Data tools / Agent memory and small utilities

x402 echo: see what the server received from your client

Use for debugging an x402 client: pay $0.001 in USDC (or USDT0 on Arbitrum) on any network in accepts and get back what the server received: the decoded payment payload (scheme, network, authorization fields, signature), checks of amount, payTo, asset and validity window against this route's requirement, and the facilitator's settlement result. Only the payment header is echoed, never other headers.

Price and access

Request

curl -i 'https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/x402-echo'

Runnable code for JavaScript, Python and LangChain: /integrations. Full schema: OpenAPI.

Example answer

{
  "ok": true,
  "ts": "2026-10-04T12:00:00.000Z",
  "route": "/x402-echo",
  "header": {
    "name": "payment-signature",
    "bytes": 824,
    "encoding": "base64-json"
  },
  "payment": {
    "x402Version": 2,
    "accepted": {
      "scheme": "exact",
      "network": "eip155:8453",
      "amount": "1000",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "payTo": "0xECa891e34b3E5873181Fb779672564E198C55354"
    },
    "payload": {
      "signature": "0xcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcd",
      "authorization": {
        "from": "0x7EF12BE6000000000000000000000000000000aa",
        "to": "0xECa891e34b3E5873181Fb779672564E198C55354",
        "value": "1000",
        "validAfter": "1791115140",
        "validBefore": "1791115500",
        "nonce": "0xefefefefefefefefefefefefefefefefefefefefefefefefefefefefefefefef"
      }
    }
  },
  "checks": {
    "decoded": true,
    "x402Version": 2,
    "scheme": "exact",
    "network": "eip155:8453",
    "amountMatches": true,
    "payToMatches": true,
    "assetMatches": true,
    "validBefore": "2026-10-04T12:05:00.000Z",
    "validAfter": "2026-10-04T11:59:00.000Z",
    "withinWindow": true
  },
  "settle": {
    "success": true,
    "transaction": "0xabababababababababababababababababababababababababababababababab",
    "network": "eip155:8453",
    "payer": "0x7EF12BE6000000000000000000000000000000aa",
    "facilitator": "coinbase-cdp"
  }
}

Use it from an AI assistant (MCP)

Remote MCP server for this topic: https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/mcp/agent-memory-utils, tool x402_echo. The tool returns the exact paid request for your input. All tools on one server: https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/mcp.

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