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A2A Registry MCP Server

MCP server providing A2A agent registry with REST API and MCP tools

Installation

Add the following to your MCP client configuration file.

Configuration

{
  "mcpServers": {
    "ericabouaf-a2a-registry": {
      "url": "http://localhost:3005/mcp"
    }
  }
}

You run a single HTTP server that exposes both a REST API for managing agents and an MCP server for programmatic control via Server-Sent Events. This MCP-enabled registry lets agents publish their metadata, be queried, and managed through a consistent, standards-based interface, making it easier to onboard agents and automate registry workflows.

How to use

Connect with an MCP client to interact with the A2A Registry through the MCP endpoint at /mcp. You can register new agents by providing an agent URL, list all registered agents, fetch details for a specific agent, update an agent by re-fetching its AgentCard, or delete an agent. The MCP tools are exposed over SSE, allowing multiple clients to stay in sync concurrently.

How to install

# Install dependencies
npm install

# Build the project
npm run build

# Run with default settings (JSON store, port 3000)
npm start

# Or run directly from the built file
node dist/index.js

Configuration options and usage notes

# Use SQLite storage
node dist/index.js --store=sqlite --file=./agents.db

# Custom port
node dist/index.js --port=4000

# Custom JSON file location
node dist/index.js --store=json --file=./my-agents.json

# Combine options
node dist/index.js --store=sqlite --file=./agents.db --port=4000

MCP server configuration and tools

The MCP server is available at /mcp using Server-Sent Events transport. You can configure an MCP client to connect to the registry at the provided URL.

Additional MCP endpoints and tools

Available MCP tools include the following, each performing a distinct action against the registry.

Notes on error handling and reliability

The registry returns clear error messages for common failure scenarios, including not found, already exists, invalid input, and internal errors. Use these messages to determine the next steps in your workflow.

Development and maintenance

Development builds produce TypeScript sources under src and compiled JavaScript under dist. Use the provided npm scripts to build, run in development mode, or perform a clean build.

Available tools

a2a_register_agent

Register a new agent by URL. Requires { url: string } and triggers intelligent AgentCard discovery, validation, and storage.

a2a_list_agents

List all registered agents.

a2a_get_agent

Get agent details by name.

a2a_update_agent

Update agent by re-fetching the AgentCard, optionally with a new URL.

a2a_delete_agent

Delete an agent from the registry.