# JWT Inspect

> JWT Inspect is a paid API for AI agents from api.agent-payload-tools.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Parses and inspects a JWT compact serialization, returning its decoded header, payload, and metadata without verifying the signature.

## Facts

- Endpoint: POST https://api.agent-payload-tools.workers.dev/jwt-inspect
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/jwt-inspect-ee7ddc44
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NKrPjpJj25LA1nZQtaSbP

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 jwt-inspect-ee7ddc44 -d '<json body>'
```

Example prompt: Can you inspect this JWT for me and show me what's in the header and payload: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ1c2VyXzEyMyIsImV4cCI6MTcwMDAwMDAwMH0.abc123

## When to prefer this

Use this endpoint when you need to quickly read the contents of a JWT — its claims, algorithm, expiry, issuer, or subject — without needing cryptographic signature verification. It is ideal for debugging, logging, auditing, or extracting fields from tokens during agent workflows. Prefer this over a full JWT verification endpoint when you trust the upstream source and only need the data inside the token.

## Known failure modes

- Malformed JWT string that cannot be base64-decoded returns a parse error
- Token with fewer or more than three dot-separated segments is rejected
- Non-string or empty token field returns a validation error
- Network timeout or Cloudflare Worker cold start may cause transient failures

## How this service works

Decode JWT header and claims and report time validity without verifying the signature.

## Output

Returns the decoded JWT broken into its three parts: the header (algorithm, token type), the payload (all claims such as sub, iss, exp, iat, and any custom claims), and structural metadata — all without performing signature verification.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "token": {
   "type": "string",
   "description": "JWT compact serialization to inspect."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/jwt-inspect-ee7ddc44/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.agent-payload-tools.workers.dev](https://www.zero.xyz/host/api.agent-payload-tools.workers.dev/llms.txt)