Pydantic · Class

SerializationInfo

Pydantic functional serializers let you change how fields or whole models are dumped. Choose plain mode to replace default serialization, or wrap mode to call the default serializer and then modify its result.

Last updated 2 November 2026

@field_serializer('field_name', mode='plain' | 'wrap', when_used='always' | 'unless-none' | 'json' | 'json-unless-none')
@model_serializer(mode='plain' | 'wrap', when_used='always' | 'unless-none' | 'json' | 'json-unless-none')

Source: Functional Serializers | Pydantic Docs. Checked 2026-11-03.