Substack-AI+

About

Have you ever struggled with finding the right title, writing an engaging opening, or optimizing your Substack newsletter for higher open rates?

Substack-AI+ adds an AI writing assistant sidebar to the Substack composer. Using your own Claude / OpenAI API key, you get suggestions tailored to your writing.

Features
- Title suggestions — Multiple title candidates optimized for newsletter open rates (AI; your API key)
- Opening paragraphs — Several opening styles (problem-first, TL;DR, story hook) to start strong (AI)
- Outline drafting — Suggested H2 section structure for your post (AI)
- Readability check — Local analysis (no API key): character / sentence counts and long-sentence hints
- SEO keyword check — Local keyword density and title-inclusion check (no API key)
- Multi-AI support — Claude and OpenAI (GPT) selectable
- Privacy first — Your content goes only to your chosen AI provider. No Substack-AI+ servers.

Pricing
- Free: Up to 10 generations per day, all features, using your own API key (transparent running cost).
- Pro ($5 / month): Unlimited AI generations plus prompt template library, generation history, and more Pro features. Upgrade via "Upgrade to Pro" in the extension popup (ExtPay / Stripe). Cancel anytime from the portal.

How it works
1. Install from the Chrome Web Store
2. Open your Substack post composer (your-publication.substack.com/publish/post). The AI sidebar appears automatically on the right side of the editor (no API key needed to see it).
3. Try Readability or SEO check in the sidebar right away. These run locally with no API key.
4. For AI generation (Titles, Opening, Outline), click the toolbar icon to open Settings and enter your own Anthropic (Claude) or OpenAI API key.
5. Draft, get AI assistance, and publish.

Note: the toolbar icon opens Settings (for your API key). The writing sidebar is injected into the Substack composer page automatically. Open a post to see it; it is not opened from the toolbar icon.