MCP Server

Mu includes an MCP (Model Context Protocol) server that allows AI assistants and tools to interact with Mu services programmatically.

The MCP server exposes 30+ tools — news, search, video, weather, places, mail, blog, apps, markets — that any MCP-compatible client can use. It implements the MCP specification using the Streamable HTTP transport at a single endpoint.

Endpoint: POST /mcp

Pay with Crypto (x402)

AI agents can pay per-request with stablecoins via the x402 protocol. No account, no API key, no signup. Just call and pay.

Accepted tokens: USDC and EURC on Base (configurable via X402_ASSETS).

When x402 is enabled on the server (X402_PAY_TO is set), any metered tool call without sufficient credits returns HTTP 402 with payment requirements. The agent pays on-chain, retries, and gets the response.

Example: x402 Payment Flow

1. Call a tool without payment:

curl -X POST https://mu.xyz/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"web_search","arguments":{"query":"latest AI news"}}}'

2. Server returns 402 with payment requirements:

HTTP/1.1 402 Payment Required
X-PAYMENT-REQUIRED: eyJzY2hlbWUiOiJleGFjdCIsIm5ldHdvcmsi...

{
  "error": "Payment required",
  "x402": [{
    "scheme": "exact",
    "network": "eip155:8453",
    "maxAmountRequired": "$0.05",
    "resource": "/mcp",
    "description": "Access to web_search",
    "payTo": "0x...",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
  }],
  "accepts": ["x402"]
}

3. Agent pays on-chain and retries with payment proof:

curl -X POST https://mu.xyz/mcp \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <base64-encoded-payment-payload>" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"web_search","arguments":{"query":"latest AI news"}}}'

4. Server verifies, settles, and returns the result.

The X-PAYMENT-REQUIRED header contains base64-encoded JSON with all the information a client needs to construct a payment: network, asset, amount, and destination address.

Pricing

Metered tools are priced at 1 credit = $0.01 USD via x402:

Free tools (news, blog_list, blog_read, video, markets, social, search, quran, hadith, reminder, etc.) don’t require payment.

Account-Based Authentication

For human users or agents that prefer account-based billing, authenticate with a session token or Personal Access Token:

{
  "mcpServers": {
    "mu": {
      "url": "https://mu.xyz/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_TOKEN"
      }
    }
  }
}

Replace YOUR_TOKEN with a session token from the login tool or a Personal Access Token created at /token.

Sign Up

curl -X POST https://mu.xyz/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"signup","arguments":{"id":"myagent","secret":"password123","name":"My Agent"}}}'

Log In

curl -X POST https://mu.xyz/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"login","arguments":{"id":"myagent","secret":"password123"}}}'

Both return a session token. Use it in subsequent requests:

Authorization: Bearer SESSION_TOKEN

Account-based users get 20 free credits per day and can top up with a card via Stripe.

Available Tools

Protocol

The MCP server uses the Streamable HTTP transport. Clients send JSON-RPC 2.0 requests via POST:

Initialize

curl -X POST https://mu.xyz/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-03-26","clientInfo":{"name":"example","version":"1.0"},"capabilities":{}}}'

List Tools

curl -X POST https://mu.xyz/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/list"}'

Call a Tool

With x402 payment:

curl -X POST https://mu.xyz/mcp \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <payment-payload>" \
  -d '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"web_search","arguments":{"query":"latest news"}}}'

With account token:

curl -X POST https://mu.xyz/mcp \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -d '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"news","arguments":{}}}'

Two Ways to Pay

Self-Hosting

When running your own Mu instance, the MCP server is available automatically at /mcp with no additional configuration required.

To enable x402 payments, set X402_PAY_TO to your wallet address. USDC and EURC on Base are accepted by default. See Configuration for details.