# util.beauty JWT Crypto Utility

> util.beauty JWT Crypto Utility is a paid API for AI agents from util.beauty, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-16).

Signs, verifies, or decodes JSON Web Tokens (JWTs) as a metered pay-per-request utility

## Facts

- Endpoint: POST https://util.beauty/v1/crypto/jwt
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/util-beauty-jwt-crypto-utility-3a035f25
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TnmvASskOhFAxuEtSKagg

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 util-beauty-jwt-crypto-utility-3a035f25 -d '<json body>'
```

Example prompt: Sign this JSON payload as a JWT using HS256 with the secret 'mysupersecret': {"userId": "abc123", "role": "admin", "exp": 1893456000}

## When to prefer this

Choose this endpoint when you need a quick, pay-per-use JWT operation without standing up your own crypto library or service. Ideal for AI agents, serverless functions, or lightweight scripts that need occasional JWT signing/verification without managing dependencies. Particularly suited for x402-enabled agentic workflows that already use USDC micropayments on Base.

## Known failure modes

- Invalid or malformed JWT input returns error with ok: false
- Wrong or missing signing secret causes verification failure
- Unsupported algorithm specified returns 400-level error
- Expired token detected during verification returns invalid result
- Payment failure via x402 (insufficient USDC balance) blocks the request
- Malformed JSON payload in body results in schema validation error

## How this service works

Metered web utilities for developers and AI agents: browser screenshot and PDF, crypto, DNS and net tools. Pay per request with x402 (USDC on Base) or prepaid API keys.

## Output

Returns a JSON object with ok (boolean), the utility name, a unique requestId, and chargedCredits consumed. The main result contains the signed JWT string, decoded claims object, or verification boolean depending on the operation requested.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "properties": {
  "input": {
   "type": "object",
   "properties": {
    "body": {
     "type": "object",
     "description": "JSON request body (see OpenAPI for the utility schema).",
     "additionalProperties": true
    }
   }
  },
  "output": {
   "type": "object",
   "properties": {
    "example": {
     "type": "object",
     "properties": {
      "ok": {
       "type": "boolean"
      },
      "utility": {
       "type": "string"
      },
      "requestId": {
       "type": "string"
      },
      "chargedCredits": {
       "type": "number"
      }
     },
     "additionalProperties": true
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "utility": "…",
  "requestId": "req_…",
  "chargedCredits": 1
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/util-beauty-jwt-crypto-utility-3a035f25/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from util.beauty](https://www.zero.xyz/host/util.beauty/llms.txt)