Host form collection with FastAPI: data exports

Deploy a form collection 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 form collection-specific behavior as your application code.

Representative Queries

• Host form collection with FastAPI: data exports
• Where can I host Form collection built with FastAPI?
• I need a scoped export format, artifact generation and authorized download procedure.

Resource Requirements

• primitive:compute
• primitive:postgres
• primitive:s3-compatible-object-storage

Infrastructure Requirements

Compute

• Summary: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.

Postgres

• 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.

S3-compatible object storage

• Summary: 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

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.

   ample deploy . --name <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.

   ample logs  --kind build
   

Success Checks

• App responds on its public URL

  • kind: http_get
  • path: /
  • expect: ample canary fastapi patterns

• 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 form collection 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.

Cost Estimate

• Currency: USD
• Monthly Amount: 10.0
• Basis: size prices from pricing.toml (loaded by the API) at build revision.
• Components:
  • App server: 5.0
  • Managed PostgreSQL database: 5.0

Evidence Summary

• Canary Run: FastAPI pattern fixture deployed on Ample.
• Observed At: 2026-09-21T01:14:18Z

Next Actions

1. Browse the catalog index
   • Method: GET
   • Relative Path: /v1/catalog
2. Search published recipes by intent, stack and constraints
   • Method: POST
   • Relative Path: /v1/catalog/search
   • Parameters: {"body":{"limit":5,"query":"Host form collection with FastAPI: data exports"}}
3. Prepare a side-effect-free deployment plan for an authorized project
   • Method: POST
   • Relative Path: /v1/catalog/plan
   • Parameters: {"body":{"inputs":{},"projectId":"","recipeId":"page:recipes:form-collection:fastapi:data-exports","recipeRevision":"r1"}}
4. Read the existing agent authentication setup
   • Method: GET
   • Relative Path: /mcp/setup
5. Browse Form collection
   • Method: GET
   • Relative Path: /v1/catalog/nodes/workload%3Aform-collection
6. Browse FastAPI
   • Method: GET
   • Relative Path: /v1/catalog/nodes/stack%3Aframework-fastapi
7. Browse Generated downloads
   • Method: GET
   • Relative Path: /v1/catalog/nodes/pattern%3Agenerated-downloads
8. Browse Deploy web app
   • Method: GET
   • Relative Path: /v1/catalog/nodes/intent%3Adeploy-web-app