Substack just launched Reply Rules, a new feature that lets writers filter comments on their posts, Notes, or Chat.
The platform announced the rollout on Wednesday. With Reply Rules, creators can establish custom guidelines for responses—blocking AI spam, profanity, or requesting specific formats like haiku-only replies.
The system learns from user behavior. When people hide replies they don't like, the algorithm picks up on patterns and automatically filters out similar comments. Writers can unhide hidden replies anytime.
The feature is live for all English-language publications now. It arrives as Substack faces criticism over its historically lenient moderation approach. The platform has allowed far-right newsletters to flourish, but this move signals the company is tightening creator-level content control.
Substack has released several products recently. Earlier this year, it launched a built-in recording studio for creators to pre-record and publish videos, and a TV app that lets subscribers watch video posts and livestreams on television.
The decentralized moderation model means writers remain responsible for their own communities, but Reply Rules should reduce the manual work of reviewing each comment. Creators already had tools like comment deletion, post locking, and user bans. Automation is new.
For newsletter writers and independent creators managing comment sections, this is the feature they have been asking for.
