Configure S3 Storage
Enable S3-compatible client endpoint and set up an S3 backend for self-hosted Supabase Storage.
Self-hosted Supabase Storage has two independent S3-related features:
- S3 protocol endpoint - an S3-compatible API that Storage exposes at
/storage/v1/s3. This allows standard S3 tools likercloneand the AWS CLI to interact with your Storage instance. - S3 backend - where Storage keeps data. By default, files are stored on the local filesystem. You can switch to an S3-compatible service (AWS S3, MinIO, etc.) for durability, scalability, or to use existing infrastructure.
You can configure either feature independently. For example, you can enable the S3 protocol endpoint to use rclone while keeping the default file-based storage, or switch to an S3 backend without enabling the S3 protocol endpoint.
Enable the S3 protocol endpoint
The S3 protocol endpoint at /storage/v1/s3 allows standard S3 clients to interact with your self-hosted Storage instance. It works with any storage backend, including the default file-based storage - you do not need to configure an S3 backend first. The Supabase REST API and SDK do not use the S3 protocol.
Make sure to check that REGION, S3_PROTOCOL_ACCESS_KEY_ID and S3_PROTOCOL_ACCESS_KEY_SECRET are properly configured in you .env file. Read more about the secrets and passwords in Configuring and securing Supabase.
1storage:2 environment:3 # ... existing variables ...4 REGION: ${REGION}5 S3_PROTOCOL_ACCESS_KEY_ID: ${S3_PROTOCOL_ACCESS_KEY_ID}6 S3_PROTOCOL_ACCESS_KEY_SECRET: ${S3_PROTOCOL_ACCESS_KEY_SECRET}Test with the AWS CLI
1( set -a && \2source .env > /dev/null 2>&1 && \3echo "" && \4AWS_ACCESS_KEY_ID=$S3_PROTOCOL_ACCESS_KEY_ID \5AWS_SECRET_ACCESS_KEY=$S3_PROTOCOL_ACCESS_KEY_SECRET \6aws s3 ls \7--endpoint-url http://localhost:8000/storage/v1/s3 \8--region $REGION \9s3://your-storage-bucket )Test with rclone
1( set -a && \2source .env > /dev/null 2>&1 && \3echo "" && \4rclone ls \5--s3-endpoint http://localhost:8000/storage/v1/s3 \6--s3-region $REGION \7--s3-provider Other \8--s3-access-key-id "$S3_PROTOCOL_ACCESS_KEY_ID" \9--s3-secret-access-key "$S3_PROTOCOL_ACCESS_KEY_SECRET" \10:s3:your-storage-bucket )Use aws login and rclone config for persistent configuration.
How to configure an S3 backend
In general, the following configuration variables define S3 backend configuration for Storage in docker-compose.yml:
1storage:2 environment:3 # ... existing variables ...4 STORAGE_BACKEND: s35 GLOBAL_S3_BUCKET: your-s3-bucket-or-dirname6 GLOBAL_S3_ENDPOINT: https://your-s3-endpoint7 GLOBAL_S3_PROTOCOL: https8 GLOBAL_S3_FORCE_PATH_STYLE: 'true'9 AWS_ACCESS_KEY_ID: your-access-key-id10 AWS_SECRET_ACCESS_KEY: your-secret-access-key11 REGION: your-regionDepending on your setup, you may need to adjust these values - for example, to use a local S3-compatible service like MinIO or a cloud provider like AWS.
Using MinIO
An overlay docker-compose.s3.yml configuration can be added to enable MinIO container and provide an S3-compatible API for Storage backend:
1docker compose -f docker-compose.yml -f docker-compose.s3.yml up -dMake sure to review the Storage section in your .env file for related configuration options.
Using AWS S3
Create an S3 bucket and an IAM user with access to it. Then configure the storage service:
1storage:2 environment:3 # ... existing variables ...4 STORAGE_BACKEND: s35 GLOBAL_S3_BUCKET: your-aws-bucket-name6 AWS_ACCESS_KEY_ID: your-aws-access-key7 AWS_SECRET_ACCESS_KEY: your-aws-secret-key8 REGION: your-aws-regionFor AWS S3, you do not need GLOBAL_S3_ENDPOINT or GLOBAL_S3_FORCE_PATH_STYLE - the Storage S3 client automatically resolves the endpoint from the region and uses virtual-hosted-style URLs, which is what AWS S3 expects. These variables are only needed for non-AWS S3-compatible providers.
S3-compatible providers
Use the same configuration as MinIO, but point to your provider's endpoint, e.g.:
1storage:2 environment:3 # ... existing variables ...4 STORAGE_BACKEND: s35 GLOBAL_S3_BUCKET: your-bucket-name6 GLOBAL_S3_ENDPOINT: https://your-account-id.r2.cloudflarestorage.comVerify
- Open Studio and upload a file to a bucket. List the file using the AWS CLI or
rcloneto confirm the S3 endpoint works. - If using an S3 backend: confirm the file appears in your S3 provider's console.
Troubleshooting
Signature mismatch errors
S3 clients sign requests using the access key ID and secret. If you see SignatureDoesNotMatch, verify that the REGION, S3_PROTOCOL_ACCESS_KEY_ID and S3_PROTOCOL_ACCESS_KEY_SECRET in your .env file match what your S3 client is using.
TUS upload errors on Cloudflare R2
If resumable (TUS) uploads fail with HTTP 500 and a message about x-amz-tagging, add TUS_ALLOW_S3_TAGS: "false" to the storage service environment. Cloudflare R2 does not implement this S3 feature.
Permission denied on uploads
Setting a bucket to "Public" only allows unauthenticated downloads. Uploads are always blocked unless you create an RLS policy on the storage.objects table. Go to Storage > Files > Policies in Studio and create a policy that allows INSERT for the appropriate roles.
Upload URLs point to localhost
If uploads from a browser fail (CORS or mixed content errors), check that API_EXTERNAL_URL and SUPABASE_PUBLIC_URL in your .env file match your actual domain and protocol - not http://localhost:8000.