## The short version

A product catalog 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).

## 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 wholesale distributors data classes may be handled at all; this blueprint models public information only

## How to do it

1.  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.  Model the SKU catalog with versioned updates

3.  Record every catalog change as an event in the same transaction

4.  Reject stale concurrent updates

5.  Deploy and verify history and conflict handling

6.  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.  Run the pattern self-test(s) from the example (/p/transactional-workflows) and your own acceptance checks for the wholesale distributors 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 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 2026-09-22T00:31:22.774679+00:00 at revision `e6446ceea69b`. Binding state at export: schema_changed. Required scopes: servers:write, databases:read, buckets:read.

## Typed next actions

- Browse the catalog index (`GET /v1/catalog` on the api origin; authentication not required, approval not required)
- Search published recipes by intent, stack and constraints (`POST /v1/catalog/search` on the api origin; authentication not required, approval not required)
- Prepare a side-effect-free deployment plan for an authorized project (`POST /v1/catalog/plan` on the api origin; authentication required, approval not required)
- Read the existing agent authentication setup (`GET /mcp/setup` on the api origin; authentication not required, approval not required)
- Browse Wholesale distributors (`GET /v1/catalog/nodes/industry%3Awholesale-distributors` on the api origin; authentication not required, approval not required)
- Browse Product catalog (`GET /v1/catalog/nodes/workload%3Aproduct-catalog` on the api origin; authentication not required, approval not required)
- Browse Django (`GET /v1/catalog/nodes/stack%3Aframework-django` on the api origin; authentication not required, approval not required)
- Browse Deploy web app (`GET /v1/catalog/nodes/intent%3Adeploy-web-app` on the api origin; authentication not required, approval not required)

## Identifiers and status

Recipe `page:blueprints:wholesale-distributors:product-catalog:django`. Revision r1.

release **published** support **verified** execution **blocked (schema_changed: live tool schema differs from the recorded binding)**