# JWT Token Decoder & Inspector

> JWT Token Decoder & Inspector is a paid API for AI agents from netintel-production-440c.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-12).

Decodes and inspects any JWT token, extracting header, payload claims, expiry status, security flags, and a security grade without requiring the signing secret.

## Facts

- Endpoint: GET https://netintel-production-440c.up.railway.app/jwt-inspector/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/netintel-production-440c-up-railway-app-1ae5b199
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_819Ak2S5t_vHvE_jfHrQR

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 netintel-production-440c-up-railway-app-1ae5b199
```

Example prompt: Can you decode this JWT token and tell me if it's expired, what algorithm it uses, who the subject is, and whether there are any security issues: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

## When to prefer this

Use this endpoint when you need to inspect JWT contents without the signing secret — ideal for debugging auth pipelines, checking token expiry before API calls, extracting identity claims for downstream logic, or auditing tokens for security weaknesses like missing expiry or weak algorithms.

## Known failure modes

- Malformed JWT (not 3 dot-separated segments) returns invalid structure error
- Missing token query parameter returns 400
- Token with invalid base64 encoding fails to decode payload
- Very large tokens may timeout

## How this service works

Decode and inspect any JWT token — extracts header algorithm, payload claims, expiry status, issued-at time, audience, issuer, and subject without requiring the secret — so agents can debug auth issues, check token expiry, and extract identity claims from tokens in pipelines.

## Output

Returns a security grade (A-F), numeric score, decoded header (algorithm, key ID, token type), parsed payload (subject, issuer, audience, issued-at, expiry timestamps, custom claims), security flags (e.g. no_expiry, weak algorithm), detailed findings with impact scores, expiry status, human-readable expiry time, seconds until expiry, and signature hex.

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {
   "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c"
  }
 }
}
```

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "token"
     ],
     "properties": {
      "token": {
       "type": "string",
       "description": "JWT token string (3 dot-separated segments); a 'Bearer ' prefix is stripped automatically"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "grade": {
       "type": "string"
      },
      "score": {
       "type": "number"
      },
      "header": {
       "type": "object"
      },
      "payload": {
       "type": "object"
      },
      "findings": {
       "type": "array"
      },
      "is_expired": {
       "type": [
        "boolean",
        "null"
       ],
       "description": "null when the token has no exp claim"
      },
      "human_expiry": {
       "type": [
        "string",
        "null"
       ]
      },
      "signature_hex": {
       "type": "string"
      },
      "security_flags": {
       "type": "array"
      },
      "valid_structure": {
       "type": "boolean"
      },
      "signature_present": {
       "type": "boolean"
      },
      "seconds_until_expiry": {
       "type": [
        "number",
        "null"
       ]
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "grade": "B",
  "score": 80,
  "header": {
   "key_id": null,
   "algorithm": "HS256",
   "token_type": "JWT"
  },
  "payload": {
   "issuer": null,
   "jwt_id": null,
   "subject": "1234567890",
   "audience": null,
   "issued_at": "2018-01-18T01:30:22.000Z",
   "expires_at": null,
   "not_before": null,
   "custom_claims": {
    "name": "John Doe"
   },
   "issued_at_unix": 1516239022,
   "expires_at_unix": null
  },
  "findings": [
   {
    "rule": "no_expiry_claim",
    "label": "No expiry claim",
    "detail": "JWT has no exp claim — token never expires",
    "impact": -20
   }
  ],
  "is_expired": null,
  "human_expiry": null,
  "signature_hex": "49f94ac7044948c78a285d904f87f0a4c7897f7e8f3a4eb2255fda750b2cc397",
  "security_flags": [
   "no_expiry"
  ],
  "valid_structure": true,
  "signature_present": true,
  "seconds_until_expiry": null
 }
}
```

## More

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