JWT Token Decoder & Inspector

x402

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.

Price / call$0.001

Seller volume →—

Success—

StatusUnknown

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 use cases

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”

Technical details

Endpoint

GEThttps://netintel-production-440c.up.railway.app/jwt-inspector/decode?utm_source=zero.xyz

When to prefer

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.

Side effects

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

Input

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

Schema · Request body

Field	Type	Description
inputrequired	object
output	object

Output

{
  "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
}

Schema · Response

{
  "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
  }
}

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