Why is my custom Assistant unable to read my uploaded file despite a successful API upload?

Below is a checklist and some debugging steps based on how the Files API and Assistant file attachment are meant to work:

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1. Ensure the File Is Properly Attached to Your Assistant

Even if the file is uploaded and shows as processed, it must be attached to your custom Assistant via the appropriate endpoint. In legacy (v1), this is done via a POST request to:

BASHCopied
curl https://api.openai.com/v1/assistants/{assistant_id}/files \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
        "file_id": "your_file_id"
      }'

Make sure that this call is successful before referencing the file in your thread message.

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2. Verify File Reference in Your Thread Message

Double-check that the file_id used in your thread message exactly matches the one verified by the content API and that it has been attached to the specific assistant. If the file is not attached (or the attachment is stale), the assistant might not be able to read the contents even though the file exists.

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3. Check File Content and Format

Even though you have tried txt and csv, confirm that:

• The content is well-formed.
• There are no invisible characters or encoding issues.
• The file is logically structured for the retrieval or code interpretation task you are trying.

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4. Monitor Timing and API Responses

The fact that the process takes ~20 seconds before completing normally (and skipping “requires_action”) suggests that the file retrieval logic might be timing out or failing to read properly. Compare the logs for the attachment endpoint and the thread submission. There may be clues indicating if the file ever reached the assistant.

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5. Possible API Bug or Transient Issue

Since the file was read correctly once and now fails on subsequent attempts, consider:

• Re-attaching the file to the assistant using the create assistant file endpoint.
• Deleting and re-uploading the file.
• Contacting support if the behavior persists.

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Summary

• Attach your file: Use the POST endpoint to attach the file to your assistant.
• Confirm file reference: Ensure the correct file_id is used.
• Validate content: Check for formatting or encoding issues.
• Review logs/timing: Look for discrepancies in API responses to pinpoint any timing issues.
• Consider transient API issues: If the problem is persistent, re-upload or re-attach the file.

These steps are designed to help you pinpoint whether the problem is due to your file usage or an issue with the API behavior. Let me know if you have further questions or need more details on using a specific endpoint.