# Agent Dev Tools – JWT Decode

> Agent Dev Tools – JWT Decode is a paid API for AI agents from agent-dev-tools.frcompanycheck.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-12).

Decodes a JWT token into its header, payload, and signature components, and reports expiry status — paid per call in USDC via x402.

## Facts

- Endpoint: GET https://agent-dev-tools.frcompanycheck.workers.dev/v1/jwt/decode?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-dev-tools-jwt-decode-e88238ae
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6-UmcZc00oTHqCfe73WCv

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 agent-dev-tools-jwt-decode-e88238ae
```

Example prompt: Can you decode this JWT for me and tell me what's in the header and payload, and whether it's expired? eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

## When to prefer this

Use this endpoint when you need a fast, keyless, no-account JWT inspection tool — ideal for debugging tokens, extracting claims for logging, or checking expiry without needing to verify the signature cryptographically. Prefer this over full auth libraries when you only need to read the token contents, not validate it against a secret.

## Known failure modes

- Malformed JWT (not three base64-separated segments) returns an error; not charged
- Missing required 'token' query parameter returns a validation error
- Token with invalid base64 encoding in header or payload returns a parse error
- signature_verified will always return false since no secret key is supplied for HMAC verification

## How this service works

Fast deterministic developer utilities for AI agents, paid per call in USDC via x402 (no account, no API key): UUID v4/v7, secure random numbers, dice, MD5/SHA/HMAC hashing, base64/hex/URL/HTML encoding, JSON validation/formatting, QR code SVG, password generation, JWT decoding and text statistics. Pure computation, nothing stored. Errors are never charged.

## Output

Returns a JSON object containing the decoded JWT header (alg, typ), the full payload with all claims, the signature verification status (true/false), a null or boolean expired field, and human-readable ISO 8601 timestamps for time-based claims like iat (issued at).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "token"
     ],
     "properties": {
      "token": {
       "type": "string",
       "example": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c",
       "description": "JWT (header.payload.signature)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "times": {
   "iat": "2018-01-18T01:30:22.000Z"
  },
  "header": {
   "alg": "HS256",
   "typ": "JWT"
  },
  "expired": null,
  "payload": {
   "iat": 1516239022,
   "sub": "1234567890"
  },
  "signature_verified": false
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-dev-tools-jwt-decode-e88238ae/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-dev-tools.frcompanycheck.workers.dev](https://www.zero.xyz/host/agent-dev-tools.frcompanycheck.workers.dev/llms.txt)