Goose Acp Integration

Goose ACP Integration for Drewgent

What is ACP

Agent Client Protocol (ACP) is a JSON-RPC-based standard for communicating with coding agents (GitHub: agentclientprotocol).

goose uses ACP to connect to agents like Claude Code as provider (subprocess communication over stdio):

goose → claude-agent-acp (NPM) → Claude Code CLI → Anthropic API

Key ACP providers in goose:

• claude_acp.rs — Claude Code via @agentclientprotocol/claude-agent-acp
• codex_acp.rs — OpenAI Codex
• copilot_acp.rs — GitHub Copilot

Key Protocol Types (agentclientprotocol schema)

InitializeRequest/Response   // handshake
NewSessionRequest/Response    // create session
PromptRequest/Response       // send messages
SessionNotification          // async events (tool calls, permissions, completion)
  - ToolCallStart { id, name, kind, raw_input }
  - ToolCallComplete { id, raw_output, content[], is_error }
  - PermissionRequest { request: RequestPermissionRequest }
  - Complete(StopReason, Option)
ToolCallContent / ToolCallStatus
RequestPermissionResponse

How goose connects to Claude Code

// crates/goose/src/providers/claude_acp.rs
let config = AcpProviderConfig {
    command: resolved_command,  // path to claude-agent-acp
    args: vec![],
    env: vec![],
    work_dir: current_dir,
    mcp_servers: extension_configs_to_mcp_servers(&extensions),  // Drewgent tools as MCP
    session_mode_id: Some(mode_mapping[&goose_mode].clone()),
    // mode_mapping:
    //   Auto → bypassPermissions (fully autonomous)
    //   Approve → default (ask before risky)
    //   SmartApprove → acceptEdits (auto-accept edits)
    //   Chat → plan (plan only)
};
AcpProvider::connect(name, model, goose_mode, config).await

AcpProvider (crates/goose/src/acp/provider.rs):

• Spawns subprocess (stdio JSON-RPC)
• Sends initialize then newSession
• Streams SessionNotification back (tool calls, permissions)
• Sends tool results via CallToolResult

Drewgent Implementation Points

1. ACP Provider Tool

Spawn any ACP agent as subprocess, communicate via newline-delimited JSON-RPC over stdio.

2. MCP Extension Bridge

Convert Drewgent tools → MCP server definitions → pass to ACP agent via mcp_servers config.

3. Permission Tiers

Map Drewgent P0-P6 brain rules to ACP permission decisions (AllowAlways/AllowOnce/RejectOnce/RejectAlways/Cancel).

Implementation Plan

Phase 1: tools/acp_provider.py — subprocess spawn + JSON-RPC over stdio + session lifecycle Phase 2: Delegate to Claude Code via claude-agent-acp, pass Drewgent tools as MCP servers Phase 3: Permission callback system bridging Drewgent P0 rules to ACP permission requests

References

• goose ACP provider impl: crates/goose/src/providers/{claude_acp,codex_acp,copilot_acp}.rs
• ACP core: crates/goose/src/acp/provider.rs
• ACP macros: crates/goose-acp-macros/src/lib.rs
• Protocol schema: agent_client_protocol Rust crate (github.com/agentclientprotocol)
• ACP npm adapter: @agentclientprotocol/claude-agent-acp
• Docs: https://goose-docs.ai/docs/guides/acp-providers

Gotchas

1. STDIO transport — newline-delimited JSON-RPC, no HTTP
2. Mode mapping — each ACP agent has different mode strings; configured per-provider
3. MCP servers — must follow Model Context Protocol schema
4. Permission suspension — ACP agent waits for async permission response; cannot block main loop
5. Nested sessions — set env_remove to prevent infinite nesting (e.g., CLAUDECODE env var)

Related

• [[@action/skills/SKILL-INDEX]]
• [[@action/skills/agent-protocol/DESCRIPTION]]

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: humanerd-drew
• Source: humanerd-drew/opencode-drewgent
• License: MIT

Install and usage instructions live in the source repository linked above.