# x402 Payment Debug

> x402 Payment Debug is a paid API for AI agents from x402.dailyelo.com, paid per call via x402, $0.25/call, status unknown (last checked 2026-10-11).

Validates whether a real x402 payment to a given endpoint would be accepted by the CDP facilitator, without moving any funds

## Facts

- Endpoint: GET https://x402.dailyelo.com/v1/payment/debug?utm_source=zero.xyz
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-payment-debug-574f79ff
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fjyzreN_PXf7vYYHrq6gI

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 x402-payment-debug-574f79ff
```

Example prompt: Can you debug my x402 payment setup for api.myservice.com — I want to know if a real payment would actually go through or if the CDP facilitator would reject it, and why?

## When to prefer this

Use this endpoint when you need to diagnose why an x402 endpoint is failing to receive payments or hasn't been purchased, and you want the CDP facilitator's own verdict rather than a static lint check. Prefer it over manual inspection when you want to catch signature errors, misconfigured payment requirements, or on-chain simulation failures without risking real funds.

## Known failure modes

- No URL or domain provided — returns market-wide stats instead of endpoint-specific result
- Endpoint does not return a valid 402 envelope — cannot construct a test payment
- CDP facilitator unreachable — upstream error propagated
- Domain or URL is malformed — query param rejected
- Endpoint's listed price is missing or unparseable — payment construction fails

## How this service works

Your 402 envelope can pass every static check and still not get you paid. We build a real signed payment at your listed price and submit it to the CDP facilitator verify endpoint, which checks signature, requirements and the on-chain transfer simulation. Nothing settles, so no money moves. You get back whether a real payment would be accepted, and if not, the facilitator own reason verbatim. Pass ?url= or ?domain=.

## Output

Returns whether a real signed payment at the endpoint's listed price would be accepted by the CDP facilitator, including the facilitator's verbatim rejection reason if validation fails, covering signature validity, payment requirements compliance, and on-chain transfer simulation outcome.

## 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": {
      "url": {
       "type": "string",
       "description": "your endpoint URL"
      },
      "domain": {
       "type": "string",
       "description": "or just your domain"
      }
     },
     "description": "Would a real payment to your x402 endpoint actually be accepted? We build a signed payment at your listed price and submit it to the CDP facilitator's verify endpoint — signature, requirements and on-chain transfer simulation. Nothing settles, so no money moves. If it fails you get the facilitator's own reason verbatim. ?url= or ?domain=; omit for market-wide stats."
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-payment-debug-574f79ff/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.dailyelo.com](https://www.zero.xyz/host/x402.dailyelo.com/llms.txt)