┌─────────────┐                ┌──────────────┐                ┌─────────────────┐
│ Claude /    │   MCP stdio    │ @gatefare/mcp│  HTTP + x402   │ gatefare.io     │
│ Cursor /    │ ─────────────► │   (this repo)│ ─────────────► │ proxy +         │
│ your agent  │                │              │                │ catalog         │
└─────────────┘                └──────┬───────┘                └─────────────────┘
                                      │
                                      │ EIP-3009 sign
                                      ▼
                                ┌─────────────┐
                                │  Base USDC  │
                                └─────────────┘

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

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

{
  "mcpServers": {
    "gatefare": {
      "command": "npx",
      "args": ["-y", "@gatefare/mcp"],
      "env": {
        "WALLET_PRIVATE_KEY": "0xYOUR_KEY",
        "WALLET_BUDGET_USD": "5.00"
      }
    }
  }
}

"env": {
  "GATEFARE_PAT": "gfpat_..."
}

from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client

server = StdioServerParameters(
    command="npx",
    args=["-y", "@gatefare/mcp"],
    env={"WALLET_PRIVATE_KEY": "0x...", "WALLET_BUDGET_USD": "1.00"},
)

async with stdio_client(server) as (r, w):
    async with ClientSession(r, w) as s:
        await s.initialize()
        result = await s.call_tool(
            "gatefare.call_api",
            arguments={"slug": "demo-weather", "query": {"city": "Tokyo"}},
        )
        print(result.content[0].text)

# Run the server in foreground; talks JSON-RPC over stdio.
npx -y @gatefare/mcp

# In another terminal, send a frame:
echo '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}' | \
  npx -y @gatefare/mcp

git clone https://github.com/gatefareio/mcp-server.git
cd mcp-server
npm install
npm run typecheck
npm test                  # 138 unit tests
npm run test:e2e          # 10 e2e tests against live gatefare.io (set GATEFARE_E2E=1)
npm run build

npm link
# in claude_desktop_config.json:
#   "command": "gatefare-mcp"

src/
├── index.ts        # entry — wires stdio transport
├── server.ts       # McpServer instance + tool registration
├── config.ts       # env parsing, capability detection
├── client.ts       # REST client (wraps fetch)
├── x402.ts         # 402 parsing + EIP-3009 signing
├── types.ts        # shared types + GatefareError
└── tools/
    ├── discovery.ts   # search_apis, get_api, list_categories, suggest
    ├── buyer.ts       # call_api, get_wallet_balance, estimate_cost
    ├── publisher.ts   # register_api, list_my_apis, update_api, get_revenue, distribute
    └── safety.ts      # report_abuse

tests/
├── config.test.ts         # env parsing edges
├── client.test.ts         # HTTP client error mapping
├── x402.test.ts           # signing + parsing primitives
├── x402-flow.test.ts      # full 402 → sign → retry handshake (mocked fetch)
├── server.test.ts         # capability-driven tool registration
├── init.test.ts           # subprocess: bootstrap, env crashes, secret leakage
├── stdio-protocol.test.ts # stdout pollution + recovery from tool errors
├── stability.test.ts      # 100 concurrent calls, memory baseline, ReDoS
├── tools/
│   ├── discovery.test.ts
│   ├── buyer.test.ts
│   ├── buyer-flow.test.ts
│   ├── publisher.test.ts
│   └── safety.test.ts
└── integration/
    └── e2e.test.ts        # real gatefare.io, gated by GATEFARE_E2E=1