWithoutSKILLmd(t *testing.T) {
+	fsys := fstest.MapFS{
+		"lark-calendar/SKILL.md": {Data: []byte("---\nname: lark-calendar\ndescription: \"Cal\"\n---\nb")},
+		"not-a-skill/readme.txt": {Data: []byte("junk")}, // dir without SKILL.md
+	}
+	stdout, _, err := run(t, fsys, "list")
+	if err != nil {
+		t.Fatalf("list error: %v", err)
+	}
+	var got struct {
+		Skills []map[string]any `json:"skills"`
+		Count  int              `json:"count"`
+	}
+	if e := json.Unmarshal([]byte(stdout), &got); e != nil {
+		t.Fatalf("invalid JSON: %v\n%s", e, stdout)
+	}
+	if got.Count != 1 || got.Skills[0]["name"] != "lark-calendar" {
+		t.Fatalf("expected only lark-calendar, got %+v", got.Skills)
+	}
+}
+
+func TestSkillReadRaw(t *testing.T) {
+	stdout, stderr, err := run(t, calFS(), "read", "lark-calendar")
+	if err != nil {
+		t.Fatalf("read error: %v", err)
+	}
+	if !strings.HasPrefix(stdout, "---\nname: lark-calendar") {
+		t.Errorf("raw output: got %q", stdout)
+	}
+	// Raw stdout is byte-pure SKILL.md — the guidance tip must NOT be appended.
+	if strings.Contains(stdout, "Tip:") {
+		t.Errorf("raw stdout must not carry the guidance tip: got %q", stdout)
+	}
+	// Guidance goes to stderr: own files via `skills read <name> ...`, and
+	// cross-skill refs routed to `skills read <other-skill> ...` (version-
+	// consistent), not "read directly".
+	if !strings.Contains(stderr, "lark-cli skills read lark-calendar <relative-path>") {
+		t.Errorf("expected own-files guidance on stderr: got %q", stderr)
+	}
+	if !strings.Contains(stderr, "lark-cli skills read lark-foo/...") {
+		t.Errorf("expected cross-skill refs routed to skills read: got %q", stderr)
+	}
+	if strings.Contains(stderr, "instead of opening them directly") ||
+		strings.Contains(stderr, "read those directly") {
+		t.Errorf("guidance must not steer cross-skill refs to direct reads: got %q", stderr)
+	}
+}
+
+func TestSkillReadJSON(t *testing.T) {
+	stdout, _, err := run(t, calFS(), "read", "lark-calendar", "--json")
+	if err != nil {
+		t.Fatalf("read --json error: %v", err)
+	}
+	var got struct {
+		Skill, Path, Content, Guidance string
+	}
+	if e := json.Unmarshal([]byte(stdout), &got); e != nil {
+		t.Fatalf("invalid JSON: %v", e)
+	}
+	if got.Skill != "lark-calendar" || got.Path != "SKILL.md" || got.Content == "" {
+		t.Errorf("envelope: %+v", got)
+	}
+	// Guidance is a separate field, not merged into content.
+	if got.Guidance == "" {
+		t.Error("expected guidance field for main SKILL.md")
+	}
+	if strings.Contains(got.Content, "Tip:") {
+		t.Error("guidance must not be merged into content")
+	}
+}
+
+func TestSkillReadFile(t *testing.T) {
+	// Both the 2-arg and slash forms read the same file, with no guidance tip.
+	for _, args := range [][]string{
+		{"read", "lark-calendar", "references/agenda.md"},
+		{"read", "lark-calendar/references/agenda.md"},
+	} {
+		stdout, stderr, err := run(t, calFS(), args...)
+		if err != nil {
+			t.Fatalf("read %v error: %v", args, err)
+		}
+		if stdout != "# Agenda" {
+			t.Errorf("read %v output: got %q", args, stdout)
+		}
+		// Reference reads carry no guidance on either stream.
+		if strings.Contains(stderr, "Tip:") {
+			t.Errorf("read %v must not emit guidance on stderr: got %q", args, stderr)
+		}
+	}
+}
+
+func TestSkillReadFileJSON(t *testing.T) {
+	stdout, _, err := run(t, calFS(), "read", "lark-calendar", "references/agenda.md", "--json")
+	if err != nil {
+		t.Fatalf("read file --json error: %v", err)
+	}
+	var got struct {
+		Skill, Path, Content, Guidance string
+	}
+	if e := json.Unmarshal([]byte(stdout), &got); e != nil {
+		t.Fatalf("invalid JSON: %v\n%s", e, stdout)
+	}
+	if got.Skill != "lark-calendar" || got.Path != "references/agenda.md" || got.Content != "# Agenda" {
+		t.Errorf("envelope: %+v", got)
+	}
+	// Reference reads do not carry the guidance tip.
+	if got.Guidance != "" {
+		t.Errorf("reference read must not include guidance, got %q", got.Guidance)
+	}
+}
+
+func TestSkillReadUnknown(t *testing.T) {
+	_, _, err := run(t, calFS(), "read", "no-such")
+	if err == nil {
+		t.Fatal("expected error")
+	}
+	if !strings.Contains(err.Error(), "unknown skill") {
+		t.Errorf("err: %v", err)
+	}
+}
+
+func TestSkillReadMissingArg(t *testing.T) {
+	_, _, err := run(t, calFS(), "read")
+	if err == nil || !strings.Contains(err.Error(), "requires 1 or 2 arguments") {
+		t.Fatalf("expected arg error, got %v", err)
+	}
+}
+
+func TestSkillReadTraversal(t *testing.T) {
+	stdout, _, err := run(t, calFS(), "read", "lark-calendar", "../../etc/passwd")
+	if err == nil {
+		t.Fatal("expected rejection")
+	}
+	if !strings.Contains(err.Error(), "invalid path") {
+		t.Errorf("err: %v", err)
+	}
+	if stdout != "" {
+		t.Errorf("stdout must be empty on rejection, got %q", stdout)
+	}
+}
+
+func TestSkillNilContentFS(t *testing.T) {
+	_, _, err := run(t, nil, "list")
+	if err == nil {
+		t.Fatal("expected error when SkillContent is nil")
+	}
+	if !strings.Contains(err.Error(), "not embedded") {
+		t.Errorf("err: %v", err)
+	}
+}

cmd/unknown_subcommand_test.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"github.com/larksuite/cli/internal/cmdutil"
 	"github.com/larksuite/cli/internal/output"
 )
 
@@ -72,6 +73,149 @@ func TestInstallUnknownSubcommandGuard_PreservesExistingRunE(t *testing.T) {
 	}
 }
 
+func TestUnknownFlagTokens(t *testing.T) {
+	_, drive, _ := newGroupTree()
+	// Give a subcommand a flag so a misplaced-but-known flag (the user omitted
+	// the subcommand) is distinguished from a genuinely unknown one.
+	for _, c := range drive.Commands() {
+		if c.Name() == "+search" {
+			c.Flags().String("query", "", "")
+		}
+	}
+	cases := []struct {
+		name    string
+		rawArgs []string
+		want    []string
+	}{
+		{"genuinely unknown long flag", []string{"drive", "--badflag"}, []string{"--badflag"}},
+		{"flag known on a subcommand (misplaced)", []string{"drive", "--query", "x"}, nil},
+		{"no flags at all", []string{"drive"}, nil},
+		{"tokens after -- are positional", []string{"drive", "--", "--badflag"}, nil},
+		{"unknown shorthand", []string{"drive", "-Z"}, []string{"-Z"}},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := unknownFlagTokens(drive, tc.rawArgs)
+			if len(got) != len(tc.want) {
+				t.Fatalf("unknownFlagTokens(%v) = %v, want %v", tc.rawArgs, got, tc.want)
+			}
+			for i := range got {
+				if got[i] != tc.want[i] {
+					t.Errorf("token[%d] = %q, want %q", i, got[i], tc.want[i])
+				}
+			}
+		})
+	}
+}
+
+func TestUnknownSubcommandRunE_FlagBeforeSubcommandIsStructured(t *testing.T) {
+	_, drive, _ := newGroupTree()
+	installUnknownSubcommandGuard(drive.Root())
+
+	// Simulate `lark-cli drive --badflag`: the UnknownFlags whitelist swallows
+	// --badflag, so RunE sees no args; the guard must recover it from
+	// rawInvocationArgs and fail structured rather than print help + exit 0.
+	rawInvocationArgs = []string{"drive", "--badflag"}
+	t.Cleanup(func() { rawInvocationArgs = nil })
+
+	err := drive.RunE(drive, nil)
+	if err == nil {
+		t.Fatal("expected a structured unknown_flag error, got nil (help fallthrough)")
+	}
+	if !strings.Contains(err.Error(), "unknown flag") {
+		t.Errorf("error = %q, want it to mention an unknown flag", err.Error())
+	}
+
+	// The detail must stay schema-compatible with flagDidYouMean's unknown_flag
+	// (same Type → same keys), so a consumer keyed on Type reads a stable shape.
+	exitErr, ok := err.(*output.ExitError)
+	if !ok || exitErr.Detail == nil {
+		t.Fatalf("expected *output.ExitError with Detail, got %T", err)
+	}
+	if exitErr.Detail.Type != "unknown_flag" {
+		t.Errorf("detail.Type = %q, want unknown_flag", exitErr.Detail.Type)
+	}
+	detail, ok := exitErr.Detail.Detail.(map[string]any)
+	if !ok {
+		t.Fatalf("expected detail to be map[string]any, got %T", exitErr.Detail.Detail)
+	}
+	if detail["unknown"] != "--badflag" {
+		t.Errorf("detail.unknown = %v, want --badflag", detail["unknown"])
+	}
+	if got, _ := detail["unknown_flags"].([]string); len(got) != 1 || got[0] != "--badflag" {
+		t.Errorf("detail.unknown_flags = %v, want [--badflag]", detail["unknown_flags"])
+	}
+	for _, key := range []string{"suggestions", "valid_flags"} {
+		if _, present := detail[key]; !present {
+			t.Errorf("detail.%s missing; must be present (empty) to match the unknown_flag schema", key)
+		}
+	}
+}
+
+func TestUnknownSubcommandRunE_ValidFlagWithoutSubcommandIsStructured(t *testing.T) {
+	_, drive, _ := newGroupTree()
+	// --query is defined on the +search subcommand, so it is a *valid* flag that
+	// was placed before the (omitted) subcommand. Unlike an unknown flag, this
+	// must still fail structured (missing_subcommand) rather than fall through to
+	// help + exit 0 — `drive --query x` is a malformed call, not a help request.
+	for _, c := range drive.Commands() {
+		if c.Name() == "+search" {
+			c.Flags().String("query", "", "")
+		}
+	}
+	installUnknownSubcommandGuard(drive.Root())
+
+	rawInvocationArgs = []string{"drive", "--query", "x"}
+	t.Cleanup(func() { rawInvocationArgs = nil })
+
+	err := drive.RunE(drive, nil)
+	if err == nil {
+		t.Fatal("expected a structured missing_subcommand error, got nil (help fallthrough)")
+	}
+	var exitErr *output.ExitError
+	if !errors.As(err, &exitErr) {
+		t.Fatalf("expected *output.ExitError, got %T", err)
+	}
+	if exitErr.Code != output.ExitValidation {
+		t.Errorf("exit code = %d, want %d", exitErr.Code, output.ExitValidation)
+	}
+	if exitErr.Detail == nil || exitErr.Detail.Type != "missing_subcommand" {
+		t.Fatalf("detail.Type = %v, want missing_subcommand", exitErr.Detail)
+	}
+	detail, ok := exitErr.Detail.Detail.(map[string]any)
+	if !ok {
+		t.Fatalf("detail is not a map: %#v", exitErr.Detail.Detail)
+	}
+	if flags, _ := detail["flags"].([]string); len(flags) != 1 || flags[0] != "--query" {
+		t.Errorf("detail.flags = %v, want [--query]", detail["flags"])
+	}
+	if detail["command_path"] != "lark-cli drive" {
+		t.Errorf("detail.command_path = %v, want lark-cli drive", detail["command_path"])
+	}
+}
+
+// A bare group carrying only a group-valid global flag (e.g. the inherited
+// --profile) is not missing a subcommand — those flags do not belong to a
+// subcommand — so it must print help, not fail with missing_subcommand.
+func TestUnknownSubcommandRunE_GroupValidGlobalFlagShowsHelp(t *testing.T) {
+	_, drive, _ := newGroupTree()
+	drive.Root().PersistentFlags().String("profile", "", "") // global, inherited by drive
+	installUnknownSubcommandGuard(drive.Root())
+
+	rawInvocationArgs = []string{"--profile", "p", "drive"}
+	t.Cleanup(func() { rawInvocationArgs = nil })
+
+	var buf bytes.Buffer
+	drive.SetOut(&buf)
+	drive.SetErr(&buf)
+	if err := drive.RunE(drive, nil); err != nil {
+		t.Fatalf("bare group with only a global flag should print help, got error: %v", err)
+	}
+	if !strings.Contains(buf.String(), "drive ops") {
+		t.Errorf("expected help output, got:\n%s", buf.String())
+	}
+}
+
 func TestUnknownSubcommandRunE_NoArgsShowsHelp(t *testing.T) {
 	_, drive, _ := newGroupTree()
 	installUnknownSubcommandGuard(drive.Root())
@@ -113,11 +257,11 @@ func TestUnknownSubcommandRunE_UnknownReturnsStructuredError(t *testing.T) {
 	if !strings.Contains(exitErr.Detail.Message, `"+bogus"`) {
 		t.Errorf("message should echo the unknown token, got %q", exitErr.Detail.Message)
 	}
-	if !strings.Contains(exitErr.Detail.Hint, "+search") || !strings.Contains(exitErr.Detail.Hint, "+upload") {
-		t.Errorf("hint should list available shortcuts, got %q", exitErr.Detail.Hint)
-	}
-	if strings.Contains(exitErr.Detail.Hint, "+secret") {
-		t.Error("hidden commands must not appear in the hint")
+	// "+bogus" has no close neighbor among drive's subcommands, so the hint falls
+	// back to pointing at --help; the full machine-readable list lives in
+	// detail.available below (which also excludes hidden commands).
+	if !strings.Contains(exitErr.Detail.Hint, "--help") {
+		t.Errorf("hint should guide to --help when there is no suggestion, got %q", exitErr.Detail.Hint)
 	}
 
 	detail, ok := exitErr.Detail.Detail.(map[string]any)
@@ -164,7 +308,7 @@ func TestAvailableSubcommandNames_FiltersHelpAndCompletion(t *testing.T) {
 		&cobra.Command{Use: "gamma", RunE: func(*cobra.Command, []string) error { return nil }},
 	)
 
-	got := availableSubcommandNames(root)
+	got, _ := availableSubcommandNames(root)
 	want := []string{"alpha", "gamma"}
 	if len(got) != len(want) {
 		t.Fatalf("expected %v, got %v", want, got)
@@ -175,3 +319,61 @@ func TestAvailableSubcommandNames_FiltersHelpAndCompletion(t *testing.T) {
 		}
 	}
 }
+
+func TestAvailableSubcommandNames_SplitsDeprecatedGroup(t *testing.T) {
+	root := &cobra.Command{Use: "lark-cli"}
+	root.AddGroup(&cobra.Group{ID: cmdutil.DeprecatedGroupID, Title: "Deprecated"})
+	root.AddCommand(
+		&cobra.Command{Use: "+new-cmd", RunE: func(*cobra.Command, []string) error { return nil }},
+		&cobra.Command{Use: "+old-cmd", GroupID: cmdutil.DeprecatedGroupID, RunE: func(*cobra.Command, []string) error { return nil }},
+	)
+
+	available, deprecated := availableSubcommandNames(root)
+	if len(available) != 1 || available[0] != "+new-cmd" {
+		t.Errorf("available = %v, want [+new-cmd]", available)
+	}
+	if len(deprecated) != 1 || deprecated[0] != "+old-cmd" {
+		t.Errorf("deprecated = %v, want [+old-cmd]", deprecated)
+	}
+}
+
+// unknownSubcommandRunE must split current vs deprecated subcommands into
+// separate detail buckets, while suggestions still rank across both so a
+// mistyped legacy alias resolves.
+func TestUnknownSubcommandRunE_SplitsDeprecatedBucket(t *testing.T) {
+	svc := &cobra.Command{Use: "sheets"}
+	svc.AddGroup(&cobra.Group{ID: cmdutil.DeprecatedGroupID, Title: "Deprecated"})
+	svc.AddCommand(
+		&cobra.Command{Use: "+cells-get", RunE: func(*cobra.Command, []string) error { return nil }},
+		&cobra.Command{Use: "+read", GroupID: cmdutil.DeprecatedGroupID, RunE: func(*cobra.Command, []string) error { return nil }},
+	)
+
+	err := unknownSubcommandRunE(svc, []string{"+reat"})
+	var exitErr *output.ExitError
+	if !errors.As(err, &exitErr) {
+		t.Fatalf("expected *output.ExitError, got %T", err)
+	}
+	detail, ok := exitErr.Detail.Detail.(map[string]any)
+	if !ok {
+		t.Fatalf("detail is not a map: %#v", exitErr.Detail.Detail)
+	}
+
+	if available, _ := detail["available"].([]string); len(available) != 1 || available[0] != "+cells-get" {
+		t.Errorf("available = %v, want [+cells-get]", available)
+	}
+	deprecated, ok := detail["deprecated"].([]string)
+	if !ok || len(deprecated) != 1 || deprecated[0] != "+read" {
+		t.Errorf("deprecated = %v, want [+read]", deprecated)
+	}
+	// suggestions rank across both buckets: "+reat" is closest to +read.
+	suggestions, _ := detail["suggestions"].([]string)
+	found := false
+	for _, s := range suggestions {
+		if s == "+read" {
+			found = true
+		}
+	}
+	if !found {
+		t.Errorf("suggestions %v should include +read (typo target)", suggestions)
+	}
+}

cmd/update/update_test.go

@@ -49,18 +49,29 @@ func mockDetectAndNpm(t *testing.T, result selfupdate.DetectResult, npmFn func(s
 		u.DetectOverride = func() selfupdate.DetectResult { return result }
 		u.NpmInstallOverride = npmFn
 		u.VerifyOverride = func(string) error { return nil }
+		u.SkillsIndexFetchOverride = successfulSkillsIndexFetch()
 		u.SkillsCommandOverride = successfulSkillsCommand()
 		return u
 	}
 	t.Cleanup(func() { newUpdater = origNew })
 }
 
+func successfulSkillsIndexFetch() func() *selfupdate.NpmResult {
+	return func() *selfupdate.NpmResult {
+		r := &selfupdate.NpmResult{}
+		r.Stdout.WriteString(`{"skills":[{"name":"lark-calendar"},{"name":"lark-mail"}]}`)
+		return r
+	}
+}
+
 func successfulSkillsCommand() func(args ...string) *selfupdate.NpmResult {
 	return func(args ...string) *selfupdate.NpmResult {
 		r := &selfupdate.NpmResult{}
 		switch strings.Join(args, " ") {
 		case "-y skills add https://open.feishu.cn --list":
 			r.Stdout.WriteString("Available Skills\n │    lark-calendar\n │    lark-mail\n")
+		case "-y skills ls -g --json":
+			r.Stdout.WriteString(`[{"name":"lark-calendar","path":"/tmp/lark-calendar","scope":"global","agents":["Codex"]},{"name":"custom-skill","path":"/tmp/custom-skill","scope":"global","agents":["Codex"]}]`)
 		case "-y skills ls -g":
 			r.Stdout.WriteString("Global Skills\nlark-calendar /tmp/lark-calendar\ncustom-skill /tmp/custom-skill\n")
 		default:
@@ -476,6 +487,10 @@ func TestUpdateNpmVerifyFail_JSON_NoRestoreHintWhenBackupUnavailable(t *testing.
 		u.NpmInstallOverride = func(version string) *selfupdate.NpmResult { return &selfupdate.NpmResult{} }
 		u.VerifyOverride = func(string) error { return errors.New("bad binary") }
 		u.RestoreAvailableOverride = func() bool { return false }
+		u.SkillsIndexFetchOverride = func() *selfupdate.NpmResult {
+			t.Fatal("skills sync should not run when binary verification fails")
+			return nil
+		}
 		u.SkillsCommandOverride = func(args ...string) *selfupdate.NpmResult {
 			t.Fatal("skills sync should not run when binary verification fails")
 			return nil
@@ -808,6 +823,11 @@ func TestUpdateNpm_SkillsFail_JSON(t *testing.T) {
 		}
 		u.NpmInstallOverride = func(version string) *selfupdate.NpmResult { return &selfupdate.NpmResult{} }
 		u.VerifyOverride = func(string) error { return nil }
+		u.SkillsIndexFetchOverride = func() *selfupdate.NpmResult {
+			r := &selfupdate.NpmResult{}
+			r.Err = fmt.Errorf("index unavailable")
+			return r
+		}
 		u.SkillsCommandOverride = func(args ...string) *selfupdate.NpmResult {
 			r := &selfupdate.NpmResult{}
 			r.Stderr.WriteString("npx: command not found")
@@ -860,6 +880,11 @@ func TestUpdateNpm_SkillsFail_Human(t *testing.T) {
 		}
 		u.NpmInstallOverride = func(version string) *selfupdate.NpmResult { return &selfupdate.NpmResult{} }
 		u.VerifyOverride = func(string) error { return nil }
+		u.SkillsIndexFetchOverride = func() *selfupdate.NpmResult {
+			r := &selfupdate.NpmResult{}
+			r.Err = fmt.Errorf("index unavailable")
+			return r
+		}
 		u.SkillsCommandOverride = func(args ...string) *selfupdate.NpmResult {
 			r := &selfupdate.NpmResult{}
 			r.Stderr.WriteString("npx: command not found")
@@ -1004,6 +1029,7 @@ func TestUpdateRun_AlreadyLatest_RunsSkillsSync(t *testing.T) {
 	t.Cleanup(func() { newUpdater = origNew })
 	newUpdater = func() *selfupdate.Updater {
 		return &selfupdate.Updater{
+			SkillsIndexFetchOverride: successfulSkillsIndexFetch(),
 			SkillsCommandOverride: func(args ...string) *selfupdate.NpmResult {
 				skillsCalled = true
 				return successfulSkillsCommand()(args...)
@@ -1042,6 +1068,7 @@ func TestUpdateRun_Manual_RunsSkillsSync(t *testing.T) {
 	t.Cleanup(func() { newUpdater = origNew })
 	newUpdater = func() *selfupdate.Updater {
 		return &selfupdate.Updater{
+			SkillsIndexFetchOverride: successfulSkillsIndexFetch(),
 			DetectOverride: func() selfupdate.DetectResult {
 				return selfupdate.DetectResult{
 					Method:       selfupdate.InstallManual,
@@ -1086,6 +1113,7 @@ func TestUpdateRun_Npm_RunsSkillsSync_WritesLatestState(t *testing.T) {
 	t.Cleanup(func() { newUpdater = origNew })
 	newUpdater = func() *selfupdate.Updater {
 		return &selfupdate.Updater{
+			SkillsIndexFetchOverride: successfulSkillsIndexFetch(),
 			DetectOverride: func() selfupdate.DetectResult {
 				return selfupdate.DetectResult{
 					Method: selfupdate.InstallNpm, NpmAvailable: true,
@@ -1145,6 +1173,10 @@ func TestUpdateRun_CheckIncludesSkillsStatus(t *testing.T) {
 			DetectOverride: func() selfupdate.DetectResult {
 				return selfupdate.DetectResult{Method: selfupdate.InstallNpm, NpmAvailable: true}
 			},
+			SkillsIndexFetchOverride: func() *selfupdate.NpmResult {
+				skillsCalled = true
+				return successfulSkillsIndexFetch()()
+			},
 			SkillsCommandOverride: func(args ...string) *selfupdate.NpmResult {
 				skillsCalled = true
 				return successfulSkillsCommand()(args...)
@@ -1194,6 +1226,10 @@ func TestUpdateRun_CheckAlreadyLatest_NoSideEffect(t *testing.T) {
 	t.Cleanup(func() { newUpdater = origNew })
 	newUpdater = func() *selfupdate.Updater {
 		return &selfupdate.Updater{
+			SkillsIndexFetchOverride: func() *selfupdate.NpmResult {
+				skillsCalled = true
+				return successfulSkillsIndexFetch()()
+			},
 			SkillsCommandOverride: func(args ...string) *selfupdate.NpmResult {
 				skillsCalled = true
 				return successfulSkillsCommand()(args...)

errs/ERROR_CONTRACT.md

@@ -155,7 +155,30 @@ caller scripts.
 
 New code should not reach for `ErrBare` unless the command is
 genuinely a predicate. Anything carrying recoverable error content
-belongs in a typed `*errs.XxxError`.
+belongs in a typed `*errs.XxxError` — or, for a batch result, in the
+partial-failure outcome below.
+
+### Partial failure (batch / multi-status)
+
+A batch command (e.g. `drive +push` / `+pull` / `+sync`) that processes
+many items can finish in a third state, neither full success nor a single
+error: some items succeeded and some failed. Its primary output is the
+per-item result, so it does **not** belong in a `stderr` error envelope.
+
+Such a command returns `runtime.OutPartialFailure(data, meta)`, which:
+
+1. writes the full result to **stdout** as an `ok:false` envelope — the
+   summary and every per-item outcome (succeeded *and* failed) stay
+   machine-readable, exactly as a successful `Out(...)` would carry them,
+   but with `ok` honestly reporting failure; and
+2. returns `*output.PartialFailureError`, a typed exit signal the
+   dispatcher maps to a non-zero exit code while writing nothing further
+   to `stderr`.
+
+This is distinct from `ErrBare` (a predicate's one-bit answer) and from a
+typed `*errs.XxxError` (a `stderr` error envelope): a partial failure is a
+*result*, reported on stdout, that also failed. Consumers branch on
+`ok == false` and then read `data.summary` / `data.items[]`.
 
 ## Consumers
 

errs/subtypes.go

@@ -12,7 +12,8 @@ const (
 
 // CategoryValidation subtypes
 const (
-	SubtypeInvalidArgument Subtype = "invalid_argument" // user-supplied flag / arg failed validation (gRPC INVALID_ARGUMENT alignment)
+	SubtypeInvalidArgument    Subtype = "invalid_argument"    // user-supplied flag / arg failed validation (gRPC INVALID_ARGUMENT alignment)
+	SubtypeFailedPrecondition Subtype = "failed_precondition" // request is valid but the system/resource state is not in the state required to execute; caller must change state (not retry) — e.g. ambiguous remote mapping (gRPC FAILED_PRECONDITION alignment)
 )
 
 // CategoryAuthentication subtypes

errs/types.go

@@ -61,8 +61,22 @@ type TypedError interface {
 // it is intentionally not serialized.
 type ValidationError struct {
 	Problem
-	Param string `json:"param,omitempty"`
-	Cause error  `json:"-"`
+	Param  string         `json:"param,omitempty"`
+	Params []InvalidParam `json:"params,omitempty"`
+	Cause  error          `json:"-"`
+}
+
+// InvalidParam is one structured validation diagnostic: the parameter that
+// failed (Name) and why (Reason). It mirrors an RFC 7807 "invalid-params"
+// item (RFC 7807 §3.1 extension members).
+//
+// The wire key on ValidationError is "params" rather than "invalid_params"
+// because the enclosing envelope already carries type:"validation", so the
+// "invalid" qualifier would be redundant on the wire. The Go type keeps the
+// InvalidParam prefix because, at package level, the name must self-describe.
+type InvalidParam struct {
+	Name   string `json:"name"`
+	Reason string `json:"reason"`
 }
 
 // Unwrap exposes the wrapped cause so errors.Unwrap / errors.Is can traverse
@@ -122,6 +136,11 @@ func (e *ValidationError) WithParam(param string) *ValidationError {
 	return e
 }
 
+func (e *ValidationError) WithParams(params ...InvalidParam) *ValidationError {
+	e.Params = append(e.Params, params...)
+	return e
+}
+
 func (e *ValidationError) WithCause(cause error) *ValidationError {
 	e.Cause = cause
 	return e

errs/types_test.go

@@ -558,6 +558,71 @@ func TestTypedError_UnwrapSymmetry(t *testing.T) {
 	})
 }
 
+// TestValidationError_WithParams covers the structured-validation extension:
+// WithParams appends InvalidParam items, the scalar Param setter is unaffected,
+// and the wire shape nests {name, reason} under "params" (omitted when empty).
+func TestValidationError_WithParams(t *testing.T) {
+	t.Run("appends and exposes fields", func(t *testing.T) {
+		e := errs.NewValidationError(errs.SubtypeInvalidArgument, "duplicate rel_path").
+			WithParams(errs.InvalidParam{Name: "a.md", Reason: "duplicate"})
+		if len(e.Params) != 1 {
+			t.Fatalf("len(Params) = %d, want 1", len(e.Params))
+		}
+		if e.Params[0].Name != "a.md" {
+			t.Errorf("Params[0].Name = %q, want %q", e.Params[0].Name, "a.md")
+		}
+		if e.Params[0].Reason != "duplicate" {
+			t.Errorf("Params[0].Reason = %q, want %q", e.Params[0].Reason, "duplicate")
+		}
+	})
+
+	t.Run("appends across multiple calls and returns receiver", func(t *testing.T) {
+		e := errs.NewValidationError(errs.SubtypeInvalidArgument, "x")
+		returned := e.WithParams(errs.InvalidParam{Name: "a.md", Reason: "dup"})
+		if returned != e {
+			t.Errorf("WithParams returned different pointer; want same as receiver")
+		}
+		e.WithParams(
+			errs.InvalidParam{Name: "b.md", Reason: "dup"},
+			errs.InvalidParam{Name: "c.md", Reason: "dup"},
+		)
+		if len(e.Params) != 3 {
+			t.Fatalf("len(Params) = %d after two calls, want 3", len(e.Params))
+		}
+	})
+
+	t.Run("wire shape nests name and reason under params", func(t *testing.T) {
+		e := errs.NewValidationError(errs.SubtypeInvalidArgument, "duplicate rel_path").
+			WithParam("--rel-path").
+			WithParams(errs.InvalidParam{Name: "a.md", Reason: "duplicate"})
+		b, err := json.Marshal(e)
+		if err != nil {
+			t.Fatalf("marshal failed: %v", err)
+		}
+		got := string(b)
+		for _, want := range []string{
+			`"type":"validation"`,
+			`"param":"--rel-path"`,
+			`"params":[{"name":"a.md","reason":"duplicate"}]`,
+		} {
+			if !strings.Contains(got, want) {
+				t.Errorf("missing %q in %s", want, got)
+			}
+		}
+	})
+
+	t.Run("empty Params omitted from wire", func(t *testing.T) {
+		e := errs.NewValidationError(errs.SubtypeInvalidArgument, "x")
+		b, err := json.Marshal(e)
+		if err != nil {
+			t.Fatalf("marshal failed: %v", err)
+		}
+		if strings.Contains(string(b), `"params"`) {
+			t.Errorf("empty Params should be omitted from wire; got %s", b)
+		}
+	})
+}
+
 func TestBuilderSetter_DefensiveCopy(t *testing.T) {
 	t.Run("WithMissingScopes clones input", func(t *testing.T) {
 		scopes := []string{"docx:document", "im:message:send"}

events/minutes/preconsume.go

@@ -5,9 +5,9 @@ package minutes
 
 import (
 	"context"
-	"fmt"
 	"time"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/event"
 )
 
@@ -16,7 +16,8 @@ const cleanupTimeout = 5 * time.Second
 func subscriptionPreConsume(eventType, subscribePath, unsubscribePath string) func(context.Context, event.APIClient, map[string]string) (func(), error) {
 	return func(ctx context.Context, rt event.APIClient, _ map[string]string) (func(), error) {
 		if rt == nil {
-			return nil, fmt.Errorf("runtime API client is required for pre-consume subscription")
+			return nil, errs.NewInternalError(errs.SubtypeUnknown,
+				"runtime API client is required for pre-consume subscription")
 		}
 
 		body := map[string]string{"event_type": eventType}

events/register.go

@@ -8,6 +8,7 @@ import (
 	"github.com/larksuite/cli/events/im"
 	"github.com/larksuite/cli/events/minutes"
 	"github.com/larksuite/cli/events/vc"
+	"github.com/larksuite/cli/events/whiteboard"
 	"github.com/larksuite/cli/internal/event"
 )
 
@@ -17,6 +18,7 @@ func init() {
 		im.Keys(),
 		minutes.Keys(),
 		vc.Keys(),
+		whiteboard.Keys(),
 	}
 	for _, keys := range all {
 		for _, k := range keys {

events/vc/note_detail_retry_test.go

@@ -0,0 +1,35 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package vc
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/larksuite/cli/errs"
+)
+
+// isLarkCode must match the API code on typed errs.* errors — the consume
+// runtime classifies OAPI failures via errclass.BuildAPIError, so the
+// not-found retry in fillVCNoteGeneratedDetails depends on this reading
+// Problem.Code rather than the legacy envelope shape.
+func TestIsLarkCode_MatchesTypedAPIErrorCode(t *testing.T) {
+	typedNotFound := errs.NewAPIError(errs.SubtypeNotFound, "note not ready").
+		WithCode(vcNoteDetailNotFoundCode)
+	if !isLarkCode(typedNotFound, vcNoteDetailNotFoundCode) {
+		t.Fatal("typed API error carrying the not-found code must match (retry path)")
+	}
+	if isLarkCode(typedNotFound, 99999) {
+		t.Error("a different expected code must not match")
+	}
+
+	otherTyped := errs.NewAPIError(errs.SubtypeServerError, "boom").WithCode(500)
+	if isLarkCode(otherTyped, vcNoteDetailNotFoundCode) {
+		t.Error("typed error with another code must not match")
+	}
+
+	if isLarkCode(errors.New("plain failure"), vcNoteDetailNotFoundCode) {
+		t.Error("untyped error must not match")
+	}
+}

events/vc/note_generated.go

@@ -6,12 +6,11 @@ package vc
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"time"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/event"
-	"github.com/larksuite/cli/internal/output"
 	"github.com/larksuite/cli/internal/validate"
 )
 
@@ -148,9 +147,8 @@ func fillVCNoteGeneratedDetails(ctx context.Context, rt event.APIClient, out *VC
 }
 
 func isLarkCode(err error, code int) bool {
-	var exitErr *output.ExitError
-	if errors.As(err, &exitErr) && exitErr.Detail != nil {
-		return exitErr.Detail.Code == code
+	if p, ok := errs.ProblemOf(err); ok {
+		return p.Code == code
 	}
 	return false
 }

events/vc/preconsume.go

@@ -5,9 +5,9 @@ package vc
 
 import (
 	"context"
-	"fmt"
 	"time"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/event"
 )
 
@@ -16,7 +16,8 @@ const cleanupTimeout = 5 * time.Second
 func subscriptionPreConsume(eventType, subscribePath, unsubscribePath string) func(context.Context, event.APIClient, map[string]string) (func(), error) {
 	return func(ctx context.Context, rt event.APIClient, _ map[string]string) (func(), error) {
 		if rt == nil {
-			return nil, fmt.Errorf("runtime API client is required for pre-consume subscription")
+			return nil, errs.NewInternalError(errs.SubtypeUnknown,
+				"runtime API client is required for pre-consume subscription")
 		}
 
 		body := map[string]string{"event_type": eventType}

events/whiteboard/native.go

@@ -0,0 +1,23 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package whiteboard
+
+// BoardWhiteboardUpdatedV1Data is the flattened whiteboard updated source payload.
+type BoardWhiteboardUpdatedV1Data struct {
+	// WhiteboardID is the id of the whiteboard whose content was updated.
+	WhiteboardID string `json:"whiteboard_id"`
+	// OperatorIDs lists the operators that produced this update batch.
+	OperatorIDs []OperatorID `json:"operator_ids"`
+}
+
+// OperatorID identifies an operator that produced the whiteboard update,
+// expressed in the three Lark identity formats.
+type OperatorID struct {
+	// OpenID is the operator's open_id within the current app.
+	OpenID string `json:"open_id"`
+	// UnionID is the operator's union_id across apps under the same ISV.
+	UnionID string `json:"union_id"`
+	// UserID is the operator's user_id within the tenant.
+	UserID string `json:"user_id"`
+}

events/whiteboard/preconsume.go

@@ -0,0 +1,53 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package whiteboard
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/larksuite/cli/errs"
+	"github.com/larksuite/cli/internal/event"
+	"github.com/larksuite/cli/internal/validate"
+)
+
+// cleanupTimeout bounds how long the unsubscribe call has to finish during
+// PreConsume cleanup so a stuck OAPI cannot block process shutdown.
+const cleanupTimeout = 5 * time.Second
+
+// whiteboardSubscriptionPreConsume calls the whiteboard event subscribe OAPI
+// and returns a cleanup that invokes the matching unsubscribe.
+//
+// board.whiteboard.updated_v1 is subscribed per-whiteboard (by whiteboard_id),
+// so the path contains a :whiteboard_id placeholder that must be supplied via params.
+func whiteboardSubscriptionPreConsume(eventType string) func(context.Context, event.APIClient, map[string]string) (func(), error) {
+	return func(ctx context.Context, rt event.APIClient, params map[string]string) (func(), error) {
+		if rt == nil {
+			return nil, errs.NewInternalError(errs.SubtypeUnknown,
+				"runtime API client is required for pre-consume subscription")
+		}
+		whiteboardID := params["whiteboard_id"]
+		if whiteboardID == "" {
+			return nil, errs.NewValidationError(errs.SubtypeInvalidArgument,
+				"param whiteboard_id is required for %s", eventType).
+				WithParam("--param").
+				WithHint("pass it as --param whiteboard_id=<id>; run `lark-cli event schema %s` for details", eventType)
+		}
+		encoded := validate.EncodePathSegment(whiteboardID)
+		subscribePath := fmt.Sprintf("/open-apis/board/v1/whiteboards/%s/subscribe", encoded)
+		unsubscribePath := fmt.Sprintf("/open-apis/board/v1/whiteboards/%s/unsubscribe", encoded)
+
+		body := map[string]string{"event_type": eventType}
+		if _, err := rt.CallAPI(ctx, "POST", subscribePath, body); err != nil {
+			return nil, err
+		}
+
+		return func() {
+			cleanupCtx, cancel := context.WithTimeout(context.Background(), cleanupTimeout)
+			defer cancel()
+			_, _ = rt.CallAPI(cleanupCtx, "POST", unsubscribePath, body)
+		}, nil
+	}
+}

events/whiteboard/preconsume_test.go

@@ -0,0 +1,212 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package whiteboard
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"strings"
+	"sync"
+	"testing"
+
+	"github.com/larksuite/cli/errs"
+	"github.com/larksuite/cli/internal/event"
+)
+
+// recordedCall captures a single APIClient invocation for assertion.
+type recordedCall struct {
+	method string
+	path   string
+	body   interface{}
+}
+
+// fakeAPIClient is a minimal event.APIClient stub that records calls and
+// can be configured to fail when the request path matches errOnPath.
+type fakeAPIClient struct {
+	mu        sync.Mutex
+	calls     []recordedCall
+	errOnPath string
+}
+
+// CallAPI records the invocation and optionally returns a simulated error
+// when the path contains the configured errOnPath substring.
+func (f *fakeAPIClient) CallAPI(_ context.Context, method, path string, body interface{}) (json.RawMessage, error) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	f.calls = append(f.calls, recordedCall{method: method, path: path, body: body})
+	if f.errOnPath != "" && strings.Contains(path, f.errOnPath) {
+		return nil, errors.New("simulated subscribe failure")
+	}
+	return json.RawMessage(`{}`), nil
+}
+
+// TestWhiteboardSubscriptionPreConsume_MissingWhiteboardID verifies that the
+// PreConsume hook fails fast with an actionable error when whiteboard_id
+// is absent from the params map.
+func TestWhiteboardSubscriptionPreConsume_MissingWhiteboardID(t *testing.T) {
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+
+	pc := whiteboardSubscriptionPreConsume(eventTypeWhiteboardUpdated)
+	cleanup, err := pc(context.Background(), &fakeAPIClient{}, map[string]string{})
+	if err == nil {
+		t.Fatalf("expected error when whiteboard_id missing")
+	}
+	if cleanup != nil {
+		t.Fatalf("expected nil cleanup on error")
+	}
+	if !strings.Contains(err.Error(), "whiteboard_id") {
+		t.Fatalf("error should mention whiteboard_id, got: %v", err)
+	}
+	var ve *errs.ValidationError
+	if !errors.As(err, &ve) {
+		t.Fatalf("expected *errs.ValidationError, got %T: %v", err, err)
+	}
+	if ve.Subtype != errs.SubtypeInvalidArgument || ve.Param != "--param" {
+		t.Errorf("subtype/param = %s/%q, want %s/%q", ve.Subtype, ve.Param, errs.SubtypeInvalidArgument, "--param")
+	}
+	if ve.Hint == "" {
+		t.Error("missing whiteboard_id should carry a hint")
+	}
+}
+
+// TestWhiteboardSubscriptionPreConsume_NilRuntime verifies that PreConsume
+// returns an error when the runtime APIClient dependency is missing.
+func TestWhiteboardSubscriptionPreConsume_NilRuntime(t *testing.T) {
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+
+	pc := whiteboardSubscriptionPreConsume(eventTypeWhiteboardUpdated)
+	_, err := pc(context.Background(), nil, map[string]string{"whiteboard_id": "wb1"})
+	if err == nil {
+		t.Fatalf("expected error when runtime client is nil")
+	}
+	if p, ok := errs.ProblemOf(err); !ok || p.Category != errs.CategoryInternal {
+		t.Errorf("nil-runtime invariant should be a typed internal error, got %T: %v", err, err)
+	}
+}
+
+// TestWhiteboardSubscriptionPreConsume_SubscribeError verifies that a
+// failed subscribe call surfaces the error and skips registering a cleanup,
+// so no spurious unsubscribe is invoked.
+func TestWhiteboardSubscriptionPreConsume_SubscribeError(t *testing.T) {
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+
+	pc := whiteboardSubscriptionPreConsume(eventTypeWhiteboardUpdated)
+	rt := &fakeAPIClient{errOnPath: "/subscribe"}
+	cleanup, err := pc(context.Background(), rt, map[string]string{"whiteboard_id": "wb1"})
+	if err == nil {
+		t.Fatalf("expected error from subscribe call")
+	}
+	if cleanup != nil {
+		t.Fatalf("expected nil cleanup when subscribe fails")
+	}
+	// only the failed subscribe call should have been made; no unsubscribe.
+	if len(rt.calls) != 1 {
+		t.Fatalf("expected exactly 1 call (subscribe), got %d", len(rt.calls))
+	}
+}
+
+// TestWhiteboardSubscriptionPreConsume_SubscribeAndCleanup verifies the full
+// happy-path: subscribe is called once with the correct method/path/body,
+// and the returned cleanup invokes the matching unsubscribe.
+func TestWhiteboardSubscriptionPreConsume_SubscribeAndCleanup(t *testing.T) {
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+
+	pc := whiteboardSubscriptionPreConsume(eventTypeWhiteboardUpdated)
+	rt := &fakeAPIClient{}
+	cleanup, err := pc(context.Background(), rt, map[string]string{"whiteboard_id": "wb1"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if cleanup == nil {
+		t.Fatalf("expected non-nil cleanup")
+	}
+
+	if len(rt.calls) != 1 {
+		t.Fatalf("expected 1 call after subscribe, got %d", len(rt.calls))
+	}
+	got := rt.calls[0]
+	if got.method != "POST" {
+		t.Errorf("subscribe method: got %q, want POST", got.method)
+	}
+	wantSubPath := "/open-apis/board/v1/whiteboards/wb1/subscribe"
+	if got.path != wantSubPath {
+		t.Errorf("subscribe path: got %q, want %q", got.path, wantSubPath)
+	}
+	body, _ := got.body.(map[string]string)
+	if body["event_type"] != eventTypeWhiteboardUpdated {
+		t.Errorf("subscribe body event_type: got %q, want %q", body["event_type"], eventTypeWhiteboardUpdated)
+	}
+
+	cleanup()
+	if len(rt.calls) != 2 {
+		t.Fatalf("expected 2 calls after cleanup, got %d", len(rt.calls))
+	}
+	got2 := rt.calls[1]
+	if got2.method != "POST" {
+		t.Errorf("unsubscribe method: got %q, want POST", got2.method)
+	}
+	wantUnsubPath := "/open-apis/board/v1/whiteboards/wb1/unsubscribe"
+	if got2.path != wantUnsubPath {
+		t.Errorf("unsubscribe path: got %q, want %q", got2.path, wantUnsubPath)
+	}
+	body2, _ := got2.body.(map[string]string)
+	if body2["event_type"] != eventTypeWhiteboardUpdated {
+		t.Errorf("unsubscribe body event_type: got %q, want %q", body2["event_type"], eventTypeWhiteboardUpdated)
+	}
+}
+
+// TestWhiteboardSubscriptionPreConsume_PathSegmentEncoded verifies that
+// whiteboard_id values containing reserved URL characters are properly
+// path-segment encoded so they cannot escape into adjacent path segments.
+func TestWhiteboardSubscriptionPreConsume_PathSegmentEncoded(t *testing.T) {
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+
+	pc := whiteboardSubscriptionPreConsume(eventTypeWhiteboardUpdated)
+	rt := &fakeAPIClient{}
+	// 含特殊字符的 whiteboard_id 应被 path-segment 编码，避免越界到其他 path 段。
+	_, err := pc(context.Background(), rt, map[string]string{"whiteboard_id": "wb/1?evil"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(rt.calls) != 1 {
+		t.Fatalf("expected 1 call, got %d", len(rt.calls))
+	}
+	if strings.Contains(rt.calls[0].path, "wb/1?evil") {
+		t.Errorf("whiteboard_id was not encoded; path: %s", rt.calls[0].path)
+	}
+}
+
+// TestWhiteboardUpdatedV1HasPreConsume ensures the registered EventKey for
+// board.whiteboard.updated_v1 wires the PreConsume hook and declares the
+// required whiteboard_id parameter.
+func TestWhiteboardUpdatedV1HasPreConsume(t *testing.T) {
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", t.TempDir())
+
+	keys := Keys()
+	for _, k := range keys {
+		if k.Key == eventTypeWhiteboardUpdated {
+			if k.PreConsume == nil {
+				t.Fatalf("EventKey %s should have PreConsume hook", eventTypeWhiteboardUpdated)
+			}
+			if len(k.Params) == 0 {
+				t.Fatalf("EventKey %s should declare whiteboard_id param", eventTypeWhiteboardUpdated)
+			}
+			var found bool
+			for _, p := range k.Params {
+				if p.Name == "whiteboard_id" && p.Required {
+					found = true
+				}
+			}
+			if !found {
+				t.Fatalf("EventKey %s must declare required whiteboard_id param", eventTypeWhiteboardUpdated)
+			}
+			return
+		}
+	}
+	t.Fatalf("EventKey %s not registered", eventTypeWhiteboardUpdated)
+}
+
+// 确保 event.APIClient 接口与本测试 mock 一致。
+var _ event.APIClient = (*fakeAPIClient)(nil)

events/whiteboard/register.go

@@ -0,0 +1,48 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+// Package whiteboard registers Board-domain EventKeys.
+package whiteboard
+
+import (
+	"reflect"
+
+	"github.com/larksuite/cli/internal/event"
+	"github.com/larksuite/cli/internal/event/schemas"
+)
+
+// eventTypeWhiteboardUpdated is the OAPI event type for whiteboard content updates.
+const eventTypeWhiteboardUpdated = "board.whiteboard.updated_v1"
+
+// Keys returns all Board-domain EventKey definitions.
+func Keys() []event.KeyDefinition {
+	return []event.KeyDefinition{
+		{
+			Key:         eventTypeWhiteboardUpdated,
+			DisplayName: "Whiteboard updated",
+			Description: "Pushed when the whiteboard content is updated.",
+			EventType:   eventTypeWhiteboardUpdated,
+			Params: []event.ParamDef{
+				{
+					Name:        "whiteboard_id",
+					Type:        event.ParamString,
+					Required:    true,
+					Description: "Whiteboard id to subscribe; subscription is per-whiteboard.",
+				},
+			},
+			Schema: event.SchemaDef{
+				Native: &event.SchemaSpec{Type: reflect.TypeOf(BoardWhiteboardUpdatedV1Data{})},
+				FieldOverrides: map[string]schemas.FieldMeta{
+					"/event/whiteboard_id":           {Kind: "whiteboard_id", Description: "whiteboard id to subscribe"},
+					"/event/operator_ids/*/open_id":  {Kind: "open_id"},
+					"/event/operator_ids/*/union_id": {Kind: "union_id"},
+					"/event/operator_ids/*/user_id":  {Kind: "user_id"},
+				},
+			},
+			PreConsume:            whiteboardSubscriptionPreConsume(eventTypeWhiteboardUpdated),
+			Scopes:                []string{"board:whiteboard:node:read"},
+			AuthTypes:             []string{"user", "bot"},
+			RequiredConsoleEvents: []string{eventTypeWhiteboardUpdated},
+		},
+	}
+}

go.mod

@@ -14,7 +14,7 @@ require (
 	github.com/sergi/go-diff v1.4.0
 	github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e
 	github.com/smartystreets/goconvey v1.8.1
-	github.com/spf13/cobra v1.10.2
+	github.com/spf13/cobra v1.10.2 // flag-error-text contract: see cmd/root.go unknownFlagName
 	github.com/spf13/pflag v1.0.9
 	github.com/stretchr/testify v1.11.1
 	github.com/tidwall/gjson v1.18.0

internal/auth/transport.go

@@ -14,7 +14,7 @@ import (
 
 	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/errclass"
-	"github.com/larksuite/cli/internal/util"
+	"github.com/larksuite/cli/internal/transport"
 )
 
 // SecurityPolicyTransport is an http.RoundTripper that intercepts all responses
@@ -28,7 +28,7 @@ func (t *SecurityPolicyTransport) base() http.RoundTripper {
 	if t.Base != nil {
 		return t.Base
 	}
-	return util.FallbackTransport()
+	return transport.Fallback()
 }
 
 // RoundTrip implements http.RoundTripper.

internal/cmdpolicy/suggest.go

@@ -5,6 +5,7 @@ package cmdpolicy
 
 import (
 	"github.com/larksuite/cli/extension/platform"
+	"github.com/larksuite/cli/internal/suggest"
 )
 
 // suggestRisk returns the closest valid Risk literal by edit distance
@@ -20,9 +21,9 @@ func suggestRisk(bad string) string {
 		platform.RiskRead, platform.RiskWrite, platform.RiskHighRiskWrite,
 	}
 	best := string(candidates[0])
-	bestDist := levenshtein(lowered, best)
+	bestDist := suggest.Levenshtein(lowered, best)
 	for _, c := range candidates[1:] {
-		if d := levenshtein(lowered, string(c)); d < bestDist {
+		if d := suggest.Levenshtein(lowered, string(c)); d < bestDist {
 			bestDist, best = d, string(c)
 		}
 	}
@@ -40,47 +41,3 @@ func toLower(s string) string {
 	}
 	return string(b)
 }
-
-// levenshtein computes the classic edit distance between two strings.
-// O(len(a)*len(b)) time, O(min(a,b)) space. Three-element string set
-// makes raw performance irrelevant — clarity beats trickiness here.
-func levenshtein(a, b string) int {
-	if len(a) == 0 {
-		return len(b)
-	}
-	if len(b) == 0 {
-		return len(a)
-	}
-	prev := make([]int, len(b)+1)
-	curr := make([]int, len(b)+1)
-	for j := 0; j <= len(b); j++ {
-		prev[j] = j
-	}
-	for i := 1; i <= len(a); i++ {
-		curr[0] = i
-		for j := 1; j <= len(b); j++ {
-			cost := 1
-			if a[i-1] == b[j-1] {
-				cost = 0
-			}
-			curr[j] = min3(
-				prev[j]+1,      // deletion
-				curr[j-1]+1,    // insertion
-				prev[j-1]+cost, // substitution
-			)
-		}
-		prev, curr = curr, prev
-	}
-	return prev[len(b)]
-}
-
-func min3(a, b, c int) int {
-	m := a
-	if b < m {
-		m = b
-	}
-	if c < m {
-		m = c
-	}
-	return m
-}

internal/cmdpolicy/suggest_test.go

@@ -29,23 +29,3 @@ func TestSuggestRisk(t *testing.T) {
 		}
 	}
 }
-
-func TestLevenshtein(t *testing.T) {
-	cases := []struct {
-		a, b string
-		want int
-	}{
-		{"", "", 0},
-		{"", "abc", 3},
-		{"abc", "", 3},
-		{"abc", "abc", 0},
-		{"wrtie", "write", 2},
-		{"kitten", "sitting", 3},
-	}
-	for _, c := range cases {
-		got := levenshtein(c.a, c.b)
-		if got != c.want {
-			t.Errorf("levenshtein(%q,%q) = %d, want %d", c.a, c.b, got, c.want)
-		}
-	}
-}

internal/cmdutil/factory.go

@@ -6,6 +6,7 @@ package cmdutil
 import (
 	"context"
 	"io"
+	"io/fs"
 	"net/http"
 	"strings"
 
@@ -43,6 +44,8 @@ type Factory struct {
 	Credential *credential.CredentialProvider
 
 	FileIOProvider fileio.Provider // file transfer provider (default: local filesystem)
+
+	SkillContent fs.FS // embedded skill tree (rooted at the skill list); nil when the build embeds no skills
 }
 
 // ResolveFileIO resolves a FileIO instance using the current execution context.

internal/cmdutil/factory_default.go

@@ -23,7 +23,7 @@ import (
 	"github.com/larksuite/cli/internal/keychain"
 	"github.com/larksuite/cli/internal/registry"
 	_ "github.com/larksuite/cli/internal/security/contentsafety" // register content safety provider
-	"github.com/larksuite/cli/internal/util"
+	"github.com/larksuite/cli/internal/transport"
 	_ "github.com/larksuite/cli/internal/vfs/localfileio" // register default FileIO provider
 )
 
@@ -102,15 +102,15 @@ func safeRedirectPolicy(req *http.Request, via []*http.Request) error {
 
 func cachedHttpClientFunc(f *Factory) func() (*http.Client, error) {
 	return sync.OnceValues(func() (*http.Client, error) {
-		util.WarnIfProxied(f.IOStreams.ErrOut)
+		transport.WarnIfProxied(f.IOStreams.ErrOut)
 
-		var transport http.RoundTripper = util.SharedTransport()
-		transport = &RetryTransport{Base: transport}
-		transport = &SecurityHeaderTransport{Base: transport}
-		transport = &auth.SecurityPolicyTransport{Base: transport} // Add our global response interceptor
-		transport = wrapWithExtension(transport)
+		var rt http.RoundTripper = transport.Shared()
+		rt = &RetryTransport{Base: rt}
+		rt = &SecurityHeaderTransport{Base: rt}
+		rt = &auth.SecurityPolicyTransport{Base: rt} // Add our global response interceptor
+		rt = wrapWithExtension(rt)
 		client := &http.Client{
-			Transport:     transport,
+			Transport:     rt,
 			Timeout:       30 * time.Second,
 			CheckRedirect: safeRedirectPolicy,
 		}
@@ -129,7 +129,7 @@ func cachedLarkClientFunc(f *Factory) func() (*lark.Client, error) {
 			lark.WithLogLevel(larkcore.LogLevelError),
 			lark.WithHeaders(BaseSecurityHeaders()),
 		}
-		util.WarnIfProxied(f.IOStreams.ErrOut)
+		transport.WarnIfProxied(f.IOStreams.ErrOut)
 		opts = append(opts, lark.WithHttpClient(&http.Client{
 			Transport:     buildSDKTransport(),
 			CheckRedirect: safeRedirectPolicy,
@@ -141,7 +141,7 @@ func cachedLarkClientFunc(f *Factory) func() (*lark.Client, error) {
 }
 
 func buildSDKTransport() http.RoundTripper {
-	var sdkTransport http.RoundTripper = util.SharedTransport()
+	var sdkTransport http.RoundTripper = transport.Shared()
 	sdkTransport = &RetryTransport{Base: sdkTransport}
 	sdkTransport = &UserAgentTransport{Base: sdkTransport}
 	sdkTransport = &BuildHeaderTransport{Base: sdkTransport}

internal/cmdutil/groups.go

@@ -0,0 +1,18 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package cmdutil
+
+import "github.com/spf13/cobra"
+
+// DeprecatedGroupID is the cobra GroupID that marks a backward-compatibility
+// command — one kept alive for users whose skill predates a refactor. Service
+// registration assigns it (e.g. the sheets pre-refactor aliases); both --help
+// rendering and unknown-subcommand suggestions read it to separate these
+// aliases from the current commands.
+const DeprecatedGroupID = "deprecated"
+
+// IsDeprecatedCommand reports whether c was tagged into the deprecated group.
+func IsDeprecatedCommand(c *cobra.Command) bool {
+	return c != nil && c.GroupID == DeprecatedGroupID
+}

internal/cmdutil/secheader.go

@@ -41,7 +41,7 @@ const (
 
 	officialModulePath = "github.com/larksuite/cli"
 
-	agentTraceMaxLen = 256
+	agentTraceMaxLen = 1024
 )
 
 // UserAgentValue returns the User-Agent value: "lark-cli/{version}".

internal/cmdutil/transport.go

@@ -9,7 +9,7 @@ import (
 	"time"
 
 	exttransport "github.com/larksuite/cli/extension/transport"
-	"github.com/larksuite/cli/internal/util"
+	"github.com/larksuite/cli/internal/transport"
 )
 
 // RetryTransport is an http.RoundTripper that retries on 5xx responses
@@ -24,7 +24,7 @@ func (t *RetryTransport) base() http.RoundTripper {
 	if t.Base != nil {
 		return t.Base
 	}
-	return util.FallbackTransport()
+	return transport.Fallback()
 }
 
 func (t *RetryTransport) delay() time.Duration {
@@ -69,7 +69,7 @@ func (t *UserAgentTransport) RoundTrip(req *http.Request) (*http.Response, error
 	if t.Base != nil {
 		return t.Base.RoundTrip(req)
 	}
-	return util.FallbackTransport().RoundTrip(req)
+	return transport.Fallback().RoundTrip(req)
 }
 
 // BuildHeaderTransport is an http.RoundTripper that force-writes the
@@ -87,7 +87,7 @@ func (t *BuildHeaderTransport) RoundTrip(req *http.Request) (*http.Response, err
 	if t.Base != nil {
 		return t.Base.RoundTrip(req)
 	}
-	return util.FallbackTransport().RoundTrip(req)
+	return transport.Fallback().RoundTrip(req)
 }
 
 // SecurityHeaderTransport is an http.RoundTripper that injects CLI security
@@ -100,7 +100,7 @@ func (t *SecurityHeaderTransport) base() http.RoundTripper {
 	if t.Base != nil {
 		return t.Base
 	}
-	return util.FallbackTransport()
+	return transport.Fallback()
 }
 
 // RoundTrip implements http.RoundTripper.

internal/cmdutil/transport_test.go

@@ -332,7 +332,7 @@ func TestBuildHeaderTransport_OverridesEvenWithoutTamper(t *testing.T) {
 
 // TestBuildHeaderTransport_NilBase_UsesFallback verifies that when Base is nil,
 // the transport still sets X-Cli-Build and routes the request through
-// util.FallbackTransport rather than panicking. This covers the fallback
+// transport.Fallback rather than panicking. This covers the fallback
 // branch in RoundTrip that is otherwise unreachable with a non-nil Base.
 func TestBuildHeaderTransport_NilBase_UsesFallback(t *testing.T) {
 	var receivedBuild string

internal/credential/default_provider.go

@@ -4,9 +4,7 @@
 package credential
 
 import (
-	"bytes"
 	"context"
-	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
@@ -166,42 +164,9 @@ func (p *DefaultTokenProvider) doResolveTAT(ctx context.Context) (*TokenResult,
 	if err != nil {
 		return nil, err
 	}
-	ep := core.ResolveEndpoints(acct.Brand)
-	url := ep.Open + "/open-apis/auth/v3/tenant_access_token/internal"
-
-	body, err := json.Marshal(map[string]string{
-		"app_id":     acct.AppID,
-		"app_secret": acct.AppSecret,
-	})
-	if err != nil {
-		return nil, fmt.Errorf("failed to marshal TAT request: %w", err)
-	}
-	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
+	token, err := FetchTAT(ctx, httpClient, acct.Brand, acct.AppID, acct.AppSecret)
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("Content-Type", "application/json")
-
-	resp, err := httpClient.Do(req)
-	if err != nil {
-		return nil, err
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("TAT API returned HTTP %d", resp.StatusCode)
-	}
-
-	var result struct {
-		Code              int    `json:"code"`
-		Msg               string `json:"msg"`
-		TenantAccessToken string `json:"tenant_access_token"`
-	}
-	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
-		return nil, fmt.Errorf("failed to parse TAT response: %w", err)
-	}
-	if result.Code != 0 {
-		return nil, classifyTATResponseCode(result.Code, result.Msg, string(acct.Brand), acct.AppID)
-	}
-	return &TokenResult{Token: result.TenantAccessToken}, nil
+	return &TokenResult{Token: token}, nil
 }

internal/credential/tat_fetch.go

@@ -0,0 +1,70 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package credential
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/larksuite/cli/internal/core"
+)
+
+// FetchTAT performs a single HTTP POST to mint a tenant access token with the
+// given credentials. It does not read configuration or keychain, so callers
+// that already hold plaintext credentials (e.g. the post-`config init` probe)
+// can validate them without a second keychain round-trip.
+//
+// A non-zero TAT response code means the server inspected the payload and
+// rejected the credentials; FetchTAT returns the canonical typed error from
+// classifyTATResponseCode — the SAME classification doResolveTAT (and thus
+// every token-resolving command) produces, so callers see one consistent
+// envelope (CategoryConfig / SubtypeInvalidClient for 10003 / 10014, etc.).
+// Transport, HTTP-status and JSON-parse failures are returned raw (untyped),
+// leaving them ambiguous; a caller can use errs.IsTyped to tell a deterministic
+// credential rejection apart from upstream/transport noise.
+//
+// The caller owns the context timeout.
+func FetchTAT(ctx context.Context, httpClient *http.Client, brand core.LarkBrand, appID, appSecret string) (string, error) {
+	ep := core.ResolveEndpoints(brand)
+	url := ep.Open + "/open-apis/auth/v3/tenant_access_token/internal"
+
+	body, err := json.Marshal(map[string]string{
+		"app_id":     appID,
+		"app_secret": appSecret,
+	})
+	if err != nil {
+		return "", fmt.Errorf("failed to marshal TAT request: %w", err)
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("TAT API returned HTTP %d", resp.StatusCode)
+	}
+
+	var result struct {
+		Code              int    `json:"code"`
+		Msg               string `json:"msg"`
+		TenantAccessToken string `json:"tenant_access_token"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return "", fmt.Errorf("failed to parse TAT response: %w", err)
+	}
+	if result.Code != 0 {
+		return "", classifyTATResponseCode(result.Code, result.Msg, string(brand), appID)
+	}
+	return result.TenantAccessToken, nil
+}

internal/credential/tat_fetch_test.go

@@ -0,0 +1,237 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package credential
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/larksuite/cli/errs"
+	"github.com/larksuite/cli/internal/core"
+)
+
+// stubRoundTripper lets us assert request shape and return canned responses.
+type stubRoundTripper struct {
+	gotReq   *http.Request
+	gotBody  string
+	respCode int
+	respBody string
+	err      error
+}
+
+func (s *stubRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	s.gotReq = req
+	if req.Body != nil {
+		b, _ := io.ReadAll(req.Body)
+		s.gotBody = string(b)
+	}
+	if s.err != nil {
+		return nil, s.err
+	}
+	return &http.Response{
+		StatusCode: s.respCode,
+		Body:       io.NopCloser(strings.NewReader(s.respBody)),
+		Header:     make(http.Header),
+	}, nil
+}
+
+func TestFetchTAT_Success(t *testing.T) {
+	rt := &stubRoundTripper{
+		respCode: 200,
+		respBody: `{"code":0,"tenant_access_token":"t-abc","msg":"ok"}`,
+	}
+	hc := &http.Client{Transport: rt}
+
+	token, err := FetchTAT(context.Background(), hc, core.BrandFeishu, "cli_app", "secret_x")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if token != "t-abc" {
+		t.Errorf("token = %q, want t-abc", token)
+	}
+	if rt.gotReq.URL.String() != "https://open.feishu.cn/open-apis/auth/v3/tenant_access_token/internal" {
+		t.Errorf("url = %s", rt.gotReq.URL.String())
+	}
+	if !strings.Contains(rt.gotBody, `"app_id":"cli_app"`) || !strings.Contains(rt.gotBody, `"app_secret":"secret_x"`) {
+		t.Errorf("request body missing credentials: %s", rt.gotBody)
+	}
+}
+
+// 10003 (bad / non-existent app_id, "invalid param") is classified locally by
+// classifyTATResponseCode as CategoryConfig / SubtypeInvalidClient — the same
+// typed error doResolveTAT (and thus every token-resolving command) returns.
+func TestFetchTAT_Code10003_ConfigInvalidClient(t *testing.T) {
+	rt := &stubRoundTripper{respCode: 200, respBody: `{"code":10003,"msg":"invalid param"}`}
+	hc := &http.Client{Transport: rt}
+
+	token, err := FetchTAT(context.Background(), hc, core.BrandFeishu, "cli_app", "secret_x")
+	if err == nil {
+		t.Fatal("expected error for code 10003")
+	}
+	if token != "" {
+		t.Errorf("token = %q, want empty", token)
+	}
+	var cfgErr *errs.ConfigError
+	if !errors.As(err, &cfgErr) {
+		t.Fatalf("error not *errs.ConfigError: %T %v", err, err)
+	}
+	if cfgErr.Category != errs.CategoryConfig {
+		t.Errorf("Category = %q, want %q", cfgErr.Category, errs.CategoryConfig)
+	}
+	if cfgErr.Subtype != errs.SubtypeInvalidClient {
+		t.Errorf("Subtype = %q, want %q", cfgErr.Subtype, errs.SubtypeInvalidClient)
+	}
+	if cfgErr.Code != 10003 {
+		t.Errorf("Code = %d, want 10003", cfgErr.Code)
+	}
+}
+
+// 10014 ("app secret invalid") — the most common real-world rejection (real
+// app_id + wrong secret) — is globally mapped in codemeta to
+// CategoryConfig / SubtypeInvalidClient via BuildAPIError.
+func TestFetchTAT_Code10014_ConfigInvalidClient(t *testing.T) {
+	rt := &stubRoundTripper{respCode: 200, respBody: `{"code":10014,"msg":"app secret invalid"}`}
+	hc := &http.Client{Transport: rt}
+
+	_, err := FetchTAT(context.Background(), hc, core.BrandFeishu, "cli_app", "secret_x")
+	var cfgErr *errs.ConfigError
+	if !errors.As(err, &cfgErr) {
+		t.Fatalf("error not *errs.ConfigError: %T %v", err, err)
+	}
+	if cfgErr.Subtype != errs.SubtypeInvalidClient || cfgErr.Code != 10014 {
+		t.Errorf("got Subtype=%q Code=%d, want invalid_client/10014", cfgErr.Subtype, cfgErr.Code)
+	}
+}
+
+// Any non-zero body code is a deterministic server-side rejection, so it
+// always yields a typed error (errs.IsTyped). An unrecognized code falls back
+// to CategoryAPI / SubtypeUnknown via BuildAPIError — still typed, so a probe
+// caller still surfaces it rather than silently swallowing.
+func TestFetchTAT_UnknownBodyCode_Typed(t *testing.T) {
+	rt := &stubRoundTripper{respCode: 200, respBody: `{"code":99999,"msg":"future-unknown"}`}
+	hc := &http.Client{Transport: rt}
+
+	_, err := FetchTAT(context.Background(), hc, core.BrandFeishu, "cli_app", "secret_x")
+	if err == nil {
+		t.Fatal("expected error for code 99999")
+	}
+	if !errs.IsTyped(err) {
+		t.Fatalf("expected a typed errs.* error, got %T %v", err, err)
+	}
+	var apiErr *errs.APIError
+	if !errors.As(err, &apiErr) {
+		t.Errorf("unknown code should fall back to *errs.APIError, got %T", err)
+	}
+}
+
+// Non-2xx HTTP is ambiguous (not a payload-level credential rejection) — it
+// must stay UNTYPED so a probe caller treats it as upstream noise and stays
+// silent.
+func TestFetchTAT_HTTPNon200_Untyped(t *testing.T) {
+	for _, code := range []int{401, 403, 500, 503} {
+		rt := &stubRoundTripper{respCode: code, respBody: `whatever`}
+		hc := &http.Client{Transport: rt}
+		_, err := FetchTAT(context.Background(), hc, core.BrandFeishu, "cli_app", "secret_x")
+		if err == nil {
+			t.Fatalf("HTTP %d: expected error", code)
+		}
+		if errs.IsTyped(err) {
+			t.Errorf("HTTP %d: must be UNTYPED (ambiguous), got typed %T %v", code, err, err)
+		}
+	}
+}
+
+func TestFetchTAT_TransportError_Untyped(t *testing.T) {
+	sentinel := errors.New("network down")
+	rt := &stubRoundTripper{err: sentinel}
+	hc := &http.Client{Transport: rt}
+
+	_, err := FetchTAT(context.Background(), hc, core.BrandFeishu, "cli_app", "secret_x")
+	if err == nil {
+		t.Fatal("expected error")
+	}
+	if errs.IsTyped(err) {
+		t.Errorf("transport error must be UNTYPED, got typed %T", err)
+	}
+	if !errors.Is(err, sentinel) {
+		t.Errorf("error chain missing sentinel: %v", err)
+	}
+}
+
+func TestFetchTAT_ParseError_Untyped(t *testing.T) {
+	rt := &stubRoundTripper{respCode: 200, respBody: `not json`}
+	hc := &http.Client{Transport: rt}
+
+	_, err := FetchTAT(context.Background(), hc, core.BrandFeishu, "cli_app", "secret_x")
+	if err == nil {
+		t.Fatal("expected parse error")
+	}
+	if errs.IsTyped(err) {
+		t.Errorf("parse error must be UNTYPED, got typed %T", err)
+	}
+}
+
+func TestFetchTAT_BrandRouting(t *testing.T) {
+	tests := []struct {
+		brand   core.LarkBrand
+		wantURL string
+	}{
+		{core.BrandFeishu, "https://open.feishu.cn/open-apis/auth/v3/tenant_access_token/internal"},
+		{core.BrandLark, "https://open.larksuite.com/open-apis/auth/v3/tenant_access_token/internal"},
+	}
+	for _, tc := range tests {
+		t.Run(string(tc.brand), func(t *testing.T) {
+			rt := &stubRoundTripper{respCode: 200, respBody: `{"code":0,"tenant_access_token":"t"}`}
+			hc := &http.Client{Transport: rt}
+			if _, err := FetchTAT(context.Background(), hc, tc.brand, "a", "b"); err != nil {
+				t.Fatal(err)
+			}
+			if got := rt.gotReq.URL.String(); got != tc.wantURL {
+				t.Errorf("url = %s, want %s", got, tc.wantURL)
+			}
+		})
+	}
+}
+
+func TestFetchTAT_ContextCanceled(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		<-r.Context().Done()
+	}))
+	defer srv.Close()
+
+	rt := &urlRewriteRT{base: srv.URL}
+	hc := &http.Client{Transport: rt}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel() // pre-canceled
+
+	_, err := FetchTAT(ctx, hc, core.BrandFeishu, "a", "b")
+	if err == nil {
+		t.Fatal("expected error for canceled context")
+	}
+	if errs.IsTyped(err) {
+		t.Errorf("canceled context must be UNTYPED, got typed %T", err)
+	}
+	if !errors.Is(err, context.Canceled) {
+		t.Errorf("error chain missing context.Canceled: %v", err)
+	}
+}
+
+// urlRewriteRT forwards requests to a fixed base URL (test server).
+type urlRewriteRT struct{ base string }
+
+func (r *urlRewriteRT) RoundTrip(req *http.Request) (*http.Response, error) {
+	newURL := r.base + req.URL.Path
+	req2, err := http.NewRequestWithContext(req.Context(), req.Method, newURL, req.Body)
+	if err != nil {
+		return nil, err
+	}
+	req2.Header = req.Header
+	return http.DefaultTransport.RoundTrip(req2)
+}

internal/deprecation/deprecation.go

@@ -0,0 +1,57 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+// Package deprecation carries a process-level notice that the command currently
+// being executed is a backward-compatibility alias, kept alive for users whose
+// skill predates a refactor. The notice is surfaced in JSON output envelopes via
+// output.PendingNotice (wired in cmd/root.go), mirroring internal/skillscheck.
+//
+// A CLI process runs exactly one shortcut, so a single process-level slot is
+// sufficient: the command's Execute records the notice before producing output,
+// and the output layer reads it back when building the envelope.
+package deprecation
+
+import (
+	"strings"
+	"sync/atomic"
+)
+
+// Notice describes a deprecated command alias and the current command that
+// replaces it. Replacement and Skill are optional.
+type Notice struct {
+	Command     string `json:"command"`
+	Replacement string `json:"replacement,omitempty"`
+	Skill       string `json:"skill,omitempty"`
+}
+
+// Message returns a single-line, AI-agent-parseable description of the alias
+// plus the canonical fix (update the skill). Mirrors the style of
+// internal/skillscheck.StaleNotice.Message ("..., run: lark-cli update").
+func (n *Notice) Message() string {
+	var b strings.Builder
+	b.WriteString(n.Command)
+	b.WriteString(" is a pre-refactor compatibility alias")
+	if n.Replacement != "" {
+		b.WriteString("; use ")
+		b.WriteString(n.Replacement)
+		b.WriteString(" instead")
+	}
+	if n.Skill != "" {
+		b.WriteString("; update your ")
+		b.WriteString(n.Skill)
+		b.WriteString(" skill, run: lark-cli update")
+	} else {
+		b.WriteString("; update your skill, run: lark-cli update")
+	}
+	return b.String()
+}
+
+// pending stores the latest deprecation notice for the current process.
+var pending atomic.Pointer[Notice]
+
+// SetPending stores the notice for consumption by output decorators.
+// Pass nil to clear.
+func SetPending(n *Notice) { pending.Store(n) }
+
+// GetPending returns the pending deprecation notice, or nil.
+func GetPending() *Notice { return pending.Load() }

internal/deprecation/deprecation_test.go

@@ -0,0 +1,58 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package deprecation
+
+import "testing"
+
+func TestNoticeMessage(t *testing.T) {
+	tests := []struct {
+		name   string
+		notice Notice
+		want   string
+	}{
+		{
+			name:   "replacement and skill",
+			notice: Notice{Command: "+read", Replacement: "+cells-get", Skill: "lark-sheets"},
+			want:   "+read is a pre-refactor compatibility alias; use +cells-get instead; update your lark-sheets skill, run: lark-cli update",
+		},
+		{
+			name:   "no replacement",
+			notice: Notice{Command: "+read", Skill: "lark-sheets"},
+			want:   "+read is a pre-refactor compatibility alias; update your lark-sheets skill, run: lark-cli update",
+		},
+		{
+			name:   "no skill",
+			notice: Notice{Command: "+read", Replacement: "+cells-get"},
+			want:   "+read is a pre-refactor compatibility alias; use +cells-get instead; update your skill, run: lark-cli update",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.notice.Message(); got != tt.want {
+				t.Errorf("Message() =\n  %q\nwant\n  %q", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestSetGetPending(t *testing.T) {
+	t.Cleanup(func() { SetPending(nil) })
+
+	SetPending(nil)
+	if got := GetPending(); got != nil {
+		t.Fatalf("expected nil pending after clear, got %#v", got)
+	}
+
+	n := &Notice{Command: "+write", Replacement: "+cells-set", Skill: "lark-sheets"}
+	SetPending(n)
+	got := GetPending()
+	if got == nil || got.Command != "+write" || got.Replacement != "+cells-set" {
+		t.Fatalf("GetPending() = %#v, want %#v", got, n)
+	}
+
+	SetPending(nil)
+	if GetPending() != nil {
+		t.Fatal("expected nil after clearing")
+	}
+}

internal/envvars/envvars.go

@@ -20,4 +20,8 @@ const (
 	CliContentSafetyMode = "LARKSUITE_CLI_CONTENT_SAFETY_MODE"
 
 	CliAgentTrace = "LARKSUITE_CLI_AGENT_TRACE"
+
+	CliProxyEnable  = "LARKSUITE_CLI_PROXY_ENABLE"
+	CliProxyAddress = "LARKSUITE_CLI_PROXY_ADDRESS"
+	CliCAPath       = "LARKSUITE_CLI_CA_PATH"
 )

internal/errclass/classify.go

@@ -92,6 +92,18 @@ func BuildAPIError(resp map[string]any, cc ClassifyContext) error {
 			base.Troubleshooter = ts
 		}
 	}
+	// Upstream-provided field-level reasons (resp.error.details[].value). Lark
+	// returns these as free-text reason strings with no machine-readable field
+	// name (verified for code 190014:
+	// {"error":{"details":[{"value":"end_time should be later than start_time"}]}}),
+	// so they are lifted into Problem.Hint — the sanctioned free-text recovery
+	// prompt — rather than fabricated structured params. Lifted before the
+	// category switch so any classified arm inherits it; the CategoryAPI arm
+	// below prefers this server detail over the context-free APIHint default.
+	detailHint := liftErrorDetailValues(resp)
+	if detailHint != "" {
+		base.Hint = detailHint
+	}
 
 	switch meta.Category {
 	case errs.CategoryAuthorization:
@@ -129,6 +141,11 @@ func BuildAPIError(resp map[string]any, cc ClassifyContext) error {
 			Action:  action,
 		}
 	case errs.CategoryAPI:
+		// A server-supplied detail (lifted into base.Hint above) wins over the
+		// context-free APIHint default; only fall back to APIHint when absent.
+		if base.Hint == "" {
+			base.Hint = APIHint(base.Subtype) // "" for subtypes without a context-free default
+		}
 		return &errs.APIError{Problem: base}
 	default:
 		// Fail closed: an unrecognized Category routes to InternalError
@@ -213,6 +230,10 @@ func stringFromAny(v any) string {
 // per-subtype recovery hint before returning it, so the wire envelope
 // emitted via BuildAPIError always carries a hint for known config subtypes.
 func buildConfigError(p errs.Problem) *errs.ConfigError {
+	// Config categories have authoritative recovery guidance, so the curated
+	// ConfigHint deliberately overrides any server detail lifted into p.Hint
+	// (the opposite precedence from the CategoryAPI arm, where the lifted
+	// detail wins).
 	p.Hint = ConfigHint(p.Subtype)
 	return &errs.ConfigError{Problem: p}
 }
@@ -231,6 +252,24 @@ func ConfigHint(subtype errs.Subtype) string {
 	return ""
 }
 
+// APIHint returns the canonical per-subtype recovery hint for a typed APIError
+// emitted via BuildAPIError, for API subtypes whose recovery is context-free.
+// Context-specific guidance (e.g. a command's flags, an API's own quota) is
+// layered on by the caller after BuildAPIError returns and overrides this.
+func APIHint(subtype errs.Subtype) string {
+	switch subtype {
+	case errs.SubtypeConflict:
+		return "retry later and avoid concurrent duplicate requests on the same resource"
+	case errs.SubtypeCrossTenant:
+		return "operate on source and target within the same tenant and region/unit"
+	case errs.SubtypeCrossBrand:
+		return "operate on source and target within the same brand environment"
+	case errs.SubtypeQuotaExceeded:
+		return "reduce the request volume or free quota, then retry after the relevant quota resets"
+	}
+	return ""
+}
+
 func buildPermissionError(p errs.Problem, resp map[string]any, cc ClassifyContext) *errs.PermissionError {
 	missing := extractMissingScopes(resp)
 	identity := cc.Identity
@@ -239,6 +278,10 @@ func buildPermissionError(p errs.Problem, resp map[string]any, cc ClassifyContex
 	}
 	consoleURL := ConsoleURL(cc.Brand, cc.AppID, missing)
 	p.Message = CanonicalPermissionMessage(p.Subtype, cc.AppID, missing, p.Message)
+	// Permission categories have authoritative recovery guidance (scopes to
+	// grant, console URL), so the curated PermissionHint deliberately overrides
+	// any server detail lifted into p.Hint (the opposite precedence from the
+	// CategoryAPI arm, where the lifted detail wins).
 	p.Hint = PermissionHint(missing, identity, p.Subtype, consoleURL)
 	permErr := &errs.PermissionError{
 		Problem:       p,
@@ -347,6 +390,32 @@ func PermissionHint(missing []string, identity string, subtype errs.Subtype, con
 	return "check the calling identity has the required scope"
 }
 
+// liftErrorDetailValues collects the non-empty resp.error.details[].value reason
+// strings and joins them with "; ". Returns "" when the structure is absent or
+// carries no non-empty value. The shape (verified for code 190014) is
+// {"error":{"details":[{"value":"<reason>"}]}}.
+func liftErrorDetailValues(resp map[string]any) string {
+	errBlock, ok := resp["error"].(map[string]any)
+	if !ok {
+		return ""
+	}
+	details, ok := errBlock["details"].([]any)
+	if !ok || len(details) == 0 {
+		return ""
+	}
+	var values []string
+	for _, d := range details {
+		m, ok := d.(map[string]any)
+		if !ok {
+			continue
+		}
+		if v, _ := m["value"].(string); v != "" {
+			values = append(values, v)
+		}
+	}
+	return strings.Join(values, "; ")
+}
+
 // extractMissingScopes walks resp["error"]["permission_violations"][].subject.
 // Returns nil when the structure is absent.
 func extractMissingScopes(resp map[string]any) []string {

internal/errclass/classify_test.go

@@ -220,6 +220,111 @@ func TestBuildAPIError_TroubleshooterLiftedOnPermissionArm(t *testing.T) {
 	}
 }
 
+// TestBuildAPIError_DetailsLiftedToHintOnAPIArm pins that BuildAPIError lifts
+// resp.error.details[].value into Problem.Hint when the response routes to the
+// catch-all CategoryAPI arm. The real Lark shape (verified for code 190014) is
+// {"error":{"details":[{"value":"end_time should be later than start_time"}]}}
+// — only a human-readable reason string, no machine-readable field name. It is
+// lifted into Hint (sanctioned free-text recovery prompt) rather than fabricated
+// structured params.
+func TestBuildAPIError_DetailsLiftedToHintOnAPIArm(t *testing.T) {
+	resp := map[string]any{
+		"code": 190014,
+		"msg":  "invalid params",
+		"error": map[string]any{
+			"details": []any{
+				map[string]any{"value": "end_time should be later than start_time"},
+			},
+		},
+	}
+	err := errclass.BuildAPIError(resp, errclass.ClassifyContext{})
+	p, ok := errs.ProblemOf(err)
+	if !ok {
+		t.Fatal("ProblemOf returned !ok")
+	}
+	if !strings.Contains(p.Hint, "end_time should be later than start_time") {
+		t.Errorf("Hint = %q, want it to contain the server detail value", p.Hint)
+	}
+}
+
+// TestBuildAPIError_MultipleDetailsJoinedIntoHint pins that multiple non-empty
+// detail values are joined with "; " into a single Hint, and empty values are
+// skipped.
+func TestBuildAPIError_MultipleDetailsJoinedIntoHint(t *testing.T) {
+	resp := map[string]any{
+		"code": 190014,
+		"msg":  "invalid params",
+		"error": map[string]any{
+			"details": []any{
+				map[string]any{"value": "first reason"},
+				map[string]any{"value": ""},
+				map[string]any{"value": "second reason"},
+			},
+		},
+	}
+	err := errclass.BuildAPIError(resp, errclass.ClassifyContext{})
+	p, ok := errs.ProblemOf(err)
+	if !ok {
+		t.Fatal("ProblemOf returned !ok")
+	}
+	if p.Hint != "first reason; second reason" {
+		t.Errorf("Hint = %q, want %q", p.Hint, "first reason; second reason")
+	}
+}
+
+// TestBuildAPIError_DetailsSkipsNonMapEntries pins that malformed entries in
+// the details array (not a JSON object) are skipped rather than panicking, and
+// well-formed siblings still surface in the Hint.
+func TestBuildAPIError_DetailsSkipsNonMapEntries(t *testing.T) {
+	resp := map[string]any{
+		"code": 190014,
+		"msg":  "invalid params",
+		"error": map[string]any{
+			"details": []any{
+				"i am a bare string, not an object",
+				map[string]any{"value": "the real reason"},
+				42,
+			},
+		},
+	}
+	err := errclass.BuildAPIError(resp, errclass.ClassifyContext{})
+	p, ok := errs.ProblemOf(err)
+	if !ok {
+		t.Fatal("ProblemOf returned !ok")
+	}
+	if p.Hint != "the real reason" {
+		t.Errorf("Hint = %q, want %q", p.Hint, "the real reason")
+	}
+}
+
+// TestBuildAPIError_DetailsMalformedShapesNoHint pins that a missing error
+// block, a non-array details field, and an empty details array all leave the
+// Hint untouched (no lifted detail) instead of erroring.
+func TestBuildAPIError_DetailsMalformedShapesNoHint(t *testing.T) {
+	cases := []struct {
+		name string
+		resp map[string]any
+	}{
+		{"no error block", map[string]any{"code": 190014, "msg": "invalid params"}},
+		{"details not array", map[string]any{"code": 190014, "msg": "invalid params", "error": map[string]any{"details": "nope"}}},
+		{"empty details", map[string]any{"code": 190014, "msg": "invalid params", "error": map[string]any{"details": []any{}}}},
+		{"detail values all empty", map[string]any{"code": 190014, "msg": "invalid params", "error": map[string]any{"details": []any{map[string]any{"value": ""}}}}},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := errclass.BuildAPIError(tc.resp, errclass.ClassifyContext{})
+			p, ok := errs.ProblemOf(err)
+			if !ok {
+				t.Fatal("ProblemOf returned !ok")
+			}
+			// With no liftable detail, the Hint must not echo a server detail.
+			if strings.Contains(p.Hint, "nope") {
+				t.Errorf("Hint should not lift a non-array details field, got %q", p.Hint)
+			}
+		})
+	}
+}
+
 // TestBuildAPIError_TroubleshooterAbsent pins that Troubleshooter stays empty
 // when the upstream response omits it — wire envelope must omit the field.
 func TestBuildAPIError_TroubleshooterAbsent(t *testing.T) {

internal/errclass/codemeta_calendar.go

@@ -0,0 +1,16 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package errclass
+
+import "github.com/larksuite/cli/errs"
+
+// calendarCodeMeta holds calendar-service Lark code → CodeMeta mappings.
+// Only codes whose meaning is verifiable from repo evidence are registered;
+// ambiguous codes fall back to CategoryAPI via BuildAPIError.
+// BuildAPIError consumes this map via mergeCodeMeta + LookupCodeMeta.
+var calendarCodeMeta = map[int]CodeMeta{
+	190014: {Category: errs.CategoryAPI, Subtype: errs.SubtypeInvalidParameters}, // invalid params (carries a field-level detail lifted into Hint)
+}
+
+func init() { mergeCodeMeta(calendarCodeMeta, "calendar") }

internal/errclass/codemeta_calendar_test.go

@@ -0,0 +1,39 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package errclass
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/larksuite/cli/errs"
+)
+
+// TestLookupCodeMeta_CalendarCodes pins each calendar-service code registered
+// via the codemeta_calendar.go init() merge to its expected
+// Category/Subtype/Retryable.
+func TestLookupCodeMeta_CalendarCodes(t *testing.T) {
+	cases := []struct {
+		code        int
+		wantCat     errs.Category
+		wantSubtype errs.Subtype
+		wantRetry   bool
+	}{
+		// 190014: calendar "invalid params" with a field-level detail
+		// (error.details[].value) lifted into Hint by BuildAPIError.
+		{190014, errs.CategoryAPI, errs.SubtypeInvalidParameters, false},
+	}
+	for _, tc := range cases {
+		t.Run(fmt.Sprintf("%d", tc.code), func(t *testing.T) {
+			meta, ok := LookupCodeMeta(tc.code)
+			if !ok {
+				t.Fatalf("code %d not registered in codeMeta", tc.code)
+			}
+			if meta.Category != tc.wantCat || meta.Subtype != tc.wantSubtype || meta.Retryable != tc.wantRetry {
+				t.Errorf("code %d: got %+v, want Category=%v Subtype=%v Retryable=%v",
+					tc.code, meta, tc.wantCat, tc.wantSubtype, tc.wantRetry)
+			}
+		})
+	}
+}

internal/errclass/codemeta_drive.go

@@ -0,0 +1,17 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package errclass
+
+import "github.com/larksuite/cli/errs"
+
+// driveCodeMeta holds drive/docs-service Lark code → CodeMeta mappings.
+// Only codes whose meaning is verifiable from repo evidence are registered;
+// ambiguous codes fall back to CategoryAPI via BuildAPIError.
+// BuildAPIError consumes this map via mergeCodeMeta + LookupCodeMeta.
+var driveCodeMeta = map[int]CodeMeta{
+	1061044: {Category: errs.CategoryAPI, Subtype: errs.SubtypeNotFound},          // parent folder does not exist (upload)
+	1069302: {Category: errs.CategoryAPI, Subtype: errs.SubtypeInvalidParameters}, // comment endpoint "Invalid or missing parameters"
+}
+
+func init() { mergeCodeMeta(driveCodeMeta, "drive") }

internal/errclass/codemeta_drive_test.go

@@ -0,0 +1,43 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package errclass
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/larksuite/cli/errs"
+)
+
+// TestLookupCodeMeta_DriveCodes pins each drive-service code registered via the
+// codemeta_drive.go init() merge to its expected Category/Subtype/Retryable.
+// Each case traces to repo evidence (see codemeta_drive.go comments).
+func TestLookupCodeMeta_DriveCodes(t *testing.T) {
+	cases := []struct {
+		code        int
+		wantCat     errs.Category
+		wantSubtype errs.Subtype
+		wantRetry   bool
+	}{
+		// 1061044: upload with a nonexistent parent folder token. The drive E2E
+		// (tests_e2e/drive/2026_06_01_errs_migrate_drive_test.go) drives this
+		// producer via a nonexistent parent folder → referenced resource missing.
+		{1061044, errs.CategoryAPI, errs.SubtypeNotFound, false},
+		// 1069302: comment endpoint's opaque "Invalid or missing parameters"
+		// (shortcuts/drive/drive_add_comment.go) → API-side parameter rejection.
+		{1069302, errs.CategoryAPI, errs.SubtypeInvalidParameters, false},
+	}
+	for _, tc := range cases {
+		t.Run(fmt.Sprintf("%d", tc.code), func(t *testing.T) {
+			meta, ok := LookupCodeMeta(tc.code)
+			if !ok {
+				t.Fatalf("code %d not registered in codeMeta", tc.code)
+			}
+			if meta.Category != tc.wantCat || meta.Subtype != tc.wantSubtype || meta.Retryable != tc.wantRetry {
+				t.Errorf("code %d: got %+v, want Category=%v Subtype=%v Retryable=%v",
+					tc.code, meta, tc.wantCat, tc.wantSubtype, tc.wantRetry)
+			}
+		})
+	}
+}

internal/errclass/codemeta_mail.go

@@ -0,0 +1,20 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package errclass
+
+import "github.com/larksuite/cli/errs"
+
+// mailCodeMeta holds mail-service Lark code -> CodeMeta mappings.
+// Only codes whose meaning is verifiable from repo evidence are registered;
+// ambiguous codes fall back to CategoryAPI via BuildAPIError.
+var mailCodeMeta = map[int]CodeMeta{
+	1234013: {Category: errs.CategoryAPI, Subtype: errs.SubtypeNotFound},      // mailbox not found or not active
+	1236007: {Category: errs.CategoryAPI, Subtype: errs.SubtypeQuotaExceeded}, // user daily send count exceeded
+	1236008: {Category: errs.CategoryAPI, Subtype: errs.SubtypeQuotaExceeded}, // user daily external recipient count exceeded
+	1236009: {Category: errs.CategoryAPI, Subtype: errs.SubtypeQuotaExceeded}, // tenant daily external recipient count exceeded
+	1236010: {Category: errs.CategoryAPI, Subtype: errs.SubtypeQuotaExceeded}, // mail quota limit
+	1236013: {Category: errs.CategoryAPI, Subtype: errs.SubtypeQuotaExceeded}, // tenant storage limit exceeded
+}
+
+func init() { mergeCodeMeta(mailCodeMeta, "mail") }

internal/errclass/codemeta_minutes.go

@@ -0,0 +1,18 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package errclass
+
+import "github.com/larksuite/cli/errs"
+
+// minutesCodeMeta holds minutes-service Lark code → CodeMeta mappings.
+// Only codes whose meaning is stable across minutes endpoints are registered;
+// endpoint-specific codes fall back to CategoryAPI via BuildAPIError.
+// Command-specific messages, hints, and subtypes are layered on top via
+// per-command enrichment.
+// BuildAPIError consumes this map via mergeCodeMeta + LookupCodeMeta.
+var minutesCodeMeta = map[int]CodeMeta{
+	2091005: {Category: errs.CategoryAuthorization, Subtype: errs.SubtypePermissionDenied}, // caller lacks edit/read permission for the minute
+}
+
+func init() { mergeCodeMeta(minutesCodeMeta, "minutes") }

internal/errclass/codemeta_test.go

@@ -70,6 +70,12 @@ func TestLookupCodeMeta_TaskPermissionDenied_MergedViaInit(t *testing.T) {
 	}
 }
 
+func TestLookupCodeMeta_MinutesEndpointSpecificCode_NotGlobal(t *testing.T) {
+	if got, ok := LookupCodeMeta(2091001); ok {
+		t.Fatalf("LookupCodeMeta(2091001) = %+v, want unregistered; minutes endpoints use this code for different failures", got)
+	}
+}
+
 func TestLookupCodeMeta_RetryableAuthCode(t *testing.T) {
 	got, ok := LookupCodeMeta(20050)
 	if !ok {

internal/errclass/codemeta_vc.go

@@ -0,0 +1,19 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package errclass
+
+import "github.com/larksuite/cli/errs"
+
+// vcCodeMeta holds vc-service Lark code → CodeMeta mappings.
+// Only codes whose meaning is verifiable from repo evidence are registered;
+// ambiguous codes (e.g. 124002 "recording still generating", which has no
+// precise taxonomy fit) fall back to CategoryAPI via BuildAPIError and rely on
+// per-command enrichment for a retry hint.
+// BuildAPIError consumes this map via mergeCodeMeta + LookupCodeMeta.
+var vcCodeMeta = map[int]CodeMeta{
+	121004: {Category: errs.CategoryAPI, Subtype: errs.SubtypeNotFound},                   // meeting has no minute file
+	121005: {Category: errs.CategoryAuthorization, Subtype: errs.SubtypePermissionDenied}, // caller is not a participant / lacks view permission
+}
+
+func init() { mergeCodeMeta(vcCodeMeta, "vc") }

internal/event/consume/consume.go

@@ -14,6 +14,7 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/event"
 	"github.com/larksuite/cli/internal/event/transport"
 )
@@ -44,7 +45,9 @@ func Run(ctx context.Context, tr transport.IPC, appID, profileName, domain strin
 
 	keyDef, ok := event.Lookup(opts.EventKey)
 	if !ok {
-		return fmt.Errorf("unknown EventKey: %s\nRun 'lark-cli event list' to see available keys", opts.EventKey)
+		return errs.NewValidationError(errs.SubtypeInvalidArgument,
+			"unknown EventKey: %s", opts.EventKey).
+			WithHint("run `lark-cli event list` to see available keys")
 	}
 
 	if err := validateParams(keyDef, opts.Params); err != nil {
@@ -80,7 +83,8 @@ func Run(ctx context.Context, tr transport.IPC, appID, profileName, domain strin
 
 	ack, br, err := doHello(conn, opts.EventKey, []string{keyDef.EventType})
 	if err != nil {
-		return fmt.Errorf("handshake failed: %w", err)
+		return errs.NewInternalError(errs.SubtypeUnknown,
+			"event bus handshake failed: %s", err).WithCause(err)
 	}
 
 	var cleanup func()
@@ -90,7 +94,11 @@ func Run(ctx context.Context, tr transport.IPC, appID, profileName, domain strin
 		}
 		cleanup, err = keyDef.PreConsume(ctx, opts.Runtime, opts.Params)
 		if err != nil {
-			return fmt.Errorf("pre-consume failed: %w", err)
+			if _, ok := errs.ProblemOf(err); ok {
+				return err
+			}
+			return errs.NewInternalError(errs.SubtypeUnknown,
+				"pre-consume failed: %s", err).WithCause(err)
 		}
 	}
 
@@ -130,7 +138,7 @@ func Run(ctx context.Context, tr transport.IPC, appID, profileName, domain strin
 	if !opts.Quiet {
 		fmt.Fprintln(errOut, listeningText(opts))
 		if !opts.IsTTY {
-			fmt.Fprintln(errOut, stopHintText())
+			fmt.Fprintln(errOut, stopHintText(opts))
 		}
 	}
 
@@ -152,8 +160,10 @@ func validateParams(def *event.KeyDefinition, params map[string]string) error {
 	for _, p := range def.Params {
 		if p.Required {
 			if _, ok := params[p.Name]; !ok {
-				return fmt.Errorf("required param %q missing for EventKey %s. Run 'lark-cli event schema %s' for details",
-					p.Name, def.Key, def.Key)
+				return errs.NewValidationError(errs.SubtypeInvalidArgument,
+					"required param %q missing for EventKey %s", p.Name, def.Key).
+					WithParam("--param").
+					WithHint("pass it as --param %s=<value>; run `lark-cli event schema %s` for details", p.Name, def.Key)
 			}
 		}
 	}
@@ -169,11 +179,15 @@ func validateParams(def *event.KeyDefinition, params map[string]string) error {
 			continue
 		}
 		if len(validNames) == 0 {
-			return fmt.Errorf("unknown param %q: EventKey %s accepts no params. Run 'lark-cli event schema %s' for details",
-				k, def.Key, def.Key)
+			return errs.NewValidationError(errs.SubtypeInvalidArgument,
+				"unknown param %q: EventKey %s accepts no params", k, def.Key).
+				WithParam("--param").
+				WithHint("run `lark-cli event schema %s` for details", def.Key)
 		}
-		return fmt.Errorf("unknown param %q for EventKey %s. valid params: %s. Run 'lark-cli event schema %s' for details",
-			k, def.Key, strings.Join(validNames, ", "), def.Key)
+		return errs.NewValidationError(errs.SubtypeInvalidArgument,
+			"unknown param %q for EventKey %s. valid params: %s", k, def.Key, strings.Join(validNames, ", ")).
+			WithParam("--param").
+			WithHint("run `lark-cli event schema %s` for details", def.Key)
 	}
 	return nil
 }
@@ -213,7 +227,11 @@ func exitReason(ctx context.Context, emitted int64, opts Options) string {
 	return "signal"
 }
 
-func stopHintText() string {
+func stopHintText(opts Options) string {
+	if opts.MaxEvents > 0 || opts.Timeout > 0 {
+		return "[event] to stop gracefully: send SIGTERM (kill <pid>). " +
+			"Avoid kill -9 — it skips cleanup and may leak server-side subscriptions."
+	}
 	return "[event] to stop gracefully: send SIGTERM (kill <pid>) or close stdin. " +
 		"Avoid kill -9 — it skips cleanup and may leak server-side subscriptions."
 }

internal/event/consume/jq.go

@@ -8,17 +8,21 @@ import (
 	"fmt"
 
 	"github.com/itchyny/gojq"
+
+	"github.com/larksuite/cli/errs"
 )
 
 // CompileJQ compiles once for hot-path reuse; exported so callers can preflight before side effects.
 func CompileJQ(expr string) (*gojq.Code, error) {
 	query, err := gojq.Parse(expr)
 	if err != nil {
-		return nil, fmt.Errorf("invalid jq expression: %w", err)
+		return nil, errs.NewValidationError(errs.SubtypeInvalidArgument,
+			"invalid jq expression: %s", err).WithParam("--jq").WithCause(err)
 	}
 	code, err := gojq.Compile(query)
 	if err != nil {
-		return nil, fmt.Errorf("jq compile error: %w", err)
+		return nil, errs.NewValidationError(errs.SubtypeInvalidArgument,
+			"jq compile error: %s", err).WithParam("--jq").WithCause(err)
 	}
 	return code, nil
 }

internal/event/consume/listening_text_test.go

@@ -50,12 +50,32 @@ func TestListeningText_NonTTY_MaxEventsAndTimeout(t *testing.T) {
 }
 
 // AI-facing contract: must name "kill -9" + "cleanup" so agents parsing stderr are steered away from SIGKILL.
-func TestStopHintText_Content(t *testing.T) {
-	got := stopHintText()
-	mustContain := []string{"SIGTERM", "kill -9", "cleanup"}
+func TestStopHintText_Unbounded(t *testing.T) {
+	got := stopHintText(Options{})
+	mustContain := []string{"SIGTERM", "kill -9", "cleanup", "close stdin"}
 	for _, s := range mustContain {
 		if !bytes.Contains([]byte(got), []byte(s)) {
-			t.Errorf("stopHintText missing %q; got %q", s, got)
+			t.Errorf("stopHintText(unbounded) missing %q; got %q", s, got)
+		}
+	}
+}
+
+// AI-facing contract: must name "kill -9" + "cleanup" so agents parsing stderr are steered away from SIGKILL.
+func TestStopHintText_Bounded(t *testing.T) {
+	cases := []Options{
+		{MaxEvents: 1},
+		{Timeout: 30 * time.Second},
+	}
+	for _, opts := range cases {
+		got := stopHintText(opts)
+		mustContain := []string{"SIGTERM", "kill -9", "cleanup"}
+		for _, s := range mustContain {
+			if !bytes.Contains([]byte(got), []byte(s)) {
+				t.Errorf("stopHintText(bounded) missing %q; got %q", s, got)
+			}
+		}
+		if bytes.Contains([]byte(got), []byte("close stdin")) {
+			t.Errorf("stopHintText(bounded) must not contain \"close stdin\"; got %q", got)
 		}
 	}
 }

internal/event/consume/loop_jq_test.go

@@ -5,10 +5,13 @@ package consume
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"strings"
 	"sync"
 	"testing"
+
+	"github.com/larksuite/cli/errs"
 )
 
 func TestCompileJQReportsErrorEarly(t *testing.T) {
@@ -20,6 +23,16 @@ func TestCompileJQReportsErrorEarly(t *testing.T) {
 	if !strings.Contains(msg, "compile") && !strings.Contains(msg, "parse") && !strings.Contains(msg, "invalid") {
 		t.Errorf("error should mention compile/parse/invalid, got: %v", err)
 	}
+	var ve *errs.ValidationError
+	if !errors.As(err, &ve) {
+		t.Fatalf("expected *errs.ValidationError, got %T: %v", err, err)
+	}
+	if ve.Subtype != errs.SubtypeInvalidArgument || ve.Param != "--jq" {
+		t.Errorf("subtype/param = %s/%q, want %s/%q", ve.Subtype, ve.Param, errs.SubtypeInvalidArgument, "--jq")
+	}
+	if errors.Unwrap(err) == nil {
+		t.Error("compile error should preserve its cause")
+	}
 }
 
 func TestCompileJQReturnsUsableCode(t *testing.T) {

internal/event/consume/sink.go

@@ -13,6 +13,7 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/vfs"
 )
 
@@ -23,7 +24,8 @@ type Sink interface {
 func newSink(opts Options) (Sink, error) {
 	if opts.OutputDir != "" {
 		if err := vfs.MkdirAll(opts.OutputDir, 0755); err != nil {
-			return nil, fmt.Errorf("create output dir: %w", err)
+			return nil, errs.NewInternalError(errs.SubtypeFileIO,
+				"create output dir: %s", err).WithCause(err)
 		}
 		// PID disambiguates filenames across processes sharing a Dir.
 		return &DirSink{Dir: opts.OutputDir, pid: os.Getpid()}, nil

internal/event/consume/startup.go

@@ -16,6 +16,7 @@ import (
 	"path/filepath"
 	"time"
 
+	"github.com/larksuite/cli/errs"
 	"github.com/larksuite/cli/internal/core"
 	"github.com/larksuite/cli/internal/event"
 	"github.com/larksuite/cli/internal/event/protocol"
@@ -51,10 +52,9 @@ func EnsureBus(ctx context.Context, tr transport.IPC, appID, profileName, domain
 		} else {
 			fmt.Fprintf(errOut, "[event] remote connection check: online_instance_cnt=%d\n", count)
 			if count > 0 {
-				return nil, fmt.Errorf("another event bus is already connected to this app "+
-					"(%d active connection(s) detected via API).\n"+
-					"Only one bus should run globally to avoid duplicate event delivery.\n"+
-					"Use 'lark-cli event status' to check, or 'lark-cli event stop' on the other machine first", count)
+				return nil, errs.NewValidationError(errs.SubtypeFailedPrecondition,
+					"another event bus is already connected to this app (%d active connection(s) detected via API); only one bus should run globally to avoid duplicate event delivery", count).
+					WithHint("use `lark-cli event status` to check, or `lark-cli event stop` on the other machine first")
 			}
 		}
 	} else {
@@ -65,8 +65,10 @@ func EnsureBus(ctx context.Context, tr transport.IPC, appID, profileName, domain
 	pid, forkErr := forkBus(tr, appID, profileName, domain)
 	if forkErr != nil && !errors.Is(forkErr, lockfile.ErrHeld) {
 		eventsRoot := filepath.Join(core.GetConfigDir(), "events")
-		return nil, fmt.Errorf("failed to start event bus daemon: %w\n"+
-			"Check: disk space, permissions on %s, and 'lark-cli doctor'", forkErr, eventsRoot)
+		return nil, errs.NewInternalError(errs.SubtypeUnknown,
+			"failed to start event bus daemon: %s", forkErr).
+			WithCause(forkErr).
+			WithHint("check disk space, permissions on %s, and `lark-cli doctor`", eventsRoot)
 	}
 	if pid > 0 {
 		announceForkedBus(errOut, pid)
@@ -88,7 +90,9 @@ func EnsureBus(ctx context.Context, tr transport.IPC, appID, profileName, domain
 	fmt.Fprintln(errOut, "[event] event bus exited unexpectedly.")
 	fmt.Fprintln(errOut, "[event] please check app credentials (lark-cli config show) and retry.")
 	fmt.Fprintf(errOut, "[event] logs: %s\n", logPath)
-	return nil, fmt.Errorf("failed to connect to event bus within %v (app=%s)", dialTimeout, appID)
+	return nil, errs.NewInternalError(errs.SubtypeUnknown,
+		"failed to connect to event bus within %v (app=%s)", dialTimeout, appID).
+		WithHint("check app credentials (`lark-cli config show`) and retry; bus logs: %s", logPath)
 }
 
 // probeAndDialBus distinguishes a healthy bus from a mid-shutdown listener via StatusQuery first.

internal/event/consume/startup_guard_test.go

@@ -0,0 +1,99 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package consume
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"net"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/larksuite/cli/errs"
+	"github.com/larksuite/cli/internal/event"
+)
+
+// failDialTransport refuses every dial so EnsureBus falls through to the
+// remote-connection check without a local bus.
+type failDialTransport struct{}
+
+func (failDialTransport) Listen(string) (net.Listener, error) { return nil, errors.New("no listen") }
+func (failDialTransport) Dial(string) (net.Conn, error)       { return nil, errors.New("refused") }
+func (failDialTransport) Address(string) string               { return "guard-test-addr" }
+func (failDialTransport) Cleanup(string)                      {}
+
+// remoteBusyAPIClient reports active remote WebSocket connections.
+type remoteBusyAPIClient struct{ count int }
+
+func (c remoteBusyAPIClient) CallAPI(context.Context, string, string, interface{}) (json.RawMessage, error) {
+	return json.RawMessage(`{"code":0,"msg":"ok","data":{"online_instance_cnt":` +
+		strconv.Itoa(c.count) + `}}`), nil
+}
+
+func TestEnsureBus_RemoteBusAlreadyConnectedIsFailedPrecondition(t *testing.T) {
+	conn, err := EnsureBus(context.Background(), failDialTransport{},
+		"cli_guard_test", "", "", remoteBusyAPIClient{count: 2}, io.Discard)
+	if conn != nil {
+		t.Fatal("expected nil conn when a remote bus is already connected")
+	}
+	if err == nil {
+		t.Fatal("expected single-bus guard error")
+	}
+	var ve *errs.ValidationError
+	if !errors.As(err, &ve) {
+		t.Fatalf("expected *errs.ValidationError, got %T: %v", err, err)
+	}
+	if ve.Subtype != errs.SubtypeFailedPrecondition {
+		t.Errorf("subtype = %s, want %s", ve.Subtype, errs.SubtypeFailedPrecondition)
+	}
+	if !strings.Contains(ve.Hint, "event stop") {
+		t.Errorf("hint should point at `event stop`, got: %q", ve.Hint)
+	}
+}
+
+func TestRun_UnknownEventKeyIsTypedValidation(t *testing.T) {
+	err := Run(context.Background(), failDialTransport{}, "cli_x", "", "", Options{
+		EventKey: "bogus.run.key",
+		ErrOut:   io.Discard,
+	})
+	if err == nil {
+		t.Fatal("expected unknown EventKey error")
+	}
+	var ve *errs.ValidationError
+	if !errors.As(err, &ve) {
+		t.Fatalf("expected *errs.ValidationError, got %T: %v", err, err)
+	}
+	if ve.Subtype != errs.SubtypeInvalidArgument {
+		t.Errorf("subtype = %s, want %s", ve.Subtype, errs.SubtypeInvalidArgument)
+	}
+	if !strings.Contains(ve.Hint, "event list") {
+		t.Errorf("hint should point at `event list`, got: %q", ve.Hint)
+	}
+}
+
+func TestRun_InvalidJQFailsBeforeAnySideEffect(t *testing.T) {
+	event.RegisterKey(event.KeyDefinition{
+		Key:       "consume.runtest.jq",
+		EventType: "consume.runtest.jq_v1",
+		Schema:    event.SchemaDef{Custom: &event.SchemaSpec{Raw: json.RawMessage(`{}`)}},
+	})
+	err := Run(context.Background(), failDialTransport{}, "cli_x", "", "", Options{
+		EventKey: "consume.runtest.jq",
+		JQExpr:   "[invalid{{{",
+		ErrOut:   io.Discard,
+	})
+	if err == nil {
+		t.Fatal("expected jq validation error")
+	}
+	var ve *errs.ValidationError
+	if !errors.As(err, &ve) {
+		t.Fatalf("expected *errs.ValidationError, got %T: %v", err, err)
+	}
+	if ve.Param != "--jq" {
+		t.Errorf("param = %q, want %q", ve.Param, "--jq")
+	}
+}

internal/event/consume/validate_params_test.go

@@ -0,0 +1,64 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package consume
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/larksuite/cli/errs"
+	"github.com/larksuite/cli/internal/event"
+)
+
+func requireParamValidationError(t *testing.T, err error) {
+	t.Helper()
+	if err == nil {
+		t.Fatal("expected validation error, got nil")
+	}
+	var ve *errs.ValidationError
+	if !errors.As(err, &ve) {
+		t.Fatalf("expected *errs.ValidationError, got %T: %v", err, err)
+	}
+	if ve.Subtype != errs.SubtypeInvalidArgument || ve.Param != "--param" {
+		t.Errorf("subtype/param = %s/%q, want %s/%q", ve.Subtype, ve.Param, errs.SubtypeInvalidArgument, "--param")
+	}
+	if ve.Hint == "" {
+		t.Error("param validation error should hint at `lark-cli event schema`")
+	}
+}
+
+func TestValidateParams_RequiredMissing(t *testing.T) {
+	def := &event.KeyDefinition{
+		Key:    "x.test",
+		Params: []event.ParamDef{{Name: "chat_id", Required: true}},
+	}
+	requireParamValidationError(t, validateParams(def, map[string]string{}))
+}
+
+func TestValidateParams_UnknownParam(t *testing.T) {
+	def := &event.KeyDefinition{
+		Key:    "x.test",
+		Params: []event.ParamDef{{Name: "chat_id"}},
+	}
+	requireParamValidationError(t, validateParams(def, map[string]string{"nope": "1"}))
+}
+
+func TestValidateParams_UnknownParamNoParamsAccepted(t *testing.T) {
+	def := &event.KeyDefinition{Key: "x.test"}
+	requireParamValidationError(t, validateParams(def, map[string]string{"nope": "1"}))
+}
+
+func TestValidateParams_DefaultAppliedAndValidPasses(t *testing.T) {
+	def := &event.KeyDefinition{
+		Key:    "x.test",
+		Params: []event.ParamDef{{Name: "mode", Required: true, Default: "all"}},
+	}
+	params := map[string]string{}
+	if err := validateParams(def, params); err != nil {
+		t.Fatalf("default should satisfy required param, got: %v", err)
+	}
+	if params["mode"] != "all" {
+		t.Errorf("default not applied, params=%v", params)
+	}
+}

internal/output/errors.go

@@ -170,6 +170,28 @@ func ErrBare(code int) *ExitError {
 	return &ExitError{Code: code}
 }
 
+// PartialFailureError is the exit signal for a batch / multi-status command that
+// has already written an ok:false result envelope to stdout. The per-item
+// outcomes are the primary, machine-readable output and live on stdout, so the
+// dispatcher sets only the exit code and writes nothing to stderr.
+//
+// It is deliberately distinct from ErrBare (the predicate silent-exit signal)
+// so the predicate contract stays narrow, and from a typed *errs.XxxError
+// (which owns the stderr error envelope): a partial failure is a result, not an
+// error envelope.
+type PartialFailureError struct {
+	Code int
+}
+
+func (e *PartialFailureError) Error() string {
+	return fmt.Sprintf("partial failure (exit %d)", e.Code)
+}
+
+// PartialFailure builds the partial-failure exit signal with the given code.
+func PartialFailure(code int) *PartialFailureError {
+	return &PartialFailureError{Code: code}
+}
+
 // WriteTypedErrorEnvelope writes the JSON error envelope for a typed error.
 // Each typed error owns its wire shape via its own struct tags: Problem fields
 // are promoted to the top level through embedding, and extension fields

internal/output/exitcode.go

@@ -61,6 +61,10 @@ func ExitCodeOf(err error) int {
 	if _, ok := errs.ProblemOf(err); ok {
 		return ExitCodeForCategory(errs.CategoryOf(err))
 	}
+	var pfErr *PartialFailureError
+	if errors.As(err, &pfErr) {
+		return pfErr.Code
+	}
 	var exitErr *ExitError
 	if errors.As(err, &exitErr) {
 		return exitErr.Code

internal/registry/registry_test.go

@@ -231,14 +231,9 @@ func TestLoadAutoApproveSet(t *testing.T) {
 		t.Fatal("expected non-empty auto-approve set")
 	}
 
-	// From scope_overrides.json allow list
-	if !aaSet["calendar:calendar.event:create"] {
-		t.Error("expected calendar:calendar.event:create in auto-approve set (from allow list)")
-	}
-
-	// Verify allow list entries are present
+	// From scope_priorities.json recommend=="true"
 	if !aaSet["sheets:spreadsheet:read"] {
-		t.Error("expected sheets:spreadsheet:read in auto-approve set (from allow list)")
+		t.Error("expected sheets:spreadsheet:read in auto-approve set (recommend=true in priorities)")
 	}
 
 	t.Logf("Auto-approve set has %d scopes", len(aaSet))
@@ -257,16 +252,10 @@ func TestLoadPlatformAutoApproveSet(t *testing.T) {
 
 func TestLoadOverrideAutoApproveAllow(t *testing.T) {
 	allowSet := LoadOverrideAutoApproveAllow()
-	if len(allowSet) == 0 {
-		t.Fatal("expected non-empty override allow set")
-	}
-
-	// Known entries from scope_overrides.json
-	if !allowSet["calendar:calendar.event:create"] {
-		t.Error("expected calendar:calendar.event:create in allow set")
-	}
-	if !allowSet["mail:event"] {
-		t.Error("expected mail:event in allow set")
+	// recommend.allow in scope_overrides.json is intentionally empty:
+	// no scopes are special-cased into the auto-approve set anymore.
+	if len(allowSet) != 0 {
+		t.Errorf("expected empty override allow set, got %d entries", len(allowSet))
 	}
 }
 
@@ -277,9 +266,9 @@ func TestLoadOverrideAutoApproveDeny(t *testing.T) {
 }
 
 func TestIsAutoApproveScope(t *testing.T) {
-	// Known auto-approve scope (in allow list)
-	if !IsAutoApproveScope("calendar:calendar.event:create") {
-		t.Error("expected calendar:calendar.event:create to be auto-approve")
+	// Known auto-approve scope (recommend=true in scope_priorities.json)
+	if !IsAutoApproveScope("sheets:spreadsheet:read") {
+		t.Error("expected sheets:spreadsheet:read to be auto-approve")
 	}
 
 	// Completely unknown scope
@@ -290,9 +279,8 @@ func TestIsAutoApproveScope(t *testing.T) {
 
 func TestFilterAutoApproveScopes(t *testing.T) {
 	scopes := []string{
-		"calendar:calendar.event:create", // auto-approve (in allow list)
-		"zzz:unknown:scope",              // not in auto-approve
-		"sheets:spreadsheet:read",        // auto-approve (in allow list)
+		"sheets:spreadsheet:read", // auto-approve (recommend=true in priorities)
+		"zzz:unknown:scope",       // not in auto-approve
 	}
 
 	result := FilterAutoApproveScopes(scopes)
@@ -300,10 +288,10 @@ func TestFilterAutoApproveScopes(t *testing.T) {
 		t.Fatal("expected at least 1 auto-approve scope in result")
 	}
 
-	// Check that calendar:calendar.event:create is included
+	// Check that sheets:spreadsheet:read is included
 	found := false
 	for _, s := range result {
-		if s == "calendar:calendar.event:create" {
+		if s == "sheets:spreadsheet:read" {
 			found = true
 		}
 		// Ensure unknown scopes are not included
@@ -312,7 +300,7 @@ func TestFilterAutoApproveScopes(t *testing.T) {
 		}
 	}
 	if !found {
-		t.Error("expected calendar:calendar.event:create in result")
+		t.Error("expected sheets:spreadsheet:read in result")
 	}
 }
 

internal/registry/remote.go

@@ -17,6 +17,7 @@ import (
 
 	"github.com/larksuite/cli/internal/build"
 	"github.com/larksuite/cli/internal/core"
+	"github.com/larksuite/cli/internal/transport"
 	"github.com/larksuite/cli/internal/validate"
 	"github.com/larksuite/cli/internal/vfs"
 )
@@ -178,7 +179,9 @@ func saveCachedMerged(data []byte, meta CacheMeta) error {
 // localVersion is sent as data_version query param for server-side version comparison.
 // Returns (data, reg, err). A nil reg means the version is unchanged (not modified).
 func fetchRemoteMerged(localVersion string) (data []byte, reg *MergedRegistry, err error) {
-	client := &http.Client{Timeout: fetchTimeout}
+	// Route through the shared proxy-plugin-aware transport so remote API
+	// definition fetches honor proxy plugin mode instead of bypassing it.
+	client := transport.NewHTTPClient(fetchTimeout)
 	req, err := http.NewRequest("GET", remoteMetaURL(localVersion), nil)
 	if err != nil {
 		return nil, nil, err

internal/registry/scope_overrides.json

@@ -12,25 +12,7 @@
     "vc:meeting.meetingevent:read": 75
   },
   "recommend": {
-    "allow": [
-      "calendar:calendar.event:create",
-      "calendar:calendar.event:delete",
-      "calendar:calendar.event:read",
-      "calendar:calendar.event:update",
-      "calendar:calendar.free_busy:read",
-      "calendar:calendar:create",
-      "calendar:calendar:delete",
-      "calendar:calendar:read",
-      "calendar:calendar:update",
-      "contact:user.basic_profile:readonly",
-      "mail:event",
-      "mail:user_mailbox.mail_contact:read",
-      "mail:user_mailbox.mail_contact:write",
-      "mail:user_mailbox.message.address:read",
-      "mail:user_mailbox.message.body:read",
-      "mail:user_mailbox.message.subject:read",
-      "mail:user_mailbox.message:readonly"
-    ],
+    "allow": [],
     "deny": [
       "im:chat",
       "im:message.send_as_user"

internal/selfupdate/updater.go

@@ -10,10 +10,13 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"io"
+	"net/http"
 	"os/exec"
 	"strings"
 	"time"
 
+	"github.com/larksuite/cli/internal/transport"
 	"github.com/larksuite/cli/internal/vfs"
 )
 
@@ -37,9 +40,15 @@ const (
 )
 
 const (
-	npmInstallTimeout   = 10 * time.Minute
-	skillsUpdateTimeout = 2 * time.Minute
-	verifyTimeout       = 10 * time.Second
+	npmInstallTimeout      = 10 * time.Minute
+	skillsUpdateTimeout    = 2 * time.Minute
+	skillsIndexMaxBodySize = 1 << 20
+	verifyTimeout          = 10 * time.Second
+)
+
+var (
+	skillsIndexFetchTimeout = 10 * time.Second
+	officialSkillsIndexURL  = "https://open.feishu.cn/.well-known/skills/index.json"
 )
 
 // DetectResult holds installation detection results.
@@ -83,6 +92,7 @@ func (r *NpmResult) CombinedOutput() string {
 type Updater struct {
 	DetectOverride           func() DetectResult
 	NpmInstallOverride       func(version string) *NpmResult
+	SkillsIndexFetchOverride func() *NpmResult
 	SkillsCommandOverride    func(args ...string) *NpmResult
 	VerifyOverride           func(expectedVersion string) error
 	RestoreAvailableOverride func() bool
@@ -153,6 +163,53 @@ func (u *Updater) RunNpmInstall(version string) *NpmResult {
 	return r
 }
 
+func (u *Updater) ListOfficialSkillsIndex() *NpmResult {
+	if u.SkillsIndexFetchOverride != nil {
+		return u.SkillsIndexFetchOverride()
+	}
+
+	r := &NpmResult{}
+	ctx, cancel := context.WithTimeout(context.Background(), skillsIndexFetchTimeout)
+	defer cancel()
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, officialSkillsIndexURL, nil)
+	if err != nil {
+		r.Err = err
+		return r
+	}
+
+	client := transport.NewHTTPClient(0)
+	client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
+		if req.URL.Scheme != "https" {
+			return fmt.Errorf("official skills index redirected to non-HTTPS URL: %s", req.URL.Redacted())
+		}
+		return nil
+	}
+	resp, err := client.Do(req)
+	if err != nil {
+		r.Err = err
+		return r
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode < http.StatusOK || resp.StatusCode >= http.StatusMultipleChoices {
+		r.Err = fmt.Errorf("official skills index returned HTTP %d", resp.StatusCode)
+		return r
+	}
+
+	limited := io.LimitReader(resp.Body, skillsIndexMaxBodySize+1)
+	if _, err := io.Copy(&r.Stdout, limited); err != nil {
+		r.Err = err
+		return r
+	}
+	if r.Stdout.Len() > skillsIndexMaxBodySize {
+		r.Stdout.Reset()
+		r.Err = fmt.Errorf("official skills index exceeds %d bytes", skillsIndexMaxBodySize)
+		return r
+	}
+	return r
+}
+
 func (u *Updater) ListOfficialSkills() *NpmResult {
 	r := u.runSkillsListOfficial("https://open.feishu.cn")
 	if r.Err != nil {
@@ -165,6 +222,10 @@ func (u *Updater) ListGlobalSkills() *NpmResult {
 	return u.runSkillsListGlobal()
 }
 
+func (u *Updater) ListGlobalSkillsJSON() *NpmResult {
+	return u.runSkillsCommand("-y", "skills", "ls", "-g", "--json")
+}
+
 func (u *Updater) InstallSkill(nameList []string) *NpmResult {
 	r := u.runSkillsInstall("https://open.feishu.cn", nameList)
 	if r.Err != nil {

internal/selfupdate/updater_test.go

@@ -4,12 +4,18 @@
 package selfupdate
 
 import (
+	"context"
+	"errors"
 	"fmt"
+	"net"
+	"net/http"
+	"net/http/httptest"
 	"os"
 	"path/filepath"
 	"runtime"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/larksuite/cli/internal/vfs"
 )
@@ -188,6 +194,13 @@ func TestSkillsCommandsUseExpectedArgs(t *testing.T) {
 			},
 			want: "-y skills ls -g",
 		},
+		{
+			name: "list global json",
+			run: func(u *Updater) *NpmResult {
+				return u.ListGlobalSkillsJSON()
+			},
+			want: "-y skills ls -g --json",
+		},
 		{
 			name: "install skill primary",
 			run: func(u *Updater) *NpmResult {
@@ -225,6 +238,113 @@ func TestSkillsCommandsUseExpectedArgs(t *testing.T) {
 	}
 }
 
+func TestListOfficialSkillsIndexSuccess(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprint(w, `{"skills":[{"name":"lark-calendar"}]}`)
+	}))
+	defer server.Close()
+
+	oldURL := officialSkillsIndexURL
+	officialSkillsIndexURL = server.URL
+	t.Cleanup(func() { officialSkillsIndexURL = oldURL })
+
+	result := New().ListOfficialSkillsIndex()
+	if result.Err != nil {
+		t.Fatalf("ListOfficialSkillsIndex() err = %v, want nil", result.Err)
+	}
+	if got := result.Stdout.String(); !strings.Contains(got, "lark-calendar") {
+		t.Fatalf("ListOfficialSkillsIndex() stdout = %q, want skill JSON", got)
+	}
+}
+
+func TestListOfficialSkillsIndexHTTPError(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.Error(w, "not found", http.StatusNotFound)
+	}))
+	defer server.Close()
+
+	oldURL := officialSkillsIndexURL
+	officialSkillsIndexURL = server.URL
+	t.Cleanup(func() { officialSkillsIndexURL = oldURL })
+
+	result := New().ListOfficialSkillsIndex()
+	if result.Err == nil || !strings.Contains(result.Err.Error(), "HTTP 404") {
+		t.Fatalf("ListOfficialSkillsIndex() err = %v, want HTTP 404", result.Err)
+	}
+}
+
+func TestListOfficialSkillsIndexBodyTooLarge(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprint(w, strings.Repeat("x", skillsIndexMaxBodySize+1))
+	}))
+	defer server.Close()
+
+	oldURL := officialSkillsIndexURL
+	officialSkillsIndexURL = server.URL
+	t.Cleanup(func() { officialSkillsIndexURL = oldURL })
+
+	result := New().ListOfficialSkillsIndex()
+	if result.Err == nil || !strings.Contains(result.Err.Error(), "exceeds") {
+		t.Fatalf("ListOfficialSkillsIndex() err = %v, want exceeds", result.Err)
+	}
+	if result.Stdout.Len() != 0 {
+		t.Fatalf("ListOfficialSkillsIndex() stdout len = %d, want 0", result.Stdout.Len())
+	}
+}
+
+func TestListOfficialSkillsIndexTimeout(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		time.Sleep(200 * time.Millisecond)
+		fmt.Fprint(w, `{"skills":[{"name":"lark-calendar"}]}`)
+	}))
+	defer server.Close()
+
+	oldURL := officialSkillsIndexURL
+	oldTimeout := skillsIndexFetchTimeout
+	officialSkillsIndexURL = server.URL
+	skillsIndexFetchTimeout = 50 * time.Millisecond
+	t.Cleanup(func() {
+		officialSkillsIndexURL = oldURL
+		skillsIndexFetchTimeout = oldTimeout
+	})
+
+	result := New().ListOfficialSkillsIndex()
+	var netErr net.Error
+	if result.Err == nil || (!errors.Is(result.Err, context.DeadlineExceeded) && !(errors.As(result.Err, &netErr) && netErr.Timeout())) {
+		t.Fatalf("ListOfficialSkillsIndex() err = %v, want timeout error", result.Err)
+	}
+}
+
+func TestListOfficialSkillsIndexRejectsNonHTTPSRedirect(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.Redirect(w, r, "http://example.com/skills.json", http.StatusFound)
+	}))
+	defer server.Close()
+
+	oldURL := officialSkillsIndexURL
+	officialSkillsIndexURL = server.URL
+	t.Cleanup(func() { officialSkillsIndexURL = oldURL })
+
+	result := New().ListOfficialSkillsIndex()
+	if result.Err == nil || !strings.Contains(result.Err.Error(), "non-HTTPS") {
+		t.Fatalf("ListOfficialSkillsIndex() err = %v, want non-HTTPS redirect", result.Err)
+	}
+}
+
+func TestListOfficialSkillsIndexUsesOverride(t *testing.T) {
+	result := (&Updater{SkillsIndexFetchOverride: func() *NpmResult {
+		r := &NpmResult{}
+		r.Stdout.WriteString(`{"skills":[{"name":"override-skill"}]}`)
+		return r
+	}}).ListOfficialSkillsIndex()
+	if result.Err != nil {
+		t.Fatalf("ListOfficialSkillsIndex() err = %v, want nil", result.Err)
+	}
+	if !strings.Contains(result.Stdout.String(), "override-skill") {
+		t.Fatalf("ListOfficialSkillsIndex() stdout = %q, want override result", result.Stdout.String())
+	}
+}
+
 func TestListOfficialSkillsFallsBack(t *testing.T) {
 	called := []string{}
 	updater := &Updater{

internal/skillcontent/reader.go

@@ -0,0 +1,209 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+// Package skillcontent reads embedded skill content from an injected fs.FS
+// rooted at the skill list (entries like "lark-calendar/SKILL.md").
+package skillcontent
+
+import (
+	"io/fs"
+	"path"
+	"sort"
+	"strings"
+
+	"github.com/larksuite/cli/errs"
+	"gopkg.in/yaml.v3"
+)
+
+type Reader struct {
+	fsys fs.FS
+}
+
+func New(fsys fs.FS) *Reader { return &Reader{fsys: fsys} }
+
+type SkillInfo struct {
+	Name        string         `json:"name"`
+	Description string         `json:"description"`
+	Version     string         `json:"version,omitempty"`
+	Metadata    map[string]any `json:"metadata,omitempty"`
+}
+
+// DirEntry.Path is skill-prefixed (e.g. "lark-doc/references/x.md") so it can be
+// fed straight back into `read`.
+type DirEntry struct {
+	Path  string `json:"path"`
+	IsDir bool   `json:"is_dir"`
+}
+
+func (r *Reader) List() ([]SkillInfo, error) {
+	entries, err := fs.ReadDir(r.fsys, ".")
+	if err != nil {
+		return nil, errs.NewInternalError(errs.SubtypeFileIO, "failed to read embedded skills: %v", err)
+	}
+	out := make([]SkillInfo, 0, len(entries))
+	for _, e := range entries {
+		if !e.IsDir() {
+			continue
+		}
+		// Skip dirs that aren't real skills (no SKILL.md).
+		if info, ok := r.skillInfo(e.Name()); ok {
+			out = append(out, info)
+		}
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].Name < out[j].Name })
+	return out, nil
+}
+
+func (r *Reader) skillInfo(name string) (SkillInfo, bool) {
+	data, err := fs.ReadFile(r.fsys, name+"/SKILL.md")
+	if err != nil {
+		return SkillInfo{}, false
+	}
+	desc, version, metadata := parseFrontmatter(data)
+	return SkillInfo{Name: name, Description: desc, Version: version, Metadata: metadata}, true
+}
+
+// ListPath lists one directory layer (no recursion) under "<name>" or
+// "<name>/<sub>", returning the entries and the cleaned path listed.
+func (r *Reader) ListPath(arg string) ([]DirEntry, string, error) {
+	name, sub := SplitArg(arg)
+	if err := r.ensureSkill(name); err != nil {
+		return nil, "", err
+	}
+	dir := name
+	if sub != "" {
+		cleaned, err := cleanSubPath(sub)
+		if err != nil {
+			return nil, "", err
+		}
+		dir = name + "/" + cleaned
+		info, err := fs.Stat(r.fsys, dir)
+		if err != nil {
+			return nil, "", errs.NewValidationError(errs.SubtypeInvalidArgument,
+				"path %q not found in skill %q", sub, name).
+				WithHint("run 'lark-cli skills list " + name + "' to see files in this skill")
+		}
+		if !info.IsDir() {
+			return nil, "", errs.NewValidationError(errs.SubtypeInvalidArgument,
+				"path %q is a file, not a directory; use 'lark-cli skills read %s/%s' to read it", sub, name, cleaned)
+		}
+	}
+	entries, err := fs.ReadDir(r.fsys, dir)
+	if err != nil {
+		return nil, "", errs.NewInternalError(errs.SubtypeFileIO,
+			"failed to read embedded skill content: %v", err)
+	}
+	out := make([]DirEntry, 0, len(entries))
+	for _, e := range entries {
+		out = append(out, DirEntry{Path: dir + "/" + e.Name(), IsDir: e.IsDir()})
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].Path < out[j].Path })
+	return out, dir, nil
+}
+
+// SplitArg splits "<name>/<rest>" at the first separator; an argument with no
+// separator is a bare skill name (rest "").
+func SplitArg(arg string) (name, rest string) {
+	name, rest, _ = strings.Cut(arg, "/")
+	return name, rest
+}
+
+// parseFrontmatter best-effort-extracts the frontmatter fields; missing or
+// unparseable frontmatter yields ("", "", nil), never an error.
+func parseFrontmatter(skillMD []byte) (description, version string, metadata map[string]any) {
+	lines := strings.Split(string(skillMD), "\n")
+	if strings.TrimRight(lines[0], "\r") != "---" {
+		return "", "", nil
+	}
+	block := make([]string, 0, len(lines))
+	closed := false
+	for _, ln := range lines[1:] {
+		if strings.TrimRight(ln, "\r") == "---" {
+			closed = true
+			break
+		}
+		block = append(block, ln)
+	}
+	if !closed {
+		return "", "", nil
+	}
+	var fm struct {
+		Description string         `yaml:"description"`
+		Version     string         `yaml:"version"`
+		Metadata    map[string]any `yaml:"metadata"`
+	}
+	if err := yaml.Unmarshal([]byte(strings.Join(block, "\n")), &fm); err != nil {
+		return "", "", nil
+	}
+	return fm.Description, fm.Version, fm.Metadata
+}
+
+func (r *Reader) ReadSkill(name string) ([]byte, error) {
+	if err := r.ensureSkill(name); err != nil {
+		return nil, err
+	}
+	data, err := fs.ReadFile(r.fsys, name+"/SKILL.md")
+	if err != nil {
+		return nil, errs.NewInternalError(errs.SubtypeFileIO,
+			"failed to read embedded skill content: %v", err)
+	}
+	return data, nil
+}
+
+func (r *Reader) ensureSkill(name string) error {
+	if name == "" || strings.ContainsAny(name, `/\`) || name == "." || name == ".." {
+		return unknownSkill(name)
+	}
+	info, err := fs.Stat(r.fsys, name)
+	if err != nil || !info.IsDir() {
+		return unknownSkill(name)
+	}
+	return nil
+}
+
+func unknownSkill(name string) error {
+	return errs.NewValidationError(errs.SubtypeInvalidArgument, "unknown skill %q", name).
+		WithHint("run 'lark-cli skills list' to see available skills")
+}
+
+// cleanSubPath returns the cleaned form of relpath, rejecting absolute paths and
+// ".." escapes. relpath must be non-empty (callers handle the skill-root case).
+func cleanSubPath(relpath string) (string, error) {
+	cleaned := path.Clean(relpath)
+	// path.Clean only treats '/' as a separator, so a Windows-style "..\" prefix
+	// survives; reject it explicitly alongside "../".
+	if relpath == "" || path.IsAbs(relpath) || cleaned == "." ||
+		cleaned == ".." || strings.HasPrefix(cleaned, "../") || strings.HasPrefix(cleaned, `..\`) {
+		return "", errs.NewValidationError(errs.SubtypeInvalidArgument,
+			"invalid path %q: must be a relative path without '..'", relpath)
+	}
+	return cleaned, nil
+}
+
+// ReadReference returns the bytes of <name>/<relpath> and the cleaned path.
+func (r *Reader) ReadReference(name, relpath string) ([]byte, string, error) {
+	if err := r.ensureSkill(name); err != nil {
+		return nil, "", err
+	}
+	cleaned, err := cleanSubPath(relpath)
+	if err != nil {
+		return nil, "", err
+	}
+	full := name + "/" + cleaned
+	info, err := fs.Stat(r.fsys, full)
+	if err != nil {
+		return nil, "", errs.NewValidationError(errs.SubtypeInvalidArgument,
+			"reference %q not found in skill %q", relpath, name).
+			WithHint("run 'lark-cli skills list " + name + "' to see files in this skill")
+	}
+	if info.IsDir() {
+		return nil, "", errs.NewValidationError(errs.SubtypeInvalidArgument,
+			"reference %q is a directory, not a file", relpath)
+	}
+	data, err := fs.ReadFile(r.fsys, full)
+	if err != nil {
+		return nil, "", errs.NewInternalError(errs.SubtypeFileIO,
+			"failed to read embedded skill content: %v", err)
+	}
+	return data, cleaned, nil
+}

internal/skillcontent/reader_test.go

@@ -0,0 +1,290 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package skillcontent
+
+import (
+	"errors"
+	"strings"
+	"testing"
+	"testing/fstest"
+
+	"github.com/larksuite/cli/errs"
+)
+
+func testFS() fstest.MapFS {
+	return fstest.MapFS{
+		"lark-calendar/SKILL.md":             {Data: []byte("---\nname: lark-calendar\nversion: 1.0.0\ndescription: \"Calendar skill\"\nmetadata:\n  requires:\n    bins: [\"lark-cli\"]\n  cliHelp: \"lark-cli calendar --help\"\n---\nbody\n")},
+		"lark-calendar/references/agenda.md": {Data: []byte("# Agenda")},
+		"lark-calendar/references/create.md": {Data: []byte("# Create")},
+		"lark-calendar/assets/tpl.html":      {Data: []byte("<html></html>")},
+		"lark-im/SKILL.md":                   {Data: []byte("no frontmatter here\n")},
+		"lark-im/references/send.md":         {Data: []byte("# Send")},
+	}
+}
+
+func TestList(t *testing.T) {
+	r := New(testFS())
+	skills, err := r.List()
+	if err != nil {
+		t.Fatalf("List() error: %v", err)
+	}
+	if len(skills) != 2 {
+		t.Fatalf("got %d skills, want 2", len(skills))
+	}
+	if skills[0].Name != "lark-calendar" || skills[1].Name != "lark-im" {
+		t.Fatalf("skills not sorted by name: %v", skills)
+	}
+	if skills[0].Description != "Calendar skill" {
+		t.Errorf("description: got %q, want %q", skills[0].Description, "Calendar skill")
+	}
+	// version is the frontmatter `version:` field, passed through for drift checks.
+	if skills[0].Version != "1.0.0" {
+		t.Errorf("version: got %q, want %q", skills[0].Version, "1.0.0")
+	}
+	// metadata is the frontmatter `metadata:` block, passed through verbatim.
+	if skills[0].Metadata == nil {
+		t.Fatal("expected metadata for lark-calendar")
+	}
+	if skills[0].Metadata["cliHelp"] != "lark-cli calendar --help" {
+		t.Errorf("metadata.cliHelp: got %v", skills[0].Metadata["cliHelp"])
+	}
+	// No frontmatter → empty description and nil metadata (omitted from JSON).
+	if skills[1].Description != "" {
+		t.Errorf("lark-im description: got %q, want empty", skills[1].Description)
+	}
+	if skills[1].Metadata != nil {
+		t.Errorf("lark-im metadata: got %v, want nil", skills[1].Metadata)
+	}
+	if skills[1].Version != "" {
+		t.Errorf("lark-im version: got %q, want empty", skills[1].Version)
+	}
+}
+
+func TestListPath(t *testing.T) {
+	r := New(testFS())
+
+	// Skill root: direct children only (one layer), each path skill-prefixed.
+	entries, listed, err := r.ListPath("lark-calendar")
+	if err != nil {
+		t.Fatalf("ListPath root error: %v", err)
+	}
+	if listed != "lark-calendar" {
+		t.Errorf("listed path: got %q", listed)
+	}
+	want := map[string]bool{ // path → isDir
+		"lark-calendar/SKILL.md":   false,
+		"lark-calendar/references": true,
+		"lark-calendar/assets":     true,
+	}
+	if len(entries) != len(want) {
+		t.Fatalf("root entries: got %v, want %d entries", entries, len(want))
+	}
+	for _, e := range entries {
+		isDir, ok := want[e.Path]
+		if !ok {
+			t.Errorf("unexpected entry %q", e.Path)
+			continue
+		}
+		if e.IsDir != isDir {
+			t.Errorf("%q is_dir: got %v, want %v", e.Path, e.IsDir, isDir)
+		}
+	}
+	// Entries are sorted by path.
+	if entries[0].Path != "lark-calendar/SKILL.md" {
+		t.Errorf("entries not sorted: %v", entries)
+	}
+
+	// Subdirectory: one layer under <name>/<subpath>.
+	subEntries, subListed, err := r.ListPath("lark-calendar/references")
+	if err != nil {
+		t.Fatalf("ListPath subdir error: %v", err)
+	}
+	if subListed != "lark-calendar/references" {
+		t.Errorf("listed subpath: got %q", subListed)
+	}
+	if len(subEntries) != 2 ||
+		subEntries[0].Path != "lark-calendar/references/agenda.md" ||
+		subEntries[1].Path != "lark-calendar/references/create.md" {
+		t.Errorf("subdir entries: got %v", subEntries)
+	}
+
+	// Unknown skill → typed validation error.
+	if _, _, err := r.ListPath("no-such-skill"); err == nil {
+		t.Error("expected error for unknown skill")
+	} else {
+		var verr *errs.ValidationError
+		if !errors.As(err, &verr) {
+			t.Errorf("expected *errs.ValidationError, got %T", err)
+		}
+	}
+
+	// Path that points at a file (not a dir) → validation error.
+	if _, _, err := r.ListPath("lark-calendar/SKILL.md"); err == nil {
+		t.Error("expected error listing a file")
+	} else if !strings.Contains(err.Error(), "is a file") {
+		t.Errorf("message: got %q", err.Error())
+	}
+
+	// Nonexistent subpath → validation error.
+	if _, _, err := r.ListPath("lark-calendar/nope"); err == nil {
+		t.Error("expected not-found error")
+	} else if !strings.Contains(err.Error(), "not found") {
+		t.Errorf("message: got %q", err.Error())
+	}
+
+	// Traversal in the subpath is rejected, no listing leaked.
+	for _, bad := range []string{"lark-calendar/../lark-im", "lark-calendar/../../etc", `lark-calendar/..\x`} {
+		entries, _, err := r.ListPath(bad)
+		if err == nil {
+			t.Errorf("expected rejection for %q", bad)
+		}
+		if entries != nil {
+			t.Errorf("entries leaked for %q: %v", bad, entries)
+		}
+	}
+}
+
+func TestReadSkill(t *testing.T) {
+	r := New(testFS())
+
+	data, err := r.ReadSkill("lark-calendar")
+	if err != nil {
+		t.Fatalf("ReadSkill error: %v", err)
+	}
+	if !strings.HasPrefix(string(data), "---\nname: lark-calendar") {
+		t.Errorf("unexpected content: %q", string(data))
+	}
+
+	_, err = r.ReadSkill("no-such-skill")
+	if err == nil {
+		t.Fatal("expected error for unknown skill")
+	}
+	var verr *errs.ValidationError
+	if !errors.As(err, &verr) {
+		t.Fatalf("expected *errs.ValidationError, got %T", err)
+	}
+	if !strings.Contains(verr.Message, `unknown skill "no-such-skill"`) {
+		t.Errorf("message: got %q", verr.Message)
+	}
+
+	if _, err := r.ReadSkill("../etc"); err == nil {
+		t.Error("expected error for name with separator")
+	}
+}
+
+func TestReadReference(t *testing.T) {
+	r := New(testFS())
+
+	data, cleaned, err := r.ReadReference("lark-calendar", "references/agenda.md")
+	if err != nil {
+		t.Fatalf("ReadReference error: %v", err)
+	}
+	if string(data) != "# Agenda" {
+		t.Errorf("content: got %q", string(data))
+	}
+	if cleaned != "references/agenda.md" {
+		t.Errorf("cleaned path: got %q", cleaned)
+	}
+
+	if _, _, err := r.ReadReference("lark-calendar", "references/nope.md"); err == nil {
+		t.Error("expected not-found error")
+	} else if !strings.Contains(err.Error(), "not found") {
+		t.Errorf("message: got %q", err.Error())
+	}
+
+	if _, _, err := r.ReadReference("lark-calendar", "references"); err == nil {
+		t.Error("expected directory error")
+	} else if !strings.Contains(err.Error(), "is a directory") {
+		t.Errorf("message: got %q", err.Error())
+	}
+
+	for _, bad := range []string{"../../etc/passwd", "/etc/passwd", "..", "", "references/../../im/SKILL.md", `..\..\x`} {
+		data, _, err := r.ReadReference("lark-calendar", bad)
+		if err == nil {
+			t.Errorf("expected rejection for %q", bad)
+		}
+		if data != nil {
+			t.Errorf("content leaked for %q: %q", bad, string(data))
+		}
+		var verr *errs.ValidationError
+		if !errors.As(err, &verr) {
+			t.Errorf("expected validation error for %q, got %T", bad, err)
+		}
+	}
+}
+
+func TestParseFrontmatter(t *testing.T) {
+	cases := []struct {
+		name        string
+		input       string
+		wantDesc    string
+		wantVer     string
+		wantHasMeta bool
+	}{
+		{
+			name:        "description, version and metadata",
+			input:       "---\ndescription: My skill\nversion: 2.1.0\nmetadata:\n  cliHelp: \"x\"\n---\nbody\n",
+			wantDesc:    "My skill",
+			wantVer:     "2.1.0",
+			wantHasMeta: true,
+		},
+		{
+			name:     "description only, no metadata",
+			input:    "---\ndescription: Plain\n---\nbody\n",
+			wantDesc: "Plain",
+		},
+		{
+			name:  "no frontmatter",
+			input: "no frontmatter here\n",
+		},
+		{
+			name:  "unclosed frontmatter",
+			input: "---\ndescription: Never closed\n",
+		},
+		{
+			name:  "malformed YAML inside frontmatter",
+			input: "---\n: bad: yaml: [\n---\nbody\n",
+		},
+		{
+			name:        "CRLF line endings",
+			input:       "---\r\ndescription: CRLF skill\r\nmetadata:\r\n  cliHelp: \"y\"\r\n---\r\nbody\r\n",
+			wantDesc:    "CRLF skill",
+			wantHasMeta: true,
+		},
+		{
+			name:  "empty input",
+			input: "",
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			desc, ver, meta := parseFrontmatter([]byte(tc.input))
+			if desc != tc.wantDesc {
+				t.Errorf("description = %q, want %q", desc, tc.wantDesc)
+			}
+			if ver != tc.wantVer {
+				t.Errorf("version = %q, want %q", ver, tc.wantVer)
+			}
+			if (meta != nil) != tc.wantHasMeta {
+				t.Errorf("metadata = %v, wantHasMeta %v", meta, tc.wantHasMeta)
+			}
+		})
+	}
+}
+
+func TestReadSkillMissingFile(t *testing.T) {
+	// Use a separate MapFS so testFS() (and TestList) are unaffected.
+	emptyFS := fstest.MapFS{
+		"lark-empty/references/x.md": {Data: []byte("# X")},
+	}
+	r := New(emptyFS)
+	_, err := r.ReadSkill("lark-empty")
+	if err == nil {
+		t.Fatal("expected error when SKILL.md is absent")
+	}
+	var ierr *errs.InternalError
+	if !errors.As(err, &ierr) {
+		t.Fatalf("expected *errs.InternalError, got %T: %v", err, err)
+	}
+}

internal/skillscheck/sync.go

@@ -4,6 +4,7 @@
 package skillscheck
 
 import (
+	"encoding/json"
 	"fmt"
 	"regexp"
 	"sort"
@@ -57,6 +58,52 @@ func ParseSkillsList(text string) []string {
 	return nil
 }
 
+func ParseGlobalSkillsJSON(text string) []string {
+	type globalSkill struct {
+		Name string `json:"name"`
+	}
+
+	var skills []globalSkill
+	if err := json.Unmarshal([]byte(text), &skills); err != nil {
+		return nil
+	}
+
+	seen := map[string]bool{}
+	for _, skill := range skills {
+		candidate := strings.TrimSpace(skill.Name)
+		if candidate == "" || !skillNamePattern.MatchString(candidate) {
+			continue
+		}
+		seen[candidate] = true
+	}
+
+	return sortedKeys(seen)
+}
+
+func ParseOfficialSkillsIndexJSON(text string) ([]string, error) {
+	type officialSkill struct {
+		Name string `json:"name"`
+	}
+	type officialIndex struct {
+		Skills []officialSkill `json:"skills"`
+	}
+
+	var index officialIndex
+	if err := json.Unmarshal([]byte(text), &index); err != nil {
+		return nil, err
+	}
+
+	seen := map[string]bool{}
+	for _, skill := range index.Skills {
+		candidate := strings.TrimSpace(skill.Name)
+		if skillNamePattern.MatchString(candidate) {
+			seen[candidate] = true
+		}
+	}
+
+	return sortedKeys(seen), nil
+}
+
 // parseGlobalSkillsList parses the output of "npx -y skills ls -g"
 func parseGlobalSkillsList(lines []string) []string {
 	seen := map[string]bool{}
@@ -77,8 +124,11 @@ func parseGlobalSkillsList(lines []string) []string {
 			continue
 		}
 
-		// Skip indented lines (Agents: ...)
-		if strings.HasPrefix(line, "  ") || strings.HasPrefix(line, "\t") {
+		if strings.HasPrefix(trimmed, "Agents:") {
+			continue
+		}
+
+		if isGlobalSkillsSectionHeader(trimmed) {
 			continue
 		}
 
@@ -91,21 +141,24 @@ func parseGlobalSkillsList(lines []string) []string {
 		candidate := parts[0]
 
 		// Validate and add
-		if candidate == "" || strings.Contains(candidate, " ") || strings.HasSuffix(candidate, ":") {
+		if candidate == "" || !skillNamePattern.MatchString(candidate) {
 			continue
 		}
-		if !skillNamePattern.MatchString(candidate) {
-			continue
-		}
-		if at := strings.Index(candidate, "@"); at > 0 {
-			candidate = candidate[:at]
-		}
 		seen[candidate] = true
 	}
 
 	return sortedKeys(seen)
 }
 
+func isGlobalSkillsSectionHeader(line string) bool {
+	switch line {
+	case "General", "Project", "Local":
+		return true
+	default:
+		return false
+	}
+}
+
 // parseOfficialSkillsList parses the output of "npx -y skills add ... --list"
 func parseOfficialSkillsList(lines []string) []string {
 	seen := map[string]bool{}
@@ -131,8 +184,7 @@ func parseOfficialSkillsList(lines []string) []string {
 
 			if len(parts) > 0 {
 				candidate := parts[0]
-				// Check if it's a valid official skill name
-				if strings.HasPrefix(candidate, "lark-") && skillNamePattern.MatchString(candidate) {
+				if skillNamePattern.MatchString(candidate) {
 					seen[candidate] = true
 				}
 			}
@@ -194,7 +246,9 @@ func PlanSync(input SyncInput) SyncPlan {
 }
 
 type SkillsRunner interface {
+	ListOfficialSkillsIndex() *selfupdate.NpmResult
 	ListOfficialSkills() *selfupdate.NpmResult
+	ListGlobalSkillsJSON() *selfupdate.NpmResult
 	ListGlobalSkills() *selfupdate.NpmResult
 	InstallSkill(nameList []string) *selfupdate.NpmResult
 	InstallAllSkills() *selfupdate.NpmResult
@@ -228,21 +282,15 @@ func SyncSkills(opts SyncOptions) *SyncResult {
 	}
 
 	// --- Step 1: List official skills ---
-	officialResult := opts.Runner.ListOfficialSkills()
-	if officialResult == nil || officialResult.Err != nil {
-		return fallbackFullInstall(opts, resultDetail(officialResult), nil)
-	}
-	official := ParseSkillsList(officialResult.Stdout.String())
-
-	if len(official) == 0 && strings.TrimSpace(officialResult.Stdout.String()) != "" {
-		return fallbackFullInstall(opts, "official skills list parsed as empty despite non-empty stdout", nil)
+	official, reason, ok := listOfficialSkills(opts.Runner)
+	if !ok {
+		return fallbackFullInstall(opts, reason, nil)
 	}
 
 	// --- Step 2: List local (installed) skills ---
-	local := []string{}
-	localResult := opts.Runner.ListGlobalSkills()
-	if localResult != nil && localResult.Err == nil {
-		local = ParseSkillsList(localResult.Stdout.String())
+	local, ok := listLocalSkills(opts.Runner)
+	if !ok {
+		return fallbackFullInstall(opts, "local skills list failed or parsed as empty", official)
 	}
 
 	// --- Step 3: Read previous state ---
@@ -270,6 +318,10 @@ func SyncSkills(opts SyncOptions) *SyncResult {
 		Force:          opts.Force,
 	}
 
+	if len(plan.ToUpdate) == 0 {
+		return fallbackFullInstall(opts, "toUpdate skills empty fallback", official)
+	}
+
 	if len(plan.ToUpdate) > 0 {
 		installResult := opts.Runner.InstallSkill(plan.ToUpdate)
 		if installResult == nil || installResult.Err != nil {
@@ -294,6 +346,58 @@ func SyncSkills(opts SyncOptions) *SyncResult {
 	return result
 }
 
+func listOfficialSkills(runner SkillsRunner) ([]string, string, bool) {
+	reasons := []string{}
+
+	indexResult := runner.ListOfficialSkillsIndex()
+	if indexResult == nil || indexResult.Err != nil {
+		reasons = append(reasons, "official skills index failed: "+resultDetail(indexResult))
+	} else {
+		official, err := ParseOfficialSkillsIndexJSON(indexResult.Stdout.String())
+		if err != nil {
+			reasons = append(reasons, "official skills index JSON invalid: "+err.Error())
+		} else if len(official) > 0 {
+			return official, "", true
+		} else {
+			reasons = append(reasons, "official skills index contains no skills")
+		}
+	}
+
+	officialResult := runner.ListOfficialSkills()
+	if officialResult == nil || officialResult.Err != nil {
+		reasons = append(reasons, "official skills list failed: "+resultDetail(officialResult))
+		return nil, strings.Join(reasons, "; "), false
+	}
+	official := ParseSkillsList(officialResult.Stdout.String())
+	if len(official) > 0 {
+		return official, "", true
+	}
+	if strings.TrimSpace(officialResult.Stdout.String()) != "" {
+		reasons = append(reasons, "official skills list parsed as empty despite non-empty stdout")
+	} else {
+		reasons = append(reasons, "official skills list returned no skills")
+	}
+	return nil, strings.Join(reasons, "; "), false
+}
+
+func listLocalSkills(runner SkillsRunner) ([]string, bool) {
+	jsonResult := runner.ListGlobalSkillsJSON()
+	if jsonResult != nil && jsonResult.Err == nil {
+		if local := ParseGlobalSkillsJSON(jsonResult.Stdout.String()); len(local) > 0 {
+			return local, true
+		}
+	}
+
+	textResult := runner.ListGlobalSkills()
+	if textResult != nil && textResult.Err == nil {
+		if local := ParseSkillsList(textResult.Stdout.String()); len(local) > 0 {
+			return local, true
+		}
+	}
+
+	return nil, false
+}
+
 // fallbackFullInstall performs a full skills install (npx -y skills add <source> -g -y)
 // when incremental sync is not possible. On success it writes a state file so that
 // subsequent syncs can use incremental mode. When official is non-nil the state

internal/skillscheck/sync_test.go

@@ -30,6 +30,19 @@ lark-cli-harness:dev@0.1.0
 	}
 }
 
+func TestParseOfficialSkillsListAcceptsNonLarkOfficialNames(t *testing.T) {
+	input := `Available Skills
+│    lark-calendar
+│    official-shared
+│    bad/name
+`
+	got := ParseSkillsList(input)
+	want := []string{"lark-calendar", "official-shared"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("ParseSkillsList() (Available Skills) = %#v, want %#v", got, want)
+	}
+}
+
 func TestParseGlobalSkillsList(t *testing.T) {
 	input := `Global Skills
 
@@ -67,6 +80,86 @@ func TestParseGlobalSkillsListWithANSI(t *testing.T) {
 	}
 }
 
+func TestParseGlobalSkillsListWithIndentedGroupedRows(t *testing.T) {
+	input := `Global Skills
+
+General
+  lark-apps ~/.agents/skills/lark-apps
+  lark-base ~/.agents/skills/lark-base
+`
+	got := ParseSkillsList(input)
+	want := []string{"lark-apps", "lark-base"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("ParseSkillsList() (indented Global Skills) = %#v, want %#v", got, want)
+	}
+}
+
+func TestParseGlobalSkillsJSON(t *testing.T) {
+	input := `[
+  {"name":"lark-calendar","path":"/Users/example/.agents/skills/lark-calendar","scope":"global","agents":["Codex"]},
+  {"name":"lark-mail@1.2.3","path":"/Users/example/.agents/skills/lark-mail","scope":"global","agents":["Codex"]},
+  {"name":"lark-calendar","path":"/Users/example/.agents/skills/lark-calendar","scope":"global","agents":["Codex"]},
+  {"name":"  lark-base  ","path":"/Users/example/.agents/skills/lark-base","scope":"global","agents":["Codex"]},
+  {"name":""},
+  {"name":"   "},
+  {"name":"bad skill"}
+]`
+	got := ParseGlobalSkillsJSON(input)
+	want := []string{"lark-base", "lark-calendar", "lark-mail@1.2.3"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("ParseGlobalSkillsJSON() = %#v, want %#v", got, want)
+	}
+}
+
+func TestParseGlobalSkillsJSONInvalidOrUnsupported(t *testing.T) {
+	for _, input := range []string{
+		`not json`,
+		`{"name":"lark-calendar"}`,
+		`[]`,
+	} {
+		if got := ParseGlobalSkillsJSON(input); len(got) != 0 {
+			t.Fatalf("ParseGlobalSkillsJSON(%q) = %#v, want empty", input, got)
+		}
+	}
+}
+
+func TestParseOfficialSkillsIndexJSON(t *testing.T) {
+	input := `{
+  "skills": [
+    {"name":"lark-calendar","description":"Calendar","files":["SKILL.md"]},
+    {"name":"lark-mail","description":"Mail","files":["SKILL.md","references/lark-mail-search.md"]},
+    {"name":"  lark-base  ","description":"Base","files":[]},
+    {"name":"lark-calendar","description":"duplicate","files":["SKILL.md"]},
+    {"name":"custom-skill","description":"not official","files":["SKILL.md"]},
+    {"name":"bad skill","description":"invalid","files":["SKILL.md"]},
+    {"name":"","description":"empty","files":["SKILL.md"]}
+  ]
+}`
+	got, err := ParseOfficialSkillsIndexJSON(input)
+	if err != nil {
+		t.Fatalf("ParseOfficialSkillsIndexJSON() err = %v, want nil", err)
+	}
+	want := []string{"custom-skill", "lark-base", "lark-calendar", "lark-mail"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("ParseOfficialSkillsIndexJSON() = %#v, want %#v", got, want)
+	}
+}
+
+func TestParseOfficialSkillsIndexJSONInvalidOrUnsupported(t *testing.T) {
+	for _, input := range []string{
+		`not json`,
+		`[{"name":"lark-calendar"}]`,
+		`{"name":"lark-calendar"}`,
+		`{"skills":[]}`,
+		`{"skills":[{"name":"bad skill"}]}`,
+	} {
+		got, err := ParseOfficialSkillsIndexJSON(input)
+		if err == nil && len(got) != 0 {
+			t.Fatalf("ParseOfficialSkillsIndexJSON(%q) = %#v, want empty", input, got)
+		}
+	}
+}
+
 func TestPlanNormal_WithReadableStatePreservesDeletedAndAddsNew(t *testing.T) {
 	previous := &SkillsState{OfficialSkills: []string{"lark-calendar", "lark-mail"}}
 	got := PlanSync(SyncInput{
@@ -113,14 +206,22 @@ func TestPlanForceRestoresAllOfficial(t *testing.T) {
 }
 
 type fakeSkillsRunner struct {
-	officialOut   string
-	globalOut     string
-	officialErr   error
-	globalErr     error
-	installErr    error
-	installAllErr error
-	installed     [][]string
-	installedAll  int
+	officialIndexOut string
+	officialOut      string
+	globalJSONOut    string
+	globalOut        string
+	officialIndexErr error
+	officialErr      error
+	globalJSONErr    error
+	globalErr        error
+	installErr       error
+	installAllErr    error
+	installed        [][]string
+	installedAll     int
+	listedIndex      int
+	listedOfficial   int
+	listedGlobalJSON int
+	listedGlobalText int
 }
 
 func officialSkillsOutput(names ...string) string {
@@ -134,6 +235,19 @@ func officialSkillsOutput(names ...string) string {
 	return b.String()
 }
 
+func officialSkillsIndexOutput(names ...string) string {
+	var b strings.Builder
+	b.WriteString(`{"skills":[`)
+	for i, name := range names {
+		if i > 0 {
+			b.WriteString(",")
+		}
+		fmt.Fprintf(&b, `{"name":%q,"description":"test skill","files":["SKILL.md"]}`, name)
+	}
+	b.WriteString(`]}`)
+	return b.String()
+}
+
 func globalSkillsOutput(names ...string) string {
 	var b strings.Builder
 	b.WriteString("Global Skills\n\n")
@@ -146,14 +260,45 @@ func globalSkillsOutput(names ...string) string {
 	return b.String()
 }
 
+func globalSkillsJSONOutput(names ...string) string {
+	var b strings.Builder
+	b.WriteString("[")
+	for i, name := range names {
+		if i > 0 {
+			b.WriteString(",")
+		}
+		fmt.Fprintf(&b, `{"name":%q,"path":"/Users/example/.agents/skills/%s","scope":"global","agents":["Codex"]}`, name, name)
+	}
+	b.WriteString("]")
+	return b.String()
+}
+
+func (f *fakeSkillsRunner) ListOfficialSkillsIndex() *selfupdate.NpmResult {
+	f.listedIndex++
+	r := &selfupdate.NpmResult{}
+	r.Stdout.WriteString(f.officialIndexOut)
+	r.Err = f.officialIndexErr
+	return r
+}
+
 func (f *fakeSkillsRunner) ListOfficialSkills() *selfupdate.NpmResult {
+	f.listedOfficial++
 	r := &selfupdate.NpmResult{}
 	r.Stdout.WriteString(f.officialOut)
 	r.Err = f.officialErr
 	return r
 }
 
+func (f *fakeSkillsRunner) ListGlobalSkillsJSON() *selfupdate.NpmResult {
+	f.listedGlobalJSON++
+	r := &selfupdate.NpmResult{}
+	r.Stdout.WriteString(f.globalJSONOut)
+	r.Err = f.globalJSONErr
+	return r
+}
+
 func (f *fakeSkillsRunner) ListGlobalSkills() *selfupdate.NpmResult {
+	f.listedGlobalText++
 	r := &selfupdate.NpmResult{}
 	r.Stdout.WriteString(f.globalOut)
 	r.Err = f.globalErr
@@ -186,8 +331,10 @@ func TestSyncSkills_WritesStateAndDoesNotWriteStamp(t *testing.T) {
 	}
 
 	runner := &fakeSkillsRunner{
-		officialOut: officialSkillsOutput("lark-calendar", "lark-mail", "lark-new"),
-		globalOut:   globalSkillsOutput("lark-calendar", "lark-custom"),
+		officialIndexOut: officialSkillsIndexOutput("lark-calendar", "lark-mail", "lark-new"),
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail", "lark-new"),
+		globalJSONOut:    globalSkillsJSONOutput("lark-calendar", "lark-custom"),
+		globalOut:        globalSkillsOutput("lark-mail"),
 	}
 	result := SyncSkills(SyncOptions{
 		Version: "1.0.33",
@@ -199,6 +346,12 @@ func TestSyncSkills_WritesStateAndDoesNotWriteStamp(t *testing.T) {
 		t.Fatalf("SyncSkills() err = %v, want nil", result.Err)
 	}
 	assertStrings(t, runner.installed[0], []string{"lark-calendar", "lark-new"})
+	if runner.listedGlobalJSON != 1 {
+		t.Fatalf("listedGlobalJSON = %d, want 1", runner.listedGlobalJSON)
+	}
+	if runner.listedGlobalText != 0 {
+		t.Fatalf("listedGlobalText = %d, want 0 when JSON list succeeds", runner.listedGlobalText)
+	}
 
 	state, readable, err := ReadState()
 	if err != nil || !readable {
@@ -213,12 +366,119 @@ func TestSyncSkills_WritesStateAndDoesNotWriteStamp(t *testing.T) {
 	}
 }
 
+func TestSyncSkills_OfficialIndexSuccessSkipsOfficialListCommand(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
+	runner := &fakeSkillsRunner{
+		officialIndexOut: officialSkillsIndexOutput("lark-calendar", "lark-mail", "lark-new"),
+		officialOut:      officialSkillsOutput("lark-should-not-be-used"),
+		globalJSONOut:    globalSkillsJSONOutput("lark-calendar"),
+		globalOut:        globalSkillsOutput("lark-mail"),
+	}
+
+	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
+	if result.Err != nil {
+		t.Fatalf("SyncSkills() err = %v, want nil", result.Err)
+	}
+	assertStrings(t, result.Official, []string{"lark-calendar", "lark-mail", "lark-new"})
+	assertStrings(t, runner.installed[0], []string{"lark-calendar", "lark-mail", "lark-new"})
+	if runner.listedIndex != 1 {
+		t.Fatalf("listedIndex = %d, want 1", runner.listedIndex)
+	}
+	if runner.listedOfficial != 0 {
+		t.Fatalf("listedOfficial = %d, want 0 when index succeeds", runner.listedOfficial)
+	}
+}
+
+func TestSyncSkills_OfficialIndexFailureFallsBackToOfficialList(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
+	runner := &fakeSkillsRunner{
+		officialIndexErr: fmt.Errorf("index unavailable"),
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail"),
+		globalJSONOut:    globalSkillsJSONOutput("lark-calendar"),
+	}
+
+	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
+	if result.Err != nil {
+		t.Fatalf("SyncSkills() err = %v, want nil", result.Err)
+	}
+	assertStrings(t, result.Official, []string{"lark-calendar", "lark-mail"})
+	if runner.listedIndex != 1 || runner.listedOfficial != 1 {
+		t.Fatalf("listed index/official = %d/%d, want 1/1", runner.listedIndex, runner.listedOfficial)
+	}
+	if runner.installedAll != 0 {
+		t.Fatalf("installedAll = %d, want 0", runner.installedAll)
+	}
+}
+
+func TestSyncSkills_OfficialIndexEmptyFallsBackToOfficialList(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
+	runner := &fakeSkillsRunner{
+		officialIndexOut: `{"skills":[]}`,
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail"),
+		globalJSONOut:    globalSkillsJSONOutput("lark-calendar"),
+	}
+
+	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
+	if result.Err != nil {
+		t.Fatalf("SyncSkills() err = %v, want nil", result.Err)
+	}
+	assertStrings(t, result.Official, []string{"lark-calendar", "lark-mail"})
+	if runner.listedIndex != 1 || runner.listedOfficial != 1 {
+		t.Fatalf("listed index/official = %d/%d, want 1/1", runner.listedIndex, runner.listedOfficial)
+	}
+}
+
+func TestSyncSkills_OfficialDiscoveryFailuresFallBackToFullInstallWithReasons(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
+	runner := &fakeSkillsRunner{
+		officialIndexErr: fmt.Errorf("index unavailable"),
+		officialErr:      fmt.Errorf("list failed"),
+		installAllErr:    nil,
+	}
+
+	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
+	if result.Action != "fallback_synced" {
+		t.Fatalf("SyncSkills() action = %q, want fallback_synced", result.Action)
+	}
+	if runner.installedAll != 1 {
+		t.Fatalf("installedAll = %d, want 1", runner.installedAll)
+	}
+	if !strings.Contains(result.Detail, "official skills index failed") || !strings.Contains(result.Detail, "official skills list failed") {
+		t.Fatalf("SyncSkills() detail = %q, want both discovery failure reasons", result.Detail)
+	}
+}
+
+func TestSyncSkills_OfficialDiscoveryEmptyFallsBackToFullInstallWithReasons(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
+	runner := &fakeSkillsRunner{
+		officialIndexOut: `{"skills":[]}`,
+		installAllErr:    nil,
+	}
+
+	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
+	if result.Action != "fallback_synced" {
+		t.Fatalf("SyncSkills() action = %q, want fallback_synced", result.Action)
+	}
+	if runner.installedAll != 1 {
+		t.Fatalf("installedAll = %d, want 1", runner.installedAll)
+	}
+	if !strings.Contains(result.Detail, "official skills index contains no skills") || !strings.Contains(result.Detail, "official skills list returned no skills") {
+		t.Fatalf("SyncSkills() detail = %q, want both empty discovery reasons", result.Detail)
+	}
+}
+
 func TestSyncSkills_ListOfficialFailureFallsBackToFullInstall(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialErr:   fmt.Errorf("list failed"),
-		installAllErr: nil,
+		officialIndexErr: fmt.Errorf("index unavailable"),
+		officialErr:      fmt.Errorf("list failed"),
+		installAllErr:    nil,
 	}
 
 	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
@@ -246,8 +506,9 @@ func TestSyncSkills_ListOfficialFailureAndFullInstallFails(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialErr:   fmt.Errorf("list failed"),
-		installAllErr: fmt.Errorf("full install failed"),
+		officialIndexErr: fmt.Errorf("index unavailable"),
+		officialErr:      fmt.Errorf("list failed"),
+		installAllErr:    fmt.Errorf("full install failed"),
 	}
 
 	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
@@ -262,58 +523,123 @@ func TestSyncSkills_ListOfficialFailureAndFullInstallFails(t *testing.T) {
 	}
 }
 
-func TestSyncSkills_GlobalListFailureDegradesToColdStart(t *testing.T) {
+func TestSyncSkills_GlobalJSONFailureFallsBackToTextList(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialOut: officialSkillsOutput("lark-calendar", "lark-mail"),
-		globalErr:   fmt.Errorf("global list failed"),
+		officialIndexOut: officialSkillsIndexOutput("lark-calendar", "lark-mail"),
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail"),
+		globalJSONErr:    fmt.Errorf("json list failed"),
+		globalOut:        globalSkillsOutput("lark-calendar"),
 	}
 
 	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
 	if result.Err != nil {
-		t.Fatalf("SyncSkills() err = %v, want nil (degraded to cold start)", result.Err)
+		t.Fatalf("SyncSkills() err = %v, want nil", result.Err)
 	}
 	if result.Action != "synced" {
 		t.Fatalf("SyncSkills() action = %q, want synced", result.Action)
 	}
 	assertStrings(t, result.Updated, []string{"lark-calendar", "lark-mail"})
-	assertStrings(t, result.SkippedDeleted, []string{})
+	if runner.listedGlobalJSON != 1 || runner.listedGlobalText != 1 {
+		t.Fatalf("listed JSON/text = %d/%d, want 1/1", runner.listedGlobalJSON, runner.listedGlobalText)
+	}
+	if runner.installedAll != 0 {
+		t.Fatalf("installedAll = %d, want 0", runner.installedAll)
+	}
 }
 
-func TestSyncSkills_ParseEmptyGlobalListWithNonEmptyStdoutDegradesToColdStart(t *testing.T) {
+func TestSyncSkills_LocalListsFailureFallsBackToFullInstall(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialOut: officialSkillsOutput("lark-calendar", "lark-mail"),
-		globalOut:   "Some unrecognized output format\n",
+		officialIndexOut: officialSkillsIndexOutput("lark-calendar", "lark-mail"),
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail"),
+		globalJSONErr:    fmt.Errorf("json list failed with /Users/example/.agents/skills/lark-calendar agents Codex"),
+		globalErr:        fmt.Errorf("text list failed with /Users/example/.agents/skills/lark-mail agents Codex"),
 	}
 
 	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
-	if result.Err != nil {
-		t.Fatalf("SyncSkills() err = %v, want nil (degraded to cold start)", result.Err)
+	if result.Action != "fallback_synced" {
+		t.Fatalf("SyncSkills() action = %q, want fallback_synced", result.Action)
 	}
-	if result.Action != "synced" {
-		t.Fatalf("SyncSkills() action = %q, want synced", result.Action)
+	if len(runner.installed) != 0 {
+		t.Fatalf("installed = %#v, want no incremental installs", runner.installed)
 	}
+	if runner.installedAll != 1 {
+		t.Fatalf("installedAll = %d, want 1", runner.installedAll)
+	}
+	if strings.Contains(result.Detail, "/Users/example") || strings.Contains(result.Detail, "agents") {
+		t.Fatalf("SyncSkills() detail leaks local command output: %q", result.Detail)
+	}
+}
+
+func TestSyncSkills_ParseEmptyLocalListsFallBackToFullInstall(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
+	runner := &fakeSkillsRunner{
+		officialIndexOut: officialSkillsIndexOutput("lark-calendar", "lark-mail"),
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail"),
+		globalJSONOut:    `[]`,
+		globalOut:        "Some unrecognized output format\n",
+	}
+
+	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
+	if result.Action != "fallback_synced" {
+		t.Fatalf("SyncSkills() action = %q, want fallback_synced", result.Action)
+	}
+	if len(runner.installed) != 0 {
+		t.Fatalf("installed = %#v, want no incremental installs", runner.installed)
+	}
+	if runner.installedAll != 1 {
+		t.Fatalf("installedAll = %d, want 1", runner.installedAll)
+	}
+}
+
+func TestSyncSkills_EmptyToUpdateFallsBackToFullInstall(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
+	if err := WriteState(SkillsState{
+		Version:        "1.0.30",
+		OfficialSkills: []string{"lark-calendar", "lark-mail"},
+		UpdatedAt:      "2026-05-18T00:00:00Z",
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	runner := &fakeSkillsRunner{
+		officialIndexOut: officialSkillsIndexOutput("lark-calendar", "lark-mail"),
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail"),
+		globalOut:        globalSkillsOutput(),
+		installAllErr:    nil,
+	}
+
+	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
+	if result.Action != "fallback_synced" {
+		t.Fatalf("SyncSkills() action = %q, want fallback_synced", result.Action)
+	}
+	if len(runner.installed) != 0 {
+		t.Fatalf("installed = %#v, want no incremental installs", runner.installed)
+	}
+	if runner.installedAll != 1 {
+		t.Fatalf("installedAll = %d, want 1 (fallback triggered)", runner.installedAll)
+	}
+	assertStrings(t, result.Official, []string{"lark-calendar", "lark-mail"})
 	assertStrings(t, result.Updated, []string{"lark-calendar", "lark-mail"})
+	assertStrings(t, result.Added, []string{"lark-calendar", "lark-mail"})
 	assertStrings(t, result.SkippedDeleted, []string{})
-	if runner.installedAll != 0 {
-		t.Fatalf("installedAll = %d, want 0 (no fallback)", runner.installedAll)
-	}
-	if len(runner.installed) != 1 {
-		t.Fatalf("installed = %d calls, want 1 (incremental)", len(runner.installed))
-	}
 }
 
 func TestSyncSkills_InstallFailureFallsBackToFullInstall(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialOut:   officialSkillsOutput("lark-calendar", "lark-mail"),
-		globalOut:     globalSkillsOutput("lark-calendar", "lark-mail"),
-		installErr:    fmt.Errorf("incremental boom"),
-		installAllErr: nil,
+		officialIndexOut: officialSkillsIndexOutput("lark-calendar", "lark-mail"),
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail"),
+		globalJSONOut:    globalSkillsJSONOutput("lark-calendar", "lark-mail"),
+		globalOut:        globalSkillsOutput("lark-calendar", "lark-mail"),
+		installErr:       fmt.Errorf("incremental boom"),
+		installAllErr:    nil,
 	}
 
 	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
@@ -341,10 +667,12 @@ func TestSyncSkills_InstallFailureAndFullInstallFails(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialOut:   officialSkillsOutput("lark-calendar", "lark-mail"),
-		globalOut:     globalSkillsOutput("lark-calendar", "lark-mail"),
-		installErr:    fmt.Errorf("incremental boom"),
-		installAllErr: fmt.Errorf("full install boom"),
+		officialIndexOut: officialSkillsIndexOutput("lark-calendar", "lark-mail"),
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail"),
+		globalJSONOut:    globalSkillsJSONOutput("lark-calendar", "lark-mail"),
+		globalOut:        globalSkillsOutput("lark-calendar", "lark-mail"),
+		installErr:       fmt.Errorf("incremental boom"),
+		installAllErr:    fmt.Errorf("full install boom"),
 	}
 
 	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
@@ -373,8 +701,9 @@ func TestSyncSkills_ParseEmptyWithNonEmptyStdoutFallsBack(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialOut:   "Some unrecognized output format\n",
-		installAllErr: nil,
+		officialIndexErr: fmt.Errorf("index unavailable"),
+		officialOut:      "Some unrecognized output format\n",
+		installAllErr:    nil,
 	}
 
 	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
@@ -390,8 +719,9 @@ func TestSyncSkills_ParseEmptyWithNonEmptyStdoutAndFullInstallFails(t *testing.T
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialOut:   "Some unrecognized output format\n",
-		installAllErr: fmt.Errorf("full install failed"),
+		officialIndexErr: fmt.Errorf("index unavailable"),
+		officialOut:      "Some unrecognized output format\n",
+		installAllErr:    fmt.Errorf("full install failed"),
 	}
 
 	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
@@ -414,8 +744,9 @@ func TestSyncSkills_FallbackWithUnknownOfficialWritesMinimalState(t *testing.T)
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialOut:   "Some unrecognized output format\n",
-		installAllErr: nil,
+		officialIndexErr: fmt.Errorf("index unavailable"),
+		officialOut:      "Some unrecognized output format\n",
+		installAllErr:    nil,
 	}
 
 	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
@@ -439,10 +770,12 @@ func TestSyncSkills_FallbackWithKnownOfficialWritesFullState(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialOut:   officialSkillsOutput("lark-calendar", "lark-mail"),
-		globalOut:     globalSkillsOutput("lark-calendar", "lark-mail"),
-		installErr:    fmt.Errorf("incremental boom"),
-		installAllErr: nil,
+		officialIndexOut: officialSkillsIndexOutput("lark-calendar", "lark-mail"),
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail"),
+		globalJSONOut:    globalSkillsJSONOutput("lark-calendar", "lark-mail"),
+		globalOut:        globalSkillsOutput("lark-calendar", "lark-mail"),
+		installErr:       fmt.Errorf("incremental boom"),
+		installAllErr:    nil,
 	}
 
 	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
@@ -463,10 +796,12 @@ func TestSyncSkills_FallbackResultContainsMetadata(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialOut:   officialSkillsOutput("lark-calendar", "lark-mail"),
-		globalOut:     globalSkillsOutput("lark-calendar", "lark-mail"),
-		installErr:    fmt.Errorf("incremental boom"),
-		installAllErr: nil,
+		officialIndexOut: officialSkillsIndexOutput("lark-calendar", "lark-mail"),
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail"),
+		globalJSONOut:    globalSkillsJSONOutput("lark-calendar", "lark-mail"),
+		globalOut:        globalSkillsOutput("lark-calendar", "lark-mail"),
+		installErr:       fmt.Errorf("incremental boom"),
+		installAllErr:    nil,
 	}
 
 	result := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
@@ -486,8 +821,9 @@ func TestSyncSkills_FallbackBreaksDegradationLoop(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LARKSUITE_CLI_CONFIG_DIR", dir)
 	runner := &fakeSkillsRunner{
-		officialErr:   fmt.Errorf("list failed"),
-		installAllErr: nil,
+		officialIndexErr: fmt.Errorf("index unavailable"),
+		officialErr:      fmt.Errorf("list failed"),
+		installAllErr:    nil,
 	}
 
 	result1 := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner, Now: time.Now})
@@ -504,8 +840,10 @@ func TestSyncSkills_FallbackBreaksDegradationLoop(t *testing.T) {
 	}
 
 	runner2 := &fakeSkillsRunner{
-		officialOut: officialSkillsOutput("lark-calendar", "lark-mail"),
-		globalOut:   globalSkillsOutput("lark-calendar", "lark-mail"),
+		officialIndexOut: officialSkillsIndexOutput("lark-calendar", "lark-mail"),
+		officialOut:      officialSkillsOutput("lark-calendar", "lark-mail"),
+		globalJSONOut:    globalSkillsJSONOutput("lark-calendar", "lark-mail"),
+		globalOut:        globalSkillsOutput("lark-calendar", "lark-mail"),
 	}
 	result2 := SyncSkills(SyncOptions{Version: "1.0.33", Runner: runner2, Now: time.Now})
 	if result2.Action != "synced" {

internal/suggest/suggest.go

@@ -0,0 +1,104 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+// Package suggest provides the shared "did you mean" primitives: a rune-aware
+// Levenshtein edit distance and a prefix-weighted Closest ranker. It is the
+// single home for these so cmd, cmd/event, and internal/cmdpolicy stop each
+// carrying their own copy.
+package suggest
+
+import "sort"
+
+// Levenshtein computes the classic edit distance between two strings. It is
+// rune-aware, so it is correct for multi-byte input.
+func Levenshtein(a, b string) int {
+	if a == b {
+		return 0
+	}
+	ra, rb := []rune(a), []rune(b)
+	if len(ra) == 0 {
+		return len(rb)
+	}
+	if len(rb) == 0 {
+		return len(ra)
+	}
+	prev := make([]int, len(rb)+1)
+	curr := make([]int, len(rb)+1)
+	for j := range prev {
+		prev[j] = j
+	}
+	for i := 1; i <= len(ra); i++ {
+		curr[0] = i
+		for j := 1; j <= len(rb); j++ {
+			cost := 1
+			if ra[i-1] == rb[j-1] {
+				cost = 0
+			}
+			curr[j] = min(prev[j]+1, curr[j-1]+1, prev[j-1]+cost)
+		}
+		prev, curr = curr, prev
+	}
+	return prev[len(rb)]
+}
+
+// Closest returns up to maxN of candidates that plausibly match typed, ranked
+// by shared-prefix length (desc) then edit distance (asc), keeping only
+// reasonably-close ones.
+//
+// Shared prefix is weighted first on purpose: hallucinated names are often
+// semantically close but lexically far (e.g. "+cells-find" vs "+cells-search",
+// "--with-styles" vs nothing close), where the common prefix is the strongest
+// signal of intent that raw edit distance misses.
+func Closest(typed string, candidates []string, maxN int) []string {
+	type scored struct {
+		name   string
+		prefix int
+		dist   int
+	}
+	limit := editLimit(typed)
+	ranked := make([]scored, 0, len(candidates))
+	for _, c := range candidates {
+		p := sharedPrefixLen(typed, c)
+		d := Levenshtein(typed, c)
+		// Keep only plausible matches: a meaningful shared prefix, or an edit
+		// distance within budget. Drop everything else so the hint stays short.
+		if p >= 3 || d <= limit {
+			ranked = append(ranked, scored{name: c, prefix: p, dist: d})
+		}
+	}
+	sort.Slice(ranked, func(i, j int) bool {
+		if ranked[i].prefix != ranked[j].prefix {
+			return ranked[i].prefix > ranked[j].prefix
+		}
+		if ranked[i].dist != ranked[j].dist {
+			return ranked[i].dist < ranked[j].dist
+		}
+		return ranked[i].name < ranked[j].name
+	})
+	if maxN <= 0 || maxN > len(ranked) {
+		maxN = len(ranked)
+	}
+	out := make([]string, 0, maxN)
+	for _, s := range ranked[:maxN] {
+		out = append(out, s.name)
+	}
+	return out
+}
+
+// editLimit allows roughly one third of the typed length in edits (min 2), so
+// short names tolerate a couple of typos and longer ones proportionally more.
+func editLimit(s string) int {
+	if l := len([]rune(s)) / 3; l > 2 {
+		return l
+	}
+	return 2
+}
+
+func sharedPrefixLen(a, b string) int {
+	ra, rb := []rune(a), []rune(b)
+	n := 0
+	for n < len(ra) && n < len(rb) && ra[n] == rb[n] {
+		n++
+	}
+	return n
+}

internal/suggest/suggest_test.go

@@ -0,0 +1,74 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package suggest
+
+import (
+	"slices"
+	"testing"
+)
+
+func TestClosest_HallucinatedSharesPrefix(t *testing.T) {
+	cmds := []string{
+		"+cells-get", "+cells-set", "+cells-search", "+cells-replace",
+		"+cells-clear", "+cells-merge", "+csv-get", "+chart-create",
+		"+pivot-create", "+sheet-info",
+	}
+	// "+cells-find" is semantically +cells-search but lexically far; the shared
+	// "+cells-" prefix should still surface the right family (incl. +cells-search).
+	got := Closest("+cells-find", cmds, 6)
+	if len(got) == 0 || len(got) > 6 {
+		t.Fatalf("expected 1..6 suggestions, got %v", got)
+	}
+	if !slices.Contains(got, "+cells-search") {
+		t.Errorf("expected +cells-search among suggestions, got %v", got)
+	}
+	for _, s := range got {
+		if len(s) < 7 || s[:7] != "+cells-" {
+			t.Errorf("suggestion %q does not share the +cells- prefix", s)
+		}
+	}
+}
+
+func TestClosest_TypoRanksExactNeighborFirst(t *testing.T) {
+	got := Closest("+cell-get", []string{"+cells-get", "+cells-set", "+csv-get", "+sheet-info"}, 3)
+	if len(got) == 0 || got[0] != "+cells-get" {
+		t.Errorf("expected +cells-get first for typo +cell-get, got %v", got)
+	}
+}
+
+func TestClosest_NoPlausibleMatch(t *testing.T) {
+	if got := Closest("+zzzzzz", []string{"+cells-get", "+csv-get"}, 6); len(got) != 0 {
+		t.Errorf("expected no suggestions for unrelated input, got %v", got)
+	}
+}
+
+func TestLevenshtein(t *testing.T) {
+	cases := []struct {
+		a, b string
+		want int
+	}{
+		{"", "abc", 3},
+		{"abc", "", 3},
+		{"abc", "abc", 0},
+		{"kitten", "sitting", 3},
+		{"cell-get", "cells-get", 1},
+		{"--query", "--find", 5},
+		{"飞书", "飞书", 0}, // rune-aware: multi-byte equal
+		{"飞书", "飞s", 1}, // one rune substitution, not byte count
+	}
+	for _, c := range cases {
+		if d := Levenshtein(c.a, c.b); d != c.want {
+			t.Errorf("Levenshtein(%q,%q) = %d, want %d", c.a, c.b, d, c.want)
+		}
+	}
+}
+
+func TestSharedPrefixLen(t *testing.T) {
+	if got := sharedPrefixLen("+cells-find", "+cells-search"); got != 7 {
+		t.Errorf("sharedPrefixLen = %d, want 7", got)
+	}
+	if got := sharedPrefixLen("abc", "xyz"); got != 0 {
+		t.Errorf("sharedPrefixLen = %d, want 0", got)
+	}
+}