Agent Client Protocol

fast-agent has comprehensive support for Zed Industries Agent Client Protocol. Why use fast-agent?:

Robust, native LLM Provider infrastructure, with Streaming and Structured outputs.
Comprehensive MCP and Agent Skills support, including Tool Progress Notifications and Sampling.
Build custom, multi-agent experiences in a few lines of code.
Each Agent or Workflow appears as a "Mode" and transmits workflow events to the your ACP Client.

Getting Started

To try it out straight away with your Client, set an API Key environment variable and add:

Hugging Face

export HF_TOKEN=hf_.......

uvx fast-agent-mcp@latest serve --transport acp --model <your_model>

Open AI

export OPENAI_API_KEY=......

uvx fast-agent-mcp@latest serve --transport acp --model <your_model>

Anthropic

export ANTHROPIC_API_KEY=......

uvx fast-agent-mcp@latest serve --transport acp --model <your_model>

Tip: Use uvx fast-agent-mcp check to help diagnose issues.

Note: OAuth keys are stored in your keyring, so check may prompt to read the credential store.

uv tool install -U fast-agent-mcp

Documentation in Progress.

fast-agent adds the shell tool, read and write tools from the Client to allow "follow-along" functionality.