app/services/base.py

"""Abstract base class for ML inference services."""

from abc import ABC, abstractmethod
from typing import Generic, TypeVar
from pydantic import BaseModel

TRequest = TypeVar('TRequest', bound=BaseModel)
TResponse = TypeVar('TResponse', bound=BaseModel)


class InferenceService(ABC, Generic[TRequest, TResponse]):
    """
    Base class for inference services. Subclass this to integrate your model.
    """

    @abstractmethod
    def load_model(self) -> None:
        """Load model weights and processors. Called once at startup."""
        pass

    @abstractmethod
    def predict(self, request: TRequest) -> TResponse:
        """Run inference and return typed response."""
        pass

    @property
    @abstractmethod
    def is_loaded(self) -> bool:
        """Check if model is loaded and ready."""
        pass