ci: add protected public domain allowlists (#2111)

Co-authored-by: HanShaoshuai-k <268785735+HanShaoshuai-k@users.noreply.github.com>

internal/qualitygate/config/README.md

@@ -45,6 +45,18 @@ Adding a new row requires approval from the matching CODEOWNERS or quality gate
 
 `legacy-commands.txt` only covers hand-authored legacy commands. Generated OpenAPI service commands are intentionally excluded from `command-manifest.json`; they are included in `command-index.json` only so command references can be checked against the real CLI surface.
 
+## Public Domain Allowlists
+
+`internal/qualitygate/config/allowlists/public-domains.txt` contains supported public hostnames approved for Go source. `fixture-domains.txt` contains test-only hostnames used by `*_test.go`, the repository-root `tests/` directory, or any `testdata/` directory; fixture entries do not apply to production Go files or `skills/`.
+
+Keep one lowercase exact hostname per line, sorted alphabetically. Wildcards, suffix rules, duplicates, schemes, ports, and paths are rejected; approving `larkoffice.com` does not approve its subdomains.
+
+RFC 2606 reserves the `.test`, `.example`, `.invalid`, and `.localhost` namespaces plus the exact names `example.com`, `example.net`, and `example.org`. These names are accepted without an allowlist entry and must not be listed.
+
+Every public entry needs a current non-fixture Go use, evidence that it is a supported public endpoint, and CODEOWNER approval. Other test-only hostnames belong in the fixture list. Tenant-specific, private-control-plane, and internal API hostnames are not eligible.
+
+`lint/domaincontract` validates both lists and scans complete Go files. In CI, unapproved-host findings are limited to values whose expressions intersect added lines; list validation and unused-entry checks remain repository-wide. See `lint/README.md` for scanner semantics.
+
 ## Semantic Blocker Policy
 
 The semantic reviewer can propose findings, but the local gatekeeper recomputes whether each finding is reproducible from `facts.json`. A finding blocks only when all of these are true:

internal/qualitygate/config/allowlists/fixture-domains.txt

@@ -0,0 +1,24 @@
+# Exact test-only hostnames. Keep sorted.
+abc.feishu.cn
+attacker.example.com
+bytedance.feishu.cn
+cdn.feishu.cn
+evil.example.com
+example.feishu.cn
+example.larkoffice.com
+example.larksuite.com
+feishu.cn
+feishu.doubao.com
+gateway.docker.internal
+host.containers.internal
+host.docker.internal
+host.lima.internal
+lf3-static.bytednsdoc.com
+meetings.feishu.cn
+meetings.larksuite.com
+p3-lark-file.byteimg.com
+passport.feishu.cn
+sample.feishu.cn
+x.feishu.cn
+xxx.feishu.cn
+xxx.larksuite.com

internal/qualitygate/config/allowlists/public-domains.txt

@@ -0,0 +1,18 @@
+# Exact public hostnames. Keep sorted.
+accounts.feishu.cn
+accounts.larksuite.com
+applink.feishu.cn
+applink.larksuite.com
+ark.ap-southeast.bytepluses.com
+github.com
+larkoffice.com
+lf-larkemail.bytetos.com
+mcp.feishu.cn
+mcp.larksuite.com
+open.feishu.cn
+open.larksuite.com
+registry.npmjs.org
+registry.npmmirror.com
+sf16-sg.tiktokcdn.com
+www.feishu.cn
+www.larksuite.com

lint/README.md

@@ -19,7 +19,7 @@ lint/
 ├── lintapi/            # shared types every domain returns
 │   └── violation.go    # Violation, Action, ActionReject / ActionLabel / ActionWarning
 └── errscontract/       # first domain: typed-error contract guards
-    ├── scan.go         # ScanRepo(root) ([]lintapi.Violation, error)  ← public entry
+    ├── scan.go         # ScanRepoWithOptions(root, opts)  ← public entry
     ├── runner.go
     ├── typecheck.go
     ├── violation.go    # local type aliases to lintapi
@@ -30,16 +30,19 @@ lint/
     ├── rule_subtype_classifier.go
     ├── rule_typed_error_completeness.go
     └── *_test.go
-└── domaincontract/     # endpoint domain contract: no hardcoded resolver hosts
-    ├── scan.go         # ScanRepo(root) ([]lintapi.Violation, error)  ← public entry
-    └── scan_test.go
+└── domaincontract/     # resolver ownership + approved public hostname policy
+    ├── scan.go         # ScanRepoWithOptions(root, opts)  ← public entry
+    ├── unapproved.go   # Go AST/type-aware hostname extraction
+    ├── policy.go       # exact public/fixture allowlist validation
+    ├── diff.go         # added-line attribution
+    └── *_test.go
 ```
 
 ## Endpoint domain contract (`domaincontract`)
 
-`domaincontract` is a syntax-level regression guard for the resolver-owned
-Open, Accounts, MCP, and AppLink hosts used by the Go CLI. In production `.go`
-files it rejects:
+`domaincontract` contains two complementary Go source guards.
+
+The resolver-ownership guard rejects:
 
 - string literals containing a resolver-owned host FQDN
   (`{open,accounts,mcp,applink}.{feishu.cn,larksuite.com}`), and
@@ -59,17 +62,54 @@ parse-level guard). The forbidden-host list is bound to the resolver source by
 `TestForbiddenHostsMatchResolver`, so adding a resolver domain without updating
 the guard fails the lint module's tests.
 
-This is not a general outbound-URL or data-flow analyzer. It does not inspect
-non-Go assets, hosts assembled from string fragments, SDK constructor option
-flow, or previously unknown Feishu/Lark hosts. The literal rule and code review
-remain the backstop for those cases.
+The approved-domain guard parses every Git-tracked Go file in full. In CI,
+unapproved-host findings are limited to values whose expressions intersect an
+added line; policy validation and unused-entry checks remain repository-wide.
+It rejects an exact hostname unless it is present in one of:
 
-To add or change an outbound endpoint, edit the resolver — never hardcode a host.
+- `internal/qualitygate/config/allowlists/public-domains.txt`, for production
+  and test code; or
+- `internal/qualitygate/config/allowlists/fixture-domains.txt`, only for
+  `*_test.go`, the repository-root `tests/`, and any `testdata/` (never
+  `skills/`).
+
+RFC 2606 example/test names are accepted independently of those lists. This
+includes the reserved `.test`, `.example`, `.invalid`, and `.localhost`
+namespaces and the exact names `example.com`, `example.net`, and `example.org`;
+they are safe placeholders rather than supported public endpoints.
+
+High-confidence evidence is deliberately limited to static string expressions
+assigned to `host`, `hostname`, or `domain` semantic names (including common
+case/plural forms and collections), plus static strings whose entire value is
+an absolute `http`, `https`, `ws`, or `wss` URL. It supports Go literals,
+escapes, compile-time concatenation, constant references, grouped declarations,
+multi-value assignments, and multiline expressions. Bare domain-shaped strings
+without hostname semantics are not blocked.
+
+Sequence values are scanned individually. For a hostname-semantic map, a key or
+value is evidence only when it is the sole hostname-shaped side of that entry;
+ambiguous string-to-string entries are not guessed. Struct fields use Go type
+information so known non-network `Host` / `Domain` fields do not become hostname
+evidence merely because an enum or command category contains a dot.
+
+Allowlist matching is lowercase and exact: there are no wildcard, suffix, DNS,
+or public-suffix exceptions. Entries must be sorted and unique, use ASCII
+hostnames, and have a current in-scope use. See
+`internal/qualitygate/config/README.md` for admission and approval rules.
+
+This is not a general outbound-URL or cross-language data-flow analyzer. It does
+not inspect non-Go assets or dynamically constructed values.
+
+To add or change a resolver-owned Feishu/Lark endpoint, edit the resolver rather
+than hardcoding the host elsewhere.
 
 ## Running
 
 ```bash
-# from the repo root (one level above lint/)
+# PR-scoped scan from the repo root (one level above lint/)
+go run -C lint . --changed-from <base-revision> ..
+
+# Full inventory (also reports historical unapproved hostnames)
 go run -C lint . ..
 ```
 
@@ -100,10 +140,14 @@ Exit codes follow `lint/main.go`:
 
    import "github.com/larksuite/cli/lint/lintapi"
 
-   // ScanRepo walks root and returns every violation produced by this
-   // domain's checks. Domains MUST return []lintapi.Violation so the
-   // top-level dispatcher can aggregate uniformly.
-   func ScanRepo(root string) ([]lintapi.Violation, error) { ... }
+   type ScanOptions struct {
+       ChangedFrom string
+   }
+
+   // ScanRepoWithOptions walks root and returns every violation produced
+   // by this domain's checks. Domains MUST return []lintapi.Violation so
+   // the top-level dispatcher can aggregate uniformly.
+   func ScanRepoWithOptions(root string, opts ScanOptions) ([]lintapi.Violation, error) { ... }
    ```
 
 3. Per-rule files are named `rule_<name>.go` with sibling
@@ -114,8 +158,12 @@ Exit codes follow `lint/main.go`:
 
    ```go
    var scanners = []scanner{
-       {name: "errscontract", fn: errscontract.ScanRepo},
-       {name: "<domain>",     fn: <domain>.ScanRepo},  // ← add here
+       {name: "errscontract", fn: errscontract.ScanRepoWithOptions},
+       {name: "<domain>", fn: func(root string, opts errscontract.ScanOptions) ([]lintapi.Violation, error) {
+           return <domain>.ScanRepoWithOptions(root, <domain>.ScanOptions{
+               ChangedFrom: opts.ChangedFrom,
+           })
+       }},
    }
    ```
 

lint/domaincontract/diff.go

@@ -0,0 +1,171 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package domaincontract
+
+import (
+	"bytes"
+	"fmt"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+type addedLineRange struct {
+	Start int
+	End   int
+}
+
+type changedGoPath struct {
+	Old string
+	New string
+}
+
+var unifiedHunkRE = regexp.MustCompile(`^@@ -[0-9]+(?:,[0-9]+)? \+([0-9]+)(?:,([0-9]+))? @@`)
+
+func changedGoLineRanges(root, from string) (map[string][]addedLineRange, error) {
+	if from == "" {
+		return nil, nil
+	}
+	names, err := gitCommandOutput(
+		root,
+		"diff",
+		"--name-status",
+		"-z",
+		"--find-renames",
+		"--diff-filter=ACMR",
+		from+"...HEAD",
+		"--",
+	)
+	if err != nil {
+		return nil, fmt.Errorf("list changed Go files: %w", err)
+	}
+	paths, err := parseChangedGoPaths(names)
+	if err != nil {
+		return nil, fmt.Errorf("parse changed Go files: %w", err)
+	}
+
+	out := map[string][]addedLineRange{}
+	for _, path := range paths {
+		args := []string{
+			"diff",
+			"--unified=0",
+			"--no-color",
+			"--no-ext-diff",
+			"--find-renames",
+			"--diff-filter=ACMR",
+			from + "...HEAD",
+			"--",
+		}
+		if path.Old != path.New {
+			args = append(args, path.Old)
+		}
+		args = append(args, path.New)
+		patch, err := gitCommandOutput(root, args...)
+		if err != nil {
+			return nil, fmt.Errorf("read diff for %s: %w", path.New, err)
+		}
+		ranges, err := parseAddedLineRanges(patch)
+		if err != nil {
+			return nil, fmt.Errorf("parse diff for %s: %w", path.New, err)
+		}
+		out[path.New] = ranges
+	}
+	return out, nil
+}
+
+func parseChangedGoPaths(raw []byte) ([]changedGoPath, error) {
+	fields := bytes.Split(raw, []byte{0})
+	var out []changedGoPath
+	for i := 0; i < len(fields); {
+		status := string(fields[i])
+		i++
+		if status == "" {
+			break
+		}
+		if i >= len(fields) || len(fields[i]) == 0 {
+			return nil, fmt.Errorf("truncated name-status record")
+		}
+		oldPath := filepath.ToSlash(string(fields[i]))
+		i++
+		newPath := oldPath
+		if status[0] == 'R' || status[0] == 'C' {
+			if i >= len(fields) || len(fields[i]) == 0 {
+				return nil, fmt.Errorf("truncated rename/copy record for %q", oldPath)
+			}
+			newPath = filepath.ToSlash(string(fields[i]))
+			i++
+			if status[0] == 'C' {
+				// A copy introduces every destination line. Diff only the new
+				// path so Git presents it as an added file rather than a
+				// metadata-only copy with no added-line ranges.
+				oldPath = newPath
+			}
+		}
+		if !strings.HasSuffix(newPath, ".go") {
+			continue
+		}
+		out = append(out, changedGoPath{Old: oldPath, New: newPath})
+	}
+	return out, nil
+}
+
+func parseAddedLineRanges(patch []byte) ([]addedLineRange, error) {
+	var out []addedLineRange
+	for _, raw := range bytes.Split(patch, []byte{'\n'}) {
+		line := string(raw)
+		if !strings.HasPrefix(line, "@@") {
+			continue
+		}
+		match := unifiedHunkRE.FindStringSubmatch(line)
+		if match == nil {
+			return nil, fmt.Errorf("unsupported unified hunk header %q", line)
+		}
+		start, err := strconv.Atoi(match[1])
+		if err != nil {
+			return nil, fmt.Errorf("parse added start line in %q: %w", line, err)
+		}
+		count := 1
+		if match[2] != "" {
+			count, err = strconv.Atoi(match[2])
+			if err != nil {
+				return nil, fmt.Errorf("parse added line count in %q: %w", line, err)
+			}
+		}
+		if count == 0 {
+			continue
+		}
+		out = append(out, addedLineRange{Start: start, End: start + count - 1})
+	}
+	return out, nil
+}
+
+func firstAddedLineInSpan(ranges []addedLineRange, start, end int) (int, bool) {
+	for _, r := range ranges {
+		if start <= r.End && end >= r.Start {
+			if start > r.Start {
+				return start, true
+			}
+			return r.Start, true
+		}
+	}
+	return 0, false
+}
+
+func gitCommandOutput(root string, args ...string) ([]byte, error) {
+	cmd := exec.Command("git", args...)
+	cmd.Dir = root
+	out, err := cmd.Output()
+	if err == nil {
+		return out, nil
+	}
+	if exitErr, ok := err.(*exec.ExitError); ok {
+		stderr := strings.TrimSpace(string(exitErr.Stderr))
+		if stderr != "" {
+			return nil, fmt.Errorf("%w: %s", err, stderr)
+		}
+	}
+	return nil, err
+}

lint/domaincontract/diff_test.go

@@ -0,0 +1,96 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package domaincontract
+
+import "testing"
+
+func TestParseChangedGoPaths(t *testing.T) {
+	raw := []byte("M\x00changed.go\x00R100\x00old.go\x00renamed.go\x00C100\x00source.go\x00copied.go\x00A\x00README.md\x00")
+	got, err := parseChangedGoPaths(raw)
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := []changedGoPath{
+		{Old: "changed.go", New: "changed.go"},
+		{Old: "old.go", New: "renamed.go"},
+		{Old: "copied.go", New: "copied.go"},
+	}
+	if len(got) != len(want) {
+		t.Fatalf("paths = %#v, want %#v", got, want)
+	}
+	for i := range got {
+		if got[i] != want[i] {
+			t.Fatalf("paths = %#v, want %#v", got, want)
+		}
+	}
+}
+
+func TestParseChangedGoPathsRejectsTruncatedRename(t *testing.T) {
+	if _, err := parseChangedGoPaths([]byte("R100\x00old.go\x00")); err == nil {
+		t.Fatal("expected truncated rename error")
+	}
+}
+
+func TestParseAddedLineRanges(t *testing.T) {
+	patch := []byte(`diff --git a/x.go b/x.go
+index 1111111..2222222 100644
+--- a/x.go
++++ b/x.go
+@@ -2,0 +3,2 @@
++first
++second
+@@ -10 +12 @@
+-old
++new
+@@ -20 +21,0 @@
+-deleted
+`)
+	got, err := parseAddedLineRanges(patch)
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := []addedLineRange{{Start: 3, End: 4}, {Start: 12, End: 12}}
+	if len(got) != len(want) {
+		t.Fatalf("ranges = %#v, want %#v", got, want)
+	}
+	for i := range got {
+		if got[i] != want[i] {
+			t.Fatalf("ranges = %#v, want %#v", got, want)
+		}
+	}
+}
+
+func TestParseAddedLineRangesRejectsUnknownHunk(t *testing.T) {
+	if _, err := parseAddedLineRanges([]byte("@@@ unsupported @@@\n")); err == nil {
+		t.Fatal("expected unsupported hunk error")
+	}
+}
+
+func TestFirstAddedLineInSpan(t *testing.T) {
+	ranges := []addedLineRange{{Start: 5, End: 7}, {Start: 10, End: 10}}
+	tests := []struct {
+		start, end int
+		line       int
+		ok         bool
+	}{
+		{start: 1, end: 4, ok: false},
+		{start: 4, end: 6, line: 5, ok: true},
+		{start: 6, end: 9, line: 6, ok: true},
+		{start: 8, end: 12, line: 10, ok: true},
+	}
+	for _, tc := range tests {
+		line, ok := firstAddedLineInSpan(ranges, tc.start, tc.end)
+		if line != tc.line || ok != tc.ok {
+			t.Errorf(
+				"firstAddedLineInSpan(%d, %d) = (%d, %v), want (%d, %v)",
+				tc.start,
+				tc.end,
+				line,
+				ok,
+				tc.line,
+				tc.ok,
+			)
+		}
+	}
+}

lint/domaincontract/policy.go

@@ -0,0 +1,126 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package domaincontract
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const (
+	publicDomainsPath  = "internal/qualitygate/config/allowlists/public-domains.txt"
+	fixtureDomainsPath = "internal/qualitygate/config/allowlists/fixture-domains.txt"
+)
+
+type domainPolicyEntry struct {
+	Host string
+	File string
+	Line int
+}
+
+type domainPolicy struct {
+	Public   map[string]domainPolicyEntry
+	Fixtures map[string]domainPolicyEntry
+}
+
+// isReservedExampleHostname recognizes only names reserved by RFC 2606 for
+// examples, testing, invalid-name examples, and localhost use. These names are
+// safe source placeholders and are policy exceptions, not supported public
+// endpoints.
+func isReservedExampleHostname(host string) bool {
+	host = strings.TrimSuffix(strings.ToLower(strings.TrimSpace(host)), ".")
+	switch host {
+	case "example.com", "example.net", "example.org":
+		return true
+	}
+	labels := strings.Split(host, ".")
+	switch labels[len(labels)-1] {
+	case "test", "example", "invalid", "localhost":
+		return true
+	default:
+		return false
+	}
+}
+
+func loadDomainPolicy(root string) (domainPolicy, error) {
+	public, err := loadDomainList(root, publicDomainsPath)
+	if err != nil {
+		return domainPolicy{}, err
+	}
+	fixtures, err := loadDomainList(root, fixtureDomainsPath)
+	if err != nil {
+		return domainPolicy{}, err
+	}
+	for host, entry := range fixtures {
+		if publicEntry, ok := public[host]; ok {
+			return domainPolicy{}, fmt.Errorf(
+				"%s:%d: hostname %q is already listed at %s:%d",
+				entry.File, entry.Line, host, publicEntry.File, publicEntry.Line,
+			)
+		}
+	}
+	return domainPolicy{Public: public, Fixtures: fixtures}, nil
+}
+
+func loadDomainList(root, rel string) (map[string]domainPolicyEntry, error) {
+	path := filepath.Join(root, filepath.FromSlash(rel))
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("open domain allowlist %s: %w", rel, err)
+	}
+	defer file.Close()
+
+	entries := map[string]domainPolicyEntry{}
+	var previous string
+	scanner := bufio.NewScanner(file)
+	for line := 1; scanner.Scan(); line++ {
+		host := strings.TrimSpace(scanner.Text())
+		if host == "" || strings.HasPrefix(host, "#") {
+			continue
+		}
+		if host != strings.ToLower(host) {
+			return nil, fmt.Errorf("%s:%d: hostname must be lowercase: %q", rel, line, host)
+		}
+		if err := validatePolicyHostname(host); err != nil {
+			return nil, fmt.Errorf("%s:%d: %w", rel, line, err)
+		}
+		if previous != "" && host <= previous {
+			return nil, fmt.Errorf("%s:%d: hostnames must be unique and sorted: %q", rel, line, host)
+		}
+		entries[host] = domainPolicyEntry{Host: host, File: rel, Line: line}
+		previous = host
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("read domain allowlist %s: %w", rel, err)
+	}
+	if len(entries) == 0 {
+		return nil, fmt.Errorf("%s: domain list must not be empty", rel)
+	}
+	return entries, nil
+}
+
+func validatePolicyHostname(host string) error {
+	if len(host) > 253 || !strings.Contains(host, ".") || strings.HasSuffix(host, ".") {
+		return fmt.Errorf("invalid exact hostname %q", host)
+	}
+	labels := strings.Split(host, ".")
+	for _, label := range labels {
+		if len(label) == 0 || len(label) > 63 || label[0] == '-' || label[len(label)-1] == '-' {
+			return fmt.Errorf("invalid exact hostname %q", host)
+		}
+		for _, r := range label {
+			if (r >= 'a' && r <= 'z') || (r >= '0' && r <= '9') || r == '-' {
+				continue
+			}
+			return fmt.Errorf("invalid exact hostname %q", host)
+		}
+	}
+	if !strings.ContainsAny(labels[len(labels)-1], "abcdefghijklmnopqrstuvwxyz") {
+		return fmt.Errorf("invalid exact hostname %q", host)
+	}
+	return nil
+}

lint/domaincontract/policy_test.go

@@ -0,0 +1,120 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package domaincontract
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestLoadDomainPolicy(t *testing.T) {
+	root := t.TempDir()
+	writeFile(t, root, publicDomainsPath, "# public\napi.example.com\nwww.example.com\n")
+	writeFile(t, root, fixtureDomainsPath, "# fixtures\nfixture.example.com\n")
+
+	policy, err := loadDomainPolicy(root)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(policy.Public) != 2 || len(policy.Fixtures) != 1 {
+		t.Fatalf("unexpected policy sizes: public=%d fixtures=%d", len(policy.Public), len(policy.Fixtures))
+	}
+	if policy.Public["api.example.com"].Line != 2 {
+		t.Fatalf("api.example.com line = %d, want 2", policy.Public["api.example.com"].Line)
+	}
+}
+
+func TestLoadDomainPolicyRejectsInvalidLists(t *testing.T) {
+	tests := []struct {
+		name     string
+		public   string
+		fixtures string
+		want     string
+	}{
+		{
+			name:     "uppercase",
+			public:   "API.example.com\n",
+			fixtures: "fixture.example.com\n",
+			want:     "must be lowercase",
+		},
+		{
+			name:     "unsorted",
+			public:   "www.example.com\napi.example.com\n",
+			fixtures: "fixture.example.com\n",
+			want:     "unique and sorted",
+		},
+		{
+			name:     "duplicate",
+			public:   "api.example.com\napi.example.com\n",
+			fixtures: "fixture.example.com\n",
+			want:     "unique and sorted",
+		},
+		{
+			name:     "wildcard",
+			public:   "*.example.com\n",
+			fixtures: "fixture.example.com\n",
+			want:     "invalid exact hostname",
+		},
+		{
+			name:     "scheme",
+			public:   "https://example.com\n",
+			fixtures: "fixture.example.com\n",
+			want:     "invalid exact hostname",
+		},
+		{
+			name:     "path",
+			public:   "api.example.com/v1\n",
+			fixtures: "fixture.example.com\n",
+			want:     "invalid exact hostname",
+		},
+		{
+			name:     "port",
+			public:   "api.example.com:443\n",
+			fixtures: "fixture.example.com\n",
+			want:     "invalid exact hostname",
+		},
+		{
+			name:     "cross-list duplicate",
+			public:   "api.example.com\n",
+			fixtures: "api.example.com\n",
+			want:     "already listed",
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			root := t.TempDir()
+			writeFile(t, root, publicDomainsPath, tc.public)
+			writeFile(t, root, fixtureDomainsPath, tc.fixtures)
+			_, err := loadDomainPolicy(root)
+			if err == nil || !strings.Contains(err.Error(), tc.want) {
+				t.Fatalf("loadDomainPolicy() error = %v, want substring %q", err, tc.want)
+			}
+		})
+	}
+}
+
+func TestReservedExampleHostname(t *testing.T) {
+	for _, host := range []string{
+		"example.com",
+		"example.net",
+		"example.org",
+		"example.test",
+		"docs.example",
+		"missing.invalid",
+		"service.localhost",
+	} {
+		if !isReservedExampleHostname(host) {
+			t.Errorf("%q should be a reserved example hostname", host)
+		}
+	}
+	for _, host := range []string{
+		"attacker.example.com",
+		"example.dev",
+		"private.corp.internal",
+	} {
+		if isReservedExampleHostname(host) {
+			t.Errorf("%q must still require policy approval", host)
+		}
+	}
+}

lint/domaincontract/scan.go

@@ -1,8 +1,8 @@
 // Copyright (c) 2026 Lark Technologies Pte. Ltd.
 // SPDX-License-Identifier: MIT
 
-// Package domaincontract guards the Go CLI against direct reuse of the current
-// resolver-owned host FQDNs outside core.ResolveEndpoints.
+// Package domaincontract guards resolver ownership and rejects newly introduced
+// static Go hostnames that are not covered by the repository domain policy.
 package domaincontract
 
 import (
@@ -11,6 +11,7 @@ import (
 	"go/token"
 	"io/fs"
 	"path/filepath"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -75,10 +76,40 @@ func skipDir(name string) bool {
 	return false
 }
 
-// ScanRepo walks production .go files under root and flags string literals
-// containing a forbidden resolver host outside the allowlist. Comments and
-// _test.go files are not scanned.
+// ScanRepo runs the resolver-owned endpoint guard and a full repository domain
+// inventory. CI should use ScanRepoWithOptions with a changed-from revision so
+// historical unapproved domains are not attributed to an unrelated change.
 func ScanRepo(root string) ([]lintapi.Violation, error) {
+	return ScanRepoWithOptions(root, ScanOptions{})
+}
+
+type ScanOptions struct {
+	ChangedFrom string
+}
+
+func ScanRepoWithOptions(root string, opts ScanOptions) ([]lintapi.Violation, error) {
+	out, err := scanHardcodedEndpoints(root)
+	if err != nil {
+		return nil, err
+	}
+	domainViolations, err := scanUnapprovedDomains(root, opts)
+	if err != nil {
+		return nil, err
+	}
+	out = append(out, domainViolations...)
+	sort.SliceStable(out, func(i, j int) bool {
+		if out[i].File != out[j].File {
+			return out[i].File < out[j].File
+		}
+		if out[i].Line != out[j].Line {
+			return out[i].Line < out[j].Line
+		}
+		return out[i].Rule < out[j].Rule
+	})
+	return out, nil
+}
+
+func scanHardcodedEndpoints(root string) ([]lintapi.Violation, error) {
 	var out []lintapi.Violation
 	err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
 		if err != nil {

lint/domaincontract/unapproved.go

@@ -0,0 +1,911 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package domaincontract
+
+import (
+	"fmt"
+	"go/ast"
+	"go/constant"
+	"go/parser"
+	"go/token"
+	"go/types"
+	"net"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"unicode"
+
+	"github.com/larksuite/cli/lint/lintapi"
+	"golang.org/x/tools/go/packages"
+)
+
+const (
+	unapprovedDomainRule = "unapproved-domain"
+	unusedDomainRule     = "domain-allowlist-unused"
+	incompleteDomainRule = "domain-scan-incomplete"
+)
+
+type typedGoFile struct {
+	File *ast.File
+	Fset *token.FileSet
+	Info *types.Info
+}
+
+type domainEvidence struct {
+	Host string
+	Kind string
+	Expr ast.Expr
+}
+
+type evidenceKey struct {
+	Host       string
+	Start, End token.Pos
+}
+
+type fileDomainScan struct {
+	File             *ast.File
+	Fset             *token.FileSet
+	Info             *types.Info
+	Evidence         []domainEvidence
+	TypeInfoRequired []ast.Expr
+	seen             map[evidenceKey]bool
+	parents          map[ast.Node]ast.Node
+}
+
+type collectionCompositeKind uint8
+
+const (
+	notCollectionComposite collectionCompositeKind = iota
+	sequenceComposite
+	mapComposite
+)
+
+type hostnameFieldID struct {
+	Type  string
+	Field string
+}
+
+var nonNetworkHostnameFields = map[hostnameFieldID]bool{
+	{Type: "github.com/larksuite/cli/events/im.CardActionTriggerOutput", Field: "Host"}: true,
+	{Type: "github.com/larksuite/cli/internal/cmdmeta.Meta", Field: "Domain"}:           true,
+}
+
+func scanUnapprovedDomains(root string, opts ScanOptions) ([]lintapi.Violation, error) {
+	root, err := filepath.Abs(root)
+	if err != nil {
+		return nil, fmt.Errorf("resolve repository root: %w", err)
+	}
+	publicPath := filepath.Join(root, filepath.FromSlash(publicDomainsPath))
+	if _, err := os.Stat(publicPath); err != nil {
+		if os.IsNotExist(err) {
+			if _, goModErr := os.Stat(filepath.Join(root, "go.mod")); os.IsNotExist(goModErr) {
+				return nil, nil
+			}
+		}
+		return nil, fmt.Errorf("domain policy unavailable: %w", err)
+	}
+	policy, err := loadDomainPolicy(root)
+	if err != nil {
+		return nil, err
+	}
+	added, err := changedGoLineRanges(root, opts.ChangedFrom)
+	if err != nil {
+		return nil, err
+	}
+	typed, typeLoadErr := loadTypedGoFiles(root)
+	goFiles, err := trackedGoFiles(root)
+	if err != nil {
+		return nil, err
+	}
+
+	observedPublic := map[string]bool{}
+	observedFixtures := map[string]bool{}
+	inventoryComplete := typeLoadErr == nil
+	var out []lintapi.Violation
+	parseFailureReported := false
+	typeInfoGapReported := false
+	for _, rel := range goFiles {
+		path := filepath.Join(root, filepath.FromSlash(rel))
+		parsedFset := token.NewFileSet()
+		parsedFile, parseErr := parser.ParseFile(parsedFset, path, nil, 0)
+		if parseErr != nil {
+			inventoryComplete = false
+			if opts.ChangedFrom == "" {
+				out = append(out, incompleteDomainViolation(rel, parseErr))
+				parseFailureReported = true
+			} else if _, changed := added[rel]; changed {
+				out = append(out, incompleteDomainViolation(rel, parseErr))
+				parseFailureReported = true
+			}
+			continue
+		}
+		tf, ok := typed[filepath.Clean(path)]
+		if !ok {
+			tf = typedGoFile{File: parsedFile, Fset: parsedFset}
+		}
+
+		scan := newFileDomainScan(tf)
+		scan.collectSemanticEvidence()
+		scan.collectAbsoluteURLEvidence()
+		if len(scan.TypeInfoRequired) > 0 {
+			// Inventory completeness is a property of the whole HEAD. Whether
+			// this PR owns an incomplete-scan diagnostic is decided separately
+			// by the added-line intersection below.
+			inventoryComplete = false
+		}
+		for _, expr := range scan.TypeInfoRequired {
+			start := tf.Fset.Position(expr.Pos()).Line
+			end := tf.Fset.Position(expr.End()).Line
+			line := start
+			if opts.ChangedFrom != "" {
+				var intersects bool
+				line, intersects = firstAddedLineInSpan(added[rel], start, end)
+				if !intersects {
+					continue
+				}
+			}
+			typeInfoGapReported = true
+			out = append(out, incompleteDomainViolationAt(
+				rel,
+				line,
+				fmt.Errorf("Go type information unavailable for hostname-oriented field evidence"),
+			))
+			break
+		}
+		fixture := isDomainFixturePath(rel)
+		// The detector's own policy literals and contract corpus may be
+		// scanned, but they cannot justify keeping an allowlist entry.
+		policyOwner := strings.HasPrefix(rel, "lint/domaincontract/")
+		for _, evidence := range scan.Evidence {
+			if isReservedExampleHostname(evidence.Host) {
+				continue
+			}
+			if _, ok := policy.Public[evidence.Host]; ok {
+				if !fixture && !policyOwner {
+					observedPublic[evidence.Host] = true
+				}
+				continue
+			}
+			if _, ok := policy.Fixtures[evidence.Host]; ok && fixture {
+				if !policyOwner {
+					observedFixtures[evidence.Host] = true
+				}
+				continue
+			}
+			start := tf.Fset.Position(evidence.Expr.Pos()).Line
+			end := tf.Fset.Position(evidence.Expr.End()).Line
+			line := start
+			if opts.ChangedFrom != "" {
+				var intersects bool
+				line, intersects = firstAddedLineInSpan(added[rel], start, end)
+				if !intersects {
+					continue
+				}
+			}
+			suggestion := "remove the hostname or replace it with an approved public endpoint; " +
+				"public allowlist additions require evidence and CODEOWNER approval"
+			if _, fixtureOnly := policy.Fixtures[evidence.Host]; fixtureOnly && !fixture {
+				suggestion = "remove the fixture-only hostname or move this use into an approved fixture scope; " +
+					"fixture entries are not approved for production Go code or skills"
+			}
+			out = append(out, lintapi.Violation{
+				Rule:   unapprovedDomainRule,
+				Action: lintapi.ActionReject,
+				File:   rel,
+				Line:   line,
+				Message: fmt.Sprintf(
+					"unapproved hostname %q found in %s",
+					evidence.Host,
+					evidence.Kind,
+				),
+				Suggestion: suggestion,
+			})
+		}
+	}
+
+	// A syntax error is also surfaced by go/packages. Prefer the file-specific
+	// parse diagnostic when one was already reported; otherwise make a
+	// repository-wide type-loading failure explicit instead of silently
+	// continuing without the type information required by field evidence.
+	if typeLoadErr != nil && !parseFailureReported && !typeInfoGapReported {
+		out = append(out, incompleteDomainViolation("go.mod", typeLoadErr))
+	}
+
+	if inventoryComplete {
+		for host, entry := range policy.Public {
+			if !observedPublic[host] {
+				out = append(out, unusedDomainViolation(entry))
+			}
+		}
+		for host, entry := range policy.Fixtures {
+			if !observedFixtures[host] {
+				out = append(out, unusedDomainViolation(entry))
+			}
+		}
+	}
+	return out, nil
+}
+
+func trackedGoFiles(root string) ([]string, error) {
+	out, err := gitCommandOutput(root, "ls-files", "-z", "--", "*.go")
+	if err != nil {
+		return nil, fmt.Errorf("list tracked Go files: %w", err)
+	}
+	var files []string
+	for _, raw := range strings.Split(string(out), "\x00") {
+		if raw == "" {
+			continue
+		}
+		rel := filepath.ToSlash(raw)
+		if strings.HasPrefix(rel, "vendor/") || strings.HasPrefix(rel, "node_modules/") {
+			continue
+		}
+		files = append(files, rel)
+	}
+	return files, nil
+}
+
+func loadTypedGoFiles(root string) (map[string]typedGoFile, error) {
+	moduleDirs, err := trackedGoModuleDirs(root)
+	if err != nil {
+		return nil, err
+	}
+	out := map[string]typedGoFile{}
+	var firstLoadErr error
+	var loadErrCount int
+	for _, moduleDir := range moduleDirs {
+		moduleRoot := root
+		if moduleDir != "." {
+			moduleRoot = filepath.Join(root, filepath.FromSlash(moduleDir))
+		}
+		files, err := loadTypedGoModule(moduleRoot)
+		for path, file := range files {
+			out[path] = file
+		}
+		if err != nil {
+			loadErrCount++
+			if firstLoadErr == nil {
+				firstLoadErr = err
+			}
+		}
+	}
+	if loadErrCount == 1 {
+		return out, firstLoadErr
+	}
+	if loadErrCount > 1 {
+		return out, fmt.Errorf("%w (and %d more module errors)", firstLoadErr, loadErrCount-1)
+	}
+	return out, nil
+}
+
+func trackedGoModuleDirs(root string) ([]string, error) {
+	raw, err := gitCommandOutput(root, "ls-files", "-z")
+	if err != nil {
+		return nil, fmt.Errorf("list tracked Go modules: %w", err)
+	}
+	var dirs []string
+	for _, path := range strings.Split(string(raw), "\x00") {
+		path = filepath.ToSlash(path)
+		if path != "go.mod" && !strings.HasSuffix(path, "/go.mod") {
+			continue
+		}
+		dir := filepath.ToSlash(filepath.Dir(path))
+		dirs = append(dirs, dir)
+	}
+	return dirs, nil
+}
+
+func loadTypedGoModule(moduleRoot string) (map[string]typedGoFile, error) {
+	fset := token.NewFileSet()
+	cfg := &packages.Config{
+		Mode: packages.NeedName |
+			packages.NeedFiles |
+			packages.NeedCompiledGoFiles |
+			packages.NeedImports |
+			packages.NeedDeps |
+			packages.NeedTypes |
+			packages.NeedSyntax |
+			packages.NeedTypesInfo,
+		Dir:   moduleRoot,
+		Fset:  fset,
+		Tests: true,
+	}
+	pkgs, err := packages.Load(cfg, "./...")
+	if err != nil {
+		return nil, fmt.Errorf("load Go type information: %w", err)
+	}
+	out := map[string]typedGoFile{}
+	var firstPackageErr string
+	var packageErrCount int
+	packages.Visit(pkgs, nil, func(pkg *packages.Package) {
+		if pkg == nil {
+			return
+		}
+		for _, pkgErr := range pkg.Errors {
+			packageErrCount++
+			if firstPackageErr == "" {
+				firstPackageErr = pkgErr.Error()
+			}
+		}
+		if pkg.TypesInfo == nil || pkg.Fset == nil {
+			return
+		}
+		for i, file := range pkg.Syntax {
+			if i >= len(pkg.CompiledGoFiles) {
+				break
+			}
+			path := filepath.Clean(pkg.CompiledGoFiles[i])
+			if _, exists := out[path]; exists {
+				continue
+			}
+			out[path] = typedGoFile{File: file, Fset: pkg.Fset, Info: pkg.TypesInfo}
+		}
+	})
+	if packageErrCount == 1 {
+		return out, fmt.Errorf("load Go type information: %s", firstPackageErr)
+	}
+	if packageErrCount > 1 {
+		return out, fmt.Errorf(
+			"load Go type information: %s (and %d more package errors)",
+			firstPackageErr,
+			packageErrCount-1,
+		)
+	}
+	return out, nil
+}
+
+func newFileDomainScan(file typedGoFile) *fileDomainScan {
+	return &fileDomainScan{
+		File:    file.File,
+		Fset:    file.Fset,
+		Info:    file.Info,
+		seen:    map[evidenceKey]bool{},
+		parents: astParentMap(file.File),
+	}
+}
+
+func (s *fileDomainScan) collectSemanticEvidence() {
+	ast.Inspect(s.File, func(node ast.Node) bool {
+		switch n := node.(type) {
+		case *ast.AssignStmt:
+			if len(n.Lhs) != len(n.Rhs) {
+				return true
+			}
+			for i, lhs := range n.Lhs {
+				if s.Info == nil &&
+					potentialHostnameSelectorTarget(lhs) &&
+					s.hasStaticBareHostnameValue(n.Rhs[i]) {
+					s.requireTypeInfo(n.Rhs[i])
+				}
+				if index, ok := stripParens(lhs).(*ast.IndexExpr); ok {
+					switch {
+					case s.isHostnameTarget(index.X):
+						s.addMapPair(index.Index, n.Rhs[i])
+					case s.isHostnameMapKey(index.Index):
+						s.addHostValue(n.Rhs[i], "host assignment")
+					}
+					continue
+				}
+				if s.isHostnameTarget(lhs) {
+					s.addHostValue(n.Rhs[i], "host assignment")
+				}
+			}
+		case *ast.ValueSpec:
+			if len(n.Names) != len(n.Values) {
+				return true
+			}
+			for i, name := range n.Names {
+				if isHostnameSemanticName(name.Name) {
+					s.addHostValue(n.Values[i], "host assignment")
+				}
+			}
+		case *ast.KeyValueExpr:
+			if s.Info == nil && s.keyValueNeedsTypeInfo(n) {
+				s.requireTypeInfo(n.Value)
+			}
+			if s.isHostnameKeyValue(n) {
+				s.addHostValue(n.Value, "host assignment")
+			}
+		}
+		return true
+	})
+}
+
+func (s *fileDomainScan) requireTypeInfo(expr ast.Expr) {
+	for _, existing := range s.TypeInfoRequired {
+		if existing.Pos() == expr.Pos() && existing.End() == expr.End() {
+			return
+		}
+	}
+	s.TypeInfoRequired = append(s.TypeInfoRequired, expr)
+}
+
+func (s *fileDomainScan) hasStaticBareHostnameValue(expr ast.Expr) bool {
+	value, ok := staticStringValue(expr, s.Info, nil)
+	if !ok {
+		return false
+	}
+	host, ok := semanticHostname(value)
+	return ok && !isReservedExampleHostname(host)
+}
+
+func (s *fileDomainScan) keyValueNeedsTypeInfo(pair *ast.KeyValueExpr) bool {
+	composite, ok := s.parents[pair].(*ast.CompositeLit)
+	if !ok {
+		return false
+	}
+	if _, explicitMap := composite.Type.(*ast.MapType); explicitMap {
+		return false
+	}
+	key, ok := pair.Key.(*ast.Ident)
+	return ok && isHostnameSemanticName(key.Name) && s.hasStaticBareHostnameValue(pair.Value)
+}
+
+func potentialHostnameSelectorTarget(expr ast.Expr) bool {
+	switch n := stripParens(expr).(type) {
+	case *ast.SelectorExpr:
+		return isHostnameSemanticName(n.Sel.Name)
+	case *ast.StarExpr:
+		return potentialHostnameSelectorTarget(n.X)
+	case *ast.IndexExpr:
+		return potentialHostnameSelectorTarget(n.X)
+	default:
+		return false
+	}
+}
+
+func (s *fileDomainScan) collectAbsoluteURLEvidence() {
+	ast.Inspect(s.File, func(node ast.Node) bool {
+		expr, ok := node.(ast.Expr)
+		if !ok {
+			return true
+		}
+		if ident, ok := expr.(*ast.Ident); ok && s.Info != nil && s.Info.Defs[ident] != nil {
+			// A declaration name may carry the constant value in types.Info,
+			// but it is not a second source expression.
+			return true
+		}
+		value, ok := staticStringValue(expr, s.Info, nil)
+		if !ok {
+			return true
+		}
+		if s.hasStaticStringContainer(expr) {
+			return true
+		}
+		host, ok := absoluteURLHostname(value)
+		if ok {
+			s.addEvidence(host, "absolute URL", expr)
+		}
+		return true
+	})
+}
+
+func (s *fileDomainScan) hasStaticStringContainer(expr ast.Expr) bool {
+	parent, ok := s.parents[expr].(ast.Expr)
+	if !ok {
+		return false
+	}
+	switch parent.(type) {
+	case *ast.BinaryExpr, *ast.ParenExpr:
+		_, ok := staticStringValue(parent, s.Info, nil)
+		return ok
+	default:
+		return false
+	}
+}
+
+func (s *fileDomainScan) addHostValue(expr ast.Expr, kind string) {
+	expr = stripParens(expr)
+	if composite, ok := expr.(*ast.CompositeLit); ok {
+		switch s.collectionCompositeKind(composite) {
+		case sequenceComposite:
+			for _, element := range composite.Elts {
+				if valueExpr, ok := element.(ast.Expr); ok {
+					s.addHostValue(valueExpr, "host collection")
+				}
+			}
+		case mapComposite:
+			for _, element := range composite.Elts {
+				pair, ok := element.(*ast.KeyValueExpr)
+				if !ok {
+					continue
+				}
+				keyExpr, ok := pair.Key.(ast.Expr)
+				if !ok {
+					continue
+				}
+				s.addMapPair(keyExpr, pair.Value)
+			}
+		default:
+			if s.Info == nil {
+				s.requireTypeInfoForUnclassifiedCollection(composite)
+			}
+			return
+		}
+		return
+	}
+	if evidence, ok := s.hostnameEvidence(expr, kind); ok {
+		s.addEvidence(evidence.Host, evidence.Kind, evidence.Expr)
+	}
+}
+
+func (s *fileDomainScan) requireTypeInfoForUnclassifiedCollection(composite *ast.CompositeLit) {
+	for _, element := range composite.Elts {
+		if pair, ok := element.(*ast.KeyValueExpr); ok {
+			keyExpr, ok := pair.Key.(ast.Expr)
+			if !ok {
+				continue
+			}
+			keyIsHost := s.hasStaticBareHostnameValue(keyExpr)
+			valueIsHost := s.hasStaticBareHostnameValue(pair.Value)
+			if keyIsHost == valueIsHost {
+				continue
+			}
+			if keyIsHost {
+				s.requireTypeInfo(keyExpr)
+			} else {
+				s.requireTypeInfo(pair.Value)
+			}
+			continue
+		}
+		valueExpr, ok := element.(ast.Expr)
+		if ok && s.hasStaticBareHostnameValue(valueExpr) {
+			s.requireTypeInfo(valueExpr)
+		}
+	}
+}
+
+// addMapPair reports a map side only when it is the sole hostname-shaped
+// static value. A semantic map name does not establish whether a string map
+// is hostname->metadata or alias->hostname, so reporting both sides would turn
+// filenames such as client.pem into blocking hostname evidence.
+func (s *fileDomainScan) addMapPair(key, value ast.Expr) {
+	keyEvidence, keyOK := s.hostnameEvidence(key, "host collection")
+	valueEvidence, valueOK := s.hostnameEvidence(value, "host collection")
+	if keyOK == valueOK {
+		return
+	}
+	if keyOK {
+		s.addEvidence(keyEvidence.Host, keyEvidence.Kind, keyEvidence.Expr)
+		return
+	}
+	s.addEvidence(valueEvidence.Host, valueEvidence.Kind, valueEvidence.Expr)
+}
+
+func (s *fileDomainScan) hostnameEvidence(expr ast.Expr, kind string) (domainEvidence, bool) {
+	expr = stripParens(expr)
+	value, ok := staticStringValue(expr, s.Info, nil)
+	if !ok {
+		return domainEvidence{}, false
+	}
+	if host, ok := absoluteURLHostname(value); ok {
+		return domainEvidence{Host: host, Kind: "absolute URL", Expr: expr}, true
+	}
+	if host, ok := semanticHostname(value); ok {
+		return domainEvidence{Host: host, Kind: kind, Expr: expr}, true
+	}
+	return domainEvidence{}, false
+}
+
+func (s *fileDomainScan) collectionCompositeKind(expr *ast.CompositeLit) collectionCompositeKind {
+	if s.Info != nil {
+		if tv, ok := s.Info.Types[expr]; ok && tv.Type != nil {
+			switch tv.Type.Underlying().(type) {
+			case *types.Array, *types.Slice:
+				return sequenceComposite
+			case *types.Map:
+				return mapComposite
+			}
+		}
+	}
+	switch expr.Type.(type) {
+	case *ast.ArrayType:
+		return sequenceComposite
+	case *ast.MapType:
+		return mapComposite
+	default:
+		return notCollectionComposite
+	}
+}
+
+func (s *fileDomainScan) addEvidence(host, kind string, expr ast.Expr) {
+	key := evidenceKey{Host: host, Start: expr.Pos(), End: expr.End()}
+	if s.seen[key] {
+		return
+	}
+	s.seen[key] = true
+	s.Evidence = append(s.Evidence, domainEvidence{Host: host, Kind: kind, Expr: expr})
+}
+
+func staticStringValue(expr ast.Expr, info *types.Info, seen map[*ast.Object]bool) (string, bool) {
+	if info != nil {
+		if tv, ok := info.Types[expr]; ok && tv.Value != nil && tv.Value.Kind() == constant.String {
+			return constant.StringVal(tv.Value), true
+		}
+	}
+	switch n := expr.(type) {
+	case *ast.BasicLit:
+		if n.Kind != token.STRING {
+			return "", false
+		}
+		value, err := strconv.Unquote(n.Value)
+		return value, err == nil
+	case *ast.ParenExpr:
+		return staticStringValue(n.X, info, seen)
+	case *ast.BinaryExpr:
+		if n.Op != token.ADD {
+			return "", false
+		}
+		left, ok := staticStringValue(n.X, info, seen)
+		if !ok {
+			return "", false
+		}
+		right, ok := staticStringValue(n.Y, info, seen)
+		if !ok {
+			return "", false
+		}
+		return left + right, true
+	case *ast.Ident:
+		if info != nil {
+			if obj := info.ObjectOf(n); obj != nil {
+				if c, ok := obj.(*types.Const); ok {
+					if c.Val().Kind() == constant.String {
+						return constant.StringVal(c.Val()), true
+					}
+				}
+			}
+		}
+		if n.Obj == nil || n.Obj.Kind != ast.Con {
+			return "", false
+		}
+		if seen == nil {
+			seen = map[*ast.Object]bool{}
+		}
+		if seen[n.Obj] {
+			return "", false
+		}
+		seen[n.Obj] = true
+		defer delete(seen, n.Obj)
+		spec, ok := n.Obj.Decl.(*ast.ValueSpec)
+		if !ok {
+			return "", false
+		}
+		for i, name := range spec.Names {
+			if name.Name == n.Name && i < len(spec.Values) {
+				return staticStringValue(spec.Values[i], info, seen)
+			}
+		}
+	}
+	return "", false
+}
+
+func absoluteURLHostname(value string) (string, bool) {
+	value = strings.TrimSpace(value)
+	parsed, err := url.Parse(value)
+	if err != nil || parsed.Host == "" {
+		return "", false
+	}
+	switch strings.ToLower(parsed.Scheme) {
+	case "http", "https", "ws", "wss":
+	default:
+		return "", false
+	}
+	return normalizeCandidateHostname(parsed.Hostname())
+}
+
+func semanticHostname(value string) (string, bool) {
+	value = strings.TrimSpace(value)
+	if value == "" || strings.ContainsAny(value, `/\?#@`) || strings.ContainsAny(value, " \t\r\n") {
+		return "", false
+	}
+	parsed, err := url.Parse("//" + value)
+	if err != nil || parsed.Host == "" || parsed.Path != "" {
+		return "", false
+	}
+	return normalizeCandidateHostname(parsed.Hostname())
+}
+
+func normalizeCandidateHostname(host string) (string, bool) {
+	host = strings.TrimSuffix(strings.ToLower(strings.TrimSpace(host)), ".")
+	if host == "" || !strings.Contains(host, ".") || net.ParseIP(host) != nil {
+		return "", false
+	}
+	labels := strings.Split(host, ".")
+	for _, label := range labels {
+		if label == "" || strings.HasPrefix(label, "-") || strings.HasSuffix(label, "-") {
+			return "", false
+		}
+		for _, r := range label {
+			if unicode.IsLetter(r) || unicode.IsDigit(r) || r == '-' {
+				continue
+			}
+			return "", false
+		}
+	}
+	return host, true
+}
+
+func (s *fileDomainScan) isHostnameTarget(expr ast.Expr) bool {
+	switch n := stripParens(expr).(type) {
+	case *ast.Ident:
+		return isHostnameSemanticName(n.Name)
+	case *ast.SelectorExpr:
+		return s.isHostnameSelector(n)
+	case *ast.StarExpr:
+		return s.isHostnameTarget(n.X)
+	default:
+		return false
+	}
+}
+
+func (s *fileDomainScan) isHostnameKeyValue(pair *ast.KeyValueExpr) bool {
+	composite, ok := s.parents[pair].(*ast.CompositeLit)
+	if !ok {
+		return false
+	}
+	switch s.collectionCompositeKind(composite) {
+	case mapComposite:
+		key, ok := pair.Key.(ast.Expr)
+		return ok && s.isHostnameMapKey(key)
+	case notCollectionComposite:
+		ident, ok := pair.Key.(*ast.Ident)
+		return ok && s.isHostnameStructField(composite, ident.Name)
+	default:
+		return false
+	}
+}
+
+func (s *fileDomainScan) isHostnameMapKey(expr ast.Expr) bool {
+	value, ok := staticStringValue(expr, s.Info, nil)
+	return ok && isHostnameSemanticName(value)
+}
+
+func (s *fileDomainScan) isHostnameSelector(selector *ast.SelectorExpr) bool {
+	if s.Info == nil || !isHostnameSemanticName(selector.Sel.Name) {
+		return false
+	}
+	selection := s.Info.Selections[selector]
+	if selection == nil || selection.Kind() != types.FieldVal {
+		return false
+	}
+	return !nonNetworkHostnameFields[hostnameFieldID{
+		Type:  namedTypeID(selection.Recv()),
+		Field: selector.Sel.Name,
+	}]
+}
+
+func (s *fileDomainScan) isHostnameStructField(composite *ast.CompositeLit, field string) bool {
+	if s.Info == nil || !isHostnameSemanticName(field) {
+		return false
+	}
+	typeID := namedTypeID(s.Info.TypeOf(composite))
+	if typeID == "" {
+		return false
+	}
+	return !nonNetworkHostnameFields[hostnameFieldID{Type: typeID, Field: field}]
+}
+
+func namedTypeID(typ types.Type) string {
+	for {
+		switch t := typ.(type) {
+		case *types.Pointer:
+			typ = t.Elem()
+		case *types.Named:
+			obj := t.Obj()
+			if obj == nil || obj.Pkg() == nil {
+				return ""
+			}
+			return obj.Pkg().Path() + "." + obj.Name()
+		default:
+			return ""
+		}
+	}
+}
+
+func isHostnameSemanticName(name string) bool {
+	lower := strings.ToLower(name)
+	switch lower {
+	case "host", "hosts", "hostname", "hostnames", "domain", "domains":
+		return true
+	}
+	for _, marker := range []string{
+		"HostBy", "HostsBy", "HostnameBy", "HostnamesBy", "DomainBy", "DomainsBy",
+	} {
+		if i := strings.Index(name, marker); i >= 0 {
+			end := i + len(marker)
+			if end < len(name) && unicode.IsUpper(rune(name[end])) {
+				return true
+			}
+		}
+	}
+	for _, prefix := range []string{
+		"hostBy", "hostsBy", "hostnameBy", "hostnamesBy", "domainBy", "domainsBy",
+	} {
+		if strings.HasPrefix(name, prefix) &&
+			len(name) > len(prefix) &&
+			unicode.IsUpper(rune(name[len(prefix)])) {
+			return true
+		}
+	}
+	if i := strings.LastIndexAny(name, "_-"); i >= 0 {
+		return isHostnameSemanticName(name[i+1:])
+	}
+	for _, suffix := range []string{"Hostnames", "Hostname", "Domains", "Domain", "Hosts", "Host"} {
+		if strings.HasSuffix(name, suffix) && len(name) > len(suffix) {
+			return true
+		}
+	}
+	return false
+}
+
+func stripParens(expr ast.Expr) ast.Expr {
+	for {
+		paren, ok := expr.(*ast.ParenExpr)
+		if !ok {
+			return expr
+		}
+		expr = paren.X
+	}
+}
+
+func astParentMap(root ast.Node) map[ast.Node]ast.Node {
+	parents := map[ast.Node]ast.Node{}
+	var stack []ast.Node
+	ast.Inspect(root, func(node ast.Node) bool {
+		if node == nil {
+			stack = stack[:len(stack)-1]
+			return false
+		}
+		if len(stack) > 0 {
+			parents[node] = stack[len(stack)-1]
+		}
+		stack = append(stack, node)
+		return true
+	})
+	return parents
+}
+
+func isDomainFixturePath(rel string) bool {
+	rel = filepath.ToSlash(rel)
+	if strings.HasPrefix(rel, "skills/") {
+		return false
+	}
+	if strings.HasSuffix(rel, "_test.go") || strings.HasPrefix(rel, "tests/") {
+		return true
+	}
+	for _, part := range strings.Split(rel, "/") {
+		if part == "testdata" {
+			return true
+		}
+	}
+	return false
+}
+
+func unusedDomainViolation(entry domainPolicyEntry) lintapi.Violation {
+	return lintapi.Violation{
+		Rule:       unusedDomainRule,
+		Action:     lintapi.ActionReject,
+		File:       entry.File,
+		Line:       entry.Line,
+		Message:    fmt.Sprintf("domain allowlist entry %q has no in-scope Go reference", entry.Host),
+		Suggestion: "remove the unused entry; allowlist entries must be justified by a current in-scope reference",
+	}
+}
+
+func incompleteDomainViolation(file string, err error) lintapi.Violation {
+	return incompleteDomainViolationAt(file, 1, err)
+}
+
+func incompleteDomainViolationAt(file string, line int, err error) lintapi.Violation {
+	return lintapi.Violation{
+		Rule:       incompleteDomainRule,
+		Action:     lintapi.ActionReject,
+		File:       file,
+		Line:       line,
+		Message:    "domain scan incomplete: " + err.Error(),
+		Suggestion: "fix the Go parse or type-loading error so hostname analysis can complete",
+	}
+}

lint/domaincontract/unapproved_repo_test.go

@@ -0,0 +1,462 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package domaincontract
+
+import (
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/larksuite/cli/lint/lintapi"
+)
+
+func gitTestCommand(t *testing.T, root string, args ...string) string {
+	t.Helper()
+	cmd := exec.Command("git", args...)
+	cmd.Dir = root
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("git %s: %v\n%s", strings.Join(args, " "), err, out)
+	}
+	return strings.TrimSpace(string(out))
+}
+
+func setupDomainDiffRepo(t *testing.T, target string) (root, base string) {
+	t.Helper()
+	root = t.TempDir()
+	writeFile(t, root, "go.mod", "module example.com/domainfixture\n\ngo 1.23.0\n")
+	writeFile(t, root, publicDomainsPath, "# public\npublic.example.com\n")
+	writeFile(t, root, fixtureDomainsPath, "# fixtures\nfixture.example.com\n")
+	writeFile(t, root, "policy_refs.go", "package sample\n\nvar APIHost = \"public.example.com\"\n")
+	writeFile(t, root, "policy_refs_test.go", "package sample\n\nvar FixtureHost = \"fixture.example.com\"\n")
+	writeFile(t, root, "target.go", target)
+
+	gitTestCommand(t, root, "init", "-q")
+	gitTestCommand(t, root, "config", "user.name", "Domain Contract Test")
+	gitTestCommand(t, root, "config", "user.email", "domain-contract@example.com")
+	gitTestCommand(t, root, "add", ".")
+	gitTestCommand(t, root, "-c", "commit.gpgsign=false", "commit", "-qm", "base")
+	return root, gitTestCommand(t, root, "rev-parse", "HEAD")
+}
+
+func commitDomainDiff(t *testing.T, root, message string) {
+	t.Helper()
+	gitTestCommand(t, root, "add", "-A")
+	gitTestCommand(t, root, "-c", "commit.gpgsign=false", "commit", "-qm", message)
+}
+
+func violationsForRule(vs []lintapi.Violation, rule string) []lintapi.Violation {
+	var out []lintapi.Violation
+	for _, v := range vs {
+		if v.Rule == rule {
+			out = append(out, v)
+		}
+	}
+	return out
+}
+
+func scanDomainDiff(t *testing.T, root, base string) []lintapi.Violation {
+	t.Helper()
+	vs, err := ScanRepoWithOptions(root, ScanOptions{ChangedFrom: base})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return vs
+}
+
+func TestUnapprovedDomainDiffContract(t *testing.T) {
+	t.Run("new PR 1975 case", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nvar unrelated = 1\nvar APIHost = \"internal-api-drive-stream.larkoffice.com\"\n")
+		commitDomainDiff(t, root, "add internal host")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "internal-api-drive-stream.larkoffice.com") {
+			t.Fatalf("violations = %+v, want PR 1975 hostname", got)
+		}
+	})
+
+	t.Run("hostname field in nested Go module", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "nested/go.mod", "module example.com/nested\n\ngo 1.23.0\n")
+		writeFile(t, root, "nested/target.go",
+			"package nested\n\ntype Config struct{ Host string }\n\n"+
+				"var config = Config{Host: \"private.corp.internal\"}\n")
+		commitDomainDiff(t, root, "add nested module hostname")
+
+		all := scanDomainDiff(t, root, base)
+		got := violationsForRule(all, unapprovedDomainRule)
+		if len(got) != 1 || filepath.ToSlash(got[0].File) != "nested/target.go" ||
+			!strings.Contains(got[0].Message, "private.corp.internal") {
+			t.Fatalf("violations = %+v, want nested-module hostname rejection", got)
+		}
+		if incomplete := violationsForRule(all, incompleteDomainRule); len(incomplete) != 0 {
+			t.Fatalf("nested module must have complete type information: %+v", incomplete)
+		}
+	})
+
+	t.Run("changed excluded field reports incomplete scan", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "excluded.go",
+			"//go:build domaincontract_never && !domaincontract_never\n\npackage sample\n\n"+
+				"type Config struct{ Host string }\n\n"+
+				"var config = Config{Host: \"private.corp.internal\"}\n")
+		commitDomainDiff(t, root, "add excluded hostname field")
+
+		all := scanDomainDiff(t, root, base)
+		got := violationsForRule(all, incompleteDomainRule)
+		if len(got) != 1 || filepath.Base(got[0].File) != "excluded.go" || got[0].Line != 7 {
+			t.Fatalf("violations = %+v, want changed field scan-incomplete at line 7", got)
+		}
+		if unapproved := violationsForRule(all, unapprovedDomainRule); len(unapproved) != 0 {
+			t.Fatalf("untyped field must not produce an unverified hostname finding: %+v", unapproved)
+		}
+	})
+
+	t.Run("changed excluded selector reports incomplete scan", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "excluded.go",
+			"//go:build domaincontract_never && !domaincontract_never\n\npackage sample\n\n"+
+				"type Config struct{ Host string }\n\n"+
+				"func configure(config *Config) { config.Host = \"private.corp.internal\" }\n")
+		commitDomainDiff(t, root, "add excluded hostname selector")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), incompleteDomainRule)
+		if len(got) != 1 || filepath.Base(got[0].File) != "excluded.go" || got[0].Line != 7 {
+			t.Fatalf("violations = %+v, want changed selector scan-incomplete at line 7", got)
+		}
+	})
+
+	t.Run("changed excluded named slice reports incomplete scan", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "excluded.go",
+			"//go:build domaincontract_never && !domaincontract_never\n\npackage sample\n\n"+
+				"type HostList []string\n\n"+
+				"var AllowedHosts = HostList{\n\t\"attacker.zip\",\n}\n")
+		commitDomainDiff(t, root, "add excluded hostname slice")
+
+		all := scanDomainDiff(t, root, base)
+		got := violationsForRule(all, incompleteDomainRule)
+		if len(got) != 1 || filepath.Base(got[0].File) != "excluded.go" || got[0].Line != 8 {
+			t.Fatalf("violations = %+v, want named-slice scan-incomplete at line 8", got)
+		}
+		if unapproved := violationsForRule(all, unapprovedDomainRule); len(unapproved) != 0 {
+			t.Fatalf("untyped named slice must not produce an unverified hostname finding: %+v", unapproved)
+		}
+	})
+
+	t.Run("changed excluded named map reports incomplete scan", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "excluded.go",
+			"//go:build domaincontract_never && !domaincontract_never\n\npackage sample\n\n"+
+				"type HostSet map[string]struct{}\n\n"+
+				"var AllowedHosts = HostSet{\n\t\"attacker.zip\": {},\n}\n")
+		commitDomainDiff(t, root, "add excluded hostname map")
+
+		all := scanDomainDiff(t, root, base)
+		got := violationsForRule(all, incompleteDomainRule)
+		if len(got) != 1 || filepath.Base(got[0].File) != "excluded.go" || got[0].Line != 8 {
+			t.Fatalf("violations = %+v, want named-map scan-incomplete at line 8", got)
+		}
+		if unapproved := violationsForRule(all, unapprovedDomainRule); len(unapproved) != 0 {
+			t.Fatalf("untyped named map must not produce an unverified hostname finding: %+v", unapproved)
+		}
+	})
+
+	t.Run("changed excluded unrelated code stays allowed", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "excluded.go",
+			"//go:build domaincontract_never && !domaincontract_never\n\npackage sample\n\nvar unrelated = 2\n")
+		commitDomainDiff(t, root, "add excluded unrelated code")
+
+		if got := violationsForRule(scanDomainDiff(t, root, base), incompleteDomainRule); len(got) != 0 {
+			t.Fatalf("unrelated excluded code must not require hostname type information: %+v", got)
+		}
+	})
+
+	t.Run("new element in existing collection", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t,
+			"package sample\n\nvar ExtraHosts = []string{\n\t\"public.example.com\",\n}\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nvar ExtraHosts = []string{\n\t\"public.example.com\",\n\t\"attacker.zip\",\n}\n")
+		commitDomainDiff(t, root, "add collection host")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "attacker.zip") {
+			t.Fatalf("violations = %+v, want attacker.zip", got)
+		}
+		if got[0].Line != 5 {
+			t.Fatalf("violation line = %d, want 5", got[0].Line)
+		}
+	})
+
+	t.Run("multiline expression changed segment", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t,
+			"package sample\n\nvar ExtraHost = \"private.corp.\" +\n\t\"example.com\"\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nvar ExtraHost = \"private.corp.\" +\n\t\"internal\"\n")
+		commitDomainDiff(t, root, "change concatenated host")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "private.corp.internal") {
+			t.Fatalf("violations = %+v, want private.corp.internal", got)
+		}
+		if got[0].Line != 4 {
+			t.Fatalf("violation line = %d, want changed line 4", got[0].Line)
+		}
+	})
+
+	t.Run("unrelated change beside historical hostname", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t,
+			"package sample\n\nvar HistoricalHost = \"historical.private.internal\"\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nvar HistoricalHost = \"historical.private.internal\"\nvar unrelated = 1\n")
+		commitDomainDiff(t, root, "add unrelated value")
+
+		if got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule); len(got) != 0 {
+			t.Fatalf("unexpected historical-domain violation: %+v", got)
+		}
+	})
+
+	t.Run("historical hostname expression changed", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t,
+			"package sample\n\nvar HistoricalHost = \"historical.private.internal\"\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nvar HistoricalHost = \"replacement.private.internal\"\n")
+		commitDomainDiff(t, root, "change historical host")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "replacement.private.internal") {
+			t.Fatalf("violations = %+v, want replacement.private.internal", got)
+		}
+	})
+
+	t.Run("new assignment references existing constant", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t,
+			"package sample\n\nconst existingConst = \"private.corp.internal\"\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nconst existingConst = \"private.corp.internal\"\nvar APIHost = existingConst\n")
+		commitDomainDiff(t, root, "use existing hostname constant")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "private.corp.internal") {
+			t.Fatalf("violations = %+v, want private.corp.internal", got)
+		}
+		if got[0].Line != 4 {
+			t.Fatalf("violation line = %d, want 4", got[0].Line)
+		}
+	})
+
+	t.Run("allowlisted hostname", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nvar unrelated = 1\nvar BackupHost = \"public.example.com\"\n")
+		commitDomainDiff(t, root, "add public host")
+
+		if got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule); len(got) != 0 {
+			t.Fatalf("unexpected public-domain violation: %+v", got)
+		}
+	})
+
+	t.Run("reserved example URL", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nvar unrelated = 1\nfunc fakeValue() string { return \"https://example.test/resource\" }\n")
+		commitDomainDiff(t, root, "add safe example URL")
+
+		if got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule); len(got) != 0 {
+			t.Fatalf("unexpected reserved-example violation: %+v", got)
+		}
+	})
+
+	t.Run("historical type gap suppresses unused policy diagnostics", func(t *testing.T) {
+		root, _ := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, publicDomainsPath,
+			"# public\nplatform.example.com\npublic.example.com\n")
+		writeFile(t, root, "excluded.go",
+			"//go:build domaincontract_never && !domaincontract_never\n\npackage sample\n\n"+
+				"type Config struct{ Host string }\n\n"+
+				"var config = Config{Host: \"platform.example.com\"}\n")
+		commitDomainDiff(t, root, "add historical platform hostname")
+		base := gitTestCommand(t, root, "rev-parse", "HEAD")
+
+		writeFile(t, root, "target.go", "package sample\n\nvar unrelated = 2\n")
+		commitDomainDiff(t, root, "change unrelated code")
+
+		all := scanDomainDiff(t, root, base)
+		if got := violationsForRule(all, incompleteDomainRule); len(got) != 0 {
+			t.Fatalf("historical type gap must not be attributed to this change: %+v", got)
+		}
+		if got := violationsForRule(all, unusedDomainRule); len(got) != 0 {
+			t.Fatalf("incomplete inventory must not produce unused-policy diagnostics: %+v", got)
+		}
+	})
+
+	t.Run("allowlist does not approve subdomains", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nvar unrelated = 1\nvar BackupHost = \"evil.public.example.com\"\n")
+		commitDomainDiff(t, root, "add unapproved public subdomain")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "evil.public.example.com") {
+			t.Fatalf("violations = %+v, want evil.public.example.com", got)
+		}
+	})
+
+	t.Run("multi assignment pairs names and values", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, publicDomainsPath,
+			"# public\nopen.larksuite.com\npublic.example.com\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nvar unrelated = 1\nvar APIHost, BackupHost = \"open.larksuite.com\", \"attacker.zip\"\n")
+		commitDomainDiff(t, root, "add multiple hosts")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "attacker.zip") {
+			t.Fatalf("violations = %+v, want only attacker.zip", got)
+		}
+	})
+
+	t.Run("IDN hostname is rejected", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nvar unrelated = 1\nvar BackupHost = \"例子.公司.cn\"\n")
+		commitDomainDiff(t, root, "add IDN hostname")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "例子.公司.cn") {
+			t.Fatalf("violations = %+v, want IDN hostname", got)
+		}
+	})
+
+	t.Run("fixture limited to test files", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nvar unrelated = 1\nvar ProductionHost = \"fixture.example.com\"\n")
+		commitDomainDiff(t, root, "use fixture in production")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "fixture.example.com") {
+			t.Fatalf("violations = %+v, want production fixture rejection", got)
+		}
+		if !strings.Contains(got[0].Suggestion, "fixture-only hostname") ||
+			strings.Contains(got[0].Suggestion, "public allowlist") {
+			t.Fatalf("suggestion = %q, want fixture-scope guidance", got[0].Suggestion)
+		}
+	})
+
+	t.Run("fixture accepted in test file", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "new_target_test.go",
+			"package sample\n\nvar BackupHost = \"fixture.example.com\"\n")
+		commitDomainDiff(t, root, "use fixture in test")
+
+		if got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule); len(got) != 0 {
+			t.Fatalf("unexpected fixture-domain violation: %+v", got)
+		}
+	})
+
+	t.Run("fixture allowlist does not approve subdomains", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "new_target_test.go",
+			"package sample\n\nvar BackupHost = \"evil.fixture.example.com\"\n")
+		commitDomainDiff(t, root, "use unapproved fixture subdomain")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "evil.fixture.example.com") {
+			t.Fatalf("violations = %+v, want exact fixture match", got)
+		}
+	})
+
+	t.Run("fixture rejected in skills", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "skills/example/example_test.go",
+			"package example\n\nvar BackupHost = \"fixture.example.com\"\n")
+		commitDomainDiff(t, root, "use fixture in skill")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "fixture.example.com") {
+			t.Fatalf("violations = %+v, want skill fixture rejection", got)
+		}
+	})
+
+	t.Run("pure rename", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t,
+			"package sample\n\nvar HistoricalHost = \"historical.private.internal\"\n")
+		gitTestCommand(t, root, "mv", "target.go", "renamed.go")
+		commitDomainDiff(t, root, "rename file")
+
+		if got := violationsForRule(scanDomainDiff(t, root, base), unapprovedDomainRule); len(got) != 0 {
+			t.Fatalf("unexpected rename violation: %+v", got)
+		}
+	})
+}
+
+func TestUnapprovedDomainPolicyAndFailurePaths(t *testing.T) {
+	t.Run("unused policy entry", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, publicDomainsPath,
+			"# public\npublic.example.com\nunused.example.com\n")
+		commitDomainDiff(t, root, "add unused policy")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unusedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "unused.example.com") {
+			t.Fatalf("violations = %+v, want unused.example.com", got)
+		}
+	})
+
+	t.Run("public entry used only by fixture", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, publicDomainsPath,
+			"# public\npublic.example.com\ntest-only.example.com\n")
+		writeFile(t, root, "public_only_test.go",
+			"package sample\n\nvar BackupHost = \"test-only.example.com\"\n")
+		commitDomainDiff(t, root, "add test-only public policy")
+
+		got := violationsForRule(scanDomainDiff(t, root, base), unusedDomainRule)
+		if len(got) != 1 || !strings.Contains(got[0].Message, "test-only.example.com") {
+			t.Fatalf("violations = %+v, want test-only.example.com", got)
+		}
+	})
+
+	t.Run("changed Go parse failure", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "target.go", "package sample\n\nfunc broken(\n")
+		commitDomainDiff(t, root, "break source")
+
+		all := scanDomainDiff(t, root, base)
+		got := violationsForRule(all, incompleteDomainRule)
+		if len(got) != 1 || filepath.Base(got[0].File) != "target.go" {
+			t.Fatalf("violations = %+v, want target.go scan-incomplete", got)
+		}
+		if unused := violationsForRule(all, unusedDomainRule); len(unused) != 0 {
+			t.Fatalf("parse failure must not produce unreliable unused-policy diagnostics: %+v", unused)
+		}
+	})
+
+	t.Run("repository type loading failure", func(t *testing.T) {
+		root, base := setupDomainDiffRepo(t, "package sample\n\nvar unrelated = 1\n")
+		writeFile(t, root, "go.mod", "module example.com/domainfixture\n\ngo 1.23.0\n\n"+
+			"require example.com/missing v0.0.0\n\nreplace example.com/missing => ./missing\n")
+		writeFile(t, root, "target.go",
+			"package sample\n\nimport _ \"example.com/missing\"\n\n"+
+				"type Config struct{ Host string }\nvar config = Config{Host: \"malicious.corp.internal\"}\n")
+		commitDomainDiff(t, root, "break type loading")
+
+		all := scanDomainDiff(t, root, base)
+		got := violationsForRule(all, incompleteDomainRule)
+		if len(got) != 1 || filepath.Base(got[0].File) != "go.mod" {
+			t.Fatalf("violations = %+v, want go.mod scan-incomplete", got)
+		}
+		if !strings.Contains(got[0].Message, "load Go type information") {
+			t.Fatalf("message = %q, want type-loading failure", got[0].Message)
+		}
+		if unused := violationsForRule(all, unusedDomainRule); len(unused) != 0 {
+			t.Fatalf("type-loading failure must not produce unreliable unused-policy diagnostics: %+v", unused)
+		}
+	})
+}

lint/domaincontract/unapproved_test.go

@@ -0,0 +1,380 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package domaincontract
+
+import (
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"go/types"
+	"sort"
+	"testing"
+)
+
+func scanDomainEvidence(t *testing.T, source string) []domainEvidence {
+	t.Helper()
+	fset := token.NewFileSet()
+	file, err := parser.ParseFile(fset, "fixture.go", source, 0)
+	if err != nil {
+		t.Fatalf("parse fixture: %v\n%s", err, source)
+	}
+	scan := newFileDomainScan(typedGoFile{File: file, Fset: fset})
+	scan.collectSemanticEvidence()
+	scan.collectAbsoluteURLEvidence()
+	sort.Slice(scan.Evidence, func(i, j int) bool {
+		if scan.Evidence[i].Host != scan.Evidence[j].Host {
+			return scan.Evidence[i].Host < scan.Evidence[j].Host
+		}
+		return scan.Evidence[i].Expr.Pos() < scan.Evidence[j].Expr.Pos()
+	})
+	return scan.Evidence
+}
+
+func scanTypedDomainEvidence(t *testing.T, source string) []domainEvidence {
+	t.Helper()
+	return scanTypedDomainEvidenceInPackage(t, "fixture", source)
+}
+
+func scanTypedDomainEvidenceInPackage(t *testing.T, packagePath, source string) []domainEvidence {
+	t.Helper()
+	fset := token.NewFileSet()
+	file, err := parser.ParseFile(fset, "fixture.go", source, 0)
+	if err != nil {
+		t.Fatalf("parse fixture: %v\n%s", err, source)
+	}
+	info := &types.Info{
+		Types:      map[ast.Expr]types.TypeAndValue{},
+		Defs:       map[*ast.Ident]types.Object{},
+		Uses:       map[*ast.Ident]types.Object{},
+		Selections: map[*ast.SelectorExpr]*types.Selection{},
+	}
+	if _, err := (&types.Config{}).Check(packagePath, fset, []*ast.File{file}, info); err != nil {
+		t.Fatalf("type-check fixture: %v\n%s", err, source)
+	}
+	scan := newFileDomainScan(typedGoFile{File: file, Fset: fset, Info: info})
+	scan.collectSemanticEvidence()
+	scan.collectAbsoluteURLEvidence()
+	sort.Slice(scan.Evidence, func(i, j int) bool {
+		if scan.Evidence[i].Host != scan.Evidence[j].Host {
+			return scan.Evidence[i].Host < scan.Evidence[j].Host
+		}
+		return scan.Evidence[i].Expr.Pos() < scan.Evidence[j].Expr.Pos()
+	})
+	return scan.Evidence
+}
+
+func evidenceHosts(evidence []domainEvidence) []string {
+	hosts := make([]string, 0, len(evidence))
+	for _, item := range evidence {
+		hosts = append(hosts, item.Host)
+	}
+	return hosts
+}
+
+func TestTypedAbsoluteURLDeclarationProducesOneFinding(t *testing.T) {
+	evidence := scanTypedDomainEvidence(t,
+		"package p\nconst DomainContractE2EURL = \"https://private.corp.internal/v1\"\n")
+	if got := evidenceHosts(evidence); len(got) != 1 || got[0] != "private.corp.internal" {
+		t.Fatalf("hosts = %v, want [private.corp.internal]", got)
+	}
+}
+
+func TestGoDomainEvidenceTruePositives(t *testing.T) {
+	tests := []struct {
+		name   string
+		source string
+		want   []string
+	}{
+		{
+			name:   "PR 1975 Feishu assignment",
+			source: "package p\nfunc f() { host := \"internal-api-drive-stream.feishu.cn\"; _ = host }\n",
+			want:   []string{"internal-api-drive-stream.feishu.cn"},
+		},
+		{
+			name:   "PR 1975 Lark assignment",
+			source: "package p\nfunc f() { var host string; host = \"internal-api-drive-stream.larksuite.com\"; _ = host }\n",
+			want:   []string{"internal-api-drive-stream.larksuite.com"},
+		},
+		{
+			name:   "uppercase snake target",
+			source: "package p\nfunc f() { API_HOST := \"private.corp.internal\"; _ = API_HOST }\n",
+			want:   []string{"private.corp.internal"},
+		},
+		{
+			name:   "typed declaration",
+			source: "package p\nconst APIHost string = \"attacker.zip\"\n",
+			want:   []string{"attacker.zip"},
+		},
+		{
+			name:   "grouped const declaration",
+			source: "package p\nconst (\n APIHost string = \"attacker.zip\"\n)\n",
+			want:   []string{"attacker.zip"},
+		},
+		{
+			name:   "grouped var declaration",
+			source: "package p\nvar (\n APIHost string = \"attacker.zip\"\n)\n",
+			want:   []string{"attacker.zip"},
+		},
+		{
+			name: "multi assignment",
+			source: "package p\nfunc f() {\n" +
+				" APIHost, BackupHost := \"public.example.com\", \"attacker.zip\"\n" +
+				" _, _ = APIHost, BackupHost\n}\n",
+			want: []string{"attacker.zip", "public.example.com"},
+		},
+		{
+			name:   "map semantic key",
+			source: "package p\nvar c = map[string]string{\"host\": \"private.corp.internal\"}\n",
+			want:   []string{"private.corp.internal"},
+		},
+		{
+			name:   "map semantic key assignment",
+			source: "package p\nfunc f() { c := map[string]string{}; c[\"host\"] = \"private.corp.internal\" }\n",
+			want:   []string{"private.corp.internal"},
+		},
+		{
+			name:   "host collection values",
+			source: "package p\nvar ALLOWED_HOSTS = []string{\"private.corp.internal\", \"attacker.zip\"}\n",
+			want:   []string{"attacker.zip", "private.corp.internal"},
+		},
+		{
+			name:   "host collection map keys",
+			source: "package p\nvar allowedHosts = map[string]struct{}{\"attacker.zip\": {}}\n",
+			want:   []string{"attacker.zip"},
+		},
+		{
+			name:   "host collection bool map keys",
+			source: "package p\nvar AllowedHosts = map[string]bool{\"api.example.com\": true}\n",
+			want:   []string{"api.example.com"},
+		},
+		{
+			name:   "host collection map values",
+			source: "package p\nvar HostsByRegion = map[string]string{\"sg\": \"api.example.com\"}\n",
+			want:   []string{"api.example.com"},
+		},
+		{
+			name: "host collection map value assignment",
+			source: "package p\nfunc f() {\n" +
+				" HostsByRegion := map[string]string{}\n" +
+				" HostsByRegion[\"sg\"] = \"api.example.com\"\n" +
+				"}\n",
+			want: []string{"api.example.com"},
+		},
+		{
+			name:   "static concatenation",
+			source: "package p\nvar APIHost = \"attacker.\" + \"zip\"\n",
+			want:   []string{"attacker.zip"},
+		},
+		{
+			name:   "multiline assignment",
+			source: "package p\nfunc f() {\n APIHost :=\n  \"attacker.zip\"\n _ = APIHost\n}\n",
+			want:   []string{"attacker.zip"},
+		},
+		{
+			name:   "escaped hostname",
+			source: "package p\nvar APIHost = \"private\\u002ecorp\\u002einternal\"\n",
+			want:   []string{"private.corp.internal"},
+		},
+		{
+			name:   "hex escaped hostname",
+			source: "package p\nvar APIHost = \"private\\x2ecorp\\x2einternal\"\n",
+			want:   []string{"private.corp.internal"},
+		},
+		{
+			name:   "octal escaped hostname",
+			source: "package p\nvar APIHost = \"private\\056corp\\056internal\"\n",
+			want:   []string{"private.corp.internal"},
+		},
+		{
+			name:   "raw hostname",
+			source: "package p\nvar APIHost = `private.corp.internal`\n",
+			want:   []string{"private.corp.internal"},
+		},
+		{
+			name: "same-file constant reference",
+			source: "package p\nconst existingConst = \"private.corp.internal\"\n" +
+				"func f() { APIHost := existingConst; _ = APIHost }\n",
+			want: []string{"private.corp.internal"},
+		},
+		{
+			name:   "absolute URL",
+			source: "package p\nvar message = \"https://private.corp.internal/v1\"\n",
+			want:   []string{"private.corp.internal"},
+		},
+		{
+			name:   "websocket URL with port",
+			source: "package p\nvar endpoint = \"wss://private.corp.internal:443/v1\"\n",
+			want:   []string{"private.corp.internal"},
+		},
+		{
+			name:   "URL userinfo query and fragment",
+			source: "package p\nvar endpoint = \" https://user:pass@private.corp.internal:8443/v1?q=1#result \"\n",
+			want:   []string{"private.corp.internal"},
+		},
+		{
+			name:   "IDN hostname",
+			source: "package p\nvar APIHost = \"例子.公司.cn\"\n",
+			want:   []string{"例子.公司.cn"},
+		},
+		{
+			name:   "case port and trailing dot normalization",
+			source: "package p\nvar APIHost = \"EXAMPLE.COM.:443\"\n",
+			want:   []string{"example.com"},
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := evidenceHosts(scanDomainEvidence(t, tc.source))
+			if len(got) != len(tc.want) {
+				t.Fatalf("hosts = %v, want %v", got, tc.want)
+			}
+			for i := range got {
+				if got[i] != tc.want[i] {
+					t.Fatalf("hosts = %v, want %v", got, tc.want)
+				}
+			}
+		})
+	}
+}
+
+func TestGoDomainEvidenceTrueNegatives(t *testing.T) {
+	source := `package p
+
+import _ "github.com/larksuite/oapi-sdk-go/v3"
+
+var file = "archive.zip"
+var event = "card.action.trigger"
+var schema = "im.messages.list"
+var configFile = "service.prod.json"
+var version = "v1.2.3"
+var email = "name@example.com"
+var lowConfidence = "attacker.zip"
+var downloadURL = "archive.zip/file"
+var prose = "See https://private.corp.internal/v1 for details"
+// https://private.corp.internal/v1
+var ghost = "private.corp.internal"
+var hostnameParser = "private.corp.internal"
+var domainError = "private.corp.internal"
+var APIHost = "localhost"
+var BackupHost = "127.0.0.1"
+var hosts = struct{ File string }{File: "archive.zip"}
+var AllowedHosts = map[string]string{"api.example.com": "client.pem"}
+
+func dynamicValue() string { return "private.corp.internal" }
+var DynamicHost = dynamicValue()
+
+func setAmbiguousHostMetadata() {
+	AllowedHosts["api.example.com"] = "client.pem"
+}
+`
+	if got := scanDomainEvidence(t, source); len(got) != 0 {
+		t.Fatalf("unexpected evidence: %+v", got)
+	}
+}
+
+func TestTypedStructFieldHostnameSemantics(t *testing.T) {
+	t.Run("network fields", func(t *testing.T) {
+		source := `package source
+
+type Config struct { Host string }
+type FeishuSource struct { Domain string }
+
+var config = Config{Host: "api.example.com"}
+var source = FeishuSource{Domain: "events.example.com"}
+`
+		got := evidenceHosts(scanTypedDomainEvidenceInPackage(
+			t,
+			"github.com/larksuite/cli/internal/event/source",
+			source,
+		))
+		want := []string{"api.example.com", "events.example.com"}
+		if len(got) != len(want) || got[0] != want[0] || got[1] != want[1] {
+			t.Fatalf("hosts = %v, want %v", got, want)
+		}
+	})
+
+	t.Run("command metadata domain", func(t *testing.T) {
+		source := `package cmdmeta
+
+type Meta struct { Domain string }
+
+var meta = Meta{Domain: "im.messages"}
+func update(meta *Meta) { meta.Domain = "docs.pages" }
+`
+		if got := scanTypedDomainEvidenceInPackage(
+			t,
+			"github.com/larksuite/cli/internal/cmdmeta",
+			source,
+		); len(got) != 0 {
+			t.Fatalf("unexpected command metadata evidence: %+v", got)
+		}
+	})
+
+	t.Run("card action host", func(t *testing.T) {
+		source := `package im
+
+type CardActionTriggerOutput struct { Host string }
+
+var output = CardActionTriggerOutput{Host: "card.action"}
+func update(output *CardActionTriggerOutput) { output.Host = "im.message" }
+`
+		if got := scanTypedDomainEvidenceInPackage(
+			t,
+			"github.com/larksuite/cli/events/im",
+			source,
+		); len(got) != 0 {
+			t.Fatalf("unexpected card host evidence: %+v", got)
+		}
+	})
+
+	t.Run("unknown field ownership is conservative", func(t *testing.T) {
+		source := "package p\ntype Config struct { Host string }\nvar c = Config{Host: \"api.example.com\"}\n"
+		if got := scanDomainEvidence(t, source); len(got) != 0 {
+			t.Fatalf("unexpected untyped field evidence: %+v", got)
+		}
+	})
+}
+
+func TestHostnameSemanticNames(t *testing.T) {
+	for _, name := range []string{
+		"host", "HOST", "hosts", "hostname", "domains",
+		"api_host", "API_HOST", "ALLOWED_HOSTS",
+		"apiHost", "APIHost", "backupHostname",
+		"HostsByRegion", "APIHostsByRegion", "hostsByRegion",
+	} {
+		if !isHostnameSemanticName(name) {
+			t.Errorf("%q should be hostname-semantic", name)
+		}
+	}
+	for _, name := range []string{
+		"ghost", "hostnameParser", "domainError", "hostValue", "downloadURL", "endpoint", "origin",
+		"HostBypass", "APIHostBypass",
+	} {
+		if isHostnameSemanticName(name) {
+			t.Errorf("%q must not be hostname-semantic", name)
+		}
+	}
+}
+
+func TestDomainFixturePaths(t *testing.T) {
+	for _, path := range []string{
+		"internal/x/x_test.go",
+		"tests/cli_e2e/x.go",
+		"internal/x/testdata/sample.go",
+	} {
+		if !isDomainFixturePath(path) {
+			t.Errorf("%q should be fixture scope", path)
+		}
+	}
+	for _, path := range []string{
+		"internal/x/test_helper.go",
+		"examples/demo.go",
+		"skills/example/testdata/sample.go",
+		"skills/example/example_test.go",
+	} {
+		if isDomainFixturePath(path) {
+			t.Errorf("%q must not be fixture scope", path)
+		}
+	}
+}

lint/main.go

@@ -3,7 +3,7 @@
 
 // Command lintcheck runs repository source-contract guards that golangci-lint
 // cannot express directly. It currently covers typed-error contracts and the
-// resolver-owned endpoint contract.
+// resolver-owned endpoint and approved-domain contracts.
 //
 // lintcheck lives in its own Go module under lint/ so its build-time
 // dependency on golang.org/x/tools/go/packages does not leak into the
@@ -43,8 +43,10 @@ type scanner struct {
 
 var scanners = []scanner{
 	{name: "errscontract", fn: errscontract.ScanRepoWithOptions},
-	{name: "domaincontract", fn: func(root string, _ errscontract.ScanOptions) ([]lintapi.Violation, error) {
-		return domaincontract.ScanRepo(root)
+	{name: "domaincontract", fn: func(root string, opts errscontract.ScanOptions) ([]lintapi.Violation, error) {
+		return domaincontract.ScanRepoWithOptions(root, domaincontract.ScanOptions{
+			ChangedFrom: opts.ChangedFrom,
+		})
 	}},
 }
 
@@ -57,7 +59,7 @@ func main() {
 				"Runs every registered lint domain against repo-root (default: current directory).\n")
 		flag.PrintDefaults()
 	}
-	flag.StringVar(&changedFrom, "changed-from", "", "base revision for incremental boundary-error checks")
+	flag.StringVar(&changedFrom, "changed-from", "", "base revision for incremental source-contract checks")
 	flag.BoolVar(&printLegacyCommandErrorCandidates, "print-legacy-command-error-candidates", false, "print existing command boundary bare errors as allowlist candidates")
 	flag.Parse()