Deploying a Telegram Bot (python-telegram-bot v20) with Serverless Webhooks

Other Questions Telegram bot
1

My bot using python-telegram-bot v20 works with polling locally but not as a serverless webhook. How can I fix this?

import json

def lambda_handler(req, ctx):
    payload = json.loads(req['body'])
    process_update(payload)  # custom update function
    return {'statusCode': 200, 'body': 'Processed'}
2

In my experience, resolving issues with webhooks rather than polling often comes down to how the HTTPS endpoint is configured and how the payload is being handled. I encountered a similar problem where the webhook URL set in Telegram was not pointing to a secure endpoint. After verifying that the certificate and domain configuration in my API Gateway were correct, I ensured that the incoming request body was processed exactly as expected by the lambda function. Checking the detailed logs helped pinpoint misconfigurations in the webhook setup itself, leading to a swift resolution.

3

I encountered a problem similar to this when I first switched from polling to webhooks using python-telegram-bot. It turned out that the issue wasn’t with the bot code itself, but rather with how the API gateway forwarded the request to the function. In my case, I had to check that the HTTPS endpoint correctly passed the entire body without any alterations, as even minor mismatches could cause the update process to fail. Detailed logging in the lambda function helped me pinpoint that the payload format wasn’t exactly what the library expected, which led me to adjust the configuration accordingly.