Background exec and process tool

OpenClaw runs shell commands through the exec tool and keeps long-running tasks in memory. The process tool manages those background sessions.

exec tool

Parameters:

Behavior:

• Foreground runs return retained output directly and disclose when earlier output exceeded the aggregate cap.
• When backgrounded (explicit or via yieldMs timeout), the tool returns status: "running" + sessionId and a short output tail.
• Backgrounded and yieldMs runs inherit tools.exec.timeoutSeconds unless the call passes an explicit timeoutSeconds.
• Returning a background session ID does not stop the process timeout. For a persistent service on the gateway or in a sandbox, use background: true with timeoutSeconds: 0, then stop it with process action kill when finished. Host and worker lifecycle limits still apply.
• Output stays in memory up to the per-session aggregate cap until the session is polled or cleared.
• Finished sessions expire after their configured TTL, measured from completion. Each exec captures its agent's retention setting when admitted; using another agent's process tool does not change existing results' lifetimes. The registry also retains at most 50 finished sessions and 2,000,000 total retained output characters, evicting the oldest records first. The newest completed session retains its capped per-session aggregate even when that record alone exceeds the global limit.
• If the process tool is disallowed, exec runs synchronously and ignores yieldMs/background.
• Spawned exec commands receive OPENCLAW_SHELL=exec for context-aware shell/profile rules.
• For long-running work that starts now: start it once and rely on automatic completion wake (when enabled) once the command emits output or fails.
• If automatic completion wake is unavailable, or you need quiet-success confirmation for a command that exits cleanly with no output, poll with process.
• Don't emulate reminders or delayed follow-ups with sleep loops or repeated polling — use cron for future work.

Env overrides

Config (preferred over env overrides)

Worker environments

On a paired-node or node-backed cloud worker, background processes belong to the session's environment. Finishing or cancelling a turn leaves already-backgrounded commands running. A later turn in the same environment can use process to poll, send input, or stop them; foreground commands still stop when their turn is cancelled.

The retained worker occupies one node worker slot. Reusing it needs no additional slot. If a command finishes between turns, its retained output remains available to the next turn, subject to the normal process output limits and TTL. Once a turn finishes with no live background commands, the worker exits. Moving or retiring the environment, replacing its ownership, or stopping the node also stops its processes. Process handles do not survive a worker or node restart.

If the node's pairing is revoked or its provider no longer recognizes the lease, the session placement fails. Physical cleanup can remain pending until OpenClaw confirms that the exact worker has stopped; an unconfirmed stop does not release its ownership record.

Worker completion does not currently wake the Gateway session automatically; use process poll in a later turn to inspect the result. Closing a portal closes its proxy, not the development server: stop the server with process kill.

Child process bridging

When spawning long-running child processes outside the exec/process tools (CLI respawns, gateway helpers), attach the child-process bridge helper so termination signals forward and listeners detach on exit/close. This avoids orphaned processes on systemd and keeps shutdown consistent across platforms.

A supervised command's timeout also covers startup, including blocked private-input delivery. The timeout result can return while cleanup continues. Scope retirement and Gateway shutdown wait for the cleanup owner separately; when that owner reports uncertainty, they report failure instead of treating the timeout as proof that the command has stopped.

For owned POSIX process groups, cleanup also waits for the operating system to confirm that the group has disappeared after graceful shutdown. A completed command or closed output pipe alone does not establish that its descendants have stopped. Forced termination without confirmed cleanup remains uncertain. Local TUI shell shutdown uses the same cleanup owner for its own commands.

One-shot tool cleanup keeps configured sandbox runtimes on their session, agent, or shared lifetime. It joins the local command transport and backend cleanup for that command. It does not stop a shared sandbox or claim that every remote descendant has exited. Host commands, including elevated commands from sandboxed sessions, still require owned process-tree cleanup.

When a host command requires process-tree cleanup, a pty request falls back to the child-process path before starting a native PTY and reports a warning. Commands that require a terminal may fail under that fallback. Cleanup failures remain uncertain rather than being reported as a clean shutdown.

process tool

Actions:

Notes:

• Only backgrounded sessions are listed/persisted — in memory only, not on disk. Sessions are lost on process restart.
• Resetting or deleting a session clears only its completed background processes; other sessions, explicit shared scopes, and running processes remain unaffected.
• A live background session blocks cooperative host suspension and safe Gateway restart until the process owner confirms its actual exit.
• process remove can hide a running session immediately after requesting termination; suspension and restart remain blocked until exit confirmation.
• Session logs are only saved to chat history if you run process poll/log and the tool result is recorded.
• process is scoped per agent; it only sees sessions started by that agent.
• Use poll/log for status, logs, or completion confirmation when automatic completion wake is unavailable.
• Use log before recovering an interactive CLI, so the current transcript, stdin state, and input-wait hint are visible together.
• Use write/send-keys/submit/paste/kill when you need input or intervention.
• process list includes a derived name (command verb + target) for quick scans.
• process list, poll, and log report waitingForInput only when the session still has writable stdin and has been idle longer than the input-wait threshold (default 15000 ms, OPENCLAW_PROCESS_INPUT_WAIT_IDLE_MS).
• process log uses line-based offset/limit. When both are omitted, it returns the last 200 lines with a paging hint. When offset is set and limit isn't, it returns from offset to the end (not capped to 200).
• process poll and process log distinguish output discarded at the aggregate retention cap from output merely omitted by the pending buffer or retained tail. Discarded output cannot be recovered; paged logs can inspect only the retained portion.
• poll's timeout waits up to that many milliseconds before returning; values above 30000 are clamped to 30000.
• Polling is for on-demand status, not wait-loop scheduling. If the work should happen later, use cron.

In Code Mode, process returns its structured details directly. For action: "log", output contains the requested log page, including paging, retention, and input-recovery hints. Failed process actions include an error message alongside status: "failed", so the agent can choose the next action.

Examples

Run a long task and poll later:

{ "tool": "exec", "command": "sleep 5 && echo done", "yieldMs": 1000 }

{ "tool": "process", "action": "poll", "sessionId": "<id>" }

Inspect an interactive session before sending input:

{ "tool": "process", "action": "log", "sessionId": "<id>" }

Start immediately in background:

{ "tool": "exec", "command": "npm run build", "background": true }

Send stdin:

{ "tool": "process", "action": "write", "sessionId": "<id>", "data": "y\n" }

Send PTY keys:

{ "tool": "process", "action": "send-keys", "sessionId": "<id>", "keys": ["C-c"] }

Submit current line:

{ "tool": "process", "action": "submit", "sessionId": "<id>" }

Paste literal text:

{ "tool": "process", "action": "paste", "sessionId": "<id>", "text": "line1\nline2\n" }

Related

• Exec tool
• Exec approvals