F5Bot is a keyword monitoring service made by F5Bot LLC and running since 2017. It checks new posts and comments on Reddit, Hacker News and Lobsters every few minutes and sends an alert when one of a user's keywords appears.
A user signs up with an email address and enters keywords such as a brand, a product or a topic. Each match arrives by email, either at once, batched on a delay, or as a daily digest. Filters narrow matches by subreddit, exclude unwanted terms or require a second keyword, and on the higher plan an AI filter judges each new discussion against a plain-language description. Alerts can also go to Slack and Discord through webhooks, or be read as RSS or JSON feeds or through an API. Uses named on the site include brand and competitor monitoring and lead generation: finding people who ask for a product like the user's.
F5Bot is a hosted service with a free plan and paid monthly plans that add keywords and features.