Agentic MCP Pay Demo

agent mcp-pay端到端演示


它展示了什么

• 免费工具直通 --没有价格的工具会立即执行，不会触发付款流
• 透明的自动支付 --当付费工具返回时 PAYMENT_REQUIRED，客户端会自动检测到挑战，签署付款证明，并在不更改代理代码的情况下重试
• 多工具支付 --两种不同价格的付费工具(translate 0.01美元， summarize 0.05美元）
• 预算跟踪 — client.getSpendingStats() 每期回报和每日支出总额
• 收款流程 --每次成功的付费通话都会返回一个 _receipt 工具结果旁边的块

如何跑步

npm install
npm run demo

需要Node.js 18+。

预期输出

=== agentic-mcp-pay End-to-End Demo ===

Server and client connected

--- Test 1: Free tool (echo) ---
  Result: Echo: Hello world!
  Free tool works — no payment needed

--- Test 2: Paid tool (translate, $0.01) ---
  Auto-paying $0.01 for "translate" via mock
  Result: [Translated to Spanish]: Hello world
  Paid tool works — payment handled transparently

--- Test 3: Paid tool (summarize, $0.05) ---
  Auto-paying $0.05 for "summarize" via mock
  Result: Summary of "The quick brown fox jumps over the lazy dog. This ...": This is a key point.
  Second paid tool works

--- Test 4: Spending stats ---
  Total spent: $0.06
  Today: $0.06
  Calls: 2
  Budget tracking works

=== All tests passed! ===
The full payment loop works:
  Agent calls tool -> Gateway returns PAYMENT_REQUIRED
  -> Client auto-detects -> Checks budget -> Signs payment
  -> Retries with proof -> Gateway verifies -> Tool executes
  -> Receipt returned -> Spending tracked

循环是如何工作的

Agent calls tool
      │
      ▼
Gateway checks pricing table
      │
      ├─ No price set ──────────────────► Execute immediately (passthrough)
      │
      └─ Price set, no _payment arg ───► Return PAYMENT_REQUIRED + challenge
                                                    │
                                                    ▼
                                          Client receives challenge
                                                    │
                                          Check budget limits
                                                    │
                                          Sign payment proof
                                                    │
                                          Retry call with _payment arg
                                                    │
                                                    ▼
                                          Gateway verifies proof
                                                    │
                                          Execute tool, return result + receipt

另见

• 代理mcp支付 --服务器端支付网关包
• 代理mcp付费客户端 --买方客户端SDK包
• 教程：在5分钟内将MCP工具货币化