Reddit Canned Response Bot

Simple Python 3 based bot to send canned responses to specific phrases and/or username mentions/summons.

Uses praw and pushshift (psaw) to continually get new comments containing specific keywords, then regular expressions for further filtering. Sends a canned response if filter matches. Username mentions just use praw to check unread inbox messages.

Before you do anything

• Read the Reddit bottiquette rules

Setup

• Create a Reddit account for bot and create an authorised app if you haven't already
• Install python requirements pip3 install -r requirements.txt
• Create a praw.ini file (or set praw env vars) and fill out bot credentials:

  [DEFAULT]
  client_id=abcdefhijklmno
  client_secret=abcdefhijklmnopqrstuzwxyz01
  user_agent=foo
  username=foobot
  password=bar

• Create a mybotname_config.json bot configuration file. Can be as simple as this:

  {
    "subreddits": [
      "all"
    ],
    "postfix": "\n\nI am a bot (u/mymainaccountname)",
    "max_comments_per_submission": 100,
    "delete_unliked_comment_score": -5,
    "canned_responses": [
      {
        "search_keys": [
          "\"!mybotname\""
        ],
        "comment_regexes": [
          "surprised pikachu"
        ],
        "response": "https://i.imgur.com/XLSOusb.png"
      }
    ]
  }

Usage

• Run bot
  • ./bot.py mybotname_config.json
• Dry run (print replies without actually sending)
  • ./bot.py mybotname_config.json --dry-run
• Dry run starting from comments made one week (24*7=168 hours) ago
  • ./bot.py mybotname_config.json --dry-run=168

Heroku

Heroku is a free way to run your bot entirely in the cloud.

• Create a free Heroku account
• Install Heroko CLI
• Clone this repo and cd into project folder
• Create and run detached bot

  heroku login
  heroku create
  # Praw credentials (i.e. from praw.ini file)
  heroku config:set praw_client_id=abcdefhijklmno
  heroku config:set praw_client_secret=abcdefhijklmnopqrstuzwxyz01
  heroku config:set praw_user_agent=foo
  heroku config:set praw_username=foobot
  heroku config:set praw_password=bar
  # Add a Procfile that tells Heroku how to (re)start your app
  echo "worker: ./bot.py mybotname_config.json" > Procfile
  git add Procfile --force
  git commit -m "Add Heroku Procfile"
  git push heroku master
  # Start bot
  heroku ps:scale worker=1

• View logs: heroku logs --tail
• Stop bot: heroku ps:scale worker=0

Heroku Caveats

• Heroku dynos are periodically restarted/cycled (~24 hourly)
  • This will cause a few seconds of downtime each time it occurs
  • Due to Heroku's ephemeral filesystem the list of already commented on submissions will be wiped, this makes max_comments_per_submission more of a daily limit

Notes

• Don't use/run any of the example bot configurations