Utilities

JWT sign & verify (HMAC) API

Sign a JWT from a payload + secret (with optional expiry), or verify a token's signature and expiry — HS256/384/512. Cryptography an LLM cannot perform. Complements util/jwt-decode (decode only). Answers 'sign this JWT', 'create a token', 'verify this JWT signature', 'is this token valid/expired'.

Price$0.01per request

MethodPOST

Route/v1/util/jwt

StatusLive

MIME typeapplication/json

Rate limit120/minute

CacheNo cache

utiljwtsignverifyhmacauthtokencrypto

API URLhttps://x402.hexl.dev/v1/util/jwt

Integration docs

Example request

{
  "op": "sign",
  "payload": {
    "sub": "agent-123",
    "role": "buyer"
  },
  "secret": "your-secret",
  "expiresIn": 3600
}

Example response

{
  "op": "sign",
  "algorithm": "HS256",
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpYXQiOjE…"
}

Input schema

{
  "type": "object",
  "required": [
    "op",
    "secret"
  ],
  "properties": {
    "op": {
      "type": "string",
      "enum": [
        "sign",
        "verify"
      ]
    },
    "payload": {
      "type": "object",
      "additionalProperties": true
    },
    "token": {
      "type": "string"
    },
    "secret": {
      "type": "string"
    },
    "algorithm": {
      "type": "string",
      "enum": [
        "HS256",
        "HS384",
        "HS512"
      ],
      "default": "HS256"
    },
    "expiresIn": {
      "type": "number"
    }
  }
}

Output schema

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