gmfarcaster-mcp

An MCP server for the Warpee Knowledge API. Connect it once and your AI client — Claude Desktop, Claude Code, Cursor, or any other MCP host — can query the GM Farcaster archive on its own: hundreds of podcast episodes, transcripts, and metadata, answered with timestamped citations.

It exposes a single tool, ask_gmfarcaster, that takes a natural-language question and returns a grounded, source-cited answer.

Each call is a paid, account-less request (~$0.005 USDC). There are no API keys — the on-chain payment is the authorization. The server signs with your own funded wallet, on whichever rail you configure a key for: x402 (USDC on Base, gasless for the signer via EIP-3009 — wallet needs USDC but no ETH) or MPP (USDC on Tempo, client-settles — wallet needs USDC and pays its own small stablecoin-denominated network fee).

Prerequisites

• Node.js ≥ 18
• A wallet (private key) holding a small amount of USDC on Base or Tempo (whichever rail you want to use). Use a dedicated, low-balance wallet — see Security.

Connect it to your client

The server reads your wallet key from GMFARCASTER_PRIVATE_KEY (Base, x402) or GMFARCASTER_MPP_PRIVATE_KEY (Tempo, MPP) — set whichever matches the wallet you funded. The examples below use the x402/Base variable; swap in GMFARCASTER_MPP_PRIVATE_KEY with a Tempo wallet key to use MPP instead — see Configuration. Each client configures MCP servers a little differently.

Claude Desktop

Edit your claude_desktop_config.json (Settings → Developer → Edit Config), then restart Claude:

{
  "mcpServers": {
    "gmfarcaster": {
      "command": "npx",
      "args": ["-y", "gmfarcaster-mcp"],
      "env": {
        "GMFARCASTER_PRIVATE_KEY": "0xYOUR_FUNDED_BASE_WALLET_KEY"
      }
    }
  }
}

Claude Code

claude mcp add gmfarcaster \
  --env GMFARCASTER_PRIVATE_KEY=0xYOUR_FUNDED_BASE_WALLET_KEY \
  -- npx -y gmfarcaster-mcp

Cursor

Add to ~/.cursor/mcp.json (or a project .cursor/mcp.json):

{
  "mcpServers": {
    "gmfarcaster": {
      "command": "npx",
      "args": ["-y", "gmfarcaster-mcp"],
      "env": {
        "GMFARCASTER_PRIVATE_KEY": "0xYOUR_FUNDED_BASE_WALLET_KEY"
      }
    }
  }
}

Once connected, just ask naturally — the client decides when to call the tool:

"Use the gmfarcaster tool and tell me what the GM Farcaster hosts have said about prediction markets?" "Summarize the latest gmfarcaster episode." "Use the gmfarcaster tool and tell me what from @dwr been featured on the show?"

Configuration

| Variable | Required | Default | Description | |----------|----------|---------|-------------| | GMFARCASTER_PRIVATE_KEY | One of these two | — | 0x-hex private key of a wallet holding USDC on Base (x402 rail). | | GMFARCASTER_MPP_PRIVATE_KEY | One of these two | — | 0x-hex private key of a wallet holding USDC on Tempo (MPP rail). | | GMFARCASTER_PAYMENT_RAIL | No | x402 if both keys above are set | "x402" or "mpp" — which rail to use when you've configured both keys. Ignored (and unnecessary) if only one key is set. | | GMFARCASTER_API_URL | No | https://api.gmfarcaster.com/v1/query | Override the endpoint. | | GMFARCASTER_NETWORK | No | eip155:8453 | CAIP-2 network id for the x402 rail (Base mainnet). |

Security

• The private key signs real USDC payments. Treat it like a hot wallet: use a dedicated wallet funded with only a few dollars of USDC, not your main account.
• The key never leaves your machine — it lives in your local MCP client config and is used only to sign the payment for each query, on whichever rail you've configured.
• Each query spends ~$0.005 USDC. Top the wallet up as needed.

Local development (before publishing to npm)

npm install
npm run build

Then point your client's command/args at the built file instead of npx:

{
  "mcpServers": {
    "gmfarcaster": {
      "command": "node",
      "args": ["/absolute/path/to/gmfarcaster-api/mcp-server/build/index.js"],
      "env": { "GMFARCASTER_PRIVATE_KEY": "0x..." }
    }
  }
}

How it works

MCP client (Claude / Cursor)
     │  calls tool ask_gmfarcaster({ query })
     ▼
gmfarcaster-mcp ──POST /v1/query──► api.gmfarcaster.com
     │                                   │ 402 Payment Required
     │  signs payment (x402/Base or      ▼
     │  MPP/Tempo — whichever key's set)
     └──────────── retry w/ payment ──► 200 OK { answer, citations[], usage }

The server is a thin wrapper over the public HTTP API, picking whichever rail you've configured a key for. See the main README for the full dual-rail contract.

Answers are live-generated, so a tool call can take ~30 seconds, and up to ~3 minutes for complex questions — that's expected, not a hang. The server waits long enough and pays only once per call, so let the tool finish rather than cancelling and re-asking (each call is a separate on-chain payment).

License

MIT © GM Farcaster Network