# Agent Format – JWT Header/Payload Decode

> Agent Format – JWT Header/Payload Decode is a paid API for AI agents from agent-format.annushka1190.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Decodes a JWT token's header and payload sections without verifying the signature, returning the raw claims as JSON.

## Facts

- Endpoint: POST https://agent-format.annushka1190.workers.dev/v1/jwt/decode
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-format-jwt-header-payload-decode-ddcc8981
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3NgC_J0zGd9pVIhEq_PMs

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-format-jwt-header-payload-decode-ddcc8981 -d '<json body>'
```

Example prompt: Can you decode this JWT for me and show me what's in the header and payload — eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c — no need to verify the signature, just show me the claims.

## When to prefer this

Choose this endpoint when you need a lightweight, no-account, pay-per-use JWT inspection that works without the signing secret or public key. Ideal for agents that need to read token claims (expiry, subject, roles) at runtime without managing API keys. Not suitable when signature verification is required for security purposes.

## Known failure modes

- Malformed JWT string (not three base64url segments) returns an error
- Non-JWT input (plain string, random base64) causes parse failure
- Missing 'input' field in request body returns validation error
- Payment failure or insufficient USDC balance blocks the request via x402

## How this service works

Encoding utilities for AI agents: base64 encode/decode, hex encode/decode, URL slugify, JWT header/payload decode (no signature verify), and case conversion. Pay-per-request USDC via x402. No API keys, no accounts.

## Output

Returns a JSON object with ok:true and the decoded JWT header (algorithm, token type) and payload (all claims such as sub, iat, exp, iss, aud, custom fields) as plain JSON objects. Does not validate or verify the cryptographic signature.

## 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": {
    "body": {
     "type": "object"
    },
    "type": {
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ]
    },
    "bodyType": {
     "const": "json"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-format-jwt-header-payload-decode-ddcc8981/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-format.annushka1190.workers.dev](https://www.zero.xyz/host/agent-format.annushka1190.workers.dev/llms.txt)