--- name: django-expert-a31857b227ed description: "Use when building Django web applications or REST APIs with Django REST Framework. Invoke when working with settings.py, models.py, manage.py, or any Django project file. Creates Django models with proper indexes, optimizes ORM queries using select_related/prefetch_related, builds DRF serializers and viewsets, and configures JWT authentication. Trigger terms: Django, DRF, Django REST Framework, Django ORM, Django model, serializer, viewset, Python web." license: MIT metadata: author: https://github.com/Jeffallan version: "1.1.0" domain: backend triggers: Django, DRF, Django REST Framework, Django ORM, Django model, serializer, viewset, Python web role: specialist scope: implementation output-format: code related-skills: fullstack-guardian, fastapi-expert, test-master --- # Django Expert Senior Django specialist with deep expertise in Django 5.0, Django REST Framework, and production-grade web applications. ## When to Use This Skill - Building Django web applications or REST APIs - Designing Django models with proper relationships - Implementing DRF serializers and viewsets - Optimizing Django ORM queries - Setting up authentication (JWT, session) - Django admin customization ## Core Workflow 1. **Analyze requirements** — Identify models, relationships, API endpoints 2. **Design models** — Create models with proper fields, indexes, managers → run `manage.py makemigrations` and `manage.py migrate`; verify schema before proceeding 3. **Implement views** — DRF viewsets or Django 5.0 async views 4. **Validate endpoints** — Confirm each endpoint returns expected status codes with a quick `APITestCase` or `curl` check before adding auth 5. **Add auth** — Permissions, JWT authentication 6. **Test** — Django TestCase, APITestCase ## Reference Guide Load detailed guidance based on context: | Topic | Reference | Load When | |-------|-----------|-----------| | Models | `references/models-orm.md` | Creating models, ORM queries, optimization | | Serializers | `references/drf-serializers.md` | DRF serializers, validation | | ViewSets | `references/viewsets-views.md` | Views, viewsets, async views | | Authentication | `references/authentication.md` | JWT, permissions, SimpleJWT | | Testing | `references/testing-django.md` | APITestCase, fixtures, factories | ## Minimal Working Example The snippet below demonstrates the core MUST DO constraints: indexed fields, `select_related`, serializer validation, and endpoint permissions. ```python # models.py from django.db import models class Article(models.Model): title = models.CharField(max_length=255, db_index=True) author = models.ForeignKey( "auth.User", on_delete=models.CASCADE, related_name="articles" ) published_at = models.DateTimeField(auto_now_add=True, db_index=True) class Meta: ordering = ["-published_at"] indexes = [models.Index(fields=["author", "published_at"])] def __str__(self): return self.title # serializers.py from rest_framework import serializers from .models import Article class ArticleSerializer(serializers.ModelSerializer): author_username = serializers.CharField(source="author.username", read_only=True) class Meta: model = Article fields = ["id", "title", "author_username", "published_at"] def validate_title(self, value): if len(value.strip()) < 3: raise serializers.ValidationError("Title must be at least 3 characters.") return value.strip() # views.py from rest_framework import viewsets, permissions from .models import Article from .serializers import ArticleSerializer class ArticleViewSet(viewsets.ModelViewSet): """ Uses select_related to avoid N+1 on author lookups. IsAuthenticatedOrReadOnly: safe methods are public, writes require auth. """ serializer_class = ArticleSerializer permission_classes = [permissions.IsAuthenticatedOrReadOnly] def get_queryset(self): return Article.objects.select_related("author").all() def perform_create(self, serializer): serializer.save(author=self.request.user) ``` ```python # tests.py from rest_framework.test import APITestCase from rest_framework import status from django.contrib.auth.models import User class ArticleAPITest(APITestCase): def setUp(self): self.user = User.objects.create_user("alice", password="pass") def test_list_public(self): res = self.client.get("/api/articles/") self.assertEqual(res.status_code, status.HTTP_200_OK) def test_create_requires_auth(self): res = self.client.post("/api/articles/", {"title": "Test"}) self.assertEqual(res.status_code, status.HTTP_403_FORBIDDEN) def test_create_authenticated(self): self.client.force_authenticate(self.user) res = self.client.post("/api/articles/", {"title": "Hello Django"}) self.assertEqual(res.status_code, status.HTTP_201_CREATED) ``` ## Constraints ### MUST DO - Use `select_related`/`prefetch_related` for related objects - Add database indexes for frequently queried fields - Use environment variables for secrets - Implement proper permissions on all endpoints - Write tests for models and API endpoints - Use Django's built-in security features (CSRF, etc.) ### MUST NOT DO - Use raw SQL without parameterization - Skip database migrations - Store secrets in settings.py - Use DEBUG=True in production - Trust user input without validation - Ignore query optimization ## Output Templates When implementing Django features, provide: 1. Model definitions with indexes 2. Serializers with validation 3. ViewSet or views with permissions 4. Brief note on query optimization ## Knowledge Reference Django 5.0, DRF, async views, ORM, QuerySet, select_related, prefetch_related, SimpleJWT, django-filter, drf-spectacular, pytest-django [Documentation](https://jeffallan.github.io/claude-skills/skills/backend/django-expert/) --- Source attribution: andrewthomastaylor Original project: https://github.com/andrewthomastaylor/Skills/blob/cb7b4065bacb4b06224de86d509ccef568f68b79/claude-skills/skills/django-expert/SKILL.md License: MIT License information: https://opensource.org/license/mit Original upstream instructions; downloaded from Mega AI Hub. ## Upstream license notice MIT License Copyright (c) 2025 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. # Mega AI Hub resource metadata Creator / publisher: andrewthomastaylor Original project: https://github.com/andrewthomastaylor/Skills/blob/cb7b4065bacb4b06224de86d509ccef568f68b79/claude-skills/skills/django-expert/SKILL.md Attribution basis: Source repository record Fields of work: Development & Engineering, Product Management Roles: Backend Developer, Full-Stack Developer, Growth Product Manager, Product Manager, Technical Product Manager Specialties: Backend Tools: Tool not specified Country applicability: Country not specified Classification basis: Source catalog labels Instruction SHA-256: ae3b612b1186886aa2c9768ef83439d8f2317346544b09128955f4e762f254cb