Restaurants: Product Catalog Using Django

Summary

A product catalog 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).

Infrastructure Requirements

• Compute: verified (Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.)
• Postgres: 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: verified (Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.)

Prerequisites

• 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

Steps

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. Workflow step 1. Model the SKU catalog with versioned updates.
3. Workflow step 2. Record every catalog change as an event in the same transaction.
4. Workflow step 3. Reject stale concurrent updates.
5. Workflow step 4. Deploy and verify history and conflict handling.
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. 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
   

Limitations

• The technical basis (transactional workflows on Django) was verified with the pattern fixture; the restaurants schema and workflow are an original design for this blueprint and were not executed as a separate application.
• No health, financial, privacy or other compliance claim is made. Allergen information must be kept accurate by the operator; nothing here validates food-safety claims.
• Public content and synthetic examples only until actual data-handling requirements have been reviewed.
• Verified on the python-3.12 template at s-1vcpu-1gb; region, request-duration limits and other sizes are unknown or unverified.
• Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified.
• PutObject and GetObject with path-style addressing are verified; other S3 operations and CDN cache rules are not.

Cost Estimate

Estimated 10.00 USD per month (size prices from pricing.toml at build revision a1b8c38919e59cd035ebabaced73cf84ece24371).

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

Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.

Verification Evidence

• canary_run on 2026-09-20T03:31:44Z at revision 03b6402b1b3e19178985f08ea4033804521d85d4-dirty (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 2026-09-21T03:19:59.461917+00:00 at revision 49962bcade4f, binding state current, required scopes: servers:write, databases:read, buckets:read.