# gateway.apiosk.com Attestation Verifier

> gateway.apiosk.com Attestation Verifier is a paid API for AI agents from gateway.apiosk.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Verifies a JSON Web Signature (JWS) attestation, optionally checking that a provided payload hash matches the signed data

## Facts

- Endpoint: POST https://gateway.apiosk.com/attestations/verify
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/gateway-apiosk-com-attestation-verifier-b2d823af
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mX4kYVSgnlJcaLdKo_UzR

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 gateway-apiosk-com-attestation-verifier-b2d823af -d '<json body>'
```

Example prompt: Can you verify this JWS attestation token for me — eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9... — and also check that the payload 'user:alice,role:admin' matches what was signed?

## When to prefer this

Use this endpoint when you need to verify a JWS-based attestation programmatically — especially when you also want to confirm that the original payload content matches what was signed. Prefer this over manual JWT libraries when you want a hosted, paid verification service with minimal setup.

## Known failure modes

- Invalid or malformed JWS string returns signature_valid: false
- Payload hash mismatch returns payload_hash_matches: false
- Missing required jws field returns a 400 or error response
- Expired or revoked attestation may return signature_valid: false
- Network or service unavailability returns a 5xx error

## How this service works

Verify a previously issued attestation JWS and optionally confirm it matches a resubmitted payload.

## Output

Returns a JSON object with three boolean fields: ok (overall success), signature_valid (whether the JWS cryptographic signature checks out), and payload_hash_matches (whether the hash of the provided optional payload matches the hash embedded in the attestation).

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/gateway-apiosk-com-attestation-verifier-b2d823af/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gateway.apiosk.com](https://www.zero.xyz/host/gateway.apiosk.com/llms.txt)