## The short version

An inventory manager blueprint for restaurants built with Django on Ample. Domain schema:

- **menu_items** (sku, name, section, price, allergens, active): the menu as a SKU catalog;
- **stock_movements** (sku, delta, reason, moved_at): ingredient and prepared-item stock;
- **orders** (order_no, service_type, status, placed_at): dine-in, pickup and delivery orders;
- **order_lines** (order_no, sku, qty, modifiers): order contents;
- **events** (seq, record_type, record_id, kind, at): application-owned history written in the same transaction.

Public information: menu with allergens and prices, locations, hours and reservations contact, catering information. 
Kept out of scope until handling is reviewed: customer contact and payment details, staff schedules. Allergen information must be kept accurate by the operator; nothing here validates food-safety claims. Technical basis verified on Django: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected).

## 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.)
- [S3-compatible object storage](/content/discover/primitive/s3-compatible-object-storage/index.html): verified (Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.)

## Before you start

- A Django project (pip install into .ample/python from requirements.txt, then waitress serving project.wsgi from run.py reading PORT on the python-3.12 template)
- A PostgreSQL driver reading DATABASE_URL (auto-provisioned when omitted)
- Bucket credentials from `ample bucket create` passed as encrypted S3_* environment variables
- A review of which restaurants data classes may be handled at all; this blueprint models public information only

## How to do it

1. 1

### Model the restaurants domain

Create the tables menu_items, stock_movements, orders, order_lines, events. The menu as a sku catalog lives in menu_items; keep the sensitive classes (customer contact and payment details, staff schedules) out of this schema.

2. 2

### Workflow step 1

Model SKUs and stock movements; derive stock from movements

3. 3

### Workflow step 2

Apply movements transactionally with an optimistic version check on the SKU

4. 4

### Workflow step 3

Record an event per movement for history

5. 5

### Workflow step 4

Deploy and verify history and rejected stale updates

6. 6

### Deploy

Run the synchronous deploy once and read the result. Re-running with no change is a no-op.

```
ample deploy . --name <app-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=...
```

7. 7

### Verify

Run the pattern self-test(s) from the example (/p/transactional-workflows) and your own acceptance checks for the restaurants workflow.

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

## Tested examples

- **Django pattern fixture** (`tests/deploy-canaries/django-patterns`): Verified transactional workflows basis for this blueprint.

## How to know it worked

- app responds on its public URL (`/` on the live URL, expect ample canary django patterns)
- transactional-workflows self-test from the example (`/p/transactional-workflows` on the live URL, expect see the pattern fixture checks)

## 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.

## Verification evidence

- canary_run on 2026-09-20T03:31:44Z at revision `03b6402b1b3e19178985f08ea4033804521d85d4 (CLI b75e104)`: Django pattern fixture deployed on Ample (pip install into .ample/python from requirements.txt, then waitress serving project.wsgi from run.py reading PORT on the python-3.12 template); the transactional workflows checks passed: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). The blueprint's Restaurants schema and workflow below build on that verified basis and were not separately executed. (expires 2027-03-19T03:31:44Z)

## 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, buckets:read.