## The short version

Deploy a recruiting tracker built with FastAPI on Ample using the relational records 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.

WHAT WAS VERIFIED

Verified on FastAPI: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true).

INFRASTRUCTURE

## What it needs

- [Compute](/content/discover/primitive/compute/index.html): verified (Apps run in isolated x86_64 Firecracker microVMs; sizes are the priced VM sizes.)
- [Postgres](/content/discover/primitive/postgres/index.html): verified (Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.)

PREREQUISITES

## Before you start

- 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)
- An Ample account token with servers:write, databases:read

STEP BY STEP

## How to do it

1. 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. 2

### Implement the pattern on PostgreSQL

The fixture's module implements relational records: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

3. 3

### 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 <app-name> --public --start "python3 run.py"
```

4. 4

### Verify

Fetch the live URL and the pattern self-test route(s) (/p/relational-records) from the example; then run your own checks. On failure read `ample logs <deployment_id> --kind build` then `--kind runtime`.

```
ample logs <deployment_id> --kind build
```

EXAMPLES

## Tested examples

- **FastAPI pattern fixture** (`tests/deploy-canaries/fastapi-patterns`): Multi-pattern FastAPI app whose relational records module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

SUCCESS CHECKS

## How to know it worked

- app responds on its public URL (`/` on the live URL, expect ample canary fastapi patterns)
- relational-records self-test (`/p/relational-records` on the live URL, expect records=ok transitions=true isolation=true)

COST

## Cost estimate

Estimated 10.00 USD per month (size prices from pricing.toml at build revision ca0b484a7a9957c573a88d3a32dc603c3c10135a).

- app server x1 `s-1vcpu-1gb`: 5.00 USD
- managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD

Upper-bound monthly price of the tested sizes. Buckets are allocation-priced per quota and not included.

EVIDENCE

## Verification evidence

- canary_run on 2026-09-21T01:14:18Z at revision `50dbac567d2c5cc8e55e6c748a646be0025d9cfb (CLI 0.1.21)`: FastAPI pattern fixture deployed on Ample (pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 template); checks passed for relational-records and configuration-secrets. Pattern proof: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true). (expires 2027-03-20T01:14:18Z)
- canary_run on 2026-09-20T01:54:51Z at revision `199ff1dfd52683832ae75d3f98b53a7a4bff7f96 (CLI e3181f5)`: The same FastAPI app deployed with a --release-command migration; the marker it created was readable after activation. (expires 2027-03-19T01:54:51Z)

EXECUTION

## Execution binding

MCP tool `ample_deploy` (registry `mcp:ample_deploy`), schema hash `876465fce906da0c` observed 2026-09-22T00:31:22.774679+00:00 at revision `e6446ceea69b`. Binding state at export: schema_changed. Required scopes: servers:write, databases:read.