## Host mcp server with FastAPI: stored input and output artifacts

### Summary
Deploy a mcp server built with FastAPI on Ample using the generated downloads 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: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Not separately tested: your export formats, retention policy and entitlement model; treat the mcp server-specific behavior as your application code.

### Representative Queries
- Host mcp server with FastAPI: stored input and output artifacts
- Where can I host MCP server built with FastAPI?
- I need an input/output artifact contract, object metadata and access boundaries.

### 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.

### Framework
**FastAPI**

### Workload
**MCP server**

### 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**: 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 generated downloads: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). 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/generated-downloads) 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**: Multi-pattern FastAPI app whose generated downloads module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

### Success Checks
1. **App responds on its public URL**: Kind - http_get, Path - /, Expect - ample canary fastapi patterns
2. **Generated-downloads self-test**: Kind - http_get, Path - /p/generated-downloads, Expect - export=ok rows=3 (with ?token=...; 401 without)

### 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 mcp server itself (your export formats, retention policy and entitlement model) 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**:
  - **App server**: Size - s-1vcpu-1gb, Quantity - 1.0, Monthly Amount - 5.0
  - **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**: FastAPI pattern fixture deployed on Ample; checks passed for generated-downloads 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**: The same FastAPI app deployed with a --release-command migration.
   - Observed At: 2026-09-20T01:54:51Z
   - Implementation Revision: 199ff1dfd52683832ae75d3f98b53a7a4bff7f96-dirty (CLI e3181f5)
   - Expires At: 2027-03-19T01:54:51Z

### Unknowns
- Region availability is unknown until a verified region fact is recorded.
- Compliance attestations are unknown; none are claimed.

### Formats
- **HTML**: [https://ample.computer/recipes/mcp-server/fastapi/artifact-storage](/content/recipes/mcp-server/fastapi/artifact-storage/index.html)
- **Markdown**: [https://ample.computer/recipes/mcp-server/fastapi/artifact-storage.md](/content/recipes/mcp-server/fastapi/artifact-storage.md)
- **JSON**: [https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Amcp-server%3Afastapi%3Aartifact-storage](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Amcp-server%3Afastapi%3Aartifact-storage)

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