A structural editor for novels. Spine reads a full manuscript and surfaces the seams — drifting arcs, dropped subplots, continuity gaps — so editors and authors can finally look at the same map.
Spine treats a novel the way a senior engineer treats a codebase: scenes are commits, characters are contributors, plotlines are branches, abandoned subplots are dead branches. Drop in a manuscript and Spine ingests it into a fully navigable structure — every scene becomes a record with its cast, the line that holds it, and its position on the spine. What it does: • Writes a thirty-second editorial brief in the voice of someone who has just read the manuscript twice • Surfaces structural problems — drifting arcs, dropped threads, continuity issues — that usually surface only on the third or fourth read • Lets you talk to any character in their own voice, on the day after their last scene, knowing only what they know • Ships with Pride & Prejudice (321 scenes, 53 characters) and War & Peace (1,538 scenes, 489 characters) pre-loaded — no sign-up needed to explore Built for developmental editors, acquiring agents, and adaptation writers — people who already know how to read a manuscript and want a faster, sharper second pair of eyes.
The hardest part was making a tool that helps without overreaching. Spine deliberately won't write prose, generate scenes, or polish sentences — the page stays the author's. Engineering-wise, the work was about making structural reads feel instant even on novels with 1,500+ scenes: aggressive caching, a tight SQLite schema with raw prepared statements, tiered Gemini model routing (flash-lite on hot paths, pro for synthesis), and Zod validation on every LLM output so the UI never has to handle a malformed response.