@larkinsh/mcp

MCP server exposing Larkin's wallet authorization check as a tool for AI agents (Claude Code, Cursor, and any MCP-aware host).

Provides one tool: check_wallet — authorizes an EVM wallet before processing its x402 payment. Returns a 0-100 trust score, an allow/deny/surcharge decision, a 5-dimension scoring breakdown, and an Ed25519-signed receipt verifiable with @larkinsh/verify.

Install

The server is designed to run via npx:

npx @larkinsh/mcp

It speaks MCP over stdio. Set LARKIN_API_KEY in the environment of the spawning process; the value of chain_id defaults to 1 (Ethereum mainnet) when the caller omits it.

Configure in Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "larkin": {
      "command": "npx",
      "args": ["-y", "@larkinsh/mcp"],
      "env": {
        "LARKIN_API_KEY": "pf_live_..."
      }
    }
  }
}

Other MCP hosts (Cursor, custom clients) follow the same shape — spawn npx -y @larkinsh/mcp and pipe an LARKIN_API_KEY env var.

Tool reference

check_wallet

| Field | Type | Required | Description | |---|---|---|---| | wallet | string | yes | EVM wallet address (0x-prefixed, 42 chars). | | chain_id | integer | no (default 1) | EVM chain ID. 1=Ethereum, 8453=Base. |

Returns the data payload of POST https://larkin.sh/api/v1/check — score, breakdown, decision, surcharge multiplier, and signed receipt.

Environment variables

| Variable | Required | Default | Notes | |---|---|---|---| | LARKIN_API_KEY | yes | — | Your pf_live_* key from https://larkin.sh/dashboard. | | LARKIN_BASE_URL | no | https://larkin.sh | Override for self-hosted or staging deployments. |

Programmatic use

import { createServer } from "@larkinsh/mcp";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";

const server = createServer({ apiKey: process.env.LARKIN_API_KEY! });
const transport = new StdioServerTransport();
await server.connect(transport);

Documentation

Full docs: https://larkin.sh/docs Source & issues: https://github.com/larkin-dev/larkin

License

MIT