A2A Client MCP Server

An MCP server client for the Agent-to-Agent (A2A) protocol, enabling LLMs to interact with A2A agents.

GitHub

A2A Client MCP Server

An MCP server that acts as a client to the Agent-to-Agent (A2A) protocol, allowing LLMs to interact with A2A agents through the Model Context Protocol (MCP).

Features

  • Connect to any A2A-compatible agent
  • Send and receive messages
  • Track and manage tasks
  • Support for streaming responses
  • Query agent capabilities and metadata

Installation

Install globally

npm install -g a2a-client-mcp-server

Or run directly with npx

npx a2a-client-mcp-server

Configuration

Environment Variables

Usage with Claude Desktop

Add this to your claude_desktop_config.json:

NPX

npm run build npm link

{ "mcpServers": { "a2a-client": { "command": "npx", "args": ["-y", "a2a-client-mcp-server"], "env": { "A2A_ENDPOINT_URL": "http://localhost:41241" } } } }

Docker

Build the Docker image:

docker build -t a2a-client-mcp-server .

Configure Claude Desktop:

{ "mcpServers": { "a2a-client": { "command": "docker", "args": [ "run", "-i", "--rm", "-e", "A2A_ENDPOINT_URL", "a2a-client-mcp-server" ], "env": { "A2A_ENDPOINT_URL": "http://localhost:41241" } } } }

Available Tools

a2a_send_task

Send a task to an A2A agent

  • message (string): Message to send to the agent
  • taskId (string, optional): Task ID (generated if not provided)

a2a_get_task

Get the current state of a task

  • taskId (string): ID of the task to retrieve

a2a_cancel_task

Cancel a running task

  • taskId (string): ID of the task to cancel

a2a_send_task_subscribe

Send a task and subscribe to updates (streaming)

  • message (string): Message to send to the agent
  • taskId (string, optional): Task ID (generated if not provided)
  • maxUpdates (number, optional): Maximum updates to receive (default: 10)

a2a_agent_info

Get information about the connected A2A agent

  • No parameters required

Resources

The server provides access to two MCP resources:

  • a2a://agent-card: Information about the connected A2A agent
  • a2a://tasks: List of recent A2A tasks

Example Usage

This example shows how to use A2A Client MCP Server to interact with a Coder Agent:

First, let me explore what A2A agent we're connected to.

I'll use the a2a_agent_info tool to check the agent details.

The agent provides a coding service that can generate files based on natural language instructions. Let's create a simple Python script.

I'll use the a2a_send_task tool to send a request:

Task: "Create a Python function that calculates the Fibonacci sequence"

Now I can check the task status using a2a_get_task with the task ID from the previous response.

The agent has created the requested Python code. I can now retrieve and use this code in my project.

Development

Install dependencies

npm install

Build the project

npm run build

Run in development mode

npm run watch

License

MIT

Related Servers