Batch API - connection error for large files

I cannot download large batch output files (>100MB) when trying to retrieve batch processing results via the Files API. Downloads consistently fail mid-transfer with connection errors.

Timeline: This worked fine a few weeks ago, but has been failing consistently for several days now.

Details:

  • File size: 242 MB

  • Error: Connection drops after 10-30 MB downloaded

  • Small files (<10MB): Download successfully

  • Large files (>100MB): Consistently fail

Errors encountered:

  • APIConnectionError: Connection error

  • 504 Gateway Time-out

  • HTTP/2 stream error: INTERNAL_ERROR

Attempted workarounds:

  • OpenAI Python SDK with various settings

  • Chunked downloads with HTTP Range headers → results in corrupted data with duplicate truncated lines

  • curl with retry logic and HTTP/1.1

  • Different networks/VPN

Initial connection succeeds (HTTP 200 OK) but drops partway through transfer, suggesting a timeout or streaming issue on OpenAI’s infrastructure.

Has anyone else experienced this? Is there a known workaround, or is this an OpenAI infrastructure issue that needs to be addressed?

Facing the same issue. Have you found a solution?