example_fastapi.py

from typing import Optional

from fastapi import FastAPI, HTTPException, Header, Depends
from pydantic import BaseModel

from telegram_webapps_authentication import Authenticator, TelegramUser

app = FastAPI()


BOT_TOKEN = "YOUR_BOT_TOKEN"  # Replace it with your real telegram bot token
authenticator = Authenticator(BOT_TOKEN)


class Message(BaseModel):
    text: str


@app.get("/validate")
def validate_init_data(authorization: Optional[str] = Header()):
    try:
        if authenticator.validate_init_data(authorization):
            initial_data = authenticator.get_initial_data(authorization)
            return {"message": initial_data.dict()}
        else:
            raise HTTPException(status_code=400, detail="Data is not valid")
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))


@app.get("/get_user")
def get_user_instance(authorization: Optional[str] = Header()):
    user = authenticator.get_telegram_user(authorization)
    return user


@app.post("/message")
async def send_message(
    message: Message,
    user: TelegramUser = Depends(authenticator.get_telegram_user),
):
    """
    Your backend logic
    """
    ...