### Enforce Private-File Authorization for FastAPI

Private file access for a FastAPI app on Ample. Verified on FastAPI: a role-to-document access model with negative tests (401, 403) and an authorized private-bucket round-trip (private=ok).

**Build and start:** 
`pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 template.`

#### Resource Requirements
- primitive:compute
- primitive:postgres
- primitive:s3-compatible-object-storage

#### Infrastructure Requirements
1. **Compute** 
   - verified 
   - Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
2. **Postgres** 
   - verified  
   - Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.
3. **S3-compatible object storage** 
   - verified 
   - Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

#### Prerequisites
1. A FastAPI project (pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 template)
2. A PostgreSQL driver reading DATABASE_URL at runtime
3. A bucket from `ample bucket create` with credentials passed as encrypted S3_* environment variables
4. An Ample account token with servers:write, databases:read, buckets:read

#### Workflow Steps
- **Build and start** 
  `pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 template; the server must bind 0.0.0.0 on PORT.`
- **Create the bucket and pass its credentials** 
  `ample deploy . --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=...`
- **Authorize before touching storage** 
  Return 401 for unauthenticated requests and 403 for the wrong role; keep the bucket unpublished and stream objects through the app.
- **Verify** 
  Fetch the live URL and /p/private-document-library on the example; on failure read the build and runtime logs. `ample logs  --kind build`

### Examples
- **FastAPI pattern fixture** 
  Verified private file access on FastAPI.
  `sourceRef: tests/deploy-canaries/fastapi-patterns`

### Success Checks
1. app responds on its public URL 
   - kind: http_get 
   - path: / 
   - expect: ample canary fastapi patterns
2. private-document-library check from the example 
   - kind: http_get 
   - path: /p/private-document-library 
   - expect: see the pattern fixture checks

### Limitations
- Verified on the python-3.12 template at s-1vcpu-1gb; other sizes and FastAPI major versions are not verified.
- Region, compliance attestations, and request-duration limits are unknown and not claimed.
- Managed PostgreSQL 16 only; extensions, connection limits, and backup or restore procedures are not verified.
- PutObject and GetObject with path-style addressing are verified; other S3 operations are not.

### Cost Estimate
- **Currency:** USD 
- **Monthly Amount:** 10.0 
- **Basis:** size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
- **Components:** 
  - **app server**  
    - size: s-1vcpu-1gb  
    - quantity: 1.0  
    - monthlyAmount: 5.0  
  - **managed PostgreSQL database**  
    - size: s-1vcpu-1gb  
    - quantity: 1.0  
    - monthlyAmount: 5.0

- **Note:** Always-on monthly price of the tested sizes; apps auto-pause when idle. Buckets are allocation-priced per quota and not included.

### Evidence Summary
- **Canary Run** 
  Summary: FastAPI pattern fixture deployed on Ample; for this guide: a role-to-document access model with negative tests (401, 403) and an authorized private-bucket round-trip (private=ok).

### Last Verified At 
- 2026-09-21T01:14:18Z

### Next Actions
1. Browse the catalog index 
2. Search published recipes by intent, stack, and constraints 
3. Prepare a side-effect-free deployment plan for an authorized project 
4. Read the existing agent authentication setup 
5. Browse FastAPI 
6. Browse Connect app to storage 
7. Browse Private document library