Django

Django — Django & FastAPI Development

Activate When

• User invokes /godmode:django
• User says "Django", "Django project", "Django app"
• User mentions "FastAPI", "Pydantic", "dependency injection"
• User asks about "DRF", "Django REST Framework", "serializers", "viewsets"
• User mentions "Django admin", "admin customization"
• User asks about "ASGI", "async Django", "Uvicorn", "Daphne"
• User says "django view", "views.py", "Django view for"
• When /godmode:plan identifies a Python web project
• When /godmode:review flags Django or FastAPI architecture issues

Workflow

Step 1: Project Assessment

Understand the Python web application context:

PYTHON WEB PROJECT ASSESSMENT:
Project: <name and purpose>
Framework: <Django | FastAPI | both (Django + FastAPI hybrid)>
Type: <monolith | microservice | API-only | full-stack with templates>
Scale: <expected RPS, team size, data volume>
Database: <PostgreSQL, MySQL, SQLite, MongoDB>
Auth: <Django auth, OAuth2, JWT, API keys>
Async needs: <WebSocket, background tasks, streaming, long-polling>
Deployment: <Gunicorn+Nginx, Docker, serverless, PaaS>
Existing code: <greenfield | existing Django project | migration>

If the user hasn't specified, ask: "Are you building with Django, FastAPI, or both? Is this an API-only service or full-stack with templates?"

Step 2: Django Project Structure

Design the Django project layout following best practices:

DJANGO PROJECT STRUCTURE:

project/
├── manage.py
├── pyproject.toml              # Dependencies, tools config (ruff, mypy)
├── config/                     # Project-level configuration
│   ├── __init__.py
│   ├── settings/
│   │   ├── __init__.py
│   │   ├── base.py             # Shared settings
│   │   ├── development.py      # Dev overrides (DEBUG=True, etc.)
│   │   ├── production.py       # Production settings (security, caching)
│   │   └── test.py             # Test settings (fast password hasher, in-memory)
│   ├── urls.py                 # Root URL configuration
│   ├── wsgi.py                 # WSGI entry point

Step 3: Django REST Framework Patterns

Design the API layer with DRF:

DRF ARCHITECTURE PATTERNS:

1. Serializers — Data validation and transformation:

  # Base serializer pattern
  class UserSerializer(serializers.ModelSerializer):
      full_name = serializers.SerializerMethodField()

      class Meta:
          model = User
          fields = ['id', 'email', 'full_name', 'created_at']
          read_only_fields = ['id', 'created_at']

      def get_full_name(self, obj):
          return f"{obj.first_name} {obj.last_name}"

Step 4: FastAPI Architecture

Design FastAPI applications with dependency injection:

FASTAPI APPLICATION ARCHITECTURE:

app/
├── main.py                 # FastAPI app instance, lifespan events
├── config.py               # Pydantic Settings for configuration
├── dependencies.py         # Shared dependencies (get_db, get_current_user)
├── database.py             # SQLAlchemy/databases async engine setup
│
├── users/
│   ├── __init__.py
│   ├── router.py           # APIRouter with endpoints
│   ├── schemas.py          # Pydantic models (request/response)
│   ├── models.py           # SQLAlchemy/SQLModel ORM models
│   ├── service.py          # Business logic
│   ├── repository.py       # Database queries

Step 5: Async Django & ASGI

ASGI setup: config/asgi.py with get_asgi_application().
For WebSockets: channels ProtocolTypeRouter + AuthMiddlewareStack.
Use httpx.AsyncClient (not requests) in async views.

Step 6: Django Admin

Admin patterns: @admin.register(Model) + ModelAdmin.
Required: list_display, list_filter, search_fields, list_select_related.
Optional: list_editable, inlines, actions, readonly_fields.

Step 7: Database Optimization

Optimize Django ORM queries:

DJANGO ORM OPTIMIZATION:

1. N+1 query prevention:
  # BAD: N+1 queries (1 query for orders + N queries for customers)
  orders = Order.objects.all()
  for order in orders:
      print(order.customer.name)  # Each access triggers a query!

  # GOOD: select_related for ForeignKey/OneToOne (SQL JOIN)
  orders = Order.objects.select_related('customer').all()

  # GOOD: prefetch_related for ManyToMany/reverse FK (separate query)
  orders = Order.objects.prefetch_related('items', 'items__product').all()

  # GOOD: Prefetch with custom queryset

Step 8: Validation

Validate the Python web project:

PYTHON WEB PROJECT AUDIT:
| Check | Status |
|--|--|
| Business logic in services (not views) | PASS | FAIL |
| Serializers validate all input | PASS | FAIL |
| No N+1 queries (select/prefetch_related) | PASS | FAIL |
| Database indexes on filtered/ordered fields | PASS | FAIL |
| Custom user model (AbstractUser) | PASS | FAIL |
| Settings split by environment | PASS | FAIL |
| Secrets from environment variables | PASS | FAIL |
| Admin performance (list_select_related) | PASS | FAIL |
| Pagination on all list endpoints | PASS | FAIL |
| Authentication and permissions configured | PASS | FAIL |
| Tests use factories (Factory Boy) | PASS | FAIL |

Step 9: Deliverables

Generate the project artifacts:

PYTHON WEB PROJECT COMPLETE:

Artifacts:
- Framework: <Django | FastAPI | hybrid>
- Apps/modules: <N> apps, <M> models
- API: <DRF ViewSets | FastAPI routers> with <N> endpoints
- Admin: <N> ModelAdmin configs customized
- Database: <PostgreSQL> with <N> indexes, optimized queries
- Async: <ASGI configured | WSGI only>
- Audit: <PASS | NEEDS REVISION>

Next steps:
-> /godmode:api — Document the API with OpenAPI spec
-> /godmode:test — Write model, view, and integration tests
-> /godmode:deploy — Deploy with Gunicorn+Nginx or Docker
-> /godmode:migrate — Handle database schema migrations

Commit: "django: <project> — <framework>, <N> apps, <M> endpoints, <admin/async config>"

# Django development and testing
python manage.py check --deploy
pytest --tb=short
python manage.py migrate --check

Key Behaviors

Never ask to continue. Loop autonomously until done.

# Django diagnostics
python manage.py check --deploy
python manage.py test --parallel --verbosity=2
python manage.py makemigrations --check --dry-run
python manage.py showmigrations | grep '\[ \]'

IF query count per list view > 5: add select_related/prefetch_related. WHEN test coverage < 80%: add tests before shipping. IF response time P95 > 200ms: profile with django-debug-toolbar.

1. Services own business logic. Views dispatch, serializers validate, services contain logic.
2. Fat models, thin views — but not too fat. Cross-model rules belong in services.
3. DRF serializers are contracts. Never fields = '__all__'. Separate create vs read serializers.
4. Eliminate N+1 queries. select_related for FK, prefetch_related for M2M. Use django-debug-toolbar.
5. FastAPI dependencies compose. Auth, pagination, DB sessions as composable deps.
6. Pydantic is source of truth. Validation, serialization, documentation in one place.
7. Admin is a power tool. Customize list_display, search, filters. Admin N+1 is the top perf issue.

Flags & Options

HARD RULES

• NEVER put business logic in views or serializers — business rules belong in service functions
• NEVER use fields = '__all__' in DRF serializers — explicitly list every field to prevent data leakage
• NEVER use the default User model — always create a custom user model with AbstractUser at project start
• NEVER use synchronous HTTP calls (requests) in async views — use httpx.AsyncClient instead
• NEVER skip database indexes on fields used in filter(), order_by(), or WHERE clauses
• ELIMINATE ALL N+1 queries with select_related (ForeignKey) and prefetch_related (ManyToMany)
• ALL admin ModelAdmin classes MUST use list_select_related to prevent N+1 in the admin interface
• ALL API list endpoints MUST have pagination configured — unbounded queries are not acceptable

Auto-Detection

1. Scan for manage.py, settings.py → Django; main.py with FastAPI → FastAPI; both → hybrid
2. Check REST_FRAMEWORK config, AUTH_USER_MODEL, DATABASES engine
3. Scan for services.py/selectors.py (layering), factories.py (testing), Celery (tasks)
4. Maturity: scaffold | structured | optimized | production-ready

Output Format

End every Django skill invocation with this summary block:

DJANGO RESULT:
Action: <scaffold | model | view | serializer | service | optimize | test | audit | upgrade>
Files created/modified: <N>
Models created/modified: <N>
Views created/modified: <N>
Migrations created: <N>
Tests passing: <yes | no | skipped>
Build status: <passing | failing | not-checked>
Issues fixed: <N>
Notes: <one-line summary>

TSV Logging

Log every invocation to .godmode/ as TSV. Create on first run.

timestamp	project	action	files_count	models_count	views_count	migrations_count	tests_status	notes

Success Criteria

1. python manage.py check --deploy passes with 0 critical warnings
2. python manage.py test passes; coverage >= 80%
3. No business logic in views/serializers — services only
4. No fields = '__all__' — explicit field lists
5. All querysets use select_related/prefetch_related; list views <= 5 queries, detail <= 3
6. Filterable/sortable fields have DB indexes
7. Custom user model (not default auth.User)
8. Migrations consistent (makemigrations --check)

Error Recovery

Keep/Discard Discipline

KEEP if: tests pass AND quality improved AND no regressions
DISCARD if: tests fail OR performance regressed. Revert before proceeding.

Stop Conditions

STOP when: all tasks validated OR max iterations reached.
Guard: python manage.py test && python manage.py check --deploy.
On failure: git reset --hard HEAD~1.