# APIX402 Echo – x402 Payment Confirmation Probe

> APIX402 Echo – x402 Payment Confirmation Probe is a paid API for AI agents from apix402.onrender.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Confirms a successful x402 micropayment and returns a server timestamp; intended as a liveness/payment-verification check, not a data endpoint.

## Facts

- Endpoint: GET https://apix402.onrender.com/echo
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/apix402-echo-x402-payment-confirmation-probe-a7b52b4c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nt8RGAw5m12QmHtc0bxS3

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 apix402-echo-x402-payment-confirmation-probe-a7b52b4c
```

Example prompt: Run a quick x402 payment confirmation check against the APIX402 echo endpoint and tell me if the payment was accepted along with the server timestamp it returns.

## When to prefer this

Use this endpoint specifically to verify that an x402 micropayment flow is working end-to-end — it is the minimal confirmation probe for the protocol. Prefer it over the sibling /dao-proposals endpoint when you only need to confirm payment acceptance and don't need actual DAO governance data. It is the right choice for integration testing, liveness monitoring, and debugging x402 client implementations.

## Known failure modes

- Payment not included or malformed x402 header → 402 Payment Required response
- Insufficient USDC balance → payment rejected before endpoint is reached
- Server cold-start on Render free tier → slow first response or timeout
- Network error on Render hosting → 503 or connection refused
- Calling without x402-compatible client → raw 402 with no data

## How this service works

x402 protocol check: confirms payment and returns a timestamp. Returns no data — for real data see GET /dao-proposals.

## Output

Returns a JSON object with two fields: `ok` (boolean, true if payment was confirmed) and `ts` (ISO 8601 datetime string representing the server timestamp at the moment the payment was validated). No substantive data is returned beyond this confirmation pair.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "ok",
      "ts"
     ],
     "properties": {
      "ok": {
       "type": "boolean"
      },
      "ts": {
       "type": "string",
       "format": "date-time"
      }
     },
     "additionalProperties": false
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/apix402-echo-x402-payment-confirmation-probe-a7b52b4c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from apix402.onrender.com](https://www.zero.xyz/host/apix402.onrender.com/llms.txt)