Relay MCP Server

A Model Context Protocol server for Relay Protocol — cross-chain bridge and swap tools for AI agents.

Tools (16)

Quoting & Routing

Token & Chain Discovery

Chain Health

Transaction Tracking

Integrator Tools

Related MCP server: EVM MCP Server

Usage

Claude Desktop / Claude Code

Add to your claude_desktop_config.json or .claude.json:

{
  "mcpServers": {
    "relay": {
      "command": "npx",
      "args": ["-y", "@relayprotocol/relay-mcp"]
    }
  }
}

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "relay": {
      "command": "npx",
      "args": ["-y", "@relayprotocol/relay-mcp"]
    }
  }
}

Run from source

npm install
npm run build
npm start

Environment variables

Features

• Chain name resolution — Pass "base", "ethereum", "arb" instead of numeric chain IDs. Supports aliases and fuzzy matching.

• Input validation — Addresses, amounts, and chain IDs are validated before hitting the API, with clear error messages.

• Bundled tools — check_chain_status and get_app_fees combine multiple API calls into single tools with parallel fetching.

• Decision-tree descriptions — Tool descriptions guide agents to pick the right tool ("For just the price, use get_token_price. For full fundamentals, use get_token_details.").

• Slim responses — Responses are trimmed to essential fields. Chart data is downsampled from ~21KB to ~3KB.

• API schema discovery — get_api_schema lets agents explore available endpoints on demand (progressive disclosure pattern).

• Tx hash lookup — get_transaction_status accepts either a request ID or an on-chain transaction hash.

• Structured errors — Errors are categorized (validation, api, network, rate_limit, server, auth) with retryability hints.

Architecture

• Transport: Stdio (MCP spec)

• Runtime: Node.js >=20

• API: Direct HTTP calls to api.relay.link (no SDK dependency)

• Read-only: Returns quotes, fees, and status. Does not sign or broadcast transactions.

Agent flow examples

User: "Bridge 0.1 ETH from Ethereum to Base"

1. Agent calls get_bridge_quote(originChainId="ethereum", destinationChainId="base", ...)
   → chain names resolved automatically, quote returned with fees and ETA
2. Agent shows user the quote and a link to execute on relay.link

User: "What tokens are trending on Base?"

1. Agent calls get_trending_tokens(chainId="base")
   → returns token identities (no prices)
2. Agent calls get_token_price for each interesting token
   → returns current USD prices

License

MIT