telegram-bot-api/docs/getting-started/important-notes.md

Important Notes

The Telegram Bot API has a few potentially unanticipated behaviors. Here are a few of them. If any behavior was surprising to you, please feel free to open a pull request!

Callback Queries

• Every callback query must be answered, even if there is nothing to display to the user. Failure to do so will show a loading icon on the keyboard until the operation times out.

ChatMemberUpdated

• In order to receive chat_member and updates, you must explicitly add it to your allowed_updates when getting updates or setting your webhook.

Entities use UTF16

• When extracting text entities using offsets and lengths, characters can appear to be in incorrect positions. This is because Telegram uses UTF16 lengths while Golang uses UTF8. It's possible to convert between the two, see issue #231 for more details.

GetUpdatesChan

• This method is very basic and likely unsuitable for production use. Consider creating your own implementation instead, as it's very simple to replicate.
• This method only allows your bot to process one update at a time. You can spawn goroutines to handle updates concurrently or switch to webhooks instead. Webhooks are suggested for high traffic bots.

Nil Updates

• At most one of the fields in an Update will be set to a non-nil value. When evaluating updates, you must make sure you check that the field is not nil before trying to access any of it's fields.

User and Chat ID size

• These types require up to 52 significant bits to store correctly, making a 64-bit integer type required in most languages. They are already int64 types in this library, but make sure you use correct types when saving them to a database or passing them to another language.