ACP in editors¶

Agent Client Protocol (ACP) lets a compatible editor use Colossus as its local agent. You work in the editor's chat interface; Colossus supplies the model route, tools, approvals, execution boundary, and durable session record.

Connect your editor¶

Install the CLI and connect a model first. The primary model role is the route used for ACP prompts.

In your editor's ACP agent settings, select the installed colossus executable and pass the workspace and acp command. For editors that accept a command and arguments array, the configuration has this shape:

{
  "command": "colossus",
  "args": ["--workspace", "/absolute/path/to/repository", "acp"]
}

Use the executable's absolute path for command if the editor cannot find colossus on its PATH. The workspace must be the same repository the editor opens. If the configuration is elsewhere, add --config and its absolute path before acp in the arguments array. Your editor's setting names may differ from the generic command and args example.

Start a new agent conversation in the editor. Colossus creates a durable session and streams released responses and tool status back into the editor. It writes diagnostics to stderr, leaving the ACP protocol on stdin and stdout.

Approve actions in the editor¶

When a tool needs approval, the editor can offer Allow once or Reject. Allow once applies to that exact request; it cannot override a Colossus policy denial or widen the configured sandbox. ACP uses this fail-closed approval flow, so --approval-mode is unavailable with acp. Configure tools, MCP servers, access, and sandbox settings in Colossus, as you would for a terminal run. See Access and approvals for the underlying rules.

Current ACP support¶

Images, audio, and embedded resources are not accepted in ACP prompts yet. You can still inspect existing Colossus sessions with the CLI session commands. If the editor cannot start Colossus because another Colossus process owns the workspace, close that process before starting the ACP agent. Colossus Desktop does not currently act as an ACP client.

What's next?¶