A2A MCP Server
An MCP server that implements an A2A Client for the A2A Protocol. The server can be used to connect and send messages to A2A Servers (remote agents).
The server needs to be initialised with one or more Agent Card URLs, each of which can have custom headers for authentication, configuration, etc.
Agents and their skills can be viewed with the list_available_agents tool, messages can be sent to the agents with the send_message_to_agent tool, and Artifacts that would overload the context can be viewed with view_text_artifact and view_data_artifact tools.
✨ Features
Connect to any A2A Agent
Use custom headers for authentication and configuration
View Agent Cards and Skills
Send messages to agents
Continue conversations with agents
View Artifacts that would overload the context
Agent conversations are stored in JSON format
📋 Requirements
To run the server you need to install uv if you haven't already.
MacOS/Linux:
Windows:
🚀 Quick Start
Download Claude for Desktop
Add the below to your Claude Desktop config (
~/Library/Application Support/Claude/claude_desktop_config.jsonon macOS):
Tip: If you don't have an Agent Card URL
Create an account on A2A Net
Pick an agent (e.g. "Tweet Search")
Take its URL and add
/agent-card.jsonto the end of it (e.g.https://a2anet.com/agent/7TaFj4YlbpngypjX74zl/agent-card.json)Go to Dashboard
Click "+ Create Key" > Name your key (e.g. "Test") > Click "Create"
Set
A2A_AGENT_CARDSto the Agent Card URL and API key (e.g."[{\"url\": \"https://a2anet.com/agent/7TaFj4YlbpngypjX74zl/agent-card.json\"}, \"custom_headers\": {\"X-API-Key\": \"a2anet_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx\"}]")
⚙️ Configuration
A2A_AGENT_CARDS should be a JSON stringified list of objects. Each object must have a url key with the full path to the Agent Card. It can optionally have a custom_headers key with an object in the form {"header": "value"}:
🛠️ Tools
list_available_agents
Discover available agents and their capabilities.
send_message_to_agent
Send a message to an agent.
Parameter | Required | Description |
| Yes | Agent name from |
| Yes | Your message or request |
| No | Continue an existing conversation |
view_text_artifact
View text content from an artifact with optional line range selection.
Parameter | Required | Description |
| Yes | Conversation context ID |
| Yes | Artifact to view |
| No | Starting line number (1-based, inclusive) |
| No | Ending line number (1-based, inclusive) |
view_data_artifact
View structured data from an artifact with optional filtering.
Parameter | Required | Description |
| Yes | Conversation context ID |
| Yes | Artifact to view |
| No | Dot-separated path to extract specific fields |
| No | Row selection (index, list, range string, or "all") |
| No | Column selection (name, list, or "all") |
📖 Examples
List agents
Send a message
Multi-turn conversation
Use context_id to continue a conversation:
View data artifact
💾 Data Storage
Agent conversations are stored in JSON format to a standard path and can be inspected.
Linux:
~/.local/share/a2anet-mcp/conversations/macOS:
~/Library/Application Support/a2anet-mcp/conversations/Windows:
AppData/Local/A2ANet/a2anet-mcp/conversations/
🔧 Development
Claude Desktop Setup
For local development:
Clone the repository:
git clone https://github.com/a2anet/a2a-mcp.gitDownload Claude for Desktop.
Add to the below to your Claude Desktop config (
~/Library/Application Support/Claude/claude_desktop_config.jsonon macOS):
📄 License
a2anet is distributed under the terms of the Apache-2.0 license.
🤝 Join the A2A Net Community
A2A Net is a site to find and share AI agents and open-source community. Join to share your A2A agents, ask questions, stay up-to-date with the latest A2A news, be the first to hear about open-source releases, tutorials, and more!
🌍 Site: A2A Net
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