# PennyRail JWT Toolkit – Token Claims Extractor

> PennyRail JWT Toolkit – Token Claims Extractor is a paid API for AI agents from pennyrail.vercel.app, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-14).

Extracts and decodes claims from a JWT token, returning the parsed payload and header information

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/skill/jwt.toolkit--token-claims
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pennyrail-jwt-toolkit-token-claims-extractor-4a3aee1a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VtRQ6QtL8P6pkY6vHQi1n

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 pennyrail-jwt-toolkit-token-claims-extractor-4a3aee1a -d '<json body>'
```

Example prompt: Can you decode this JWT and show me all the claims inside it — I need to see the subject, issuer, expiration, and any custom fields: eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ1c2VyXzEyMyIsImlzcyI6ImF1dGgubXlhcHAuY29tIiwiZXhwIjoxNzAwMDAwMDAwfQ.signature

## When to prefer this

Choose this endpoint when you need a quick, pay-per-use JWT claims extraction without setting up a local JWT library or auth SDK. Useful in agent pipelines where you receive an opaque token and need to inspect its claims programmatically. Not suitable if you need cryptographic signature verification — use a full JWT verification service for that.

## Known failure modes

- Malformed JWT string (not three base64url segments) returns an error
- Empty or missing input token returns a validation error
- Heavily padded or non-standard JWT encoding may fail to parse
- Network timeout on the Vercel serverless function
- Payment failure via x402 protocol blocks the request before processing

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing the decoded JWT header (algorithm, token type) and payload claims (subject, issuer, audience, expiration, issued-at, and any custom claims present in the token). Does not perform cryptographic signature verification — only structural decoding and claims extraction.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-jwt-toolkit-token-claims-extractor-4a3aee1a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from pennyrail.vercel.app](https://www.zero.xyz/host/pennyrail.vercel.app/llms.txt)