app/server.py

from fastapi import FastAPI
from fastapi.responses import RedirectResponse
from langserve import add_routes
from langchain.prompts import ChatPromptTemplate
from langchain.chat_models import ChatOpenAI
from dotenv import load_dotenv

from langchain_google_genai.chat_models import ChatGoogleGenerativeAI

load_dotenv()
import os
api_url = os.getenv('PROXY_URL') + os.getenv('PROXY_PREFIX')

app = FastAPI(
  title="Dev Assistant LangServe",
  version="1.0",
  description="A simple api server using Langchain's Runnable interfaces",
  root_path_in_servers=True,
  root_path=api_url,
  debug=True,
)

@app.get("/")
async def root():
    # return json response
    return {"message": "Dev Assistant LangServe is up and running!"}

add_routes(
    path    = "/openai",
    app     = app,
    runnable= ChatOpenAI(model="gpt-4-1106-preview"),
    disabled_endpoints=[]
)

add_routes(
    path    = "/google",
    app     = app,
    runnable= ChatGoogleGenerativeAI(model="gemini-pro"),
    disabled_endpoints=[]
)

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="localhost", port=7860, root_path=api_url)