app.py

import asyncio
import os
from fastapi import FastAPI, HTTPException, Query
from PyCharacterAI import get_client
from PyCharacterAI.exceptions import SessionClosedError

# Load token and character ID from environment variables
TOKEN = os.getenv("CHARACTERAI_TOKEN")
CHARACTER_ID = os.getenv("CHARACTERAI_CHARACTER_ID")

app = FastAPI()
client = None
chat = None
me = None

@app.on_event("startup")
async def startup_event():
    global client, chat, me

    if not TOKEN or not CHARACTER_ID:
        raise RuntimeError("Missing CHARACTERAI_TOKEN or CHARACTERAI_CHARACTER_ID")

    try:
        client = await get_client(token=TOKEN)
        me = await client.account.fetch_me()
        chat_data, greeting_message = await client.chat.create_chat(CHARACTER_ID)
        chat = chat_data

    except Exception as e:
        raise RuntimeError("Failed to start CharacterAI client") from e


@app.on_event("shutdown")
async def shutdown_event():
    if client:
        await client.close_session()


@app.get("/chat")
async def chat_with_character(message: str = Query(..., description="Message to send")):
    global client, chat

    if not client or not chat:
        raise HTTPException(status_code=503, detail="Chat not initialized")

    try:
        answer = await client.chat.send_message(CHARACTER_ID, chat.chat_id, message)
        return {
            "author": answer.author_name,
            "response": answer.get_primary_candidate().text
        }
    except SessionClosedError:
        raise HTTPException(status_code=500, detail="Session was closed")
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))