Agent Client Protocol (ACP) Skill

Product Summary

The Agent Client Protocol (ACP) is a standardized JSON-RPC 2.0-based protocol for bidirectional communication between code editors/IDEs and AI coding agents. It enables agents to work with any compatible editor and editors to support any ACP-compatible agent, similar to how LSP standardized language servers.

ACP supports both local agents (running as subprocesses via stdio) and remote agents (via HTTP/WebSocket). The protocol handles initialization, session management, prompt turns, tool execution, file system access, and extensibility through custom methods and metadata fields.

Key files and concepts:

• JSON-RPC 2.0 message format (requests, responses, notifications)
• Transport: stdio (required), HTTP (draft)
• Core methods: initialize, session/new, session/prompt, session/cancel, session/update
• Capabilities negotiation during initialization
• Session-based conversation context with MCP server integration

Primary documentation: https://agentclientprotocol.com

When to Use