page:recipes:rest api:starlette:artifact storage

Host rest api with Starlette: stored input and output artifacts

Deploy a rest api built with Starlette 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 Starlette: 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 rest api-specific behavior as your application code.

Representative Queries

• Host rest api with Starlette: stored input and output artifacts
• Where can I host REST API built with Starlette?
• 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.

Prerequisites

• A Starlette 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). 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  --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.

   ample logs  --kind build
   

Examples

• Starlette pattern fixture
  Multi-pattern Starlette app whose generated downloads module was checked live.

Success Checks

1. App responds on its public URL
   HTTP GET /
   Expect: ample canary starlette patterns
2. Generated-downloads self-test
   HTTP GET /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 Starlette major versions are not verified.
• The rest api itself (your export formats, retention policy and entitlement model) is application code and was not separately tested; the pattern checks are what was verified.

Cost Estimate

• Currency: USD
• Monthly Amount: $10.00
• Basis: size prices from pricing.toml
• Components:
  • app server: s-1vcpu-1gb, quantity: 1.0, monthly amount: $5.00
  • managed PostgreSQL database: s-1vcpu-1gb, quantity: 1.0, monthly amount: $5.00
  • Note: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle.

Evidence Summary

1. Canary Run
   Starlette pattern fixture deployed on Ample; checks passed for generated-downloads and configuration-secrets.
2. Canary Run
   The same Starlette app deployed with a --release-command migration; the marker it created was readable after activation.

Last Verified At

• Date: 2026-09-21T01:21:36Z

Next Actions

• Browse the catalog index: Catalog Index
• Search published recipes by intent, stack and constraints: Search Recipes
• Prepare a side-effect-free deployment plan for an authorized project: Plan Deployment