dj-rest-filters

A Django REST Framework filter backend that lets you declaratively validate query parameters and filter querysets using DRF serializer syntax. Validate query params the same way you validate request bodies, with the same fields, the same Meta, and the same validate_* hooks.

📖 Full docs: https://dj-rest-filters.readthedocs.io/en/latest/

Features

• DRF-native syntax — filters look like serializers; reuse what you already know.
• Validation-only mode — drop the queryset to use a filter purely for query-param validation; cleaned values land on request.cleaned_args.
• ListField and RangeField for IN and range queries; accepts comma-separated, JSON-array, or repeated-key inputs.
• Custom per-field filtering via filter_<name>(self, qs, value), plus lookup_expr, exclude=True, and distinct=True on every field.
• OpenAPI / Swagger — schema parameters auto-generated for both drf-spectacular and drf-yasg.
• Browsable API support out of the box.

Requirements

Installation

pip install dj-rest-filters

Add djfilters to your INSTALLED_APPS:

INSTALLED_APPS = [
    ...,
    "djfilters",
]

Quickstart

Define a filter — same shape as a DRF serializer:

from djfilters import filters

class TodoFilter(filters.Filter):
    title = filters.CharField(required=False, lookup_expr="icontains")
    completed = filters.BooleanField(required=False)
    tags = filters.ListField(child=filters.CharField(), required=False)

Wire it into a view:

from rest_framework import generics
from djfilters.backend import DjFilterBackend

class TodoView(generics.ListAPIView):
    queryset = Todo.objects.all()
    serializer_class = TodoSerializer
    filter_class = TodoFilter
    filter_backends = [DjFilterBackend]

GET /todos/?title=buy&completed=true&tags=urgent,today filters by title__icontains="buy", completed=True, and tags__in=("urgent", "today").

Validation-only mode

Omit queryset to use a filter purely for query-param validation. The filter still runs, errors still surface as 400s, and the cleaned values land on request.cleaned_args:

class TodoView(generics.GenericAPIView):
    serializer_class = TodoSerializer
    filter_class = TodoFilter
    filter_backends = [DjFilterBackend]

    def get(self, request):
        params = request.cleaned_args  # validated query params
        ...

Filter context

Just like serializer context, extra context can be passed to the filter from the view:

class TodoView(generics.ListAPIView):
    ...

    def get_filter_context(self):
        return {"user": self.request.user}

The returned dict is merged with the default {"request": ...} and is accessible as self.context inside the filter.

Documentation

• Filters & ModelFilters guide
• Field reference
• Usage examples

License

MIT — see LICENSE.