# Host help desk with FastAPI: private attachments

Deploy a help desk built with FastAPI on Ample using the private document library pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL, a private S3-compatible bucket holds objects with credentials delivered as encrypted environment variables. Verified on FastAPI: a role-to-document access model with negative tests (401 without identity, 403 for the wrong role) and a private-bucket round-trip for the allowed role (private=ok). Not separately tested: your identity integration and role assignments; treat the help desk-specific behavior as your application code.

## Representative Queries
- Host help desk with FastAPI: private attachments
- Where can I host Help desk built with FastAPI?
- I need attachment metadata, access checks and a tested private object access path.

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

## Infrastructure Requirements
1. **Compute**  
   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**  
   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**  
   Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

## Prerequisites
- A FastAPI project that builds and starts with the documented commands (pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 template)
- A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env)
- A bucket from `ample bucket create` with its credentials passed as encrypted S3_* environment variables
- An Ample account token with servers:write, databases:read, buckets:read

## Tested Configuration
- **Template**: python-3.12
- **Runtime**: python
- **Size**: s-1vcpu-1gb
- **Install**: python3 -m pip install --target .ample/python -r requirements.txt
- **Start**: PYTHONPATH=.ample/python:${PYTHONPATH:-} python3 run.py

## Workflow Steps
### 1. 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.

### 2. Implement the pattern on PostgreSQL
The fixture's module implements private document library: a role-to-document access model with negative tests (401 without identity, 403 for the wrong role) and a private-bucket round-trip for the allowed role (private=ok). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

### 3. Wire object storage
Create the bucket(s), then pass endpoint, region, bucket and keys as --env values. Use path-style addressing. Keep private data in an unpublished bucket.

### 4. Deploy
Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op.
- Command: 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=...

### 5. Verify
Fetch the live URL and the pattern self-test route(s) (/p/private-document-library) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`.
- Command: ample logs  --kind build

## Success Checks
1. **App responds on its public URL**  
   - Kind: http_get  
   - Path: /  
   - Expect: ample canary fastapi patterns
2. **Private-document-library self-test**  
   - Kind: http_get  
   - Path: /p/private-document-library  
   - Expect: private=ok (with ?role=owner; 401 without, 403 for viewer)

## Limitations
- Verified on the python-3.12 template at s-1vcpu-1gb with the example fixture; other sizes, templates and FastAPI major versions are not verified.
- The help desk itself (your identity integration and role assignments) is application code and was not separately tested; the pattern checks are what was verified.
- 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.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.
- PutObject and GetObject with path-style addressing are verified; multipart upload, listing, presigned URLs and lifecycle rules are not verified.

## 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: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 5.0  
  - Managed PostgreSQL database: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 5.0
  
- **Note**: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.

## Next Actions
1. **Browse the catalog index**  
   - Action ID: browse-catalog  
   - Method: GET  
   - Relative Path: /v1/catalog
2. **Search published recipes by intent, stack and constraints**  
   - Action ID: search-recipes  
   - Method: POST  
   - Relative Path: /v1/catalog/search  
3. **Prepare a side-effect-free deployment plan for an authorized project**  
   - Action ID: plan:page:recipes:help-desk:fastapi:private-attachments  
   - Method: POST  
   - Relative Path: /v1/catalog/plan
4. **Read the existing agent authentication setup**  
   - Action ID: auth-setup  
   - Method: GET  
   - Relative Path: /mcp/setup
5. **Browse Help desk**  
   - Action ID: browse:workload:help-desk  
   - Method: GET  
   - Relative Path: /v1/catalog/nodes/workload%3Ahelp-desk
6. **Browse FastAPI**  
   - Action ID: browse:stack:framework-fastapi  
   - Method: GET  
   - Relative Path: /v1/catalog/nodes/stack%3Aframework-fastapi
7. **Browse Private document library**  
   - Action ID: browse:pattern:private-document-library  
   - Method: GET  
   - Relative Path: /v1/catalog/nodes/pattern%3Aprivate-document-library
8. **Browse Deploy web app**  
   - Action ID: browse:intent:deploy-web-app  
   - Method: GET  
   - Relative Path: /v1/catalog/nodes/intent%3Adeploy-web-app