Equipment rental: inventory manager using Django

Summary

A inventory manager blueprint for equipment rental built with Django on Ample. Domain schema: equipment (sku, name, category, day_rate, serial_tracked): rental catalog; stock_movements (sku, unit_serial, delta, reason, moved_at): check-outs, returns and maintenance; rentals (rental_no, period_start, period_end, status): rentals with status transitions; rental_lines (rental_no, sku, unit_serial, rate): rental contents; events (seq, record_type, record_id, kind, at): application-owned history written in the same transaction. Public information: equipment catalog and rates, availability calendar, deposit and insurance terms. Kept out of scope until handling is reviewed: renter identity documents, payment and deposit details. Identity verification and deposits are outside these flows; only availability and rental status are modeled. 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 equipment rental data classes may be handled at all; this blueprint models public information only

Exact tested configuration

• template: python-3.12
• runtime: python
• size: s-1vcpu-1gb
• install: python3 -m pip install --target .ample/python -r requirements.txt
• start: PYTHONPATH=.ample/python:${PYTHONPATH:-} python3 run.py

Steps

1. Model the equipment rental domain. Create the tables equipment, stock_movements, rentals, rental_lines, events. Rental catalog lives in equipment; keep the sensitive classes (renter identity documents, payment and deposit details) out of this schema.
2. Workflow step 1. Model SKUs and stock movements; derive stock from movements
3. Workflow step 2. Apply movements transactionally with an optimistic version check on the SKU
4. Workflow step 3. Record an event per movement for history
5. Workflow step 4. Deploy and verify history and rejected stale updates
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 equipment rental workflow.

   ample logs <deployment_id> --kind build
   

Successful checks

• 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)

Limitations

• The technical basis (transactional workflows on Django) was verified with the pattern fixture; the equipment rental schema and workflow are an original design for this blueprint and were not executed as a separate application.
• 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.

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

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.