Clarus started from a simple frustration: AI writing tools kept trying to write for writers rather than write with them. Most tools optimize for speed and output volume — Clarus optimizes for voice, craft, and the experience of the writer.
The Problem
Creative writers — novelists, essayists, screenwriters — don’t want their words replaced. They want a collaborator that understands narrative tension, character voice, pacing, and subtext. They want to get unstuck without losing the thread of what made their work theirs.
Existing tools give generic completions. Clarus gives contextual craft support.
What I Built
Clarus is a full-stack web application built on Astro with a React writing environment at its core. The AI layer is built on Anthropic’s Claude API, with custom prompt architecture designed to act as a thoughtful writing partner rather than a completion engine.
Key features include:
- Voice preservation — the system learns from a writer’s existing prose to ensure suggestions feel stylistically consistent
- Scene-level context — rather than operating sentence by sentence, Clarus maintains awareness of chapter and narrative arc
- Craft mode vs. flow mode — two distinct interaction models: one for drafting without interruption, one for deep revision work
- Block prompts — structured creative prompts for when writers are stuck, tuned to the genre and tone of their current project
Technical Highlights
The writing environment is a custom rich-text editor built in React with tiptap, with real-time AI annotations that appear in a side channel rather than inline — preserving the writer’s visual relationship with their own work.
The backend handles streaming AI responses with a custom token budget system to keep interactions snappy even on longer documents. Session state is maintained across writes using a lightweight server-side cache.
Status
Clarus is in active development and early access. Growing a community of writers through Product Hunt, direct outreach to writing communities, and partnerships with writing coaches.
