sepia

Install

npx skillfoxx add skills/sepia

npx skills add nanako0129/sepia --skill sepia -a claude-code -y

tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/nanako0129/sepia.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/sepia/
git -C "$tmp" checkout 06a5233395299ff78558b15568679c2c5c0fe942
mkdir -p .claude/skills
cp -R "$tmp/skills/sepia" .claude/skills/sepia

npx skills add nanako0129/sepia --skill sepia -a cursor -y

tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/nanako0129/sepia.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/sepia/
git -C "$tmp" checkout 06a5233395299ff78558b15568679c2c5c0fe942
mkdir -p .agents/skills
cp -R "$tmp/skills/sepia" .agents/skills/sepia

npx skills add nanako0129/sepia --skill sepia -a github-copilot -y

tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/nanako0129/sepia.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/sepia/
git -C "$tmp" checkout 06a5233395299ff78558b15568679c2c5c0fe942
mkdir -p .github/skills
cp -R "$tmp/skills/sepia" .github/skills/sepia

npx skills add nanako0129/sepia --skill sepia -a codex -y

tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/nanako0129/sepia.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/sepia/
git -C "$tmp" checkout 06a5233395299ff78558b15568679c2c5c0fe942
mkdir -p .agents/skills
cp -R "$tmp/skills/sepia" .agents/skills/sepia

npx skills add nanako0129/sepia --skill sepia -a gemini-cli -y

tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/nanako0129/sepia.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/sepia/
git -C "$tmp" checkout 06a5233395299ff78558b15568679c2c5c0fe942
mkdir -p .agents/skills
cp -R "$tmp/skills/sepia" .agents/skills/sepia

tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/nanako0129/sepia.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/sepia/
git -C "$tmp" checkout 06a5233395299ff78558b15568679c2c5c0fe942
mkdir -p .devin/skills
cp -R "$tmp/skills/sepia" .devin/skills/sepia

npx skills add nanako0129/sepia --skill sepia -a cline -y

tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/nanako0129/sepia.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/sepia/
git -C "$tmp" checkout 06a5233395299ff78558b15568679c2c5c0fe942
mkdir -p .cline/skills
cp -R "$tmp/skills/sepia" .cline/skills/sepia

npx skills add nanako0129/sepia --skill sepia -a roo -y

tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/nanako0129/sepia.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/sepia/
git -C "$tmp" checkout 06a5233395299ff78558b15568679c2c5c0fe942
mkdir -p .roo/skills
cp -R "$tmp/skills/sepia" .roo/skills/sepia

npx skills add nanako0129/sepia --skill sepia -a opencode -y

tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/nanako0129/sepia.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/sepia/
git -C "$tmp" checkout 06a5233395299ff78558b15568679c2c5c0fe942
mkdir -p .agents/skills
cp -R "$tmp/skills/sepia" .agents/skills/sepia

tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/nanako0129/sepia.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/sepia/
git -C "$tmp" checkout 06a5233395299ff78558b15568679c2c5c0fe942
mkdir -p .agents/skills
cp -R "$tmp/skills/sepia" .agents/skills/sepia

tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/nanako0129/sepia.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/sepia/
git -C "$tmp" checkout 06a5233395299ff78558b15568679c2c5c0fe942
mkdir -p .agents/skills
cp -R "$tmp/skills/sepia" .agents/skills/sepia

npx skills add Nanako0129/sepia -g

This is third-party code. Review the repository files before installing.

What it does

The skill turns model-generated text into prose that reads as written by a person. For fiction it works at the level of narrative structure, not just words: it removes the narrator explaining the theme, single-track plots, emotion rendered only as bodily sensation and other tells that give a machine away. Professional text is routed by its venue: release notes, pull request replies, incident postmortems, tickets, technical articles, long-form journalism. Four modes are available: write, review without edits, minimal in-place fix, and full rewrite. The rules draw on research into text generation, with debatable calls marked as editorial assumptions.

Who it is for. For writers, editors, developers and communications people who need text without traces of machine generation.

Example request

Strip the AI tells from this text and keep the author's voice

Limitations

The skill checks the form and structure of a text, not the truth of its facts, and it is explicitly forbidden to invent data. Some professional-text rules are editorial assumptions rather than measured findings, and this is marked in the skill itself. Chinese text loads a separate calibration. The skill works only where the agent supports the Agent Skills standard.

How to disable. Remove the sepia plugin with your agent's own command, for example claude plugin uninstall sepia@sepia, or delete the skill folder from the skills directory.

Security check

• The skill consists only of instructions and reference material and runs no code

README in short

The README explains that ordinary text cleaners edit only words, while sepia works at the level of narrative structure, where AI tells are most visible. For fiction it runs three passes: narrative architecture, discourse flow and surface style, plus a diagnostic rubric and per-model fingerprints. Professional text follows thin per-venue rule files on top of one shared checklist. The skill installs through the Skills CLI, which supports more than 77 agents, and as separate native plugins for Claude Code, Codex, Grok Build, Antigravity and QwenPaw. The full evidence base with links to studies lives in the research folder. MIT licensed.

SKILL.md

---
name: sepia
description: Make AI-generated writing read as human-written, in fiction and in professional prose. Repairs the narrative architecture of fiction and stories (based on StoryScope, arXiv:2604.03136); routes professional text through domain rules for release notes, announcements, PR and issue replies, code-review comments, incident postmortems, tickets, work orders, technical articles, blog posts, and long-form journalism. Four operations - write, review (diagnose AI tells without editing), refactor (minimal in-place edits), recreate (full rewrite). Use when asked to humanize, de-AI, unslop, or strip AI flavor from any text; when writing or revising any of these document types; or whenever output must not read as machine-written.
license: MIT
metadata:
  version: "0.10.0"
---

# Sepia — de-AI writing

This skill combines measured findings with marked editorial heuristics. In fiction, StoryScope's narrative-only classifier reached 93.2% macro-F1, while its Core Only 30-feature XGBoost held-out classifier reached 84.8% macro-F1 (AUPRC .828); the manual rubric is neither classifier. The professional path combines measured studies with editorial heuristics, and its prescriptions are Sepia inferences unless a source explicitly tested the intervention. Route first, then operate. Sepia writes for expert human readers and is tuned to pass no automated AI-text detector.

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