# Vextorium x402 Payment Echo Test

> Vextorium x402 Payment Echo Test is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-18).

Accepts a minimal x402 micropayment and echoes back the payment details the server observed — network, scheme, payer, amount, client IP, user agent, timestamp, and optional echo text — to confirm your x402 integration is working.

## Facts

- Endpoint: POST https://api.vextorium.com/prueba-x402-pago?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vextorium-x402-payment-echo-test-29f0708a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0eTeE8mcWyy5Ji6xAOJnq

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 vextorium-x402-payment-echo-test-29f0708a -d '<json body>'
```

Example prompt: Run a quick x402 payment test against the Vextorium echo endpoint and send the text 'hello world' as the eco field — I want to see the network, payer address, and amount the server actually recorded.

## When to prefer this

Choose this endpoint when you need the absolute cheapest ($0.001 USDC) and simplest way to confirm that your x402 client or AI agent can successfully attach a valid payment header, get it accepted by a real server, and read back the payment metadata the server observed. Ideal for integration smoke tests, CI pipelines, and debugging payer/network identity issues before calling more expensive x402-gated endpoints.

## Known failure modes

- Payment header missing or malformed — server returns 402 Payment Required with x402 challenge
- Incorrect USDC amount sent — payment rejected before echo response is generated
- Network mismatch between expected chain and payment — pago_visto may show unexpected values
- Body not valid JSON — request fails with 400 or parsing error
- Service temporarily unavailable — 5xx response with no echo body

## How this service works

Test your x402 client or agent for the minimum price: confirms the payment arrived and echoes back the network, scheme, payer and amount the server saw, your IP, user agent, time and any 'eco' text you send.

## Output

A JSON object with: ok (boolean success), eco (your echoed text), nota (a human-readable note confirming whether the payment was seen), hora_utc (server timestamp), ip_cliente (your public IP), pago_visto (the payment details the server observed — network, scheme, payer, amount), and user_agent (your client's user agent string).

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "eco": "hello",
  "nota": "Si ves pago_visto con tu red y pagador, tu integración x402 funciona.",
  "hora_utc": "2026-10-02T20:34:04.478+00:00",
  "ip_cliente": null,
  "pago_visto": null,
  "user_agent": null
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vextorium-x402-payment-echo-test-29f0708a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)