# JWT Decode & Expiry Check

> JWT Decode & Expiry Check is a paid API for AI agents from api.24klabs.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Decodes a JWT token's header and payload without verifying the signature, and flags whether the token is expired.

## Facts

- Endpoint: POST https://api.24klabs.ai/api/v1/jwt-decode
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/jwt-decode-expiry-check-66c7b60b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nCfSvGU1sBsodzrgQaxS1

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-decode-expiry-check-66c7b60b -d '<json body>'
```

Example prompt: Can you decode this JWT token and tell me what's in the header and payload, and whether it's already expired? eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiZXhwIjoxNjAwMDAwMDAwfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

## When to prefer this

Use this endpoint when you need to quickly inspect or debug a JWT's claims and expiry status without access to the signing secret or public key. Ideal for logging pipelines, debugging auth issues, extracting user metadata from tokens, or checking freshness before making downstream calls. Not suitable when cryptographic signature verification is required for security-sensitive decisions.

## Known failure modes

- Malformed JWT string (not three dot-separated base64 segments) returns a parse error
- Missing or non-numeric exp claim may result in expiry flag being indeterminate
- Network timeout or service unavailability returns an HTTP 5xx error
- Empty or null token input returns a validation error

## How this service works

Decode a JWT header and payload (no signature verification); flags expiry.

## Output

Returns the decoded JWT header (algorithm, token type) and payload (all claims including sub, iat, exp, and any custom claims), plus an explicit flag indicating whether the token is currently expired based on the exp claim. No signature verification is performed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "token": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "header": {},
  "payload": {}
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/jwt-decode-expiry-check-66c7b60b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.24klabs.ai](https://www.zero.xyz/host/api.24klabs.ai/llms.txt)