by Shleeble


Mastodon Welcome Bot

This is a Mastodon bot that sends out a welcome toot (DM) to new users, brought to you by

Because Mastodon's API doesn't currently have a route for getting an array of accounts in an instance, this bot queries the followers of an account and pages through for any have been created in the last x days (see configuration below). This means that you'll want ACCOUNT_ID to be an account that is auto-followed by all new users.

Deploy to Heroku


Hosting the bot on Heroku is probably the easiest (and cheapest, it's free!) way to go. There's only a few steps:

  1. Click the button above. Once you're logged in to Heroku, you'll be taken to a window where you can set the environment variables as detailed below. Then you can create the app.
  2. Once the app is created, you'll have to schedule when it should run. Heroku's Scheduler addon is used for this (don't worry, it's free). On your new app's page, click "Heroku Scheduler" under "Installed Add-ons". In the new window, set "python" as the task to run and configure the schedule for the job.



  • python3
  • pip


  1. git clone
  2. pip install -r requirements.txt (you'll probably want to setup a virtualenv for this)
  3. cp .env.dist .env
  4. Fill in the env vars as required in the .env file (see definitions below)
  5. Run the app with python

Environment Variables

The application uses the following environment variables.

name required default description ACCESS_TOKEN yes n/a the access token for the Mastodon account that you want the toots to come from DAYS_SINCE no 1 how many days back of new users you want to go INSTANCE_BASE_URL yes n/a the base url of the Mastodon instance you want to run this for (ex: "") TOOT_TEMPLATE yes n/a the template of the toot that you want to send out. Jinja2 syntax is used here and you can use any of the Account variables DEBUG no false boolean (either "true" or "false") for debug mode. If true, won't actually send out the toots, will just print the message for each to stdout ACCOUNT_ID yes n/a the account ID that you want to pull followers from

Example Welcome Toot Template

This can be copy/pasted into the TOOT_TEMPLATE environment variable. Note that \n\ndenotes a line break, as the entire var must remain on one line. Total characters cannot exceed 500, including those line breaks.

@{{ username }} Hi, and welcome to!\n\nHere are a few handy tips:\n\n- This is a great (non-technical) intro to the Mastodon platform:\n\n- Our "local" timeline is the real magic of\n\n- Some less obvious ways to find people:\n\n- Install a free mobile app! Many people like Tootdon (iOS and Android).\n\n- Asking questions is okay and encouraged! We (@mods) are here to help.\n\nEnjoy :)