Lathe for Substack

Lathe adds a few tools to Substack for people who write there. I built it for my own newsletter first. It runs in your browser with your own Substack login and it never posts anything for you.

Read / unread in Chat. Threads with new activity get a red dot in substack.com/chat. You can mark any thread as unread and come back to it later. Opening a thread marks it read again.

AI Summary on posts. Every Substack post gets an AI Summary button at the top. You pick short, medium or long in the settings. The summary is written with your own Anthropic or OpenAI key.

Promo Notes from your posts. Open Lathe, pick one of your latest posts and get three Note ideas written from it. Choose one and Substack's own composer opens with the text already in. You read it, change what you want and post it yourself.

Crosspost to Medium. This one is for paid members. One click opens a new Medium draft with your post filled in, and a small guide on the page walks you through topics, the canonical link and Publish.

Lathe is free for every Digital Craft Workshop subscriber, and a free subscription is enough. The paid plan adds the Medium crosspost. That is a paid Digital Craft Workshop subscription or a lifetime license.

Your AI key is stored only in your browser and goes only to the provider you pick. Lathe does not read your Substack password or cookies. There are no ads and no tracking in the extension. The full privacy policy is at members.digitalcraftworkshop.com/lathe/privacy.

Lathe is an independent tool by Digital Craft Workshop. It is not affiliated with Substack or Medium.