Telegram error 409: Conflict: terminated by other getUpdates request

Two (or more) processes are calling getUpdates with the same bot token at the same time. Telegram allows exactly one long-poll connection per token; when a second one arrives, the server terminates the first and returns this 409 to it. Each instance then reconnects and terminates the other, so both log a stream of 409s and each receives roughly half of the updates at random.

This is why the classic symptom is a bot that answers some messages and ignores others. The token is valid, the webhook is empty, and the code is fine. There are simply two of you. You can reproduce it in ten seconds: open two terminals, run the same polling bot in both, and watch both start logging this description.

Every major library surfaces it under its own name, which is why searches for the same problem look different per stack. python-telegram-bot raises telegram.error.Conflict (documented as "raised when a long poll or webhook conflicts with another one"). aiogram v3 raises aiogram.exceptions.TelegramConflictError. grammY throws a GrammyError with error_code: 409 and additionally logs a hint that the bot is running several times on long polling. Telegraf rejects with a TelegramError whose message is 409: Conflict: terminated by other getUpdates request, and node-telegram-bot-api emits a polling_error event with code ETELEGRAM. All of them are wrapping the identical response body shown below.

Common culprits are a local development process still polling the production token, a container platform that scaled the polling worker to two replicas, a rolling deploy that started the new process before the old one exited, and a supervisor (pm2, systemd, nodemon) restarting a crashed worker while the old one is still draining.

{"ok":false,"error_code":409,"description":"Conflict: terminated by other getUpdates request; make sure that only one bot instance is running"}

Use separate bot tokens for development, staging and production so a forgotten local process can never collide with production; verify which environment a token belongs to with the Telegram bot token checker. Treat 'one poller per token' as an infrastructure invariant enforced by a leader lock or a single-replica deployment, or remove the constraint entirely by moving to webhooks. The full diagnostic walkthrough is cause 1 in Telegram bot not responding.