# P0 Agent Economy Index – x402 Echo / Payment Verification

> P0 Agent Economy Index – x402 Echo / Payment Verification is a paid API for AI agents from x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-11).

Verifies and echoes back a decoded x402 micropayment header, confirming scheme, asset, network, timing windows, and settlement details for a $0.001 USDC call on Base

## Facts

- Endpoint: GET https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/x402-echo?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/p0-agent-economy-index-x402-echo-payment-verification-ed037b03
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZgEIPRFIMRT0GmMPxxS0d

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability p0-agent-economy-index-x402-echo-payment-verification-ed037b03
```

Example prompt: Echo back and verify my x402 payment header — confirm the scheme, asset match, payer wallet, and settlement result on Base so I know the $0.001 USDC payment went through correctly.

## When to prefer this

Use this endpoint when you need to programmatically verify that an x402 micropayment header is valid and settled on Base before fulfilling a service request. It is specifically designed for x402 protocol validation on Base/eip155:8453 with USDC, and provides a full decoded breakdown of the payment authorization — prefer it over generic payment status checks when you need to confirm scheme, timing windows, asset match, and payer identity in one atomic call.

## Known failure modes

- Missing or malformed payment-signature header returns an error with decoded: false
- Expired payment (outside validAfter–validBefore window) returns withinWindow: false
- Asset mismatch (wrong token contract) returns assetMatches: false
- PayTo address mismatch returns payToMatches: false
- Amount mismatch (e.g. wrong USDC amount) returns amountMatches: false
- Network mismatch (not eip155:8453) returns network validation failure
- Settlement failure from facilitator returns settle.success: false

## How this service works

An open index of the machine-to-machine (agent) economy. x402 routes: ranked discovery over the live x402 service market, every indexed service scored by real 30-day calls and paying-wallet bounds, with a receipt naming the snapshot hash and scoring revision. /economy routes, for Tempo MPP, Virtuals ACP, Olas, Masumi, ERC-8004 agent registries, Solana agent registries, Base agent contracts and MCP servers (Official MCP Registry): each protocol's published figures (agent or server counts, transactions or payment events; payers and USD volume only where the source publishes them: payers for x402 and Tempo MPP, USD volume for x402 and Virtuals ACP), each with its unit, window and source; units differ, so totals are not summed. L402 and per-service MPP listings are not covered.

## Output

Returns a JSON object with ok status, timestamp, and a full decoded breakdown of the x402 payment header including: scheme validation, decoded flag, network (eip155:8453 / Base), timing window (validAfter, validBefore), x402 version, asset match, payTo match, and amount match. Also returns settlement details: payer wallet address, network, success flag, facilitator (e.g. coinbase-cdp), and transaction hash. Payment payload fields include signature, authorization (to, from, nonce, value, validAfter, validBefore), and accepted asset/network/amount/scheme.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/p0-agent-economy-index-x402-echo-payment-verification-ed037b03/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev](https://www.zero.xyz/host/x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/llms.txt)