This is a great idea.

Unfortunately, it seems like it isn't working right now. I tried using it and haven't gotten a Telegram message confirming my settings even though I sent the correct memo to @null.

Looking through the code I found the likely issue. (Also please consider enabling Issues on the forked GitHub repo so there is an official place to submit these bugs. Furthermore, I noticed there is no license specified in either your repo or flowfree's repository from which it is forked.)

In this line of the code, you require that the memo be exactly 24 characters long, but the memo generated by the service is always 40 characters long.

I have also discovered another issue when experimenting with the service. I first saved settings with some set of options. Then I changed it again with another set of options. In both cases I am pretty sure they are still in an unconfirmed state in your database because of the above bug. But when I try to change the settings back to the earlier configuration, I get an internal server error. My guess is that it is because of this line. I believe it tries to insert a document with the exact same _id as a previously inserted document and that causes an error.

I think what it should do is if it finds an existing item with the same _id, it should first check to make sure that the _id does not match the _id field of find_user_settings(username) (i.e. you are not trying to set the settings to the currently active one), and if those _ids do not match then it should replace the existing found object in the database with the new one (most of the fields would of course be the same but it would have a newer created_at time and confirmed would be set to False). On the other hand if the _ids do exactly match, then it should return a user-friendly error message letting the user know that the settings they want to save are exactly already the currently active settings.

Finally, I think your service should warn users that their settings are completely public. Since they are potentially entering in email addresses and/or Telegram public channel links that could be used to find Telegram handles, it is important users are aware of this fact before entering in any data.