Session Restore

cmux saves the shape of your work so relaunching the app can bring back the same windows, workspaces, panes, terminal context, and browser state.

What cmux restores

After relaunch, cmux restores app-owned layout and metadata:

  • Window, workspace, and pane layout
  • Working directories
  • Terminal scrollback, best effort
  • Browser URL and navigation history
cmux does not checkpoint arbitrary live process state. tmux, vim, shells, and unsupported terminal apps reopen as normal terminals unless they have their own cmux resume integration.

Agent session resume

Supported AI coding agents can resume when cmux has captured the agent's native session ID. Install hooks after installing the agent CLI so the agent binary is on PATH:

cmux hooks setup
cmux hooks setup codex
cmux hooks setup --agent opencode

Running cmux hooks setup installs every supported integration it can find and prints a summary for skipped agents. Use an agent name when you only want one integration.

Supported agents

AgentBinaryResume commandFeed bridge
Claude Codeclaudeclaude --resume <id>PermissionRequest
Codexcodexcodex resume <id>PreToolUse, PermissionRequest
OpenCodeopencodeopencode --session <id>plugin event bus
Pipipi --session <id>none
Ampampamp threads continue <id>none
Cursor CLIcursor-agentcursor-agent --resume <id>beforeShellExecution
Geminigeminigemini --resume <id>PreToolUse
Rovo Devacliacli rovodev run --restore <id>none
Copilotcopilotcopilot --resume <id>PreToolUse
CodeBuddycodebuddycodebuddy --resume <id>PreToolUse
Factorydroiddroid --resume <id>PreToolUse
Qoderqodercliqodercli --resume <id>PreToolUse

Claude Code is handled by the cmux Claude wrapper when Claude integration is enabled in Settings. Rovo Dev also accepts rovo as the setup alias.

Manual restore

cmux restores the last saved snapshot on normal launch. You can also reapply the previous snapshot manually:

  • File > Reopen Previous Session
  • ⌘ ⇧ O
  • cmux restore-session

Disable automatic agent resume

To restore panes without launching saved agent resume commands, turn off Settings > Terminal > Resume Agent Sessions on Reopen or set:

~/.config/cmux/cmux.json
{
  "terminal": {
    "autoResumeAgentSessions": false
  }
}

This only disables agent resume commands. cmux still restores layout, working directories, scrollback, and browser history.

How it works

  1. cmux writes a versioned JSON snapshot to ~/Library/Application Support/cmux/session-<bundle-id>.json, plus a previous-session cache for manual reopen.
  2. Terminal scrollback is stored as bounded text and replayed through a temporary file on restore. This is best effort because terminal apps can redraw or clear their screen.
  3. Agent hooks write ~/.cmuxterm/<agent>-hook-sessions.json with the agent session ID, cmux workspace ID, surface ID, cwd, process ID when available, and a sanitized launch command.
  4. On restore, cmux rebuilds windows and panes first. If automatic agent resume is enabled, it launches a one-shot shell command that runs the agent's native resume command with the saved session ID.

The regular configuration docs cover cmux.json. Session restore keeps app layout separate from Ghostty terminal rendering settings.