Step by step guide

Define HistoryChanges model

class HistoryChanges(BaseHistoryChanges, Base):
    __tablename__ = "history_changes"

    user_id: Mapped[UUID | None] = mapped_column(
        ForeignKey("user.id", ondelete="SET NULL")
    )
    entity_id: Mapped[UUID] = mapped_column(index=True)

Define "after_update" handler

class Note(Base):
    __tablename__ = "note"

    id: Mapped[UUID] = mapped_column(primary_key=True, default=uuid7)
    is_active: Mapped[bool] = mapped_column(default=True)
    name: Mapped[str] = mapped_column(String(255))
    description: Mapped[str] = mapped_column(String(512))


class EntityName(SimpleNamespace):
    note = "note"


@event.listens_for(Note, "after_update")
def create_note_history(
    mapper: Mapper,
    connection: Connection,
    target: Note,
) -> None:
    stmt_builder = InsertStmtBuilder(history_model=HistoryChanges)
    handler = WithUserChangeEventHandler(
        entity_name=EntityName.note,
        stmt_builder=stmt_builder,
    )
    handler(mapper=mapper, connection=connection, target=target)

Set context variables

At the entry point, set the value of the EventId context variable (you can also specify the user ID if you wish.)

from fastapi import APIRouter
from sqla_history.context import CurrentUserId, EventId
from uuid import uuid4

router = APIRouter("/note")

@router.post("/{note_id}")
async def edit_note(
    note_id: UUID,
    schema: NoteEditSchema,
    user_id: UUID = Depends(get_user_id)
    repository: NoteRepository = Depends(get_note_repository),
) -> NoteSchema:
    EventId.set(uuid.uuid4())
    CurrentUserId.set(user_id)

    model = await repository.get(note_id)
    model = await repository.update(model, dto=NoteUpdateDTO.model_validate(schema))

    return NoteSchema.model_validate(model)

Check created HistoryChanges objects in database