# Wholesale distributors: inventory manager using Django ## Summary A inventory manager blueprint for wholesale distributors built with Django on Ample. Domain schema: products (sku, name, category, case_size, list_price, active): SKU catalog with case sizes; stock_movements (sku, warehouse, delta, reason, moved_at): receipts, picks and adjustments; orders (order_no, account_reference, status, placed_at): trade orders with status transitions; order_lines (order_no, sku, cases, unit_price): order contents; events (seq, record_type, record_id, kind, at): application-owned history written in the same transaction. Public information: catalog with case sizes, minimum order and delivery terms, trade account application. Kept out of scope until handling is reviewed: account pricing tiers, credit terms, delivery addresses. Account-specific pricing and credit terms are confidential; the catalog shown publicly carries list prices only. 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 wholesale distributors 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 wholesale distributors domain.** Create the tables products, stock_movements, orders, order_lines, events. Sku catalog with case sizes lives in products; keep the sensitive classes (account pricing tiers, credit terms, delivery addresses) 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 --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 wholesale distributors workflow. ``` ample logs --kind build ``` ## Tested examples - **Django pattern fixture** (tests/deploy-canaries/django-patterns): Verified transactional workflows basis for this blueprint. ## Success 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 wholesale distributors 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. Account-specific pricing and credit terms are confidential; the catalog shown publicly carries list prices only. - 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 Wholesale distributors 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.