fix(opencode): pass --agent flag when agent config option is set (#1210)

Adds optional 'agent' config option under [projects.agent.options] for
opencode. When set, the value is passed as --agent to every 'opencode run'
invocation, enabling plugin-defined agents (e.g. oh-my-openagent's
'Sisyphus - Ultraworker') to work correctly without falling back to the
default agent.

Co-authored-by: Cursor <cursoragent@cursor.com>

agent/opencode/opencode.go

@@ -33,6 +33,7 @@ type Agent struct {
 	model                string
 	mode                 string
 	cmd                  string // CLI binary name, default "opencode"
+	agentName            string // passed as --agent to opencode (for plugin-defined agents)
 	providers            []core.ProviderConfig
 	activeIdx            int
 	sessionEnv           []string
@@ -69,6 +70,7 @@ func New(opts map[string]any) (core.Agent, error) {
 	if cmd == "" {
 		cmd = "opencode"
 	}
+	agentName, _ := opts["agent"].(string) // --agent flag for plugin-defined agents (#1210)
 	ccDataDir, _ := opts["cc_data_dir"].(string)
 	ccProject, _ := opts["cc_project"].(string)
 	modelCachePath := opencodeProjectModelCachePath(ccDataDir, ccProject)
@@ -86,6 +88,7 @@ func New(opts map[string]any) (core.Agent, error) {
 		model:                model,
 		mode:                 mode,
 		cmd:                  cmd,
+		agentName:            agentName,
 		activeIdx:            -1,
 		modelCachePath:       modelCachePath,
 		persistentModelCache: persistentModelCache,
@@ -459,6 +462,7 @@ func (a *Agent) StartSession(ctx context.Context, sessionID string) (core.AgentS
 	mode := a.mode
 	cmd := a.cmd
 	workDir := a.workDir
+	agentName := a.agentName
 	extraEnv := a.providerEnvLocked()
 	extraEnv = append(extraEnv, a.sessionEnv...)
 	if a.activeIdx >= 0 && a.activeIdx < len(a.providers) {
@@ -468,7 +472,7 @@ func (a *Agent) StartSession(ctx context.Context, sessionID string) (core.AgentS
 	}
 	a.mu.Unlock()
 
-	return newOpencodeSession(ctx, cmd, workDir, model, mode, sessionID, extraEnv)
+	return newOpencodeSession(ctx, cmd, workDir, model, mode, agentName, sessionID, extraEnv)
 }
 
 // ListSessions runs `opencode session list` and parses the JSON output.

agent/opencode/session.go

@@ -28,6 +28,7 @@ type opencodeSession struct {
 	workDir           string
 	model             string
 	mode              string
+	agentName         string
 	extraEnv          []string
 	events            chan core.Event
 	chatID            atomic.Value // stores string — OpenCode session ID
@@ -39,18 +40,19 @@ type opencodeSession struct {
 	resultSent        atomic.Bool // true when EventResult has been sent for this turn
 }
 
-func newOpencodeSession(ctx context.Context, cmd, workDir, model, mode, resumeID string, extraEnv []string) (*opencodeSession, error) {
+func newOpencodeSession(ctx context.Context, cmd, workDir, model, mode, agentName, resumeID string, extraEnv []string) (*opencodeSession, error) {
 	sessionCtx, cancel := context.WithCancel(ctx)
 
 	s := &opencodeSession{
-		cmd:      cmd,
-		workDir:  workDir,
-		model:    model,
-		mode:     mode,
-		extraEnv: extraEnv,
-		events:   make(chan core.Event, 64),
-		ctx:      sessionCtx,
-		cancel:   cancel,
+		cmd:       cmd,
+		workDir:   workDir,
+		model:     model,
+		mode:      mode,
+		agentName: agentName,
+		extraEnv:  extraEnv,
+		events:    make(chan core.Event, 64),
+		ctx:       sessionCtx,
+		cancel:    cancel,
 	}
 	s.alive.Store(true)
 
@@ -158,6 +160,9 @@ func (s *opencodeSession) buildRunArgs(prompt string, imagePaths []string, chatI
 	if chatID != "" {
 		args = append(args, "--session", chatID)
 	}
+	if s.agentName != "" {
+		args = append(args, "--agent", s.agentName)
+	}
 	if s.model != "" {
 		args = append(args, "--model", s.model)
 	}

agent/opencode/session_test.go

@@ -60,7 +60,7 @@ func TestOpencodeSessionEntry_Unmarshal(t *testing.T) {
 // the ContinueSession sentinel (__continue__) is not passed as a literal
 // session ID to the CLI. This was fixed in PR #249.
 func TestNewOpencodeSession_ContinueSessionTreatedAsFresh(t *testing.T) {
-	s, err := newOpencodeSession(context.Background(), "echo", "/tmp", "", "default", core.ContinueSession, nil)
+	s, err := newOpencodeSession(context.Background(), "echo", "/tmp", "", "default", "", core.ContinueSession, nil)
 	if err != nil {
 		t.Fatalf("newOpencodeSession: %v", err)
 	}

config.example.toml

@@ -1558,6 +1558,9 @@ app_secret = "your-feishu-app-secret"
 # - "default": Standard mode / 标准模式
 # - "yolo":    Auto-approve all tool calls / 自动批准所有工具调用
 #
+# Optional: pass --agent to opencode (for plugin-defined agents) / 可选：传递 --agent 给 opencode（适用于插件定义的 agent）
+# agent = "Sisyphus - Ultraworker"
+#
 # Optional: specify a model (provider/model format) / 可选：指定模型
 # model = "anthropic/claude-sonnet-4-20250514"
 #