# JWK Inspector — Validate & Thumbprint JSON Web Keys

> JWK Inspector — Validate & Thumbprint JSON Web Keys is a paid API for AI agents from artifact-inspector.use.x402atlas.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Validates RSA, EC, or Ed25519 JWK public keys and computes their RFC 7638 SHA-256 thumbprints without making ownership or trust claims.

## Facts

- Endpoint: POST https://artifact-inspector.use.x402atlas.com/jwk
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/jwk-inspector-validate-thumbprint-json-web-keys-1f3d9168
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uRPUT_Lx20oNqN8vY42oq

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 jwk-inspector-validate-thumbprint-json-web-keys-1f3d9168 -d '<json body>'
```

Example prompt: Can you inspect this JWK public key, tell me if it's valid, and give me its RFC 7638 SHA-256 thumbprint? {"kty":"EC","crv":"P-256","x":"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU","y":"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0"}

## When to prefer this

Choose this endpoint when you need to programmatically validate a JWK's structure and compute its RFC 7638 SHA-256 thumbprint without performing any trust or ownership verification. It is purpose-built for JWK inspection specifically (RSA, EC, Ed25519) as opposed to full certificate chain validation or JWT signature verification, which are handled by sibling endpoints on the same platform.

## Known failure modes

- Malformed JSON input returns a parse error
- Private key material included in JWK may be rejected or stripped
- Unsupported key type or curve returns an unsupported algorithm error
- Missing required JWK parameters (e.g. missing 'x' for EC key) returns a validation error
- Oversized or out-of-bounds key parameters may be rejected due to bounded input constraints

## How this service works

JSON Web Key (JWK) inspector — validate bounded public RSA, EC, or Ed25519 keys and calculate RFC 7638 SHA-256 thumbprints without ownership or trust claims.

## Output

Returns a structured JSON result containing: whether the JWK is valid, the key type (RSA/EC/OKP), algorithm curve or key size, parsed key parameters, and the RFC 7638 SHA-256 thumbprint of the key. If invalid, returns error details explaining the structural or parameter issue.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/jwk-inspector-validate-thumbprint-json-web-keys-1f3d9168/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from artifact-inspector.use.x402atlas.com](https://www.zero.xyz/host/artifact-inspector.use.x402atlas.com/llms.txt)