Eigenstyle — Claude Code MCP server: what it does, how to run
Tracks quantitative writing stylometry, scores drafts against a personal corpus, and flags omitted URLs or digits. Helpful when keeping LLM outputs aligned with your tone.
Open on GitHubWhat Eigenstyle does
Eigenstyle is a Rust workspace that treats writing style as measurable data rather than prompt vibes. It tracks metrics like sentence lengths, punctuation frequency, and function-word distributions. Through the check_draft tool, connected assistants score drafted text and report whether tone drifted away from the calibrated baseline.
Six tools communicate through newline-delimited JSON-RPC over stdio. Adding texts via ingest_sample never silently overwrites the style profile: recalculations require an explicit command, complete with a dry-run preview. Users can manually tune metric averages, and those overrides persist across later recalculations.
Without Wayland, the companion desktop interface fails with black frames under X11. The core engine also rejects inputs outside strict bounds: drafts below 200 words receive an UNRELIABLE label, and building the fingerprint requires at least two corpus pieces.
What it helps with
- score draft text against calibrated voice bands
- detect omitted source numbers and corrupted URLs in generated drafts
- fetch matching genre paragraphs as reference exemplars
- store manual metric corrections on top of calculated writing statistics
Example prompts for the agent
- Run
check_drafton my latest article to see if it matches my style profile - Add
post.mdto the corpus with sole authorship under the blog genre - Fetch exemplar paragraphs for technical documentation using
get_exemplars
How to install Eigenstyle
Install
The MCP registry has no launch command for it: see the repository README
Step by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about Eigenstyle
How to run the Eigenstyle MCP server?
Build and start the stdio server binary with cargo run --release -p eigenstyle. You can pass --home <dir> to select a custom data directory instead of the default location.
What does the check_draft tool do in Eigenstyle?
It scores drafts with ratings from CLOSE to OFF-VOICE and reports any avoid-list violations. If you supply the original source text, it also flags dropped numbers and broken URLs.
What are the key limits for drafts and corpus samples?
Drafts under 200 words trigger an UNRELIABLE score, and sample texts cannot exceed 256 KiB. Fingerprint calibration requires a minimum of two included corpus documents to compute properly.
