django-api-debugger

majiayu000's avatarfrom majiayu000

Debug Django REST Framework API issues including serializers, viewsets, permissions, pagination, filtering, and response formatting. Use when troubleshooting API endpoints, serialization errors, permission denials, or unexpected response data.

⭐0stars🔀0forks📁View on GitHub🕐Updated Jan 5, 2026
[Debugging]

When & Why to Use This Skill

This Claude skill provides a specialized diagnostic framework for troubleshooting Django REST Framework (DRF) APIs. It streamlines the identification and resolution of complex backend issues involving data serialization, viewset logic, permission constraints, and response formatting, ensuring high-performance and reliable API endpoints.

Use Cases

  • Identifying and fixing serialization errors when API responses contain incorrect data or missing fields.
  • Troubleshooting 'Permission Denied' errors by auditing DRF permission classes and authentication workflows.
  • Resolving pagination and filtering issues to ensure API endpoints return the expected data subsets.
  • Debugging viewset configurations and URL routing to fix broken API endpoints and 404/500 errors.
  • Analyzing custom serializer methods like to_representation to fix nested data structure issues.
namedjango-api-debugger
descriptionDebug Django REST Framework API issues including serializers, viewsets, permissions, pagination, filtering, and response formatting. Use when troubleshooting API endpoints, serialization errors, permission denials, or unexpected response data.
allowed-toolsRead, Grep, Glob

Django API Debugger

Analyzes and debugs Django REST Framework API issues in this project.

Project Context

  • Backend: Django 5.x with Django REST Framework
  • API base path: /api/v1/
  • Key apps: core/projects, core/users, core/tools
  • Serializers located in: */serializers.py
  • Views located in: */views.py
  • URL routing: */urls.py

When to Use

  • "API returning wrong data"
  • "Serializer not including field"
  • "Permission denied on endpoint"
  • "Pagination not working"
  • "Filter not applying"
  • "API response format incorrect"

Debugging Approach

1. Identify the Endpoint

  • Check urls.py for URL pattern
  • Find the corresponding view/viewset

2. Check the Serializer

  • Verify fields are included
  • Check read_only and write_only settings
  • Look for custom to_representation or to_internal_value
  • Verify nested serializers

3. Check the View

  • Verify queryset and get_queryset()
  • Check permission_classes
  • Look for custom get_serializer_context()
  • Verify pagination settings

4. Common Issues

Missing fields in response:

  • Field not in serializer's fields
  • Field is write_only=True
  • Property not defined on model

Permission errors:

  • Missing or incorrect permission_classes
  • User not authenticated
  • Object-level permissions failing

Pagination issues:

  • Check DEFAULT_PAGINATION_CLASS in settings
  • Verify page_size parameter
  • Check for next/previous URLs in response

Key Files to Check

core/
├── projects/
│   ├── serializers.py  # Project serializers
│   ├── views.py        # Project viewsets
│   └── urls.py         # Project URL patterns
├── users/
│   ├── serializers.py  # User serializers
│   └── views.py        # User viewsets
└── tools/
    ├── serializers.py  # Tool serializers
    └── views.py        # Tool viewsets

Testing Tips

# Test endpoint directly
docker compose exec web python manage.py shell
>>> from core.projects.models import Project
>>> Project.objects.first().__dict__

# Check serializer output
>>> from core.projects.serializers import ProjectSerializer
>>> ProjectSerializer(Project.objects.first()).data