# JWT Decode

> JWT Decode is a paid API for AI agents from x402-gateway-production-1f21.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-12).

Decodes a JWT token string and returns its decoded header, payload, and signature components without verification.

## Facts

- Endpoint: POST https://x402-gateway-production-1f21.up.railway.app/jwt/decode?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/jwt-decode-ac47c69d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nekowtdWiCrW0azUNDnBl

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-ac47c69d -d '<json body>'
```

Example prompt: Can you decode this JWT token for me and show me what's in the payload: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

## When to prefer this

Use this endpoint when you need a machine-payable, infrastructure-free way to decode JWTs without setting up a local library — ideal for AI agents, serverless pipelines, or quick inspection of tokens from third-party systems. Prefer this over rolling your own decoder when operating in an x402 micropayment context or when you need a consistent, hosted utility callable by any agent regardless of runtime environment.

## Known failure modes

- Malformed JWT string (not in three-part base64 format) returns an error
- Token exceeds 200,000 character limit returns validation error
- Empty or missing token field returns required field error
- Non-JWT base64 strings passed as tokens may produce garbled output or errors

## How this service works

Machine-payable x402 utilities for hashing, Base64, UUID generation, unit and timezone conversion, realtime crypto market data, webpage/document extraction, URL-to-Markdown, metadata, RAG ingestion and deterministic website change detection.

## Output

Returns the decoded JWT broken into its constituent parts: the header (algorithm, token type), the payload (all claims such as sub, iat, exp, roles, and any custom fields), and the signature component — presented as structured JSON objects rather than base64-encoded strings.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "token"
     ],
     "properties": {
      "token": {
       "type": "string",
       "maxLength": 200000
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "status": "ready"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/jwt-decode-ac47c69d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-gateway-production-1f21.up.railway.app](https://www.zero.xyz/host/x402-gateway-production-1f21.up.railway.app/llms.txt)