lepisma

Fast, soft feedback on Markdown docs that are hard to read. It targets the habits of text written by Claude. Warnings go back to Claude so it can rewrite the text. Warnings never block a commit.

The name: Lepisma saccharina is the silverfish, which eats paper and chews through books.

Agents: start with the built-in guide. It picks setup or triage from the repo state.

uvx lepisma@latest guide

Sample output:

docs/setup.md:12:1 R1 Sentence has 31 words; consider splitting.
docs/setup.md:14:22 R2 Stack of 4 nouns ("pipeline configuration validation error"); rephrase with a verb or preposition.
docs/setup.md:15:9 R3 Habit word "leverage"; try: use.
docs/setup.md:18:5 R4 "performs validation" hides the verb; try "validate".

How it works

• Local spaCy server. A small FastAPI process keeps en_core_web_sm loaded on 127.0.0.1:8737. The hook starts it on first use and reuses it after that. It exits after 4 hours without requests.
• Commit hook client. It sends only the staged Markdown files to the server and prints the warnings. It uses only the standard library and starts in under 0.1 s.
• Fail open. If the server is down, the hook starts it and skips this commit. If the server takes longer than 300 ms, the hook skips. Either way it prints nothing.
• Output for Claude. One warning per line as file:line:col rule-id message, or JSON with --format json.

Install

Add it to the repo's dev dependencies, so the hook finds it in .venv:

uv add --dev lepisma
cp /path/to/lepisma/lepisma.toml .   # optional; every key has a default

The spaCy model

spaCy models are not on PyPI, so en_core_web_sm 3.8.0 is not a dependency. On first use, check, stats, measure and the server download the wheel once (~13 MB) and check its SHA-256. They unpack it to ~/.cache/lepisma/models/, outside any virtualenv, so every uvx run and venv shares one copy. This needs no pip. The hook client never downloads; it skips commits while the server starts.

Offline, install the model into the environment instead:

uv pip install https://github.com/explosion/spacy-models/releases/download/en_core_web_sm-3.8.0/en_core_web_sm-3.8.0-py3-none-any.whl

Or set LEPISMA_MODEL_WHEEL to a local copy (or mirror URL) of that wheel.

With madoqua (the main path)

Add a check step that wakes on staged Markdown. madoqua appends the matched files:

[tool.madoqua]
extend_check = [
  { name = "lepisma", cmd = "lepisma hook", on = ["*.md", "*.markdown"], timeout_s = 5 },
]

Gap: madoqua prints a step's output only when the step fails, and lepisma hook always exits 0. So the warnings stay hidden until madoqua gets a warn-only step mode that prints output without blocking (madoqua#19).

Without madoqua

lepisma install-hook   # adds one warn-only line to the pre-commit hook

install-hook follows core.hooksPath. It puts its line right after the shebang, so it runs even when the rest of the hook ends in exec.

Commands

The hook replaces a server whose code differs from its own. It compares a hash of the package source, so upgrades and local edits take effect. The commit that finds the mismatch is skipped.

Environment variables:

• LEPISMA_VERBOSE=1 prints why the hook skipped.
• LEPISMA_DISABLE=1 turns the hook off.
• LEPISMA_PORT and LEPISMA_TIMEOUT_MS override the config.
• LEPISMA_MODEL_WHEEL is a path or URL to fetch the spaCy model wheel from.

The server log is in ~/.cache/lepisma/server.log.

Rules

Details:

• All rules skip code blocks, inline code, tables, front matter, HTML and link targets. List items that hold only an identifier, like - max_retries, are skipped too.

• Headings get R3 only.

• R2 ignores runs made only of proper nouns, like "GitHub Actions CI". It also ignores runs with more than one proper noun (max_proper_nouns), like "Claude Code conversation logs". Inline code breaks a run, and a hyphenated word like "event-store" counts as one noun. The threshold is 4, not 3: at 3 it flagged plain technical terms like "Unix domain socket" in real docs. At 5 it would miss every true stack the rollout found. The tagger often calls a verb a noun, so R2 drops these from a run before it counts:

  • a verb that opens a list item, sentence or labelled line: "Test line number accuracy", "Purpose: Validates crossword grid structure";
  • a plural before another noun, which ends a subject: "a header toggle pins light/dark", "Claude Code loads ancestor files";
  • a plural verb that the parser made the root of a verbless sentence, like "resets" in "The progress bar resets after a logout".

  The verb test uses the WordNet verb list in spaCy's lemmatizer.

• R3 matches inflections, so "leveraging" counts as "leverage". The default list: comprehensive, robust, seamless, seamlessly, leverage, utilize, delve, crucial, streamline, ensure, facilitate, "in order to", "it is important to note", successfully, "solid foundation". "successfully" counts only right before a verb: "successfully implemented", not "runs successfully". Words in ok_at_item_start (default: ensure) are fine as the first word of a list item or checklist line, as in "- Ensure the build passes". "essential" is off the list. In real docs it mostly meant just that ("essential information").
• R4 counts nouns that end in -tion, -sion, -ment, -ance, -ence or -ity. A stoplist removes concrete words like "function", "document" and "instance". A weak verb is flagged only when its noun comes from a verb, as "placement" comes from "place". "fraction" and "flexibility" have no verb, so nothing is hidden. For "be" and "have", the noun must also take "of" and not be counted. So "is the implementation of" is flagged, but "is one placement of" is not. "provide", "give" and "offer" are skipped when they hand something over. That means a recipient ("provides guidance to Claude Code") or a named deliverable ("provide image descriptions").

Measuring whole docs

lepisma measure reports how hard a set of docs is to read, and where the hardest parts are. It never edits a doc.

uv add --dev "lepisma[measure]"
uv run lepisma measure docs/ --out stats/

It writes four files:

• sentences.parquet: one row per sentence, with file, line, column, section and source text. It counts words, passives, commas, parentheses, dashes, nominalizations and habit words. It also gives mean dependency distance, main verb position and the longest noun run.
• sections.parquet and files.parquet: sentence length as mean, median, p90 and max, and the share of sentences over 25 and 35 words. Readability as Flesch reading ease, Flesch-Kincaid grade, Gunning Fog and LIX. Part-of-speech shares and the noun-to-verb ratio. Nominalizations per 100 words, repeated 5-grams, and habit words per 1,000 words.
• report.md: medians and p90s, the 15 hardest files and sections, the 30 hardest sentences, and which metrics spread enough to make good lint thresholds.

It uses the same parser as the linter, and the R2 to R4 definitions of noun runs, nominalizations and habit words. Headings only name sections. List items under 4 words are skipped. TextDescriptives computes readability, dependency distance, part-of-speech shares and repetition.

As a library

A docs server can load the model once and measure pages on request:

from lepisma.measure import Measurer
from lepisma.measure_report import render

measurer = Measurer()  # loads spaCy once; reuse it
result = measurer.measure({"guide.md": text})  # {path: markdown}
result.files.row(0, named=True)  # dict of file metrics
result.sentences.sort("words", descending=True).head(5)
render(result, min_words=100)  # the report as Markdown

result.sentences, .sections and .files are Polars data frames.

Configuration

Put one lepisma.toml at the repo root. The sample in this repo lists every key with its default.

To turn rules off inside a document:

<!-- lepisma: disable R2 -->        off until enable or end of file
<!-- lepisma: enable R2 -->
<!-- lepisma: disable-next R1 R3 --> off for the next block only
<!-- lepisma: disable -->           all rules

Rules can be named by ID (R2) or by name (noun-stack).

Feedback loop with Claude

Add this to the CLAUDE.md of a repo that uses the hook:

When a commit prints lepisma warnings, rewrite the flagged prose and commit again. Split long sentences, turn noun stacks and nominalizations into verbs, and replace habit words with plain ones. Use <!-- lepisma: disable-next Rn --> only where a warning is wrong, and say why.

For a whole document, run lepisma check --format json doc.md, give Claude the result, and ask for a rewrite. The prose-rewrite skill in .claude/skills/ does this loop. Then check the result with people, not just with the linter.

Measuring success

• Density. Warnings per 1,000 words before and after a rewrite: lepisma stats before/ after/.
• Human rating. A quick 1 to 5 readability score on the test set.
• Noise. How often people disable each rule. Remove the noisy ones.

The baseline test set lives in corpus/:

• bad/ and good/ hold synthetic docs that read badly and well. tests/test_corpus.py checks that bad docs score far worse than good ones.
• toolbox/ holds the real docs of the aesop tools (gerenuk, madoqua, biston, zorilla, coati, ty-find). They are unlabeled. The test checks that R2 to R4 stay under 1 per 1,000 words there, which catches rules that start flagging normal prose. scripts/sync-toolbox-corpus.sh refreshes the copy.

Swap in 10 to 20 real hard-to-read docs from your team for bad/ before tuning further.

Current numbers (warnings per 1,000 words):

Roadmap

1. Baseline test set (placeholders; swap in real docs)
2. Four starter rules
3. Commit hook in warn-only mode
4. Feedback loop: rewrite with Claude, then ask people whether the result reads better.
5. Expand: try passive voice per paragraph, late main verb, deep nesting, too many parentheses, undefined acronyms, repeated openings, summary filler and Flesch score. Add an optional LLM judge in CI.
6. Port the useful rules to Rust (harper-core and Weir) if speed or distribution becomes a problem.

Development

uv sync
uv run madoqua install
uv run poe check

Releasing

Pushing a vX.Y.Z tag runs .github/workflows/release.yml. It builds, runs twine check, publishes to PyPI by trusted publishing and creates a GitHub release.

1. Bump version in pyproject.toml and commit.
2. git tag vX.Y.Z (the same version) and git push origin vX.Y.Z.