feat: OpenCode integration Phases 1-3 — types, CLI resolver, tmux spawn

Phase 1: Type system
- Add SessionMode = 'claude' | 'shell' | 'opencode' to types.ts (single source of truth)
- Add OpenCodeConfig interface (model, autoAllowTools, continueSession, etc.)
- Add openCodeConfig to SessionState
- Import SessionMode in session.ts, mux-interface.ts (remove duplicates)
- Refactor createSession/respawnPane to options objects (CreateSessionOptions, RespawnPaneOptions)

Phase 2: CLI resolver
- New opencode-cli-resolver.ts mirroring claude-cli-resolver.ts
- Searches ~/.opencode/bin, ~/.local/bin, /usr/local/bin, ~/go/bin, etc.
- Exported via utils/index.ts

Phase 3: Tmux spawn
- Extract buildSpawnCommand() shared helper (eliminates duplication)
- Add buildOpenCodeCommand() for opencode CLI flags
- Add setOpenCodeEnvVars() — API keys via tmux setenv (not visible in ps)
- Add setOpenCodeConfigContent() — JSON config via tmux setenv (prevents shell injection)
- Gate _processExpensiveParsers() for opencode mode (skip Claude-specific parsers)
- OpenCode-specific TUI ready detection (timeout-based, no ❯ prompt scanning)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/mux-interface.ts

@@ -7,7 +7,7 @@
  */
 
 import type { EventEmitter } from 'node:events';
-import type { ProcessStats, PersistedRespawnConfig, NiceConfig, ClaudeMode } from './types.js';
+import type { ProcessStats, PersistedRespawnConfig, NiceConfig, ClaudeMode, SessionMode, OpenCodeConfig } from './types.js';
 
 /**
  * Multiplexer session metadata.
@@ -23,8 +23,8 @@ export interface MuxSession {
   createdAt: number;
   /** Working directory */
   workingDir: string;
-  /** Session mode: claude or shell */
-  mode: 'claude' | 'shell';
+  /** Session mode */
+  mode: SessionMode;
   /** Whether webserver is attached to this session */
   attached: boolean;
   /** Session display name (tab name) */
@@ -43,6 +43,31 @@ export interface MuxSessionWithStats extends MuxSession {
   stats?: ProcessStats;
 }
 
+/** Options for creating a new multiplexer session. */
+export interface CreateSessionOptions {
+  sessionId: string;
+  workingDir: string;
+  mode: SessionMode;
+  name?: string;
+  niceConfig?: NiceConfig;
+  model?: string;
+  claudeMode?: ClaudeMode;
+  allowedTools?: string;
+  openCodeConfig?: OpenCodeConfig;
+}
+
+/** Options for respawning a dead pane. */
+export interface RespawnPaneOptions {
+  sessionId: string;
+  workingDir: string;
+  mode: SessionMode;
+  niceConfig?: NiceConfig;
+  model?: string;
+  claudeMode?: ClaudeMode;
+  allowedTools?: string;
+  openCodeConfig?: OpenCodeConfig;
+}
+
 /**
  * Terminal multiplexer interface.
  *
@@ -62,18 +87,9 @@ export interface TerminalMultiplexer extends EventEmitter {
 
   /**
    * Create a new multiplexer session.
-   * The session runs the appropriate command (claude or shell) in detached mode.
+   * The session runs the appropriate command (claude, opencode, or shell) in detached mode.
    */
-  createSession(
-    sessionId: string,
-    workingDir: string,
-    mode: 'claude' | 'shell',
-    name?: string,
-    niceConfig?: NiceConfig,
-    model?: string,
-    claudeMode?: ClaudeMode,
-    allowedTools?: string,
-  ): Promise<MuxSession>;
+  createSession(options: CreateSessionOptions): Promise<MuxSession>;
 
   /**
    * Kill a session and all its child processes.
@@ -165,5 +181,5 @@ export interface TerminalMultiplexer extends EventEmitter {
   isPaneDead(muxName: string): boolean;
 
   /** Respawn a dead pane with a fresh command. Returns the new PID or null on failure. */
-  respawnPane(sessionId: string, workingDir: string, mode: 'claude' | 'shell', niceConfig?: NiceConfig, model?: string, claudeMode?: ClaudeMode, allowedTools?: string): Promise<number | null>;
+  respawnPane(options: RespawnPaneOptions): Promise<number | null>;
 }

src/session.ts

@@ -18,7 +18,7 @@
 import { EventEmitter } from 'node:events';
 import { v4 as uuidv4 } from 'uuid';
 import * as pty from 'node-pty';
-import { SessionState, SessionStatus, SessionConfig, RalphTrackerState, RalphTodoItem, ActiveBashTool, NiceConfig, DEFAULT_NICE_CONFIG, type ClaudeMode } from './types.js';
+import { SessionState, SessionStatus, SessionConfig, RalphTrackerState, RalphTodoItem, ActiveBashTool, NiceConfig, DEFAULT_NICE_CONFIG, type ClaudeMode, type SessionMode, type OpenCodeConfig } from './types.js';
 import type { TerminalMultiplexer, MuxSession } from './mux-interface.js';
 import { TaskTracker, type BackgroundTask } from './task-tracker.js';
 import { RalphTracker } from './ralph-tracker.js';
@@ -196,12 +196,9 @@ export interface SessionEvents {
   cliInfoUpdated: (info: { version: string | null; model: string | null; accountType: string | null; latestVersion: string | null }) => void;
 }
 
-/**
- * Session operation mode.
- * - `'claude'`: Runs Claude CLI for AI interactions (default)
- * - `'shell'`: Runs a plain bash shell for debugging/testing
- */
-export type SessionMode = 'claude' | 'shell';
+// SessionMode is imported from types.ts (single source of truth)
+// Re-export for backwards compatibility with any external consumers
+export type { SessionMode } from './types.js';
 
 /**
  * Core session class that wraps a PTY process running Claude CLI or a shell.
@@ -325,6 +322,9 @@ export class Session extends EventEmitter {
   private _claudeMode: ClaudeMode = 'dangerously-skip-permissions';
   private _allowedTools: string | undefined;
 
+  // OpenCode configuration (only for mode === 'opencode')
+  private _openCodeConfig: OpenCodeConfig | undefined;
+
   // Session color for visual differentiation
   private _color: import('./types.js').SessionColor = 'default';
 
@@ -382,6 +382,8 @@ export class Session extends EventEmitter {
     claudeMode?: ClaudeMode;
     /** Comma-separated allowed tools (for 'allowedTools' mode) */
     allowedTools?: string;
+    /** OpenCode configuration (only for mode === 'opencode') */
+    openCodeConfig?: OpenCodeConfig;
   }) {
     super();
     this.setMaxListeners(25);
@@ -425,6 +427,11 @@ export class Session extends EventEmitter {
       this._allowedTools = config.allowedTools;
     }
 
+    // Apply OpenCode configuration
+    if (config.openCodeConfig) {
+      this._openCodeConfig = config.openCodeConfig;
+    }
+
     // Initialize task tracker and forward events (store handlers for cleanup)
     this._taskTracker = new TaskTracker();
     this._taskTrackerHandlers = {
@@ -812,6 +819,7 @@ export class Session extends EventEmitter {
       cliModel: this._cliModel || undefined,
       cliAccountType: this._cliAccountType || undefined,
       cliLatestVersion: this._cliLatestVersion || undefined,
+      openCodeConfig: this._openCodeConfig,
     };
   }
 
@@ -902,7 +910,8 @@ export class Session extends EventEmitter {
     this._lineBuffer = '';
     this._lastActivityAt = Date.now();
 
-    console.log('[Session] Starting interactive Claude session' + (this._useMux ? ` (with ${this._mux!.backend})` : ''));
+    const modeLabel = this.mode === 'opencode' ? 'OpenCode' : 'Claude';
+    console.log(`[Session] Starting interactive ${modeLabel} session` + (this._useMux ? ` (with ${this._mux!.backend})` : ''));
 
     // If mux wrapping is enabled, create or attach to a mux session
     if (this._useMux && this._mux) {
@@ -918,7 +927,11 @@ export class Session extends EventEmitter {
         let needsNewSession = false;
         if (this._muxSession && this._mux.isPaneDead(this._muxSession.muxName)) {
           console.log('[Session] Dead pane detected, respawning:', this._muxSession.muxName);
-          const newPid = await this._mux.respawnPane(this.id, this.workingDir, 'claude', this._niceConfig, this._model, this._claudeMode, this._allowedTools);
+          const newPid = await this._mux.respawnPane({
+            sessionId: this.id, workingDir: this.workingDir, mode: this.mode,
+            niceConfig: this._niceConfig, model: this._model, claudeMode: this._claudeMode,
+            allowedTools: this._allowedTools, openCodeConfig: this._openCodeConfig,
+          });
           if (!newPid) {
             console.error('[Session] Failed to respawn pane, will create new session');
             needsNewSession = true;
@@ -934,7 +947,12 @@ export class Session extends EventEmitter {
           console.log('[Session] Attaching to existing mux session:', this._muxSession!.muxName);
         } else {
           // Create a new mux session
-          this._muxSession = await this._mux.createSession(this.id, this.workingDir, 'claude', this._name, this._niceConfig, this._model, this._claudeMode, this._allowedTools);
+          this._muxSession = await this._mux.createSession({
+            sessionId: this.id, workingDir: this.workingDir, mode: this.mode,
+            name: this._name, niceConfig: this._niceConfig, model: this._model,
+            claudeMode: this._claudeMode, allowedTools: this._allowedTools,
+            openCodeConfig: this._openCodeConfig,
+          });
           console.log('[Session] Created mux session:', this._muxSession.muxName);
           // No extra sleep — createSession() already waits for tmux readiness
         }
@@ -961,39 +979,50 @@ export class Session extends EventEmitter {
           throw spawnErr;
         }
 
-        // For NEW mux sessions: wait for prompt to appear then clean buffer
+        // For NEW mux sessions: wait for readiness then clean buffer
         // For RESTORED mux sessions: don't do anything - client will fetch buffer on tab switch
         if (!isRestoredSession) {
-          this._promptCheckInterval = setInterval(() => {
-            // Wait for the prompt character (❯) which means Claude is fully initialized
-            const bufferValue = this._terminalBuffer.value;
-            if (bufferValue.includes('❯') || bufferValue.includes('\u276f')) {
+          if (this.mode === 'opencode') {
+            // OpenCode uses Bubble Tea TUI — no ❯ prompt to detect.
+            // Wait for TUI to stabilize (output stops changing), then mark ready.
+            // Don't clear the buffer — the TUI's initial render IS the useful content.
+            this._promptCheckTimeout = setTimeout(() => {
+              this._promptCheckTimeout = null;
+              this._status = 'idle';
+            }, 3000);
+          } else {
+            // Claude mode: wait for ❯ prompt
+            this._promptCheckInterval = setInterval(() => {
+              // Wait for the prompt character (❯) which means Claude is fully initialized
+              const bufferValue = this._terminalBuffer.value;
+              if (bufferValue.includes('❯') || bufferValue.includes('\u276f')) {
+                if (this._promptCheckInterval) {
+                  clearInterval(this._promptCheckInterval);
+                  this._promptCheckInterval = null;
+                }
+                if (this._promptCheckTimeout) {
+                  clearTimeout(this._promptCheckTimeout);
+                  this._promptCheckTimeout = null;
+                }
+                // Clean the buffer - remove mux init junk before actual content
+                // Strip: cursor movement (\x1b[nA/B/C/D), positioning (\x1b[n;nH),
+                // clear screen (\x1b[2J), scroll region (\x1b[n;nr), and whitespace
+                this._terminalBuffer.set(
+                  bufferValue.replace(LEADING_ANSI_WHITESPACE_PATTERN, '')
+                );
+                // Signal client to refresh
+                this.emit('clearTerminal');
+              }
+            }, 50);
+            // Timeout after 5 seconds if prompt not found
+            this._promptCheckTimeout = setTimeout(() => {
               if (this._promptCheckInterval) {
                 clearInterval(this._promptCheckInterval);
                 this._promptCheckInterval = null;
               }
-              if (this._promptCheckTimeout) {
-                clearTimeout(this._promptCheckTimeout);
-                this._promptCheckTimeout = null;
-              }
-              // Clean the buffer - remove mux init junk before actual content
-              // Strip: cursor movement (\x1b[nA/B/C/D), positioning (\x1b[n;nH),
-              // clear screen (\x1b[2J), scroll region (\x1b[n;nr), and whitespace
-              this._terminalBuffer.set(
-                bufferValue.replace(LEADING_ANSI_WHITESPACE_PATTERN, '')
-              );
-              // Signal client to refresh
-              this.emit('clearTerminal');
-            }
-          }, 50);
-          // Timeout after 5 seconds if prompt not found
-          this._promptCheckTimeout = setTimeout(() => {
-            if (this._promptCheckInterval) {
-              clearInterval(this._promptCheckInterval);
-              this._promptCheckInterval = null;
-            }
-            this._promptCheckTimeout = null;
-          }, 5000);
+              this._promptCheckTimeout = null;
+            }, 5000);
+          }
         }
       } catch (err) {
         console.error('[Session] Failed to create mux session, falling back to direct PTY:', err);
@@ -1173,6 +1202,10 @@ export class Session extends EventEmitter {
    * PTY data chunk. Receives accumulated raw data to process in one batch.
    */
   private _processExpensiveParsers(rawData: string): void {
+    // Skip Claude-specific parsers for OpenCode sessions — Ralph tracker, BashToolParser,
+    // token parsing, and CLI info parsing all depend on Claude's output format.
+    if (this.mode === 'opencode') return;
+
     // Lazy ANSI strip: only compute cleanData when a consumer actually needs it.
     let _cleanData: string | null = null;
     const getCleanData = (): string => {
@@ -1267,7 +1300,7 @@ export class Session extends EventEmitter {
         let needsNewSession = false;
         if (this._muxSession && this._mux.isPaneDead(this._muxSession.muxName)) {
           console.log('[Session] Dead pane detected, respawning:', this._muxSession.muxName);
-          const newPid = await this._mux.respawnPane(this.id, this.workingDir, 'shell', this._niceConfig);
+          const newPid = await this._mux.respawnPane({ sessionId: this.id, workingDir: this.workingDir, mode: 'shell', niceConfig: this._niceConfig });
           if (!newPid) {
             console.error('[Session] Failed to respawn pane, will create new session');
             needsNewSession = true;
@@ -1282,7 +1315,7 @@ export class Session extends EventEmitter {
           console.log('[Session] Attaching to existing mux session:', this._muxSession!.muxName);
         } else {
           // Create a new mux session
-          this._muxSession = await this._mux.createSession(this.id, this.workingDir, 'shell', this._name, this._niceConfig);
+          this._muxSession = await this._mux.createSession({ sessionId: this.id, workingDir: this.workingDir, mode: 'shell', name: this._name, niceConfig: this._niceConfig });
           console.log('[Session] Created mux session:', this._muxSession.muxName);
           // No extra sleep — createSession() already waits for tmux readiness
         }

src/tmux-manager.ts

@@ -30,13 +30,15 @@ import { existsSync, readFileSync, mkdirSync } from 'node:fs';
 import { writeFile, rename } from 'node:fs/promises';
 import { dirname, join } from 'node:path';
 import { homedir } from 'node:os';
-import { ProcessStats, PersistedRespawnConfig, getErrorMessage, NiceConfig, DEFAULT_NICE_CONFIG, type PaneInfo, type ClaudeMode } from './types.js';
+import { ProcessStats, PersistedRespawnConfig, getErrorMessage, DEFAULT_NICE_CONFIG, type PaneInfo, type ClaudeMode, type SessionMode, type OpenCodeConfig } from './types.js';
 import { wrapWithNice } from './utils/nice-wrapper.js';
 import { SAFE_PATH_PATTERN } from './utils/regex-patterns.js';
-import type { TerminalMultiplexer, MuxSession, MuxSessionWithStats } from './mux-interface.js';
+import type { TerminalMultiplexer, MuxSession, MuxSessionWithStats, CreateSessionOptions, RespawnPaneOptions } from './mux-interface.js';
 
 // Claude CLI PATH resolution — shared utility
 import { findClaudeDir } from './utils/claude-cli-resolver.js';
+// OpenCode CLI PATH resolution
+import { resolveOpenCodeDir } from './utils/opencode-cli-resolver.js';
 
 // ============================================================================
 // Timing Constants
@@ -136,6 +138,116 @@ function buildClaudePermissionFlags(claudeMode?: ClaudeMode, allowedTools?: stri
   }
 }
 
+/**
+ * Build the opencode CLI command with appropriate flags.
+ */
+function buildOpenCodeCommand(config?: OpenCodeConfig): string {
+  const parts = ['opencode'];
+
+  // Model selection — allow provider/model format (alphanumeric, dots, hyphens, slashes)
+  if (config?.model) {
+    const safeModel = /^[a-zA-Z0-9._\-/]+$/.test(config.model) ? config.model : undefined;
+    if (safeModel) parts.push('--model', safeModel);
+  }
+
+  // Continue existing session
+  if (config?.continueSession) {
+    const safeId = /^[a-zA-Z0-9_-]+$/.test(config.continueSession) ? config.continueSession : undefined;
+    if (safeId) parts.push('--session', safeId);
+    if (config.forkSession) parts.push('--fork');
+  }
+
+  return parts.join(' ');
+}
+
+/**
+ * Build the spawn command for any session mode.
+ * Shared by createSession() and respawnPane() to avoid duplication.
+ */
+function buildSpawnCommand(options: {
+  mode: SessionMode;
+  sessionId: string;
+  model?: string;
+  claudeMode?: ClaudeMode;
+  allowedTools?: string;
+  openCodeConfig?: OpenCodeConfig;
+}): string {
+  if (options.mode === 'claude') {
+    // Validate model to prevent command injection
+    const safeModel = (options.model && /^[a-zA-Z0-9._-]+$/.test(options.model)) ? options.model : undefined;
+    const modelFlag = safeModel ? ` --model ${safeModel}` : '';
+    return `claude${buildClaudePermissionFlags(options.claudeMode, options.allowedTools)} --session-id "${options.sessionId}"${modelFlag}`;
+  }
+  if (options.mode === 'opencode') {
+    return buildOpenCodeCommand(options.openCodeConfig);
+  }
+  return '$SHELL';
+}
+
+/**
+ * Set sensitive environment variables on a tmux session via setenv.
+ * These are inherited by panes but not visible in ps output or tmux history.
+ */
+function setOpenCodeEnvVars(muxName: string): void {
+  const sensitiveVars = ['ANTHROPIC_API_KEY', 'OPENAI_API_KEY', 'GOOGLE_API_KEY'];
+  for (const key of sensitiveVars) {
+    const val = process.env[key];
+    if (val) {
+      // Shell-escape: wrap in single quotes, escape any inner single quotes
+      const escaped = val.replace(/'/g, "'\\''");
+      try {
+        execSync(`tmux setenv -t '${muxName}' ${key} '${escaped}'`, {
+          encoding: 'utf8',
+          timeout: EXEC_TIMEOUT_MS,
+          stdio: ['pipe', 'pipe', 'pipe'],
+        });
+      } catch { /* Non-critical — key may not be needed */ }
+    }
+  }
+}
+
+/**
+ * Set OPENCODE_CONFIG_CONTENT on a tmux session via setenv.
+ * Uses tmux setenv to avoid shell metacharacter injection from user-supplied JSON.
+ */
+function setOpenCodeConfigContent(muxName: string, config?: OpenCodeConfig): void {
+  if (!config) return;
+
+  let jsonContent: string | undefined;
+
+  if (config.autoAllowTools) {
+    const permConfig: Record<string, unknown> = { permission: { '*': 'allow' } };
+    if (config.configContent) {
+      try {
+        const existing = JSON.parse(config.configContent) as Record<string, unknown>;
+        Object.assign(permConfig, existing);
+        permConfig.permission = { '*': 'allow' };
+      } catch { /* invalid JSON, use default permConfig */ }
+    }
+    jsonContent = JSON.stringify(permConfig);
+  } else if (config.configContent) {
+    // Validate JSON to prevent garbage config
+    try {
+      JSON.parse(config.configContent);
+      jsonContent = config.configContent;
+    } catch {
+      console.error('[TmuxManager] Invalid JSON in openCodeConfig.configContent, skipping');
+      return;
+    }
+  }
+
+  if (jsonContent) {
+    const escaped = jsonContent.replace(/'/g, "'\\''");
+    try {
+      execSync(`tmux setenv -t '${muxName}' OPENCODE_CONFIG_CONTENT '${escaped}'`, {
+        encoding: 'utf8',
+        timeout: EXEC_TIMEOUT_MS,
+        stdio: ['pipe', 'pipe', 'pipe'],
+      });
+    } catch { /* Non-critical */ }
+  }
+}
+
 /**
  * Manages tmux sessions that wrap Claude CLI or shell processes.
  *
@@ -222,16 +334,8 @@ export class TmuxManager extends EventEmitter implements TerminalMultiplexer {
    * Creates a new tmux session wrapping Claude CLI or a shell.
    * In test mode: creates an in-memory session only (no real tmux session).
    */
-  async createSession(
-    sessionId: string,
-    workingDir: string,
-    mode: 'claude' | 'shell',
-    name?: string,
-    niceConfig?: NiceConfig,
-    model?: string,
-    claudeMode?: ClaudeMode,
-    allowedTools?: string,
-  ): Promise<MuxSession> {
+  async createSession(options: CreateSessionOptions): Promise<MuxSession> {
+    const { sessionId, workingDir, mode, name, niceConfig, model, claudeMode, allowedTools, openCodeConfig } = options;
     const muxName = `claudeman-${sessionId.slice(0, 8)}`;
 
     if (!isValidMuxName(muxName)) {
@@ -258,36 +362,43 @@ export class TmuxManager extends EventEmitter implements TerminalMultiplexer {
       return session;
     }
 
-    const claudeDir = findClaudeDir();
-    if (!claudeDir && mode === 'claude') {
-      throw new Error('Claude CLI not found. Install it with: curl -fsSL https://claude.ai/install.sh | bash');
+    // Resolve CLI binary directory based on mode
+    let pathExport = '';
+    if (mode === 'claude') {
+      const claudeDir = findClaudeDir();
+      if (!claudeDir) {
+        throw new Error('Claude CLI not found. Install it with: curl -fsSL https://claude.ai/install.sh | bash');
+      }
+      pathExport = `export PATH="${claudeDir}:$PATH" && `;
+    } else if (mode === 'opencode') {
+      const openCodeDir = resolveOpenCodeDir();
+      if (!openCodeDir) {
+        throw new Error('OpenCode CLI not found. Install with: curl -fsSL https://opencode.ai/install | bash');
+      }
+      pathExport = `export PATH="${openCodeDir}:$PATH" && `;
     }
-    const pathExport = claudeDir ? `export PATH="${claudeDir}:$PATH" && ` : '';
 
     const envExports = [
       'export LANG=en_US.UTF-8',
       'export LC_ALL=en_US.UTF-8',
-      'unset CLAUDECODE',
       'unset COLORTERM',
       'export CLAUDEMAN_MUX=1',
       `export CLAUDEMAN_SESSION_ID=${sessionId}`,
       `export CLAUDEMAN_MUX_NAME=${muxName}`,
       `export CLAUDEMAN_API_URL=${process.env.CLAUDEMAN_API_URL || 'http://localhost:3000'}`,
-    ].join(' && ');
+    ];
+    // Only unset CLAUDECODE for Claude sessions
+    if (mode === 'claude') envExports.splice(2, 0, 'unset CLAUDECODE');
+    const envExportsStr = envExports.join(' && ');
 
-    // Validate model to prevent command injection (only allow alphanumeric, hyphens, dots)
-    const safeModel = (model && /^[a-zA-Z0-9._-]+$/.test(model)) ? model : undefined;
-    const modelFlag = (mode === 'claude' && safeModel) ? ` --model ${safeModel}` : '';
-    const baseCmd = mode === 'claude'
-      ? `claude${buildClaudePermissionFlags(claudeMode, allowedTools)} --session-id "${sessionId}"${modelFlag}`
-      : '$SHELL';
+    const baseCmd = buildSpawnCommand({ mode, sessionId, model, claudeMode, allowedTools, openCodeConfig });
 
     const config = niceConfig || DEFAULT_NICE_CONFIG;
     const cmd = wrapWithNice(baseCmd, config);
 
     try {
       // Build the full command to run inside tmux
-      const fullCmd = `${pathExport}${envExports} && ${cmd}`;
+      const fullCmd = `${pathExport}${envExportsStr} && ${cmd}`;
 
       // Create tmux session in three steps to handle cold-start (no server running)
       // and avoid the race where the command exits before remain-on-exit is set:
@@ -304,6 +415,13 @@ export class TmuxManager extends EventEmitter implements TerminalMultiplexer {
         execSync(`tmux set-option -t "${muxName}" remain-on-exit on`, { timeout: EXEC_TIMEOUT_MS, stdio: 'ignore' });
       } catch { /* Non-critical */ }
 
+      // For OpenCode: set sensitive env vars and config via tmux setenv
+      // (not visible in ps output or tmux history, inherited by panes)
+      if (mode === 'opencode') {
+        setOpenCodeEnvVars(muxName);
+        setOpenCodeConfigContent(muxName, openCodeConfig);
+      }
+
       // Replace the shell with the actual command (no echo in terminal)
       execSync(
         `tmux respawn-pane -k -t "${muxName}" bash -c ${JSON.stringify(fullCmd)}`,
@@ -423,37 +541,48 @@ export class TmuxManager extends EventEmitter implements TerminalMultiplexer {
    * Uses `tmux respawn-pane -k` to restart the command in the same pane,
    * preserving the session and its scrollback buffer.
    */
-  async respawnPane(sessionId: string, workingDir: string, mode: 'claude' | 'shell', niceConfig?: NiceConfig, model?: string, claudeMode?: ClaudeMode, allowedTools?: string): Promise<number | null> {
+  async respawnPane(options: RespawnPaneOptions): Promise<number | null> {
+    const { sessionId, workingDir, mode, niceConfig, model, claudeMode, allowedTools, openCodeConfig } = options;
     const session = this.sessions.get(sessionId);
     if (!session) return null;
     const muxName = session.muxName;
 
     if (!isValidMuxName(muxName) || !isValidPath(workingDir)) return null;
 
-    const claudeDir = findClaudeDir();
-    const pathExport = claudeDir ? `export PATH="${claudeDir}:$PATH" && ` : '';
+    // Resolve CLI binary directory based on mode
+    let pathExport = '';
+    if (mode === 'claude') {
+      const claudeDir = findClaudeDir();
+      pathExport = claudeDir ? `export PATH="${claudeDir}:$PATH" && ` : '';
+    } else if (mode === 'opencode') {
+      const openCodeDir = resolveOpenCodeDir();
+      pathExport = openCodeDir ? `export PATH="${openCodeDir}:$PATH" && ` : '';
+    }
+
     const envExports = [
       'export LANG=en_US.UTF-8',
       'export LC_ALL=en_US.UTF-8',
-      'unset CLAUDECODE',
       'unset COLORTERM',
       'export CLAUDEMAN_MUX=1',
       `export CLAUDEMAN_SESSION_ID=${sessionId}`,
       `export CLAUDEMAN_MUX_NAME=${muxName}`,
       `export CLAUDEMAN_API_URL=${process.env.CLAUDEMAN_API_URL || 'http://localhost:3000'}`,
-    ].join(' && ');
-
-    const safeModel = (model && /^[a-zA-Z0-9._-]+$/.test(model)) ? model : undefined;
-    const modelFlag = (mode === 'claude' && safeModel) ? ` --model ${safeModel}` : '';
-    const baseCmd = mode === 'claude'
-      ? `claude${buildClaudePermissionFlags(claudeMode, allowedTools)} --session-id "${sessionId}"${modelFlag}`
-      : '$SHELL';
+    ];
+    if (mode === 'claude') envExports.splice(2, 0, 'unset CLAUDECODE');
+    const envExportsStr = envExports.join(' && ');
 
+    const baseCmd = buildSpawnCommand({ mode, sessionId, model, claudeMode, allowedTools, openCodeConfig });
     const config = niceConfig || DEFAULT_NICE_CONFIG;
     const cmd = wrapWithNice(baseCmd, config);
-    const fullCmd = `${pathExport}${envExports} && ${cmd}`;
+    const fullCmd = `${pathExport}${envExportsStr} && ${cmd}`;
 
     try {
+      // For OpenCode: set sensitive env vars via tmux setenv before respawn
+      if (mode === 'opencode') {
+        setOpenCodeEnvVars(muxName);
+        setOpenCodeConfigContent(muxName, openCodeConfig);
+      }
+
       await execAsync(
         `tmux respawn-pane -k -t "${muxName}" bash -c ${JSON.stringify(fullCmd)}`,
         { timeout: EXEC_TIMEOUT_MS }

src/types.ts

@@ -113,6 +113,23 @@ export interface LifecycleEntry {
  */
 export type ClaudeMode = 'dangerously-skip-permissions' | 'normal' | 'allowedTools';
 
+/** Session mode: which CLI backend a session runs */
+export type SessionMode = 'claude' | 'shell' | 'opencode';
+
+/** OpenCode session configuration */
+export interface OpenCodeConfig {
+  /** Model identifier (e.g., "anthropic/claude-sonnet-4-5", "openai/gpt-5.2", "ollama/codellama") */
+  model?: string;
+  /** Whether to auto-allow all tool executions (sets permission.* = allow) */
+  autoAllowTools?: boolean;
+  /** Session ID to continue from */
+  continueSession?: string;
+  /** Whether to fork when continuing (branch the conversation) */
+  forkSession?: boolean;
+  /** Custom inline config JSON (passed via OPENCODE_CONFIG_CONTENT) */
+  configContent?: string;
+}
+
 /**
  * Configuration for creating a new session
  */
@@ -158,8 +175,8 @@ export interface SessionState {
   lastActivityAt: number;
   /** Session display name */
   name?: string;
-  /** Session mode: 'claude' or 'shell' */
-  mode?: 'claude' | 'shell';
+  /** Session mode */
+  mode?: SessionMode;
   /** Auto-clear enabled */
   autoClearEnabled?: boolean;
   /** Auto-clear token threshold */
@@ -208,6 +225,8 @@ export interface SessionState {
   cliAccountType?: string;
   /** Latest CLI version available (parsed from version check) */
   cliLatestVersion?: string;
+  /** OpenCode-specific configuration (only for mode === 'opencode') */
+  openCodeConfig?: OpenCodeConfig;
 }
 
 // ========== Global Stats Types ==========

src/utils/index.ts

@@ -33,3 +33,4 @@ export {
 export { assertNever } from './type-safety.js';
 export { wrapWithNice } from './nice-wrapper.js';
 export { findClaudeDir, getAugmentedPath } from './claude-cli-resolver.js';
+export { resolveOpenCodeDir, isOpenCodeAvailable, getOpenCodeAugmentedPath } from './opencode-cli-resolver.js';

src/utils/opencode-cli-resolver.ts

@@ -0,0 +1,95 @@
+/**
+ * @fileoverview Resolve the OpenCode CLI binary across common install paths.
+ *
+ * Mirrors claude-cli-resolver.ts pattern. Finds the `opencode` binary
+ * and provides an augmented PATH string for tmux sessions.
+ *
+ * @module utils/opencode-cli-resolver
+ */
+
+import { execSync } from 'node:child_process';
+import { existsSync } from 'node:fs';
+import { delimiter, dirname, join } from 'node:path';
+import { homedir } from 'node:os';
+
+/** Timeout for exec commands (5 seconds) */
+const EXEC_TIMEOUT_MS = 5000;
+
+/** Common directories where the OpenCode CLI binary may be installed */
+const OPENCODE_SEARCH_DIRS = [
+  join(homedir(), '.opencode', 'bin'),    // Default install location
+  join(homedir(), '.local', 'bin'),       // Alternative install location
+  '/usr/local/bin',                       // Homebrew / system
+  join(homedir(), 'go', 'bin'),           // Go install
+  join(homedir(), '.bun', 'bin'),         // Bun global
+  join(homedir(), '.npm-global', 'bin'),  // npm global
+  join(homedir(), 'bin'),                 // User bin
+];
+
+/** Cached directory containing the opencode binary (empty string = searched but not found) */
+let _openCodeDir: string | null = null;
+
+/**
+ * Finds the directory containing the `opencode` binary.
+ * Checks `which opencode` first, then falls back to common install locations.
+ * Result is cached for subsequent calls.
+ *
+ * @returns Directory path, or null if not found
+ */
+export function resolveOpenCodeDir(): string | null {
+  if (_openCodeDir !== null) return _openCodeDir || null;
+
+  // Try `which` first (respects current PATH)
+  try {
+    const result = execSync('which opencode', { encoding: 'utf-8', timeout: EXEC_TIMEOUT_MS }).trim();
+    if (result && existsSync(result)) {
+      _openCodeDir = dirname(result);
+      return _openCodeDir;
+    }
+  } catch {
+    // OpenCode not in PATH, will check common locations
+  }
+
+  // Fallback: check common installation directories
+  for (const dir of OPENCODE_SEARCH_DIRS) {
+    if (existsSync(join(dir, 'opencode'))) {
+      _openCodeDir = dir;
+      return _openCodeDir;
+    }
+  }
+
+  _openCodeDir = '';  // mark as searched, not found
+  return null;
+}
+
+/**
+ * Check if OpenCode CLI is available on the system.
+ */
+export function isOpenCodeAvailable(): boolean {
+  return resolveOpenCodeDir() !== null;
+}
+
+/**
+ * Returns a PATH string that includes the directory containing `opencode`.
+ *
+ * Finds the opencode binary (via `which` or common install locations), then
+ * prepends its directory to the current PATH if not already present.
+ * Result is cached for subsequent calls.
+ */
+export function getOpenCodeAugmentedPath(): string {
+  const currentPath = process.env.PATH || '';
+  const dir = resolveOpenCodeDir();
+
+  if (dir && !currentPath.split(delimiter).includes(dir)) {
+    return `${dir}${delimiter}${currentPath}`;
+  }
+
+  return currentPath;
+}
+
+/**
+ * Reset cached resolution (for testing).
+ */
+export function resetOpenCodeCache(): void {
+  _openCodeDir = null;
+}