Bug report

• I confirm this is a bug with Supabase, not with my own application.
• I confirm I have searched the Docs, GitHub Discussions, and Discord.

Describe the bug

When uploading files via Supabase Studio (Storage UI) using TUS resumable uploads, errors are returned during the upload process when RustFS is used as the S3-compatible storage backend.

Despite the errors, the file is successfully uploaded and appears in the bucket.

Observed errors:

• HTTP 500: multipart upload / part validation error
• HTTP 409: resource already exists

To Reproduce

Steps to reproduce the behavior, please provide code snippets or a repository:

1. Configure Supabase Storage to use RustFS as an S3-compatible backend
2. Open Supabase Studio
3. Upload a file using the UI (TUS upload)
4. Observe the upload errors in the UI and Network tab

Expected behavior

• File uploads successfully
• No HTTP 500 or 409 errors during uload
• Supabase Studio reports a clean successful upload

Actual behavior

Supabase Studio shows:
HTTP 500 error:

Something went wrong with that request
One or more of the specified parts could not be found.
The part may not have been uploaded, or the specified entity tag may not match the part's entity tag.

HTTP 409 error:

The resource already exists

Screenshots

System information

• Supabase Studio: supabase/studio:2025.12.17-sha-43f4f7f
• Supabase Storage: supabase/storage-api:v1.33.0
• Rustfs: rustfs/rustfs:1.0.0-alpha.76
• Deployment: Self-hosted