openclaw/docs/tools/acp-agents.md

summary, read_when, title

summary	read_when	title
Use ACP runtime sessions for Claude Code, Cursor, Gemini CLI, explicit Codex ACP fallback, OpenClaw ACP, and other harness agents	Running coding harnesses through ACP Setting up conversation-bound ACP sessions on messaging channels Binding a message channel conversation to a persistent ACP session Troubleshooting ACP backend and plugin wiring Debugging ACP completion delivery or agent-to-agent loops Operating /acp commands from chat	ACP agents

Agent Client Protocol (ACP) sessions let OpenClaw run external coding harnesses (for example Pi, Claude Code, Cursor, Copilot, Droid, OpenClaw ACP, OpenCode, Gemini CLI, and other supported ACPX harnesses) through an ACP backend plugin.

If you ask OpenClaw in plain language to bind or control Codex in the current conversation and the bundled codex plugin is enabled, OpenClaw should use the native Codex app-server plugin (/codex bind, /codex threads, /codex resume, /codex steer, /codex stop) instead of ACP. If you ask for /acp, ACP, acpx, or an ACP adapter test explicitly, OpenClaw can still route Codex through ACP. Each ACP session spawn is tracked as a background task.

If you ask OpenClaw in plain language to "start Claude Code in a thread" or use another external harness, OpenClaw should route that request to the ACP runtime (not the native sub-agent runtime).

If you want Codex or Claude Code to connect as an external MCP client directly to existing OpenClaw channel conversations, use openclaw mcp serve instead of ACP.

ACP is not the default Codex path. It is the external-harness path. The native Codex app-server plugin owns /codex ... controls and the embeddedHarness.runtime: "codex" embedded runtime; ACP owns /acp ... controls and sessions_spawn({ runtime: "acp" }) sessions.

Which page do I want?

There are three nearby surfaces that are easy to confuse:

You want to...	Use this	Notes
Bind or control Codex in the current conversation	/codex bind, /codex threads	Native Codex app-server path when the codex plugin is enabled; includes bound chat replies, image forwarding, model/fast/permissions, stop, and steer controls. ACP is an explicit fallback
Run Claude Code, Gemini CLI, explicit Codex ACP, or another external harness through OpenClaw	This page: ACP agents	Chat-bound sessions, /acp spawn, sessions_spawn({ runtime: "acp" }), background tasks, runtime controls
Expose an OpenClaw Gateway session as an ACP server for an editor or client	openclaw acp	Bridge mode. IDE/client talks ACP to OpenClaw over stdio/WebSocket
Reuse a local AI CLI as a text-only fallback model	CLI Backends	Not ACP. No OpenClaw tools, no ACP controls, no harness runtime

Does this work out of the box?

Usually, yes. Fresh installs ship the bundled acpx runtime plugin enabled by default, with a plugin-local pinned acpx binary that OpenClaw probes and self-repairs on startup. Run /acp doctor for a readiness check.

OpenClaw only teaches agents about ACP spawning when ACP is truly usable: ACP must be enabled, dispatch must not be disabled, the current session must not be sandbox-blocked, and a runtime backend must be loaded. If those conditions are not met, ACP plugin skills and sessions_spawn ACP guidance stay hidden so the agent does not suggest an unavailable backend.

First-run gotchas:

• If plugins.allow is set, it is a restrictive plugin inventory and must include acpx; otherwise the bundled default is intentionally blocked and /acp doctor reports the missing allowlist entry.
• Target harness adapters (Codex, Claude, etc.) may be fetched on demand with npx the first time you use them.
• Vendor auth still has to exist on the host for that harness.
• If the host has no npm or network access, first-run adapter fetches fail until caches are pre-warmed or the adapter is installed another way.

Supported harness targets

With the bundled acpx backend, use these harness ids as /acp spawn <id> or sessions_spawn({ runtime: "acp", agentId: "<id>" }) targets:

Harness id	Typical backend	Notes
claude	Claude Code ACP adapter	Requires Claude Code auth on the host.
codex	Codex ACP adapter	Explicit ACP fallback only when native /codex is unavailable or ACP is requested.
copilot	GitHub Copilot ACP adapter	Requires Copilot CLI/runtime auth.
cursor	Cursor CLI ACP (cursor-agent acp)	Override the acpx command if a local install exposes a different ACP entrypoint.
droid	Factory Droid CLI	Requires Factory/Droid auth or FACTORY_API_KEY in the harness environment.
gemini	Gemini CLI ACP adapter	Requires Gemini CLI auth or API key setup.
opencode	OpenCode ACP adapter	Requires OpenCode CLI/provider auth.
openclaw	OpenClaw Gateway bridge through openclaw acp	Lets an ACP-aware harness talk back to an OpenClaw Gateway session.
pi	Pi/embedded OpenClaw runtime	Used for OpenClaw-native harness experiments.
iflow	iFlow CLI	Adapter availability and model control depend on the installed CLI.
kilocode	Kilo Code CLI	Adapter availability and model control depend on the installed CLI.
kimi	Kimi/Moonshot CLI	Requires Kimi/Moonshot auth on the host.
kiro	Kiro CLI	Adapter availability and model control depend on the installed CLI.
qwen	Qwen Code / Qwen CLI	Requires Qwen-compatible auth on the host.

Custom acpx agent aliases can be configured in acpx itself, but OpenClaw policy still checks acp.allowedAgents and any agents.list[].runtime.acp.agent mapping before dispatch.

Runtime prerequisites

ACP launches a real external harness process. OpenClaw owns routing, background-task state, delivery, bindings, and policy; the harness owns its provider login, model catalog, filesystem behavior, and native tools.

Before blaming OpenClaw, verify:

• /acp doctor reports an enabled, healthy backend.
• The target id is allowed by acp.allowedAgents when that allowlist is set.
• The harness command can start on the Gateway host.
• Provider auth is present for that harness (claude, codex, gemini, opencode, droid, etc.).
• The selected model exists for that harness. Model ids are not portable across harnesses.
• The requested cwd exists and is accessible, or omit cwd and let the backend use its default.
• Permission mode matches the work. Non-interactive sessions cannot click native permission prompts, so write/exec-heavy coding runs usually need an ACPX permission profile that can proceed headlessly.

OpenClaw plugin tools and built-in OpenClaw tools are not exposed to ACP harnesses by default. Enable the explicit MCP bridges in ACP agents — setup only when the harness should call those tools directly.

Operator runbook

Quick /acp flow from chat:

1. Spawn — /acp spawn claude --bind here, /acp spawn gemini --mode persistent --thread auto, or explicit /acp spawn codex --bind here
2. Work in the bound conversation or thread (or target the session key explicitly).
3. Check state — /acp status
4. Tune — /acp model <provider/model>, /acp permissions <profile>, /acp timeout <seconds>
5. Steer without replacing context — /acp steer tighten logging and continue
6. Stop — /acp cancel (current turn) or /acp close (session + bindings)

Lifecycle details:

• Spawn creates or resumes an ACP runtime session, records ACP metadata in the OpenClaw session store, and may create a background task when the run is parent-owned.
• Bound follow-up messages go directly to the ACP session until the binding is closed, unfocused, reset, or expired.
• Gateway commands stay local. /acp ..., /status, and /unfocus are never sent as normal prompt text to a bound ACP harness.
• cancel aborts the active turn when the backend supports cancellation; it does not delete the binding or session metadata.
• close ends the ACP session from OpenClaw's point of view and removes the binding. A harness may still keep its own upstream history if it supports resume.
• Idle runtime workers are eligible for cleanup after acp.runtime.ttlMinutes; stored session metadata remains available for /acp sessions.

Natural-language triggers that should route to the native Codex plugin when it is enabled:

• "Bind this Discord channel to Codex."
• "Attach this chat to Codex thread <id>."
• "Show Codex threads, then bind this one."

Native Codex conversation binding is the default chat-control path. OpenClaw dynamic tools still execute through OpenClaw, while Codex-native tools such as shell/apply-patch execute inside Codex. For Codex-native tool events, OpenClaw injects a per-turn native hook relay so plugin hooks can block before_tool_call, observe after_tool_call, and route Codex PermissionRequest events through OpenClaw approvals. Codex Stop hooks are relayed to OpenClaw before_agent_finalize, where plugins can request one more model pass before Codex finalizes its answer. The relay remains deliberately conservative: it does not mutate Codex-native tool arguments or rewrite Codex thread records. Use explicit ACP only when you want the ACP runtime/session model. The embedded Codex support boundary is documented in the Codex harness v1 support contract.

For model/provider/runtime selection, remember:

• openai-codex/* is the PI Codex OAuth/subscription route.
• openai/* plus embeddedHarness.runtime: "codex" is the native Codex app-server embedded runtime route.
• /codex ... is native Codex conversation control.
• /acp ... or runtime: "acp" is explicit ACP/acpx control.

Natural-language triggers that should route to the ACP runtime:

• "Run this as a one-shot Claude Code ACP session and summarize the result."
• "Use Gemini CLI for this task in a thread, then keep follow-ups in that same thread."
• "Run Codex through ACP in a background thread."

OpenClaw picks runtime: "acp", resolves the harness agentId, binds to the current conversation or thread when supported, and routes follow-ups to that session until close/expiry. Codex only follows this path when ACP/acpx is explicit or the native Codex plugin is unavailable for the requested operation.

For sessions_spawn, runtime: "acp" is advertised only when ACP is enabled, the requester is not sandboxed, and an ACP runtime backend is loaded. It targets ACP harness ids such as codex, claude, droid, gemini, or opencode. Do not pass a normal OpenClaw config agent id from agents_list unless that entry is explicitly configured with agents.list[].runtime.type="acp"; otherwise use the default sub-agent runtime. When an OpenClaw agent is configured with runtime.type="acp", OpenClaw uses runtime.acp.agent as the underlying harness id.

ACP versus sub-agents

Use ACP when you want an external harness runtime. Use native Codex app-server for Codex conversation binding/control when the codex plugin is enabled. Use sub-agents when you want OpenClaw-native delegated runs.

Area	ACP session	Sub-agent run
Runtime	ACP backend plugin (for example acpx)	OpenClaw native sub-agent runtime
Session key	agent:<agentId>:acp:<uuid>	agent:<agentId>:subagent:<uuid>
Main commands	/acp ...	/subagents ...
Spawn tool	sessions_spawn with runtime:"acp"	sessions_spawn (default runtime)

See also Sub-agents.

How ACP runs Claude Code

For Claude Code through ACP, the stack is:

1. OpenClaw ACP session control plane
2. bundled acpx runtime plugin
3. Claude ACP adapter
4. Claude-side runtime/session machinery

Important distinction:

• ACP Claude is a harness session with ACP controls, session resume, background-task tracking, and optional conversation/thread binding.
• CLI backends are separate text-only local fallback runtimes. See CLI Backends.

For operators, the practical rule is:

• want /acp spawn, bindable sessions, runtime controls, or persistent harness work: use ACP
• want simple local text fallback through the raw CLI: use CLI backends

Bound sessions

Current-conversation binds

/acp spawn <harness> --bind here pins the current conversation to the spawned ACP session — no child thread, same chat surface. OpenClaw keeps owning transport, auth, safety, and delivery; follow-up messages in that conversation route to the same session; /new and /reset reset the session in place; /acp close removes the binding.

Mental model:

• chat surface — where people keep talking (Discord channel, Telegram topic, iMessage chat).
• ACP session — the durable Codex/Claude/Gemini runtime state OpenClaw routes to.
• child thread/topic — an optional extra messaging surface created only by --thread ....
• runtime workspace — the filesystem location (cwd, repo checkout, backend workspace) where the harness runs. Independent of the chat surface.

Examples:

• /codex bind — keep this chat, spawn or attach native Codex app-server, route future messages here.
• /codex model gpt-5.4, /codex fast on, /codex permissions yolo — tune the bound native Codex thread from chat.
• /codex stop or /codex steer focus on the failing tests first — control the active native Codex turn.
• /acp spawn codex --bind here — explicit ACP fallback for Codex.
• /acp spawn codex --thread auto — OpenClaw may create a child thread/topic and bind there.
• /acp spawn codex --bind here --cwd /workspace/repo — same chat binding, Codex runs in /workspace/repo.

Notes:

• --bind here and --thread ... are mutually exclusive.
• --bind here only works on channels that advertise current-conversation binding; OpenClaw returns a clear unsupported message otherwise. Bindings persist across gateway restarts.
• On Discord, spawnAcpSessions is only required when OpenClaw needs to create a child thread for --thread auto|here — not for --bind here.
• If you spawn to a different ACP agent without --cwd, OpenClaw inherits the target agent's workspace by default. Missing inherited paths (ENOENT/ENOTDIR) fall back to the backend default; other access errors (e.g. EACCES) surface as spawn errors.
• Gateway management commands stay local in bound conversations. In particular, /acp ... commands are handled by OpenClaw even when normal follow-up text routes to the bound ACP session; /status and /unfocus also stay local whenever command handling is enabled for that surface.

Thread-bound sessions

When thread bindings are enabled for a channel adapter, ACP sessions can be bound to threads:

• OpenClaw binds a thread to a target ACP session.
• Follow-up messages in that thread route to the bound ACP session.
• ACP output is delivered back to the same thread.
• Unfocus/close/archive/idle-timeout or max-age expiry removes the binding.
• /acp close, /acp cancel, /acp status, /status, and /unfocus are Gateway commands, not prompts to the ACP harness.

Thread binding support is adapter-specific. If the active channel adapter does not support thread bindings, OpenClaw returns a clear unsupported/unavailable message.

Required feature flags for thread-bound ACP:

• acp.enabled=true
• acp.dispatch.enabled is on by default (set false to pause ACP dispatch)
• Channel-adapter ACP thread-spawn flag enabled (adapter-specific)
  • Discord: channels.discord.threadBindings.spawnAcpSessions=true
  • Telegram: channels.telegram.threadBindings.spawnAcpSessions=true

Thread supporting channels

• Any channel adapter that exposes session/thread binding capability.
• Current built-in support:
  • Discord threads/channels
  • Telegram topics (forum topics in groups/supergroups and DM topics)
• Plugin channels can add support through the same binding interface.

Channel specific settings

For non-ephemeral workflows, configure persistent ACP bindings in top-level bindings[] entries.

Binding model

• bindings[].type="acp" marks a persistent ACP conversation binding.
• bindings[].match identifies the target conversation:
  • Discord channel or thread: match.channel="discord" + match.peer.id="<channelOrThreadId>"
  • Telegram forum topic: match.channel="telegram" + match.peer.id="<chatId>:topic:<topicId>"
  • BlueBubbles DM/group chat: match.channel="bluebubbles" + match.peer.id="<handle|chat_id:*|chat_guid:*|chat_identifier:*>" Prefer chat_id:* or chat_identifier:* for stable group bindings.
  • iMessage DM/group chat: match.channel="imessage" + match.peer.id="<handle|chat_id:*|chat_guid:*|chat_identifier:*>" Prefer chat_id:* for stable group bindings.
• bindings[].agentId is the owning OpenClaw agent id.
• Optional ACP overrides live under bindings[].acp:
  • mode (persistent or oneshot)
  • label
  • cwd
  • backend

Runtime defaults per agent

Use agents.list[].runtime to define ACP defaults once per agent:

• agents.list[].runtime.type="acp"
• agents.list[].runtime.acp.agent (harness id, for example codex or claude)
• agents.list[].runtime.acp.backend
• agents.list[].runtime.acp.mode
• agents.list[].runtime.acp.cwd

Override precedence for ACP bound sessions:

1. bindings[].acp.*
2. agents.list[].runtime.acp.*
3. global ACP defaults (for example acp.backend)

Example:

{
  agents: {
    list: [
      {
        id: "codex",
        runtime: {
          type: "acp",
          acp: {
            agent: "codex",
            backend: "acpx",
            mode: "persistent",
            cwd: "/workspace/openclaw",
          },
        },
      },
      {
        id: "claude",
        runtime: {
          type: "acp",
          acp: { agent: "claude", backend: "acpx", mode: "persistent" },
        },
      },
    ],
  },
  bindings: [
    {
      type: "acp",
      agentId: "codex",
      match: {
        channel: "discord",
        accountId: "default",
        peer: { kind: "channel", id: "222222222222222222" },
      },
      acp: { label: "codex-main" },
    },
    {
      type: "acp",
      agentId: "claude",
      match: {
        channel: "telegram",
        accountId: "default",
        peer: { kind: "group", id: "-1001234567890:topic:42" },
      },
      acp: { cwd: "/workspace/repo-b" },
    },
    {
      type: "route",
      agentId: "main",
      match: { channel: "discord", accountId: "default" },
    },
    {
      type: "route",
      agentId: "main",
      match: { channel: "telegram", accountId: "default" },
    },
  ],
  channels: {
    discord: {
      guilds: {
        "111111111111111111": {
          channels: {
            "222222222222222222": { requireMention: false },
          },
        },
      },
    },
    telegram: {
      groups: {
        "-1001234567890": {
          topics: { "42": { requireMention: false } },
        },
      },
    },
  },
}

Behavior:

• OpenClaw ensures the configured ACP session exists before use.
• Messages in that channel or topic route to the configured ACP session.
• In bound conversations, /new and /reset reset the same ACP session key in place.
• Temporary runtime bindings (for example created by thread-focus flows) still apply where present.
• For cross-agent ACP spawns without an explicit cwd, OpenClaw inherits the target agent workspace from agent config.
• Missing inherited workspace paths fall back to the backend default cwd; non-missing access failures surface as spawn errors.

Start ACP sessions (interfaces)

From sessions_spawn

Use runtime: "acp" to start an ACP session from an agent turn or tool call.

{
  "task": "Open the repo and summarize failing tests",
  "runtime": "acp",
  "agentId": "codex",
  "thread": true,
  "mode": "session"
}

Notes:

• runtime defaults to subagent, so set runtime: "acp" explicitly for ACP sessions.
• If agentId is omitted, OpenClaw uses acp.defaultAgent when configured.
• mode: "session" requires thread: true to keep a persistent bound conversation.

Interface details:

• task (required): initial prompt sent to the ACP session.
• runtime (required for ACP): must be "acp".
• agentId (optional): ACP target harness id. Falls back to acp.defaultAgent if set.
• thread (optional, default false): request thread binding flow where supported.
• mode (optional): run (one-shot) or session (persistent).
  • default is run
  • if thread: true and mode omitted, OpenClaw may default to persistent behavior per runtime path
  • mode: "session" requires thread: true
• cwd (optional): requested runtime working directory (validated by backend/runtime policy). If omitted, ACP spawn inherits the target agent workspace when configured; missing inherited paths fall back to backend defaults, while real access errors are returned.
• label (optional): operator-facing label used in session/banner text.
• resumeSessionId (optional): resume an existing ACP session instead of creating a new one. The agent replays its conversation history via session/load. Requires runtime: "acp".
• streamTo (optional): "parent" streams initial ACP run progress summaries back to the requester session as system events.
  • When available, accepted responses include streamLogPath pointing to a session-scoped JSONL log (<sessionId>.acp-stream.jsonl) you can tail for full relay history.
• runTimeoutSeconds (optional): aborts the ACP child turn after N seconds. 0 keeps the turn on the gateway's no-timeout path. The same value is applied to the Gateway run and ACP runtime so stalled/quota-exhausted harnesses do not occupy the parent agent lane indefinitely.
• model (optional): explicit model override for the ACP child session. Codex ACP spawns normalize OpenClaw Codex refs such as openai-codex/gpt-5.4 to Codex ACP startup config before session/new; slash forms such as openai-codex/gpt-5.4/high also set Codex ACP reasoning effort. Other harnesses must advertise ACP models and support session/set_model; otherwise OpenClaw/acpx fails clearly instead of silently falling back to the target agent default.
• thinking (optional): explicit thinking/reasoning effort for the ACP child session. For Codex ACP, minimal maps to low effort, low/medium/high/xhigh map directly, and off omits the reasoning-effort startup override.

Delivery model

ACP sessions can be either interactive workspaces or parent-owned background work. The delivery path depends on that shape.

Interactive ACP sessions

Interactive sessions are meant to keep talking on a visible chat surface:

• /acp spawn ... --bind here binds the current conversation to the ACP session.
• /acp spawn ... --thread ... binds a channel thread/topic to the ACP session.
• Persistent configured bindings[].type="acp" route matching conversations to the same ACP session.

Follow-up messages in the bound conversation route directly to the ACP session, and ACP output is delivered back to that same channel/thread/topic.

What OpenClaw sends to the harness:

• Normal bound follow-ups are sent as prompt text, plus attachments only when the harness/backend supports them.
• /acp management commands and local Gateway commands are intercepted before ACP dispatch.
• Runtime-generated completion events are materialized per target. OpenClaw agents get OpenClaw's internal runtime-context envelope; external ACP harnesses get a plain prompt with the child result and instruction. The raw <<<BEGIN_OPENCLAW_INTERNAL_CONTEXT>>> envelope should never be sent to external harnesses or persisted as ACP user transcript text.
• ACP transcript entries use the user-visible trigger text or the plain completion prompt. Internal event metadata stays structured in OpenClaw where possible and is not treated as user-authored chat content.

Parent-owned one-shot ACP sessions

One-shot ACP sessions spawned by another agent run are background children, similar to sub-agents:

• The parent asks for work with sessions_spawn({ runtime: "acp", mode: "run" }).
• The child runs in its own ACP harness session.
• Child turns run on the same background lane used by native sub-agent spawns, so a slow ACP harness does not block unrelated main-session work.
• Completion reports back through the task-completion announce path. OpenClaw converts internal completion metadata into a plain ACP prompt before sending it to an external harness, so harnesses do not see OpenClaw-only runtime context markers.
• The parent rewrites the child result in normal assistant voice when a user-facing reply is useful.

Do not treat this path as a peer-to-peer chat between parent and child. The child already has a completion channel back to the parent.

sessions_send and A2A delivery

sessions_send can target another session after spawn. For normal peer sessions, OpenClaw uses an agent-to-agent (A2A) follow-up path after injecting the message:

• wait for the target session's reply
• optionally let requester and target exchange a bounded number of follow-up turns
• ask the target to produce an announce message
• deliver that announce to the visible channel or thread

That A2A path is a fallback for peer sends where the sender needs a visible follow-up. It stays enabled when an unrelated session can see and message an ACP target, for example under broad tools.sessions.visibility settings.

OpenClaw skips the A2A follow-up only when the requester is the parent of its own parent-owned one-shot ACP child. In that case, running A2A on top of task completion can wake the parent with the child's result, forward the parent's reply back into the child, and create a parent/child echo loop. The sessions_send result reports delivery.status="skipped" for that owned-child case because the completion path is already responsible for the result.

Resume an existing session

Use resumeSessionId to continue a previous ACP session instead of starting fresh. The agent replays its conversation history via session/load, so it picks up with full context of what came before.

{
  "task": "Continue where we left off — fix the remaining test failures",
  "runtime": "acp",
  "agentId": "codex",
  "resumeSessionId": "<previous-session-id>"
}

Common use cases:

• Hand off a Codex session from your laptop to your phone — tell your agent to pick up where you left off
• Continue a coding session you started interactively in the CLI, now headlessly through your agent
• Pick up work that was interrupted by a gateway restart or idle timeout

Notes:

• resumeSessionId requires runtime: "acp" — returns an error if used with the sub-agent runtime.
• resumeSessionId restores the upstream ACP conversation history; thread and mode still apply normally to the new OpenClaw session you are creating, so mode: "session" still requires thread: true.
• The target agent must support session/load (Codex and Claude Code do).
• If the session ID isn't found, the spawn fails with a clear error — no silent fallback to a new session.

After a gateway deploy, run a live end-to-end check rather than trusting unit tests:

1. Verify the deployed gateway version and commit on the target host.
2. Open a temporary ACPX bridge session to a live agent.
3. Ask that agent to call sessions_spawn with runtime: "acp", agentId: "codex", mode: "run", and task Reply with exactly LIVE-ACP-SPAWN-OK.
4. Verify accepted=yes, a real childSessionKey, and no validator error.
5. Clean up the temporary bridge session.

Keep the gate on mode: "run" and skip streamTo: "parent" — thread-bound mode: "session" and stream-relay paths are separate richer integration passes.

Sandbox compatibility

ACP sessions currently run on the host runtime, not inside the OpenClaw sandbox.

Security boundary:

• The external harness can read/write according to its own CLI permissions and the selected cwd.
• OpenClaw's sandbox policy does not wrap ACP harness execution.
• OpenClaw still enforces ACP feature gates, allowed agents, session ownership, channel bindings, and Gateway delivery policy.
• Use runtime: "subagent" for sandbox-enforced OpenClaw-native work.

Current limitations:

• If the requester session is sandboxed, ACP spawns are blocked for both sessions_spawn({ runtime: "acp" }) and /acp spawn.
  • Error: Sandboxed sessions cannot spawn ACP sessions because runtime="acp" runs on the host. Use runtime="subagent" from sandboxed sessions.
• sessions_spawn with runtime: "acp" does not support sandbox: "require".
  • Error: sessions_spawn sandbox="require" is unsupported for runtime="acp" because ACP sessions run outside the sandbox. Use runtime="subagent" or sandbox="inherit".

Use runtime: "subagent" when you need sandbox-enforced execution.

From /acp command

Use /acp spawn for explicit operator control from chat when needed.

/acp spawn codex --mode persistent --thread auto
/acp spawn codex --mode oneshot --thread off
/acp spawn codex --bind here
/acp spawn codex --thread here

Key flags:

• --mode persistent|oneshot
• --bind here|off
• --thread auto|here|off
• --cwd <absolute-path>
• --label <name>

See Slash Commands.

Session target resolution

Most /acp actions accept an optional session target (session-key, session-id, or session-label).

Resolution order:

1. Explicit target argument (or --session for /acp steer)
   • tries key
   • then UUID-shaped session id
   • then label
2. Current thread binding (if this conversation/thread is bound to an ACP session)
3. Current requester session fallback

Current-conversation bindings and thread bindings both participate in step 2.

If no target resolves, OpenClaw returns a clear error (Unable to resolve session target: ...).

Spawn bind modes

/acp spawn supports --bind here|off.

Mode	Behavior
here	Bind the current active conversation in place; fail if none is active.
off	Do not create a current-conversation binding.

Notes:

• --bind here is the simplest operator path for "make this channel or chat Codex-backed."
• --bind here does not create a child thread.
• --bind here is only available on channels that expose current-conversation binding support.
• --bind and --thread cannot be combined in the same /acp spawn call.

Spawn thread modes

/acp spawn supports --thread auto|here|off.

Mode	Behavior
auto	In an active thread: bind that thread. Outside a thread: create/bind a child thread when supported.
here	Require current active thread; fail if not in one.
off	No binding. Session starts unbound.

Notes:

• On non-thread binding surfaces, default behavior is effectively off.
• Thread-bound spawn requires channel policy support:
  • Discord: channels.discord.threadBindings.spawnAcpSessions=true
  • Telegram: channels.telegram.threadBindings.spawnAcpSessions=true
• Use --bind here when you want to pin the current conversation without creating a child thread.

ACP controls

Command	What it does	Example
/acp spawn	Create ACP session; optional current bind or thread bind.	/acp spawn codex --bind here --cwd /repo
/acp cancel	Cancel in-flight turn for target session.	/acp cancel agent:codex:acp:<uuid>
/acp steer	Send steer instruction to running session.	/acp steer --session support inbox prioritize failing tests
/acp close	Close session and unbind thread targets.	/acp close
/acp status	Show backend, mode, state, runtime options, capabilities.	/acp status
/acp set-mode	Set runtime mode for target session.	/acp set-mode plan
/acp set	Generic runtime config option write.	/acp set model openai/gpt-5.4
/acp cwd	Set runtime working directory override.	/acp cwd /Users/user/Projects/repo
/acp permissions	Set approval policy profile.	/acp permissions strict
/acp timeout	Set runtime timeout (seconds).	/acp timeout 120
/acp model	Set runtime model override.	/acp model anthropic/claude-opus-4-6
/acp reset-options	Remove session runtime option overrides.	/acp reset-options
/acp sessions	List recent ACP sessions from store.	/acp sessions
/acp doctor	Backend health, capabilities, actionable fixes.	/acp doctor
/acp install	Print deterministic install and enable steps.	/acp install

/acp status shows the effective runtime options plus runtime-level and backend-level session identifiers. Unsupported-control errors surface clearly when a backend lacks a capability. /acp sessions reads the store for the current bound or requester session; target tokens (session-key, session-id, or session-label) resolve through gateway session discovery, including custom per-agent session.store roots.

Runtime options mapping

/acp has convenience commands and a generic setter.

Equivalent operations:

• /acp model <id> maps to runtime config key model. For Codex ACP, OpenClaw normalizes openai-codex/<model> to the adapter model id and maps slash reasoning suffixes such as openai-codex/gpt-5.4/high to Codex ACP reasoning_effort. For other harnesses, model control depends on adapter support for ACP models and session/set_model.
• /acp set thinking <level> maps to runtime config key thinking. For Codex ACP, OpenClaw sends the corresponding reasoning_effort where the adapter supports one.
• /acp permissions <profile> maps to runtime config key approval_policy.
• /acp timeout <seconds> maps to runtime config key timeout.
• /acp cwd <path> updates runtime cwd override directly.
• /acp set <key> <value> is the generic path.
  • Special case: key=cwd uses the cwd override path.
• /acp reset-options clears all runtime overrides for target session.

acpx harness, plugin setup, and permissions

For acpx harness configuration (Claude Code / Codex / Gemini CLI aliases), the plugin-tools and OpenClaw-tools MCP bridges, and ACP permission modes, see ACP agents — setup.

Troubleshooting

Symptom	Likely cause	Fix
ACP runtime backend is not configured	Backend plugin missing, disabled, or blocked by plugins.allow.	Install and enable backend plugin, include acpx in plugins.allow when that allowlist is set, then run /acp doctor.
ACP is disabled by policy (acp.enabled=false)	ACP globally disabled.	Set acp.enabled=true.
ACP dispatch is disabled by policy (acp.dispatch.enabled=false)	Dispatch from normal thread messages disabled.	Set acp.dispatch.enabled=true.
ACP agent "<id>" is not allowed by policy	Agent not in allowlist.	Use allowed agentId or update acp.allowedAgents.
/acp doctor reports backend not ready right after startup	Plugin dependency probe or self-repair is still running.	Wait briefly and rerun /acp doctor; if it stays unhealthy, inspect the backend install error and plugin allow/deny policy.
Harness command not found	Adapter CLI is not installed or first-run npx fetch failed.	Install/prewarm the adapter on the Gateway host, or configure the acpx agent command explicitly.
Model-not-found from the harness	Model id is valid for another provider/harness but not this ACP target.	Use a model listed by that harness, configure the model in the harness, or omit the override.
Vendor auth error from the harness	OpenClaw is healthy, but the target CLI/provider is not logged in.	Log in or provide the required provider key on the Gateway host environment.
Unable to resolve session target: ...	Bad key/id/label token.	Run /acp sessions, copy exact key/label, retry.
--bind here requires running /acp spawn inside an active ... conversation	--bind here used without an active bindable conversation.	Move to the target chat/channel and retry, or use unbound spawn.
Conversation bindings are unavailable for <channel>.	Adapter lacks current-conversation ACP binding capability.	Use /acp spawn ... --thread ... where supported, configure top-level bindings[], or move to a supported channel.
--thread here requires running /acp spawn inside an active ... thread	--thread here used outside a thread context.	Move to target thread or use --thread auto/off.
Only <user-id> can rebind this channel/conversation/thread.	Another user owns the active binding target.	Rebind as owner or use a different conversation or thread.
Thread bindings are unavailable for <channel>.	Adapter lacks thread binding capability.	Use --thread off or move to supported adapter/channel.
Sandboxed sessions cannot spawn ACP sessions ...	ACP runtime is host-side; requester session is sandboxed.	Use runtime="subagent" from sandboxed sessions, or run ACP spawn from a non-sandboxed session.
sessions_spawn sandbox="require" is unsupported for runtime="acp" ...	sandbox="require" requested for ACP runtime.	Use runtime="subagent" for required sandboxing, or use ACP with sandbox="inherit" from a non-sandboxed session.
Cannot apply --model ... did not advertise model support	The target harness does not expose generic ACP model switching.	Use a harness that advertises ACP models/session/set_model, use Codex ACP model refs, or configure the model directly in the harness if it has its own startup flag.
Missing ACP metadata for bound session	Stale/deleted ACP session metadata.	Recreate with /acp spawn, then rebind/focus thread.
AcpRuntimeError: Permission prompt unavailable in non-interactive mode	permissionMode blocks writes/exec in non-interactive ACP session.	Set plugins.entries.acpx.config.permissionMode to approve-all and restart gateway. See Permission configuration.
ACP session fails early with little output	Permission prompts are blocked by permissionMode/nonInteractivePermissions.	Check gateway logs for AcpRuntimeError. For full permissions, set permissionMode=approve-all; for graceful degradation, set nonInteractivePermissions=deny.
ACP session stalls indefinitely after completing work	Harness process finished but ACP session did not report completion.	Monitor with ps aux | grep acpx; kill stale processes manually.
Harness sees <<<BEGIN_OPENCLAW_INTERNAL_CONTEXT>>>	Internal event envelope leaked across the ACP boundary.	Update OpenClaw and rerun the completion flow; external harnesses should receive plain completion prompts only.

Related

• Sub-agents
• Multi-agent sandbox tools
• Agent send