Validate Auth0 JWT Tokens using JWKS or Signing Cert

This n8n workflow provides a robust solution for validating Auth0 JWT (JSON Web Tokens) using either the JSON Web Key Set (JWKS) endpoint or a provided signing certificate. It acts as an API endpoint that receives a JWT and returns its validation status and decoded payload.

What it does

1. Receives a JWT: The workflow starts with a Webhook node, configured to listen for incoming HTTP POST requests. It expects a JWT in the request body.
2. Processes the Request: A Code node is used to extract the JWT from the incoming webhook request and prepare it for validation.
3. Validates the JWT: (Implicit in the "Code" node's function, as the provided JSON does not include specific JWT validation nodes like "Auth0" or "JWT Verify"). The Code node is responsible for performing the actual JWT validation logic, likely by:
   • Fetching the JWKS from the Auth0 tenant's /certs or /jwks.json endpoint.
   • Or, using a pre-configured signing certificate to verify the token's signature.
   • Decoding the token and checking its claims (e.g., expiration, issuer, audience).
4. Responds to the Webhook: A Respond to Webhook node sends back the validation result (success/failure) and the decoded token payload to the client that initiated the request.
5. No Operation, do nothing: A No Operation, do nothing node is present, likely as a placeholder or for debugging purposes, indicating a path where no further action is taken.
6. Sticky Note: A Sticky Note node is included, typically used for documentation or comments within the workflow itself.

Prerequisites/Requirements

• Auth0 Account: You need an Auth0 account and an application configured to issue JWTs.
• n8n Instance: A running instance of n8n (self-hosted or cloud).
• Basic JavaScript Knowledge: To modify or understand the JWT validation logic within the Code node, familiarity with JavaScript is beneficial.

Setup/Usage

1. Import the Workflow:
   • Download the provided JSON file.
   • In your n8n instance, click "Workflows" in the left sidebar.
   • Click "New" and then "Import from JSON".
   • Paste the JSON content or upload the file.
2. Configure the Webhook:
   • The Webhook node will automatically generate a unique URL when the workflow is activated. This is the endpoint you will send your JWTs to.
3. Configure the Code Node:
   • Crucially, you will need to implement the JWT validation logic within the Code node. This will involve:
     • Auth0 Domain: Providing your Auth0 tenant domain.
     • JWKS Endpoint: If using JWKS, the code will need to fetch keys from https://YOUR_AUTH0_DOMAIN/.well-known/jwks.json.
     • Signing Certificate: If using a signing certificate, the certificate content will need to be accessible to the Code node (e.g., as an environment variable or hardcoded for testing, though not recommended for production).
     • JWT Library: You might need to use a JavaScript JWT library (e.g., jsonwebtoken if n8n's sandbox allows it, or a custom implementation) to perform the verification.
   • The Code node should output an object indicating the validation status (e.g., isValid: true/false) and the decoded token payload.
4. Activate the Workflow: Once configured, activate the workflow by toggling the switch in the top right corner of the workflow editor.
5. Send JWTs for Validation: Send a POST request to the Webhook URL with your JWT in the request body (e.g., {"jwt": "your.jwt.token"}). The workflow will respond with the validation result.