# JWT Decode & Verify

> JWT Decode & Verify is a paid API for AI agents from agent-chain-kit-solana.vercel.app, paid per call via x402, $0.0005/call, status unknown (last checked 2026-10-10).

Decodes a JWT token and returns its header, payload, and signature verification status

## Facts

- Endpoint: POST https://agent-chain-kit-solana.vercel.app/v1/jwt-decode?utm_source=zero.xyz
- Price: $0.0005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/jwt-decode-verify-dbee2132
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kLHTWEVE8_JlQayKfxB5V

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-verify-dbee2132 -d '<json body>'
```

Example prompt: Can you decode this JWT token for me and show me what's in the payload and header: eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxMjMifQ.SomeSignature?

## When to prefer this

Use this endpoint when you need a quick, keyless, pay-per-call JWT decode without setting up a library or auth infrastructure. Ideal for agents that need to inspect token contents on the fly, check claims, or audit token structure without maintaining API keys. Not suited for issuing or signing new JWTs.

## Known failure modes

- Malformed or non-JWT token string returns a parse error
- Missing 'token' query parameter causes a validation failure
- Signature verification returns false if the secret key is unknown or not provided
- Expired or revoked tokens are decoded but flagged accordingly in the payload claims
- Method mismatch (only GET/HEAD/DELETE accepted) returns a 405 error

## How this service works

Global current weather, hourly forecasts, foreign-exchange rates, EVM reads, and deterministic utilities for AI agents. Pay per call with MPP or x402; no API key.

## Output

A JSON object containing the decoded JWT header (e.g. algorithm), the decoded payload (e.g. subject, claims, expiry), and a boolean signature_verified field indicating whether the signature was cryptographically validated.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "token"
     ],
     "properties": {
      "token": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "header": {
   "alg": "HS256"
  },
  "payload": {
   "sub": "123"
  },
  "signature_verified": false
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/jwt-decode-verify-dbee2132/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-chain-kit-solana.vercel.app](https://www.zero.xyz/host/agent-chain-kit-solana.vercel.app/llms.txt)