Reddit bot hosting, PRAW or snoowrap on a loop

import os
import praw

reddit = praw.Reddit(
    client_id=os.environ["REDDIT_CLIENT_ID"],
    client_secret=os.environ["REDDIT_CLIENT_SECRET"],
    username=os.environ["REDDIT_USERNAME"],
    password=os.environ["REDDIT_PASSWORD"],
    user_agent="my-bot/1.0 by u/myaccount",
)

for submission in reddit.subreddit("test").stream.submissions(skip_existing=True):
    if "hello" in submission.title.lower():
        submission.reply("hello from FadeHost")

praw in requirements.txt, the file saved as bot.py, the five values in the environment. The credentials come from a script app in your Reddit account's app preferences, created by the account the bot posts as.

const Snoowrap = require("snoowrap");

const r = new Snoowrap({
  userAgent: "my-bot/1.0 by u/myaccount",
  clientId: process.env.REDDIT_CLIENT_ID,
  clientSecret: process.env.REDDIT_CLIENT_SECRET,
  username: process.env.REDDIT_USERNAME,
  password: process.env.REDDIT_PASSWORD,
});

setInterval(async () => {
  const posts = await r.getSubreddit("test").getNew({ limit: 10 });
  // decide and reply
}, 60000);

snoowrap is the Node.js equivalent and queues requests for you. Both libraries talk to Reddit over HTTPS, which the free plan's outbound list allows.

Reddit wants a user agent that says what the bot is and who runs it, and it returns the rate limit in every response. PRAW waits for you when you let it; snoowrap queues. The one thing neither does for you is remember what it already answered, so keep the ids you have handled in a file under /data or in a managed database. A redeploy replaces the code, not the disk, so the bot does not start the conversation again.

Reddit suspends the account, not the host, so the rules worth following are Reddit's API terms and each subreddit's own. Identify the bot, stay inside the rate limit, do not answer every thread and honour removal requests from moderators. Our terms also cover apps that break the rules of the platform they connect to.