Supabase Storage
Connect Supabase Storage to BucketMate through the S3-compatible endpoint
BucketMate connects to Supabase Storage through Supabase's S3-compatible endpoint.
Prerequisites
- Supabase project ref
- Project region
- S3 access key ID
- S3 secret access key
- S3 endpoint URL
- Storage bucket
Endpoint and region
Use this endpoint format:
https://<project-ref>.storage.supabase.co/storage/v1/s3
Select the region that matches your Supabase project. Supabase's S3 settings page is the source of truth for the exact endpoint and region.
Connection steps
- Open the Supabase dashboard.
- Open your project.
- Go to Storage settings and enable or configure S3 compatibility.
- Create S3 access keys.
- Copy the project ref, region, access key ID, and secret access key.
- Open BucketMate.
- Choose Add Connection.
- Select Supabase Storage.
- Enter
https://<project-ref>.storage.supabase.co/storage/v1/s3. - Select the project region.
- Enter the access key ID and secret access key.
- Use Test Connection.
- Save the connection.
Common issues and fixes
Signature Version 4 required
S3 compatibility requires AWS Signature Version 4 and must be enabled in Supabase Storage settings. Fix by enabling S3 compatibility in Storage settings and using SigV4 credentials.
Path-style requests are required
Path-style requests are required. Fix by setting forcePathStyle to true in your S3 client.
Unsupported S3 features
Many S3 features are not implemented, including bucket CORS, lifecycle configuration, bucket encryption, ACL headers, object lock, expected bucket owner, and checksum headers. Fix by removing those calls and using alternatives at the application level.
Public alpha behavior
The S3 compatibility layer is in public alpha, so APIs may change. Fix by pinning SDK versions and revalidating behavior after Supabase updates.
Buckets do not load
If bucket listing is restricted, turn off Credentials have permission to list buckets and add the bucket names manually.
Endpoint looks similar but fails
Use the endpoint shown in Supabase's S3 settings. For hosted projects, the recommended endpoint uses the direct storage hostname: https://<project-ref>.storage.supabase.co/storage/v1/s3.
BucketMate tips
- Use presigned links for temporary access to private Supabase Storage objects.
- Use direct copied URLs only when the bucket/object policy allows public access.
- Re-test the connection after Supabase changes S3 compatibility behavior.