## Host form collection with Django: relational workflow state

Deploy a form collection built with Django on Ample using the transactional workflows pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL. 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). Not separately tested: your domain records, validation rules and concurrency policy; treat the form collection-specific behavior as your application code.

### Summary

- **Framework**: Django
- **Workload**: Form collection
- **Release status**: Published
- **Support status**: Verified
- **Execution status**: Ready

### Representative Queries
- Host form collection with Django: relational workflow state
- Where can I host Form collection built with Django?
- I need a domain record schema, validation rules and concurrency behavior.

### Resource Requirements
- `primitive:compute`
- `primitive:postgres`

### 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.

### Prerequisites
- A Django project that builds and starts with the documented commands (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 at runtime (auto-provisioned when omitted, or supplied with --env)
- An Ample account token with servers:write, databases:read

### Workflow Steps
1. **Build and start**: 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 server must bind 0.0.0.0 on PORT.
2. **Implement the pattern on PostgreSQL**: The fixture's module implements transactional workflows: 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). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
3. **Deploy**: Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op. Command: `ample deploy . --name --public --start "python3 run.py"`
4. **Verify**: Fetch the live URL and the pattern self-test route(s) (/p/transactional-workflows) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`. Command: `ample logs  --kind build`

### Success Checks
- App responds on its public URL (kind: http_get, path: /, expect: ample canary django patterns)
- Transactional-workflows self-test (kind: http_get, path: /p/transactional-workflows, expect: tx=ok history=2 conflict=rejected)

### Limitations
- Verified on the python-3.12 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Django major versions are not verified.
- The form collection itself (your domain records, validation rules and concurrency policy) is application code and was not separately tested; the pattern checks are what was verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.

### Cost Estimate
- **Currency**: USD
- **Monthly Amount**: 10.0
- **Components**:
  - App server: size `s-1vcpu-1gb`, quantity 1.0, monthly amount 5.0
  - Managed PostgreSQL database: size `s-1vcpu-1gb`, quantity 1.0, monthly amount 5.0

### Evidence Summary
- **Canary Run**: 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); checks passed for transactional-workflows and configuration-secrets.

### Formats
- [HTML](/content/recipes/form-collection/django/relational-workflow/index.html)
- [Markdown](/content/recipes/form-collection/django/relational-workflow.md)
- [JSON](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Aform-collection%3Adjango%3Arelational-workflow)

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