Apus 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.
• Set awaitResults: true when a command result is needed to finish the task. It stays an owned tool call through process settlement and terminal collection instead of returning an uncollected background handle. This works with notifyOnExit=false; no completion notification is enabled. awaitResults: true cannot be combined with background: true, which explicitly selects an independently running service. Run, tool, and process deadlines still apply. In Apus Code Mode, the cell retains required calls and resumes on their settlement without model polling.
• When backgrounded (explicit or via yieldMs timeout), the tool returns status: "running" + sessionId and a short output tail. On the Gateway and in its sandbox, a yielded handle does not make an ordinary command independent: the browser's Stop button and typed /stop cancel the selected request's commands. Stop waits for process cleanup and reports when cleanup could not be confirmed. Completed output remains available, and canceled commands do not emit a new completion notification. Managed workers retain the separate behavior described below.
• Use background: true only for a deliberately independent service. Request Stop leaves that service running; use its process handle to stop it separately. Normal turn completion also preserves ordinary commands that are still running.
• Launch failures return the operating-system error and release worker cleanup even when no process starts.
• Managed sandbox workspace finalization bounds each container inspection, pause, and resume command to 30 seconds. A failed or timed-out operation preserves its recovery receipt rather than treating an uncertain pause or resume as successful.
• Backgrounded and yieldMs runs inherit tools.exec.timeoutSeconds unless the call passes an explicit timeoutSeconds.
• With the secret egress proxy enabled, each Gateway-hosted command retains its own proxy access across turns. Process exit, cancellation, timeout, or Gateway shutdown revokes that access and closes its connections. Use process kill to stop a background command and its proxy access together.
• 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 APUS_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). The wake fires when the command emits output or fails, and on chat channels also when it exits cleanly with no output.
• A completion wake lets the agent continue outstanding work; it does not require a new chat message. The agent is instructed to report requested results not yet delivered, meaningful outcome changes, or new actionable failures, and stay silent for routine, duplicate, superseded, or already-recovered results. A completion without captured output, such as a command that redirected its output to a file, continues the same way, so the agent can read that file and report. This is a model instruction, not a deterministic notification filter, and it does not disable the completion turn.
• A host command started in a chat conversation completes through ordinary execution in that conversation: the completion turn runs with its session history, and any reply goes back to the captured account, chat, and topic. It waits behind existing work in that session, independently of heartbeat cadence, active hours, and delivery settings. A command started in an automatically silent run keeps that restriction for its completion. Current session permissions and tool restrictions can tighten the captured permissions before execution.
• A failed background command wakes its originating session even when other sessions or automations are busy. If that session is still running, the completion waits until it is free. This also applies when a watcher exits before the work it was watching finishes.
• Timeouts also wake the session when the command produced no output. The completion includes retry-safety guidance: verify any external side effects before retrying.
• Manually canceled commands do not trigger completion notifications, even when they produced output. Retained output remains available through process poll or process log. Cleanup failures from process kill still notify; request Stop reports cleanup failures through its error response without starting a completion turn.
• Request Stop also retires the ordinary command's queued or running completion turn, including after its retained process output expires. A stopped continuation cannot deliver a late reply or retry itself. Unrelated queued events and later human requests remain eligible to run.
• If automatic completion wake is unavailable, or you need quiet-success confirmation where empty successes do not wake (tools.exec.notifyOnExitEmptySuccess), poll with process.
• Background exec does not automatically wake subagent sessions. A subagent must collect its command result with process poll before yielding without another completion source. A requested stop also needs its terminal result collected.
• A quiet foreground command with an unexpired execution allowance is reported as long-running. Once that allowance expires, stalled-session recovery can abort the owning run. Repeated process poll or process log calls with unchanged output count toward loop detection; elapsed idle time alone is not progress.
• 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)

Disable automatic completion turns

Background exec completion notifications are enabled by default. They can run a model turn marked [Apus exec completion] even when agents.defaults.heartbeat.every is "0m": that setting disables recurring polls, not completion follow-ups.

To keep background commands running without automatic completion turns, set:

apus config set tools.exec.notifyOnExit false

An agent's agents.entries.<id>.tools.exec.notifyOnExit overrides the global setting. Set that override to false too, or remove it to inherit the global value. Newly started commands use the updated setting; commands already running retain the setting they started with. Use process poll or process log to collect their results on demand. This disables the completion event and its automatic model call without disabling background: true or the process tool.

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 Apus 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.

Control UI

The chat side panel offers a separate Processes tab through its + menu and the chat header's Panels menu. Subagents remains its own tab. Processes shows the current conversation's background exec commands and retained finished records, including status, duration, exit information, and recent output. Reading the output does not drain pending agent output or acknowledge completion notifications. Stop requests termination of the exact observed process instance.

The list is bounded, prioritizes running processes, and follows the existing in-memory retention limits. It refreshes while visible; disconnected or unavailable workers show an error rather than an empty list. It does not provide an interactive terminal or enumerate unrelated operating-system processes.

Child process bridging

After a host exec command finishes, Apus releases its retained process scope before reporting completion. Children left behind by shell backgrounding (&) are stopped with that scope. To continue ordinary work across turns, let the long-running command yield a handle with yieldMs and use process to collect its result. Request Stop still cancels it on the Gateway or in its sandbox. Reserve background: true for a deliberately independent service. Each command's process scope stays owned until it finishes; sandbox runtime lifetimes remain with the sandbox backend.

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.

On Linux with the default Node runtime, the Gateway starts a small spawn broker before loading its main runtime. If initial broker startup fails, the Gateway logs the failure reason and runtime entry path, then uses in-process spawning for the rest of that Gateway process. A new Gateway process tries the broker again. When the broker is ready, exec commands, shell-snapshot capture and validation, and helpers using the shared command runner spawn from it, so Linux does not copy the Gateway's page tables for each command. The existing process supervisors and service relays still own cancellation, output, and cleanup. After the broker first becomes ready, broker loss fails affected commands rather than rerunning them; later commands use the restarted broker. One-shot CLI commands, native file-descriptor inputs, and independently launched applications keep their local process transport, as do Bun, macOS, and Windows. The broker has its own process group, which the Gateway terminates on broker loss; service relays also retain their own parent-loss cleanup. A detached child can survive a broker crash before its PID is reported, matching the existing residual for directly spawned children when the Gateway crashes.

Canonical credential readers also use the broker. If it confirms that a reader never started, the read falls back once to a local process with the original environment and working directory. Cancellation, timeouts, uncertain launches, and cleanup failures do not trigger a retry. Snapshot-backed credential readers keep their local process transport.

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.

Managed exec and negotiated worker workspace commands on Linux with Node use a dedicated child subreaper. It acquires kernel child ownership before launch, adopts orphaned descendants, and stops and reaps them even if they create another process group or session. Completion requires the kernel to report no remaining children, the matching owner receipt, and output drain. It does not depend on group-directed signals, a process-table census, or inherited-pipe closure alone.

Portable workers use the native helper supplied by their admitted Node host; the portable archive does not acquire native dependencies. Use matching current host and worker builds in environments that prohibit process-group signaling. An unsupported ownership contract fails before launch instead of downgrading to transport-only cleanup. Source installations must build their process helpers; a source loader with an independent child reaper cannot share this ownership.

The node journal records Linux descendant extinction separately from older lineage receipts. A surviving owner can publish that fact after its host stops. After restart, a missing certificate or uncertain owner identity retains the physical reservation; restarting is not proof that old descendants stopped. Older builds do not reinterpret the new certificate as lineage completion.

macOS and retained Bun process-group owners still require kernel group disappearance. Permission-denied checks never prove absence. A completed command or closed output pipe alone does not establish that its descendants stopped. Local TUI shell shutdown uses the same cleanup owner for its own commands. If the host was busy, cleanup processes queued native completion events before reporting a timeout.

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.
• After an explicit kill or task cancellation, poll and log report a confirmed requested stop as a completed observation, retaining the process's signal and cancellation reason. Unexpected termination, timeouts, and cleanup failures remain errors. The process list retains the underlying terminal status.
• 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, APUS_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.
• A waiting poll rechecks its requester's live authority before returning output. If that authority is revoked, the poll fails without consuming buffered output or acknowledging completion; an authorized caller can still collect the result within the normal retention limits.
• 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 task longer than the default 10000 ms yield window and poll later:

{ "tool": "exec", "command": "sleep 30 && echo done" }

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

Inspect an interactive session before sending input:

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

Yield an ordinary build after one second:

{ "tool": "exec", "command": "npm run build", "yieldMs": 1000 }

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