Prose

Prose is a BYOK (bring your own key) AI writing assistant with a built-in rich text editor. You connect your own OpenRouter API key and pay only when you scan — usually fractions of a cent per check. No subscription, no monthly fee, no usage cap. You own your costs entirely.

The core mechanic that makes Prose different: it gets cheaper and smarter the more you use it. Every suggestion you accept gets tracked. After a few accepts, that pattern gets promoted to a free local rule that runs instantly without touching the API at all. Over time, your most common corrections happen for free. Suggestions you consistently ignore stop showing up. The tool adapts to you rather than the other way around.

The editor itself is a full rich text editor — bold, italics, headers, lists — built for writers who want a clean, distraction-free space. Suggestions appear as inline underlines color-coded by type: grammar, style, and clarity. A side panel shows all current suggestions organized by category so you can review everything at once or work through them one by one. You can scan your entire document, a single paragraph, or just a highlighted selection — giving you full control over when and where you spend API credits.

What sets Prose apart from every other writing tool is the My Voice feature. Before you write a single word, Prose learns who you are as a writer. You go through a short onboarding quiz where you paraphrase sentences in your own words, select phrases you would naturally say, and flag ones you would never use. The AI builds a personal voice profile from your answers. From that point forward, suggestions are tailored to your voice specifically — not a generic standard. If you would never use a word, Prose won't suggest it. If you have a natural phrasing preference, Prose learns to recommend it. The profile keeps improving passively too: every time you edit a suggestion into something better, Prose remembers what you wrote instead and factors it into future recommendations. The result is a writing assistant that feels like it actually knows you after a few sessions — one that has opinions about your writing but knows when to stay out of the way. No gamification, no engagement tricks, no upgrade prompts. Just a quiet, precise tool that gets better the longer you use it.

No account required to get started. Free to use with your own OpenRouter API key.