Persistent Hugging Face API 401 Authentication Error from Base44 App (Token Validation Success, API Call Fail)

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Hello everyone,

I’m developing an application on the Base44 platform and trying to integrate it with Hugging Face, specifically a custom Hugging Face Space (aiapply-ch/aiapply-ch). I’m running into a very persistent 401 Unauthorized error when calling Hugging Face APIs from my Base44 backend, despite extensive troubleshooting and what appears to be a valid token.

My Setup:

  • Base44 Application: My frontend (React) calls backend Deno functions (deployed on Base44’s infrastructure).

  • Hugging Face Space: I have a private Hugging Face Space (aiapply-ch/aiapply-ch) configured with a Dockerfile and a app.py (FastAPI) that exposes /health and /write endpoints.

    • The app.py uses huggingface_hub and relies on an HF_TOKEN environment variable for authentication to perform operations like file commits.

  • Authentication: I’m using a Hugging Face API token (of role Write) as a secret (HUGGINGFACE_API_KEY) in my Base44 app’s environment variables, and the same token as a “Repository secret” (HF_TOKEN) within my Hugging Face Space.

The Problem:

I’m consistently getting a 401 Unauthorized error when my Base44 backend function attempts to call the main Hugging Face API (https://huggingface.co/api/whoami).

Steps I’ve Taken & Observations:

  1. Initial Setup: Configured HUGGINGFACE_API_KEY in Base44 and HF_TOKEN in HF Space secrets.

  2. First Error: Received 401 Unauthorized with a token_preview (e.g., hf_xwf...Zvty) that didn’t match my intended token. This indicated an old/incorrect token was being used by Base44’s deployment system.

  3. Resolved Token Discrepancy:

    • Confirmed the correct Write role token (hf_RPdoNErRPSCrkSbdtcMkOOLbeUAgylEbZ) was saved in Base44’s “Secrets” (after clarifying that “Environment Variables” means “Secrets” in the Base44 UI).

    • Confirmed the same token was set as HF_TOKEN in the Hugging Face Space “Repository secrets”.

    • After updating and re-saving, the error’s token_preview now correctly shows hf_RPd...lEbZ, indicating Base44 is indeed sending the right token. This confirms Base44’s secret management is working.

  4. Crucial Diagnostic - Manual Token Validation (Success!):

    • My Base44 app has a “Manual Token Validator” feature (a simple frontend component that sends the user-inputted token directly to a backend Deno function, which then calls https://huggingface.co/api/whoami).

    • When I manually paste hf_RPdoNErRPSCrkSbdtcMkOOLbeUAgylEbZ into this validator and run it, it SUCCEEDS. It returns my Hugging Face username and account details, confirming that the token itself is valid and grants access to api/whoami.

  5. Persistent 401 from Backend Function:

    • Despite the manual validation success, when my deployed Base44 backend function (testHuggingFaceConnection) calls https://huggingface.co/api/whoami using the same token from its environment variable, it still fails with:

      {
  "success": false,
  "error": "Authentication failed: Your Hugging Face API token is invalid, expired, or revoked. Please generate a new token.",
  "details": {
    "status": 401,
    "response": {
      "error": "Invalid credentials in Authorization header"
    },
    "token_preview": "hf_RPd...lEbZ"
  }
}

  6. Token Regeneration Attempts: I have regenerated the token multiple times (deleting old ones, creating new Write role tokens), and updated both Base44 and HF Space secrets each time. The result is always the same: manual validation succeeds, backend function calls fail.

My Questions for the Community:

  • **Why would a Hugging Face API token pass direct validation via a backend function (when manually entered), but consistently fail with a 401 when the same backend function retrieves the identical token from environment variables?**Is there any subtle difference in execution context (e.g., IP addresses, user-agent headers, network environment of Deno Deploy) that could cause this?

  • Are there specific nuances with Write role tokens interacting with the api/whoamiendpoint, or potential caching/propagation delays on Hugging Face’s side that could cause this inconsistency?

  • Crucially, what is the result of testHuggingFaceSpaceConnection? (This is a question I need to answer, as I haven’t explicitly checked this yet after all other troubleshooting.)

    • If the testHuggingFaceSpaceConnection succeeds (meaning the token works for interacting with my HF Space), it would imply the token is indeed valid for its intended Write purpose, and the api/whoami failure might be a red herring or a specific limitation.

    • If it also fails, it indicates a deeper issue with the token or its environment setup.

Any insights, alternative debugging strategies, or similar experiences would be greatly appreciated!

Thank you!

Adam

1 Like
2

https://huggingface.co/api/whoami

Hmm… Try https://huggingface.co/api/whoami-v2 instead.