• DATA
  • IDENTITY
  • SESSION
  • HUMAN

How to decode JWT payloads with your AI client

Connect this MCP to your AI client once. After that, you can inspect any session token just by pasting it into your chat.

Ask AI about this page

Short answer

How can I decode a JWT payload using my AI?

Paste the encoded token into your chat and ask your agent to decode it. The AI uses the decode_jwt tool to pull the JSON payload, showing you the user IDs and roles inside. You'll see the full breakdown of the session data below.

The results you get

Where your data lands

The AI processes the raw string and delivers these specific outcomes.

DATA

Readable JSON objects

The AI converts the base64 string into a clean JSON format. You get a clear view of the claims without manual work.

IDENTITY

User and role info

Your agent extracts user IDs and permission sets. This lets you see exactly who a token belongs to.

SESSION

Expiration and issuer

The AI pulls out the 'exp' and 'iss' fields. You can quickly check if a session is still valid.

HUMAN

Manual review needed

The AI shows you the contents, but you must decide if the permissions are correct. It won't change the token.

The workflow

What your AI does when a token arrives.

The AI handles the decoding so you don't have to use external websites or scripts.

  1. Receive token

    You paste the base64 encoded JWT string into your chat.

    decode_jwt

  2. Decode payload

    The AI uses the tool to strip the encoding and find the JSON data.

    decode_jwt

  3. Extract claims

    Your agent identifies specific fields like user IDs and roles.

    decode_jwt

  4. Summarize data

    The AI presents a structured view of the session contents.

    decode_jwt

Try it

Copy these to start.

Paste these lines into your chat to get moving.

Starting points

Swap the bracketed text for your actual JWT string.

JSON Web Token Connector

You're all set. Choose your MCP client and follow the setup instructions.

Connector linkhttps://edge.vinkius.com/vk_preview_D5R4DSb6SK0l9HMwb0HCmTETZzhB9BBHQbV1DXPU/mcp

Claude Desktop

Follow the steps below to connect in seconds.

  1. 1In Claude Desktop, open Settings → Connectors.
  2. 2Click “Add custom connector” and paste the connector link above as the remote MCP server URL.
  3. 3Click Add and start a new chat — JSON Web Token capabilities are ready to use.
Configuration · claude_desktop_config.jsonCopy
{
  "mcpServers": {
    "jwt-decoder-verifier-mcp": {
      "url": "https://edge.vinkius.com/vk_preview_D5R4DSb6SK0l9HMwb0HCmTETZzhB9BBHQbV1DXPU/mcp"
    }
  }
}
Copy into chat04

  • Decode this JWT payload: [paste token]

  • What roles are assigned to this user: [paste token]

  • Show me the expiration time for this token: [paste token]

  • Extract the user ID from this JWT: [paste token]

  • Claude
  • ChatGPT
  • Cursor
  • VS Code
  • Windsurf
  • Claude Code
  • JetBrains
  • Cline

Start here

Connect JWT Decoder & Verifier once, then ask.

Connect your client in one click. Your credentials stay encrypted on our side, and you can start chatting immediately.

Connect JWT Decoder & Verifier to your AI

FAQ

How this task behaves

  • 01

    Can the AI change the data in my JWT?

    No. The AI only reads and decodes the token. It cannot modify the payload or create new tokens.

  • 02

    Does it verify the cryptographic signature?

    No. The tool is for decoding the payload. It does not validate signatures against a secret key.

  • 03

    Can I use this with Cursor or VS Code?

    Yes. Any MCP-compatible client works once you connect the MCP.

  • 04

    Is my token data saved?

    No. The AI processes the token to give you the answer, but the data isn't stored by Vinkius.

  • 05

    Can the AI tell if a token is expired?

    Yes. It can read the expiration claim from the payload and tell you if it has passed.

  • More questions about JWT Decoder & Verifier? The Connector page answers them. See everything the JWT Decoder & Verifier Connector can do

Connect JSON Web Token to Claude, Cursor, ChatGPT & more