Decode JWT tokens (header, payload, expiry check) without signature verification via @mukundakatta/jwt-mcp — debugging tool

{
  "server": "@mukundakatta/jwt-mcp",
  "version": "0.1.0",
  "transport": "stdio",
  "tools": ["decode"],
  "trace": [
    {
      "call": "decode",
      "args": {
        "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c"
      },
      "result": {
        "header": {
          "alg": "HS256",
          "typ": "JWT"
        },
        "payload": {
          "sub": "1234567890",
          "name": "John Doe",
          "iat": 1516239022
        },
        "expired": null
      },
      "ms": 2,
      "note": "jwt.io standard example — no exp claim → expired: null"
    },
    {
      "call": "decode",
      "args": {
        "token": "<RS256 JWT with roles+aud+iss+exp>"
      },
      "result": {
        "header": {
          "alg": "RS256",
          "typ": "JWT"
        },
        "payload": {
          "sub": "user-42",
          "iss": "https://auth.example.com",
          "aud": "my-api",
          "roles": ["admin", "editor"],
          "exp": 1782749588
        },
        "expired": false
      },
      "ms": 1
    },
    {
      "call": "decode",
      "args": {
        "token": "<HS256 JWT with exp=1600000000>"
      },
      "result": {
        "header": {
          "alg": "HS256",
          "typ": "JWT"
        },
        "payload": {
          "sub": "expired-user",
          "exp": 1600000000
        },
        "expired": true
      },
      "ms": 0,
      "note": "past exp → expired: true"
    },
    {
      "call": "decode",
      "args": {
        "token": "<HS256 JWT no exp>"
      },
      "result": {
        "payload": {
          "sub": "no-expiry",
          "name": "Eternal Token"
        },
        "expired": null
      },
      "ms": 1,
      "note": "no exp claim → expired: null"
    },
    {
      "call": "decode",
      "args": {
        "token": "<ES256 JWT with kid+OIDC claims>"
      },
      "result": {
        "header": {
          "alg": "ES256",
          "typ": "JWT",
          "kid": "key-2024"
        },
        "payload": {
          "sub": "[email protected]",
          "iss": "auth0",
          "aud": ["api1", "api2"],
          "scope": "openid profile email",
          "nonce": "abc123",
          "azp": "client-app",
          "org_id": "org_xyz"
        },
        "expired": null
      },
      "ms": 0,
      "note": "rich OIDC claims + kid all preserved"
    },
    {
      "call": "decode",
      "args": {
        "token": "<HS256 JWT exp in future>"
      },
      "result": {
        "expired": false
      },
      "ms": 1
    },
    {
      "call": "decode",
      "args": {
        "token": "not-a-jwt"
      },
      "result": "decode failed: not a JWT: expected 3 dot-separated segments",
      "ms": 0,
      "note": "graceful error, no crash"
    },
    {
      "call": "decode",
      "args": {
        "token": "abc.def.ghi"
      },
      "result": "decode failed: failed to parse header: Unexpected token...",
      "ms": 1,
      "note": "bad base64 → clear error"
    },
    {
      "call": "decode",
      "args": {
        "token": ""
      },
      "result": "decode failed: not a JWT: expected 3 dot-separated segments",
      "ms": 0
    },
    {
      "call": "decode",
      "args": {
        "token": "<HS256 JWT with nested metadata obj>"
      },
      "result": {
        "payload": {
          "sub": "nested",
          "metadata": {
            "team": "engineering",
            "level": 3
          },
          "tags": ["mcp", "agent"]
        },
        "expired": null
      },
      "ms": 1,
      "note": "nested objects + arrays preserved"
    }
  ],
  "total_calls": 10,
  "success_rate": "100%",
  "p50_ms": 0.7
}