Feature Request: Add Agent Client Protocol (ACP) Support

[omarluq]

Problem

The Freelens AI extension currently supports LLM providers through LangChain (OpenAI, Google Gemini) and external tools via MCP servers. However, there's no way to leverage powerful agentic coding tools like Claude Code, Gemini CLI, or OpenAI Codex CLI that offer superior code understanding and autonomous task execution.

These tools use the Agent Client Protocol (ACP) — an emerging standard for editor-agent communication that's gaining rapid adoption across Zed, JetBrains, Neovim, and others.

Proposed Solution

Implement ACP client support, allowing Freelens to spawn and communicate with external ACP-compliant agents as model providers.

FreeLens (ACP Client) ──stdio (JSON-RPC)──▶ External Agent (ACP Server)
                                            • Claude Code
                                            • Gemini CLI  
                                            • Codex CLI
                                            • Goose, Aider, etc.

Benefits

• Access to agentic tools: Use Claude Code, Gemini CLI, Codex CLI directly within FreeLens
• Future-proof: ACP is becoming the standard (like LSP for AI agents)
• User choice: Switch agents without switching tools
• Builds on existing patterns: Similar to current MCP Agent configuration

Suggested Implementation

1. Configuration (similar to existing mcpServers)

{
  "acpAgents": {
    "Claude Code": {
      "command": "npx",
      "args": ["@zed-industries/claude-code-acp"]
    },
    "Gemini CLI": {
      "command": "gemini",
      "args": ["--acp"]
    }
  }
}

2. Core Components

Component	Description
ACP Client	Wraps @zed-industries/agent-client-protocol SDK for agent spawning and JSON-RPC communication
Agent Selector	UI to choose between LangChain providers and ACP agents
Permission Handler	Extends existing interrupt patterns for ACP permission requests

3. Key ACP Features to Support

• Session management (session/new, session/prompt)
• Streaming responses (session/update)
• Permission requests (file writes, command execution)
• MCP server pass-through to agents

Prior Art

• Zed's ACP implementation — reference client
• Claude Code ACP adapter — ready to use
• ACP TypeScript SDK
• VS Code ACP request — 226+ upvotes

Resources

• ACP Specification
• ACP TypeScript Library
• Intro to ACP (Block/Goose)

[robertobandini]

Thank you very much @omarluq, seems interesting!
@leo-capvano What do you think? :-)

[leo-capvano]

Hi everyone yes, I agree and it is very interesting and what I am currently going to study and industrialise. Will surely try to add to AI ext.

Thanks very much for insight!