Notary - JWT Viewer and Validator

A powerful Visual Studio Code extension for decoding, inspecting, and validating JSON Web Tokens (JWTs).

JWT Viewer with Remote Key Verification

Features

🔍 JWT Decoding

• Visual Decoding: Paste any JWT and instantly see its decoded header, payload, and signature
• Syntax Highlighting: Color-coded JSON output for easy reading
• Timestamp Conversion: Automatically converts iat, nbf, and exp claims to human-readable dates
• Expiration Badge: Visual indicator showing if the token is expired or still valid
• Multi-Panel Support: Open multiple JWT viewers simultaneously for comparison

🔐 JWT Signature Validation

• Public Key Validation: Validate JWT signatures against saved public keys
• Multiple Key Sources:
  • OIDC/JWKS URLs: Automatically fetch keys from OpenID Connect discovery endpoints
  • JWKS JSON Entry: Paste full JWKS documents directly (stored as a key set)
  • Manual Entry: Add public keys directly in PEM or raw format
• Key Management: Store, list, and delete validation keys from the sidebar
• Auto-Refresh: URL-based keys can be configured to refresh automatically (daily, weekly, or monthly)
• JWKS Key Selection: JWT kid is used first, with optional manual override in the JWT Viewer
• Key Viewing: Review stored key material and derived public keys in decoded (PEM) format

🎨 User Interface

• Sidebar View: Quick access to open viewers and key management
• Editor Panel: Full-featured JWT viewer with validation controls
• Activity Bar Icon: Dedicated Notary icon in the VS Code activity bar
• Keyboard Shortcuts: Ctrl+Shift+J / Ctrl+Alt+J (or Cmd+Shift+J / Cmd+Alt+J on Mac) to open a new viewer

Screenshots

Local Key

Entry

Edit

JWT Viewer with Local Key Verification

Remote Key

Entry

Edit

JWKS Key

Entry

Edit

JWT Viewer with JWKS Verification

Usage

Viewing a JWT

1. Press Ctrl+Shift+J (or Cmd+Shift+J on Mac), or use the fallback Ctrl+Alt+J (Cmd+Alt+J on Mac), or run the command Notary: Open JWT Viewer (Editor Panel)
2. Paste your JWT token into the input field
3. The decoded header, payload, and signature will appear automatically
4. Timestamps are converted to readable dates
5. Token expiration status is shown with a badge

Managing Validation Keys

All key creation now starts from the sidebar Add Key button, then you choose the source in the key details panel.

Adding a Key from OIDC/JWKS URL

1. Open the Notary sidebar from the activity bar
2. Click Add Key
3. Enter a name for your key
4. Select Fetch from URL
5. Enter one of the following URL formats:
   • Base URL: https://example.com (auto-discovers via .well-known)
   • OpenID Configuration: https://example.com/.well-known/openid-configuration
   • Direct JWKS URL: https://example.com/.well-known/jwks.json
6. Choose a refresh period (Daily, Weekly, or Monthly)
7. Click Add Key

The extension will automatically discover the JWKS endpoint from base URLs by attempting:

• OpenID Connect discovery via /.well-known/openid-configuration
• Direct JWKS fetch from /.well-known/jwks.json

Adding a Manual Key

1. Open the Notary sidebar
2. Click Add Key
3. Enter a name for your key
4. Select Manual Entry
5. Paste your public key in PEM format:

   -----BEGIN PUBLIC KEY-----
   MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAx1dP8pZk6jJ6VY8Z9sR7
   QeZ0+9H8g8Y1VQZk4WwzK1z9Z2bNRzRZyM4VY9r7kVb6b4r1v4Wz7h5lQ1X9P9m3
   ...
   -----END PUBLIC KEY-----
   

6. Click Add Key

Adding a Key from JWKS JSON

1. Open the Notary sidebar
2. Click Add Key
3. Enter a name for your key
4. Select Paste JWKS JSON
5. Paste a full JWKS document, for example:

   {
      "keys": [
         {
            "kty": "RSA",
            "n": "...",
            "e": "AQAB",
            "use": "sig",
            "alg": "RS256",
            "kid": "key1"
         }
      ]
   }
   

6. Review the key preview and claims shown in the panel
7. Click Add Key

When editing a JWKS JSON key, you can update the pasted JWKS document and save changes. Notary stores the full key set and uses JWT kid matching during validation.

Supported formats:

• RSA public keys (-----BEGIN PUBLIC KEY----- or -----BEGIN RSA PUBLIC KEY-----)
• Elliptic Curve (EC) public keys
• EdDSA public keys

Keys are stored securely in base64 encoding within VS Code's extension storage.

Validating a JWT

1. Decode a JWT in the viewer panel
2. In the "Validation" section, select a validation key from the dropdown
3. Click "Validate Signature"
4. The validation result will appear showing whether the signature is valid

Viewing Stored Keys

To review a stored public key:

1. Open the Notary sidebar
2. In the "Validation Keys" section, find the key you want to view
3. Click "View Key"
4. The decoded public key will open in a new editor tab

This allows you to verify the exact public key content that's stored (keys are stored in base64 encoding but displayed in their original PEM format).

Requirements

• Visual Studio Code version 1.110.0 or higher

Extension Settings

Currently, this extension does not contribute any VS Code settings. All configuration is done through the sidebar UI.

Known Issues

Please report issues on the GitHub repository.

Development

Building from Source

# Install dependencies
npm install

# Compile TypeScript
npm run compile

# Run tests
npm test

# Package for distribution
npm run package

Running in Development Mode

1. Clone the repository
2. Run npm install
3. Open in VS Code
4. Press F5 to launch the Extension Development Host

Release Notes

See CHANGELOG

License

This project is licensed under the GNU General Public License v3.0 (GPL-3.0-only).

See the LICENSE file for details.

Enjoy decoding and validating your JWTs with Notary! 🔐