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HALOWERK x402werk — Offer Validate
x402
HALOWERK x402werk — Offer Validate is a paid API for AI agents from x402.halowerk.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-13).
Validates an x402 payment challenge object (v1 or v2) by fetching and parsing it from a URL or directly from a provided challenge object, returning detailed conformance results.
Price / call$0.002
Success—
StatusUnknown
How this service works
Validates a 402 challenge — fetched from a URL without paying, or supplied directly — against PaymentRequiredV1Schema and PaymentRequiredV2Schema of the installed @x402/core reference implementation. Reports the detected version and how it was detected, every error with field, expected, found and spec_ref naming package, version, schema and field path, whether the network is valid CAIP-2, whether the asset is a known and canonical token address or a bridged variant, whether the declared inputSch
Output
Returns a structured object indicating overall validity, detected x402 version (v1/v2/unclear), schema validity, CAIP validity, price sanity, whether the asset is known and canonical, compatibility with v1 and v2 clients, a list of specific field-level errors (with field name, problem description, expected vs found values, and spec reference), warnings, extensions, cache status (hit/miss), and the thresholds used during validation.
Example use cases
Debug a malformed x402 challenge
“I just deployed an x402-gated endpoint but clients keep rejecting it — can you fetch the challenge from https://api.myapp.com/premium-data and tell me exactly what's wrong with it, including any spec errors or warnings?”
Pre-deploy validation of a new offer
“Before I go live, can you validate this x402 v2 challenge object I drafted for my USDC-on-Base paywall and tell me if the asset is recognized, the price is sane, and whether it'll work with v1 clients?”
Check third-party x402 endpoint compatibility
“I want to integrate with a third-party paid API at https://partner.example.com/data — can you fetch and validate its x402 challenge and tell me what version it is and whether my v1 client will be compatible?”
Technical details
Endpoint
POSThttps://x402.halowerk.com/offer/validateWhen to prefer
Use this endpoint when you need to programmatically validate the correctness and spec-compliance of an x402 challenge — either by URL or by direct object — especially when debugging paywall integrations, pre-deploying new x402 offers, or checking third-party API compatibility. Prefer this over manual inspection when you need structured error details, CAIP asset validation, version detection, and v1/v2 client compatibility flags in a single call.
Side effects
- Private, loopback, or link-local target URLs are rejected outright
- Timeout exceeded when fetching a slow remote challenge URL
- Malformed input object that doesn't match x402 v1 or v2 schema returns version_detected: unklar
- Remote URL returns no 402 challenge or an unexpected HTTP status
- Network errors fetching the foreign URL result in an error response
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| url | string | Absolute http or https URL whose 402 challenge should be fetched and validated. Nothing is paid. Private, loopback and link-local targets are rejected. |
| challenge | object | A 402 challenge object to validate directly, in x402 v1 or v2 form. |
| timeout_ms | integer | Time budget for fetching the foreign challenge. |
Tags
x402
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