# Configure S3-compatible access for FastAPI

## Summary
Configure S3-compatible access for a FastAPI app on Ample. Create a bucket with `ample bucket create`, pass its endpoint, region, bucket name and keys as encrypted environment variables, and use boto3 with Config(s3={'addressing_style': 'path'}). The app writes and reads objects through the S3-compatible endpoint; the bucket stays private.

## Prerequisites
- An S3 client in the app (boto3 with Config(s3={'addressing_style': 'path'})) reading S3_ENDPOINT, S3_REGION, S3_BUCKET, S3_ACCESS_KEY_ID and S3_SECRET_ACCESS_KEY
- A bucket created with `ample bucket create ` and its credentials from `ample bucket credentials `
- An Ample account token with servers:write and buckets:read

## Workflow Steps
1. **Create the bucket**  
    Create it once and keep the issued credentials out of the repository.
    ```bash
    ample bucket create --name <bucket-name>
    ```

2. **Configure the client with path-style addressing**  
    Use boto3 with Config(s3={'addressing_style': 'path'}); virtual-host addressing is not verified.

3. **Deploy with the credentials as encrypted env**  
    Pass the five S3_* variables with --env; they are stored encrypted and reused on redeploys.
    ```bash
    ample deploy . --name <app-name> --public --start "python3 run.py" --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...
    ```

4. **Test through the app**  
    Expose a route (/storage) that writes then reads an object and reports s3=ok.

5. **Verify**  
    Fetch the live URL and run the success checks below. On failure read the build log, then the runtime log, fix the cause and deploy again; do not blind-retry.
    ```bash
    ample logs <app-name> --kind build
    ```

## Success Checks
- **object write and read succeed**  
  - Type: `http_get`
  - Path: `/storage`
  - Expect: `s3=ok`

## Limitations
- Verified on the node-22 template at s-1vcpu-1gb; other templates and sizes are not verified by this recipe.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.

## Cost Estimate
- Monthly Amount: $5.00
- Basis: size prices from pricing.toml at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
- Note: Compute only. Buckets are allocation-priced per quota and capped by the plan; see `ample usage`.

## Evidence Summary
- **kind**: canary_run  
  **summary**: FastAPI app using boto3 (path-style addressing) with injected bucket credentials: put_object then get_object returned s3=ok.
  **observedAt**: 2026-09-20T01:13:26Z
- **kind**: canary_run  
  **summary**: ample bucket create issued credentials; PutObject and GetObject succeeded through the public S3 endpoint.
  **observedAt**: 2026-09-20T01:13:26Z

## Formats
- [HTML Version](/content/guides/fastapi/object-client/index.html)
- [Markdown Version](/content/guides/fastapi/object-client.md)
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