simple_example.py

from contextlib import asynccontextmanager
from http import HTTPStatus
from telegram import Update
from telegram.ext import Application, CommandHandler
from telegram.ext._contexttypes import ContextTypes
from fastapi import FastAPI, Request, Response
from dotenv import load_dotenv
import os

# Load environment variables from .env file
load_dotenv()
BOT_TOKEN = os.getenv("TELEGRAM_BOT_TOKEN")
WEBHOOK_URL = os.getenv("WEBHOOK_URL")  # Your webhook URL

# Initialize python telegram bot
ptb = (
    Application.builder()
    .updater(None)
    .token(BOT_TOKEN)  # replace <your-bot-token>
    .read_timeout(7)
    .get_updates_read_timeout(42)
    .build()
)

@asynccontextmanager
async def lifespan(_: FastAPI):
    await ptb.bot.setWebhook(f"{WEBHOOK_URL}/webhook")  # replace <your-webhook-url>
    async with ptb:
        await ptb.start()
        yield
        await ptb.stop()

# Initialize FastAPI app (similar to Flask)
app = FastAPI(lifespan=lifespan)

@app.post("/webhook")
async def process_update(request: Request):
    req = await request.json()
    print(req)
    update = Update.de_json(req, ptb.bot)
    await ptb.process_update(update)
    return Response(status_code=HTTPStatus.OK)

# Example handler
async def start(update: Update, context: ContextTypes.DEFAULT_TYPE):
    """Send a message when the command /start is issued."""
    await update.message.reply_text("starting...")

# Add the command handler to the application
ptb.add_handler(CommandHandler("start", start))