UnauthorizedError: No authorization header After Switching to Headless Initialization

[chandel-aman]

Hello Langfuse Community,
I’m currently working on integrating Langfuse into my application, and I've encountered an issue after switching from the UI-generated public and secret keys to using headless initialization with keys generated using OpenSSL.

Details:

Previous Setup: I initialized Langfuse using the public and secret keys generated from the Langfuse UI. This setup was working correctly without any errors.
Current Setup: I have transitioned to headless initialization and am now providing the initialization project public and secret keys, generated using the command:
openssl rand -hex 32

Error Encountered:

After making this change, I receive the following error in the logs when I try to run any query:

UnauthorizedError: No authorization header
    at new r (/app/web/.next/server/chunks/7297.js:1:4578)
    at new a (/app/web/.next/server/chunks/7297.js:1:6043)
    at u (/app/web/.next/server/pages/api/public/v2/prompts/[promptName].js:1:5434)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async Object.g [as POST] (/app/web/.next/server/pages/api/public/v2/prompts.js:56:1255)
    at async /app/node_modules/.pnpm/@sentry+nextjs@8.26.0_@opentelemetry+api@1.8.0_@opentelemetry+core@1.25.1_@opentelemetry+api@_s7aknkapghglpzfuqsa6sgvhge/node_modules/@sentry/nextjs/build/cjs/common/wrapApiHandlerWithSentry.js:90:43

Questions:

1. What could be causing the UnauthorizedError? Could it be due to the OpenSSL-generated keys?
2. Are there specific steps or configurations I need to ensure for the headless initialization to work correctly, other that mentioned in the doc?
3. Is there a need to include the authorization header manually, or should this be handled automatically?

Any assistance or guidance would be greatly appreciated. Thank you for your help!

[dosubot[bot]]

The "UnauthorizedError: No authorization header" issue you're encountering after switching to headless initialization could be due to a few reasons:

1. Authorization Header: The error indicates that the authorization header is missing. Ensure that your requests to the Langfuse API include the correct authorization header. The Langfuse API uses Basic Auth, where the authorization header should be formatted as Authorization: Basic <base64_encoded_credentials>. The credentials are your Langfuse Public Key as the username and the Secret Key as the password ^[1][2].

2. OpenSSL-Generated Keys: If you generated keys using OpenSSL, make sure they are correctly set in the environment variables LANGFUSE_INIT_PROJECT_PUBLIC_KEY and LANGFUSE_INIT_PROJECT_SECRET_KEY. These keys should be used in the authorization header as described above.

3. Configuration for Headless Initialization: Double-check that all necessary environment variables for headless initialization are correctly set. This includes LANGFUSE_INIT_ORG_ID, LANGFUSE_INIT_PROJECT_ID, LANGFUSE_INIT_USER_EMAIL, and others as specified in the documentation ^[3][4].

4. Manual Inclusion of Authorization Header: You need to ensure that your application includes the authorization header in each API request. This is not handled automatically by Langfuse, so you must configure your HTTP client to include it.

Review these points to ensure your setup is correct. If the issue persists, verify that the keys are correctly generated and encoded, and that all environment variables are properly configured.

To continue talking to Dosu, mention @dosu.

[chandel-aman]

@marcklingen Do we have to manually add the authorization header as the @dosu is suggesting?

[marcklingen]

Intersting, can you verify that the keys exist when signing into the langfuse instance with the created user account?

[dosubot[bot]]

This is a tough nut to crack, could really use your help on this, @marcklingen.

To continue talking to Dosu, mention @dosu.

[chandel-aman]

Intersting, can you verify that the keys exist when signing into the langfuse instance with the created user account?

If you're referring to the initialization keys, then yes, they do exist when signing into the Langfuse instance.

[marcklingen]

can you try auth_check via the SDK to verify that the credentials are correct?

[marcklingen]

@chandel-aman did this resolve your question?