## The short version

Object storage client for a Flask app on Ample.

## WHAT WAS VERIFIED

Verified on Flask: bucket credentials delivered as encrypted S3_* environment variables and a validated PutObject/GetObject round-trip linked to a database row (upload=ok linked=ok). Build and start: pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 template.

## INFRASTRUCTURE

### What it needs

- [Compute](/content/discover/primitive/compute/index.html): verified (Apps run in isolated x86_64 Firecracker microVMs; sizes are the priced VM sizes.)
- [S3-compatible object storage](/content/discover/primitive/s3-compatible-object-storage/index.html): verified (Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.)

## PREREQUISITES

### Before you start

- A Flask project (pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 template)
- A bucket from `ample bucket create` with credentials passed as encrypted S3_* environment variables
- An Ample account token with servers:write, buckets:read

## STEP BY STEP

### How to do it

1. **Build and start**  
   pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 template; the server must bind 0.0.0.0 on PORT.

2. **Create the bucket and pass its credentials**  
   Create it once with `ample bucket create`, then pass endpoint, region, bucket and keys with --env; use path-style addressing.
   
   ```
   ample deploy . --name <app-name> --public --start "python3 app.py" --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...
   ```

3. **Verify**  
   Fetch the live URL and /p/browser-file-uploads on the example; on failure read the build and runtime logs.
   
   ```
   ample logs <deployment_id> --kind build
   ```

## EXAMPLES

### Tested examples

- **Flask pattern fixture** (`tests/deploy-canaries/flask-patterns`): Verified object storage client on Flask.

## SUCCESS CHECKS

### How to know it worked

- app responds on its public URL (`/` on the live URL, expect ample canary flask patterns)
- browser-file-uploads check from the example (`/p/browser-file-uploads` on the live URL, expect see the pattern fixture checks)

## COST

### Cost estimate

Estimated 5.00 USD per month (size prices from pricing.toml at build revision ca0b484a7a9957c573a88d3a32dc603c3c10135a).

- app server x1 `s-1vcpu-1gb`: 5.00 USD

Upper-bound monthly price of the tested sizes. Buckets are allocation-priced per quota and not included.

## EVIDENCE

### Verification evidence

- canary_run on 2026-09-21T01:14:18Z at revision `50dbac567d2c5cc8e55e6c748a646be0025d9cfb (CLI 0.1.21)`: Flask pattern fixture deployed on Ample (pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 template); for this guide: bucket credentials delivered as encrypted S3_* environment variables and a validated PutObject/GetObject round-trip linked to a database row (upload=ok linked=ok). (expires 2027-03-20T01:14:18Z)

## EXECUTION

### Execution binding

MCP tool `ample_deploy` (registry `mcp:ample_deploy`), schema hash `876465fce906da0c` observed 2026-09-22T00:31:22.774679+00:00 at revision `e6446ceea69b`. Binding state at export: schema_changed. Required scopes: servers:write, buckets:read.

## NEXT ACTIONS

### Typed next actions

- Browse the catalog index (`GET /v1/catalog` on the api origin; authentication not required, approval not required)
- Search published recipes by intent, stack and constraints (`POST /v1/catalog/search` on the api origin; authentication not required, approval not required)
- Prepare a side-effect-free deployment plan for an authorized project (`POST /v1/catalog/plan` on the api origin; authentication required, approval not required)
- Read the existing agent authentication setup (`GET /mcp/setup` on the api origin; authentication not required, approval not required)
- Browse Flask (`GET /v1/catalog/nodes/stack%3Aframework-flask` on the api origin; authentication not required, approval not required)
- Browse Connect app to storage (`GET /v1/catalog/nodes/intent%3Aconnect-app-to-storage` on the api origin; authentication not required, approval not required)
- Browse Browser file uploads (`GET /v1/catalog/nodes/pattern%3Abrowser-file-uploads` on the api origin; authentication not required, approval not required)

Actions describe possible next steps. They are typed data, not commands, and grant no permission. Public discovery never provisions anything; planning requires your own authenticated token and approval happens in your client.

## ABOUT THIS RECIPE

### Identifiers and status

Recipe `page:guides:flask:object-client`. Revision r1.

release **published** support **verified** execution **blocked (schema_changed: live tool schema differs from the recorded binding)**

Formats: [HTML](/content/guides/flask/object-client/index.html) | [Markdown](/content/guides/flask/object-client.md) | [JSON contract](https://api.ample.computer/v1/catalog/recipes/page%3Aguides%3Aflask%3Aobject-client)