Quick Reference — "I See X, Do Y"

You see this	Do this	Details
`serializers.JSONField()`	Create custom field class + `@extend_schema_field(PydanticModel)`	serializer-fields.md
`serializers.ListField()` without `child=`	Add `child=serializers.CharField()` (or appropriate type)	serializer-fields.md
`serializers.DictField()` without `child=`	Add `child=` with typed values	serializer-fields.md
Any field without `help_text`	Add `help_text="..."` describing purpose, format, constraints	serializer-fields.md
`CharField` for a fixed set of values	Change to `ChoiceField(choices=[...])`	serializer-fields.md
`SerializerMethodField` without annotation	Add `@extend_schema_field(...)` on its `get_*` method	serializer-fields.md
`request: ValidatedRequest` with typed DTO	Use `TypedRequest[MyDTO]` for type-safe `validated_data`	viewset-annotations.md
Plain `ViewSet` with `serializer.is_valid()`	Replace with `@validated_request` decorator	viewset-annotations.md
`@action` without `@extend_schema`	Add `@extend_schema(request=..., responses=...)` above `@action`	viewset-annotations.md
`@extend_schema` on class (not method)	Move to the actual handler method (`get`, `post`, `create`, etc.)	viewset-annotations.md
`responses={400: OpenApiTypes.OBJECT}`	Use `OpenApiResponse(description="...")`	viewset-annotations.md
Same serializer for read + write with `read_only` fields	Split into separate read/write serializers	viewset-annotations.md
Custom `@action` returning non-paginated data	Set `pagination_class=None` on the action	viewset-annotations.md
`fields = "__all__"` on ModelSerializer	Explicitly list fields — `__all__` leaks internal fields to the API	General DRF practice
Endpoint returns raw dict/list (no response serializer)	Create a response serializer so downstream types are generated	viewset-annotations.md
Streaming/SSE endpoint	Use `@extend_schema(request=InputSerializer, responses={(200, "text/event-stream"): OpenApiTypes.STR})`	viewset-annotations.md