ZeroClaw

ZeroClaw

• Built-in name: zeroclaw
• Default command: zeroclaw acp
• Upstream: https://github.com/zeroclaw-labs/zeroclaw

acpx zeroclaw starts ZeroClaw's built-in ACP server (zeroclaw acp), a JSON-RPC 2.0 stdio server that implements Agent Client Protocol v1 (protocolVersion: 1, no auth methods). The channel-acp-server feature it needs is included in ZeroClaw's default build, so a standard zeroclaw install works out of the box; a binary compiled without it exits, reporting that the channel-acp-server feature is required.

Agent selection

acpx's session/new does not pass a ZeroClaw agent alias, so the server picks the session's agent from your ZeroClaw config in this order:

1. acp.default_agent, when set.
2. The single [agents.<alias>] entry, when exactly one agent is configured.

Single-agent setups therefore need no extra configuration. Multi-agent configs must set acp.default_agent, otherwise session/new fails, reporting that it requires an agentAlias.

Notes

• Text prompts only — the server advertises no image, audio, or embedded-context prompt capability.
• Session resume/close (acpx ensure and reuse) is advertised when ZeroClaw's ACP session store is available.
• MCP tools are opt-in per agent via [agents.<alias>].acp_enable_mcp (off by default); the mcpServers acpx sends on session/new are ignored.
• zeroclaw acp --max-sessions <n> and --session-timeout <secs> bound concurrency. Override the built-in command in acpx config to pass them.

Connecting to a running gateway

To route acpx to an already-running ZeroClaw gateway/daemon instead of spawning a fresh in-process server, override the built-in command to use zeroclaw-acp-bridge, which bridges stdio to the gateway's ACP-over-WebSocket endpoint:

{
  "agents": {
    "zeroclaw": {
      "command": "zeroclaw-acp-bridge"
    }
  }
}

The bridge is a separate Cargo binary target and is not included in ZeroClaw's normal prebuilt archives or installer, so build/install zeroclaw-acp-bridge from the ZeroClaw source tree before using this override. It reads the gateway URL from the local ZeroClaw config. When gateway pairing is active, run zeroclaw gateway get-paircode --new, then start the bridge once with zeroclaw-acp-bridge --pair-code <code> to cache a token; an existing token can instead be supplied through ZEROCLAW_ACP_BRIDGE_TOKEN.