# Independent retailers: inventory manager using Django

## Summary
A inventory manager blueprint for independent retailers built with Django on Ample. Domain schema: products (sku, name, category, price, active): the SKU catalog; stock_movements (sku, location, delta, reason, moved_at): receipts, sales and adjustments; orders (order_no, customer_reference, status, placed_at): orders with status transitions; order_lines (order_no, sku, qty, unit_price): order contents; events (seq, record_type, record_id, kind, at): application-owned history written in the same transaction. Public information: product catalog and availability, store locations and hours, returns policy. Kept out of scope until handling is reviewed: customer contact and payment details, supplier cost prices. Payment details belong to your payment provider; only order status and public catalog data are modeled here. 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).

## Representative Queries
- Independent retailers: inventory manager using Django
- Where can I host Independent retailers: Inventory manager built with Django?
- I need a genuinely specialized inventory manager workflow covering SKU catalog, stock movements and order statuses.

## 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.

## Framework
Django

## Workload
Inventory manager

## Industry
Independent retailers

## Release Status
published

## Support Status
verified

## Execution Status
ready

## 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 independent retailers data classes may be handled at all; this blueprint models public information only

## Workflow Steps
1. **Model the independent retailers domain**  
Create the tables products, stock_movements, orders, order_lines, events. The sku catalog lives in products; keep the sensitive classes (customer contact and payment details, supplier cost prices) 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.
7. **Verify**  
Run the pattern self-test(s) from the example (/p/transactional-workflows) and your own acceptance checks for the independent retailers workflow.

## Examples
- **Django pattern fixture**: Verified transactional workflows basis for this blueprint.

## Success Checks
- App responds on its public URL.
- Transactional-workflows self-test from the example.

## Limitations
- The technical basis (transactional workflows on Django) was verified with the pattern fixture; the independent retailers 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. Payment details belong to your payment provider; only order status and public catalog data are modeled here.
- Verified on the python-3.12 template at s-1vcpu-1gb; region, request-duration limits and other sizes are unknown or unverified.

## Cost Estimate
- Currency: USD
- Monthly Amount: 10.0
- Basis: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty.

### Components
1. App server: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: 5.0
2. Managed PostgreSQL database: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: 5.0

## Evidence Summary
- **Kind**: canary_run
- **Summary**: Django pattern fixture deployed on Ample.
- **Observed At**: 2026-09-20T03:31:44Z.

## Next Actions
- **Browse the catalog index**: GET /v1/catalog
- **Search published recipes by intent, stack and constraints**: POST /v1/catalog/search
- **Prepare a side-effect-free deployment plan for an authorized project**: POST /v1/catalog/plan

## Formats
- [HTML Format](/content/blueprints/independent-retailers/inventory-manager/django/index.html)
- [Markdown Format](/content/blueprints/independent-retailers/inventory-manager/django.md)
- [JSON Format](https://api.ample.computer/v1/catalog/recipes/page%3Ablueprints%3Aindependent-retailers%3Ainventory-manager%3Adjango)