# Oblique Markets x402 Endpoint Verifier

> Oblique Markets x402 Endpoint Verifier is a paid API for AI agents from api.oblique.markets, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Probes a third-party URL to confirm it returns a well-formed HTTP 402 challenge and reports x402 protocol-conformance findings including accepts[] completeness, CDP Base price floor, header/body consistency, and timeout sanity.

## Facts

- Endpoint: POST https://api.oblique.markets/api/v1/paid/x402-endpoint-verify
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/oblique-markets-x402-endpoint-verifier-e24f2ff6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mCx73V6QPddHn5XDcWrtW

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 oblique-markets-x402-endpoint-verifier-e24f2ff6 -d '<json body>'
```

Example prompt: Can you verify that my x402 endpoint at https://api.myservice.com/paid/data is properly implemented — check if it returns a valid HTTP 402 challenge, that the accepts[] array is complete, the PAYMENT-REQUIRED header and body are consistent, and that the CDP Base price floor and timeout look sane?

## When to prefer this

Use this endpoint when you need to validate that a specific URL correctly implements the x402 payment protocol before listing it on a facilitator or integrating it into an agentic payment flow. It is purpose-built for x402 conformance — covering accepts[] completeness, CDP Base price floor, header/body consistency, and timeout sanity — rather than generic HTTP testing or API health checks.

## Known failure modes

- URL is blocked by SSRF guard (private/internal IP ranges rejected)
- Target endpoint does not respond with HTTP 402 at all
- Target endpoint is unreachable or times out during probe
- Malformed or incomplete 402 response body prevents conformance analysis
- accepts[] array is empty or missing required payment network entries
- CDP Base price floor is absent or below minimum threshold

## How this service works

Use when an agent needs x402 endpoint verify. Returns Verify and lint a third-party x402 endpoint: probes the URL (SSRF-guarded), confirms it answers with a well-formed HTTP 402 challenge, and reports protocol-conformance findings — accepts[] completeness, facilitator price floor on Base, PAYMENT-REQUIRED header/body consistency, timeout sanity. $0.02.

## Output

Returns a structured conformance report indicating whether the probed URL returns a valid HTTP 402 challenge, with specific findings on: accepts[] array completeness, CDP Base price floor adequacy, PAYMENT-REQUIRED header/body consistency, timeout sanity, and overall protocol compliance pass/fail status. SSRF-guard checks are applied before probing.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "description": "The https URL of the x402 endpoint to verify"
  },
  "method": {
   "enum": [
    "GET",
    "POST"
   ],
   "type": "string",
   "description": "HTTP method the endpoint sells on"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "url": "https://api.example-seller.com/api/v1/paid/quote",
  "method": "GET",
  "is_x402": true,
  "findings": [
   "accepts[1] amount 500 is below the CDP facilitator floor of 1079 atomic on eip155:8453 — unsellable through the main facilitator",
   "PAYMENT-REQUIRED header is absent — x402 v2 clients that read the header instead of the body will not see the challenge"
  ],
  "reachable": true,
  "checked_at": "2026-08-10T12:00:00.000Z",
  "http_status": 402,
  "x402_version": 2,
  "accepts_count": 2
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/oblique-markets-x402-endpoint-verifier-e24f2ff6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.oblique.markets](https://www.zero.xyz/host/api.oblique.markets/llms.txt)