page:recipes:appointment booking:fastapi:attachments

Host appointment booking with FastAPI: file attachments

Summary
Deploy a appointment booking built with FastAPI on Ample using the browser file uploads 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: content-type and size validation that rejects disallowed files, an object written to a private bucket and a row linking the record to the object key (reject=ok upload=ok linked=ok). Not separately tested: your upload UI, allowed types, size limits and virus scanning; treat the appointment booking-specific behavior as your application code.

Representative Queries

• Host appointment booking with FastAPI: file attachments
• Where can I host Appointment booking built with FastAPI?
• I need a restricted upload flow, file validation and record-to-object linkage.

Resource Requirements

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

Infrastructure Requirements

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

• 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.

• 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

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 browser file uploads: content-type and size validation that rejects disallowed files, an object written to a private bucket and a row linking the record to the object key (reject=ok upload=ok linked=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.
   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/browser-file-uploads) from the example; then run your own checks. On failure read ample logs --kind build then --kind runtime.
   ample logs --kind build

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 appointment booking itself (your upload UI, allowed types, size limits and virus scanning) 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

Monthly Amount: $10.00

• App server: s-1vcpu-1gb, Quantity: 1, Monthly Amount: $5.00
• Managed PostgreSQL database: s-1vcpu-1gb, Quantity: 1, Monthly Amount: $5.00

  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

• Browse the catalog index
• Search published recipes by intent, stack and constraints
• Prepare a side-effect-free deployment plan for an authorized project
• Read the existing agent authentication setup
• Browse Appointment booking
• Browse FastAPI
• Browse Browser file uploads
• Browse Deploy web app