fund-tracer/backend/app/services/llm/base.py

"""Base LLM provider - abstract interface for vision extraction."""

from abc import ABC, abstractmethod

from app.schemas.transaction import TransactionExtractItem


class BaseLLMProvider(ABC):
    """Abstract base for LLM providers. Supports optional model override."""

    def __init__(self, model_override: str | None = None):
        self._model_override = model_override

    @abstractmethod
    async def extract_from_image(self, image_bytes: bytes) -> list[TransactionExtractItem]:
        pass

    @abstractmethod
    async def chat(self, system: str, user: str) -> str:
        """Plain text chat (for inference/reasoning tasks like report generation)."""
        pass