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Expose

What it is​

  • An abstract base class (ABC) defining a standard interface for exposing a component:
    • as LangChain tools (for agent use), and/or
    • as FastAPI routes (for HTTP access).

Public API​

  • class Expose(ABC)
    • as_tools(self) -> list[BaseTool]
      • Must be implemented by subclasses.
      • Should return a list of LangChain BaseTool instances usable by an Agent.
    • as_api(self, router: APIRouter, route_name: str = "", name: str = "", description: str = "", description_stream: str = "", tags: list[str | Enum] | None = []) -> None
      • Must be implemented by subclasses.
      • Should register FastAPI routes on the provided APIRouter.

Configuration/Dependencies​

  • Depends on:
    • fastapi.APIRouter
  • Type-checking only dependency:
    • langchain_core.tools.BaseTool (imported only under TYPE_CHECKING)

Usage​

from fastapi import APIRouter
from naas_abi_core.utils.Expose import Expose

class MyExpose(Expose):
    def as_tools(self):
        return []  # return a list of langchain tools

    def as_api(self, router: APIRouter, route_name: str = "", **kwargs) -> None:
        @router.get(f"/{route_name or 'my-endpoint'}")
        def ping():
            return {"ok": True}

router = APIRouter()
MyExpose().as_api(router, route_name="ping")
tools = MyExpose().as_tools()

Caveats​

  • tags default is an empty list literal ([]), which is a mutable default argument.
  • as_api contains two consecutive raise NotImplementedError() statements; both are unreachable in practice but indicate the method must be overridden.