## Host Inventory Manager with FastAPI: Private Attachments

### Summary
Deploy an inventory manager 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 inventory manager-specific behavior as your application code.

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

### Resource Requirements
- **Compute**
- **Postgres**
- **S3-compatible object storage**

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

### Framework
- **FastAPI**

### Workload
- **Inventory manager**

### Release Status
- **Published**

### Support Status
- **Verified**

### Execution Status
- **Ready**

### 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**
   - Command: 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

### Examples
- **FastAPI Pattern Fixture**
   - Description: Multi-pattern FastAPI app whose private document library module was checked live; the module is under tests/deploy-canaries/_pattern-modules.
   - Source Ref: 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 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 inventory manager 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
- **Authoritative**: true
- **Basis**: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
- **Components**:
  - Name: app server
    - Size: s-1vcpu-1gb
    - Quantity: 1.0
    - Monthly Amount: 5.0
  - Name: managed PostgreSQL database
    - Size: s-1vcpu-1gb
    - Quantity: 1.0
    - Monthly Amount: 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.

### Evidence Summary
1. **Canary Run**
   - Summary: FastAPI pattern fixture deployed on Ample; checks passed for private-document-library and configuration-secrets.
   - Observed At: 2026-09-21T01:14:18Z
   - Implementation Revision: 50dbac567d2c5cc8e55e6c748a646be0025d9cfb-dirty (CLI 0.1.21)
   - Expires At: 2027-03-20T01:14:18Z

2. **Canary Run**
   - Summary: The same FastAPI app deployed with a --release-command migration; the marker it created was readable after activation.
   - Observed At: 2026-09-20T01:54:51Z
   - Implementation Revision: 199ff1dfd52683832ae75d3f98b53a7a4bff7f96-dirty (CLI e3181f5)
   - Expires At: 2027-03-19T01:54:51Z

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