Not Ai

A source-grounded Agent Skill for clear, specific, voice-preserving prose.

It edits the paragraph's purpose, structure, and voice.
It does not disguise authorship.

Not Ai is not a detector-bypass tool. The goal is good writing, by human standards, for human readers.

Install in one command

npx skills add udaysharmadev/Not-Ai

Works with Claude Code, Codex, Antigravity, Cursor, GitHub Copilot, Windsurf, Gemini, and 20+ other agents.

Why it's different

Not Ai first protects facts, claims, citations, terminology, and the writer's actual position. It then edits paragraph purpose, information order, agency, specificity, rhythm, and register. A deterministic gate supports editorial review without pretending to determine authorship or writing quality.

Star History

How it works

Not Ai has two layers: an editorial contract executed by the host agent, and a dependency-free Python gate that provides deterministic checks. It is not a text-generation model, an authorship classifier, or a detector bypasser.

flowchart LR
    I["Input<br/>text, notes, constraints"] --> C["Writing contract<br/>purpose, audience, genre"]
    C --> L["Source ledger<br/>facts, claims, voice, protected literals"]
    L --> M{"Intervention mode"}
    M -->|"notes"| D["Detailed draft"]
    M -->|"passage"| R["Full rewrite"]
    M -->|"explicit request"| P["Preserve or diagnose"]
    D --> O["Candidate output"]
    R --> O
    P --> O

    subgraph Runtime["Host agent and canonical skill"]
        C
        L
        M
        D
        R
        P
    end

    O --> G["tools/gate.py<br/>evaluate()"]
    Policy["policy.py<br/>9 genre profiles"] --> G
    G -->|"hard failure"| X["empty output or missing protected literal"]
    G -->|"advisory findings"| Q["editorial review"]
    Q --> O
    G -->|"pass"| F["Deliverable"]

    B["benchmark.py<br/>fixtures, metadata, preservation checks"] --> T["Regression evidence"]
    S["sync_skill.py"] --> K["Canonical skill equals local copy"]

    classDef input fill:#0f172a,stroke:#38bdf8,color:#f8fafc,stroke-width:2px
    classDef runtime fill:#172554,stroke:#60a5fa,color:#eff6ff,stroke-width:2px
    classDef gate fill:#3f1d2e,stroke:#fb7185,color:#fff1f2,stroke-width:2px
    classDef evidence fill:#153a32,stroke:#34d399,color:#ecfdf5,stroke-width:2px
    class I,O,F input
    class C,L,M,D,R,P runtime
    class G,X,Q gate
    class B,T,S,K,Policy evidence

For a high-resolution, interactive version of this architecture, open the technical pipeline diagram.

1. Editorial contract and source model

The host agent reads plugins/not-ai/skills/not-ai/SKILL.md. The skill builds a writing contract with purpose, audience, genre, register, and protected content. It then creates a source ledger that keeps facts, claims, quotations, citations, terminology, formatting constraints, and voice evidence separate from unsupported gaps.

The mode is selected from the input shape, not an arbitrary speed setting: notes produce a detailed draft from supplied material, while a supplied passage receives a full rewrite. preserve, diagnose, and voice-match remain explicit opt-in modes. Missing information becomes a bracketed prompt rather than a fabricated detail.

2. Deterministic pre-output gate

plugins/not-ai/tools/gate.py accepts a file or standard input and calls not_ai_core.gate.evaluate(). The repository wrapper at scripts/gate.py exposes the same tool from the project root. The gate uses the nine profiles in policy.py: linkedin, personal, email, social, fiction, readme, technical, student, and academic.

It fails only for empty output and explicitly missing --protect literals. Typography, vocabulary tiers, templated transitions, participial openers, sentence openings, rhythm, and choppy runs are advisory findings. The gate does not claim factual fidelity, semantic equivalence, authorship, or writing quality. The skill separately requires a final scan that removes em dashes from newly authored prose.

3. Regression and packaging checks

scripts/benchmark.py evaluates human-provided original and rewritten pairs. It reports token-overlap proxy, structural delta, readability delta, word-count change, protected-literal preservation, and the expected action from fixture metadata. These are reproducible diagnostics, not claims that a rewrite is good or semantically identical.

The plugin ships its own gate implementation. scripts/sync_skill.py verifies that .claude/skills/not-ai.md is byte-identical to the canonical plugin skill, and the unit suite exercises the gate, benchmark fixtures, package layout, and sync check.

Why this exists

Word swapping cannot fix unclear purpose, generic claims, weak information order, or a missing point of view. Not Ai works at those levels while treating the source as a constraint rather than raw material to embellish.

A 2025 PNAS study (Reinhert et al.) measured 66 morphosyntactic features across 17,905 texts. The differences were structural, not just vocabulary:

Pattern	LLM rate vs. human
Present participial clause openers	224% to 527% of human rate
Nominalization density (`-tion`, `-ment`, `-ness`)	145% to 214% of human rate
Past participial clauses	150% to 307% of human rate
Phrasal co-ordination	144% to 194% of human rate
Contractions (conversational)	measurably below human rate
Hedging phrases (`probably`, `I think`)	50 to 67% of human rate
Tier 1 vocabulary (`camaraderie`, `palpable`, `tapestry`)	84 to 171x human rate

The research is useful as editorial evidence, not as a recipe for manufacturing a statistical profile. A feature that is common in model output may still be the right choice for a particular author, genre, or sentence.

Pre-output validation

The gate blocks empty output and explicitly missing protected text. Typography, vocabulary, openings, rhythm, participial openers, and contractions are review findings by default. An ASCII-only punctuation rule is available when a writer or publication actually requires that house style.

python3 scripts/gate.py draft.txt --genre linkedin
python3 plugins/not-ai/tools/gate.py draft.txt --genre academic --protect "p = 0.03" --json
python3 scripts/gate.py draft.txt --genre readme --ascii-punctuation

Valid profiles: linkedin, personal, email, social, fiction, readme, technical, student, and academic. An already-natural passage may validly need no rewrite.

Nine genre profiles

mindmap
  root((Not Ai))
    LinkedIn Post
      Hook opener
      Contractions
      Short paragraphs
    Personal Essay
      First person
      Hedges
      Uneven lengths
    Academic Abstract
      Keep passive
      Keep nominalization
      Third person
    Student Report
      Evidence first
      Natural formality
      No forced slang
    Technical Docs
      Imperative
      Precision
      No marketing
    Professional Email
      Match tone
      Direct purpose first
    GitHub README
      Factual
      No marketing opener
    Social Media
      Fragments normal
      Very short
    Fiction/Narrative
      Show not tell
      Sensory detail

Genre detection runs first. Every profile still obeys the same fidelity and no-invention rules.

Vocabulary review

graph LR
    T1["Corpus pattern\nclusters of repeatedly favored words"]
    T2["Reader question\ndoes the phrase carry a precise claim?"]
    T3["Source check\nis evidence or a concrete detail available?"]
    T4["Editorial choice\nkeep, clarify, cut, or ask the writer"]

    T1 --> T2
    T2 --> T3
    T3 --> T4

    style T1 fill:#7f1d1d,color:#fff
    style T2 fill:#78350f,color:#fff
    style T3 fill:#713f12,color:#fff
    style T4 fill:#064e3b,color:#fff

A flagged word can be correct, characteristic, or required by the field. The review asks what the wording does for this reader; it does not infer authorship.

Install

Method 1: skills.sh (recommended, works on all agents)

npx skills add udaysharmadev/Not-Ai

Works with Claude Code, Cursor, Codex, GitHub Copilot, Windsurf, Gemini, Cline, AMP, and 20+ more agents. Installs to .agents/skills/ automatically.

Method 2: Claude Marketplace (for Claude.ai)

Open Claude.ai → click your profile → Plugins → Directory
Click + Add marketplace (top right of the Directory modal)

Paste the URL:

https://github.com/udaysharmadev/Not-Ai

Toggle "Sync automatically" ON → click Sync

Once installed, type /not-ai in any Claude conversation to activate. Syncs automatically when the repo updates.

Method 2: Claude Skills (ZIP upload) (for Claude.ai Skills)

Claude.ai also supports uploading skills directly via ZIP:

Go to claude.ai → Settings (bottom-left) → Customize → Skills
Click Add → Upload skill

Download the ZIP from GitHub:

https://github.com/udaysharmadev/Not-Ai/archive/refs/heads/main.zip

Drag and drop the ZIP file into the upload dialog

File requirements shown by Claude: .md file must contain skill name and description formatted in YAML · .zip or .skill file must include a SKILL.md file

After upload, the skill goes through a brief security scan (usually 1 to 2 minutes) before it's ready to use.

Method 3: Codex Marketplace (for OpenAI Codex)

Not Ai is available as a Personal plugin in Codex, added the same way as Claude via the marketplace URL.

Open Codex → Plugins → click the + to add a marketplace

Paste the GitHub URL:

https://github.com/udaysharmadev/Not-Ai

Confirm and sync

Once installed it shows up under Personal plugins as Not Ai · not-ai, "Prose that reads like a person wrote it..."

Method 4: Claude Code (terminal)

claude plugin marketplace add udaysharmadev/Not-Ai && claude plugin install not-ai@not-ai

Method 5: ZIP file, manual copy (no git, works everywhere)

Download: github.com/udaysharmadev/Not-Ai → Code → Download ZIP
Extract and copy:

# Claude Code (reads skills at startup)
cp path/to/Not-Ai/plugins/not-ai/skills/not-ai/SKILL.md ~/.claude/skills/not-ai/SKILL.md

# Claude Desktop (Project Knowledge)
# Upload plugins/not-ai/skills/not-ai/SKILL.md to your Project Knowledge
# Then invoke: "Using the Not Ai skill, rewrite this:"

Method 6: Other agents (Cursor, Windsurf, Aider, Gemini CLI)

git clone https://github.com/udaysharmadev/Not-Ai /tmp/not-ai
cp /tmp/not-ai/plugins/not-ai/skills/not-ai/SKILL.md ~/.claude/skills/not-ai/SKILL.md

Works with any agent that reads context files at startup.

Usage

/not-ai [paste text]                    fast, source-grounded rewrite
/not-ai --mode diagnose [text]          report only, no changes
/not-ai --mode preserve [text]          fewest useful edits
/not-ai --mode voice-match [text]       match supplied author samples
/not-ai write [brief]                   draft only from supplied material

Measurement scripts

python3 scripts/analyze_structure.py input.txt   # structural measurements
python3 scripts/repetition.py input.txt          # phrase and pattern repetition
python3 scripts/metrics.py input.txt             # readability, density, stance
python3 scripts/measure.py input.txt             # all three in one pass
python3 scripts/gate.py input.txt --genre linkedin # portable pre-output gate

Repository structure

Not-Ai/
├── plugins/not-ai/
│   ├── .claude-plugin/marketplace.json     Claude marketplace config
│   ├── .codex-plugin/plugin.json           Codex plugin config
│   ├── skills/not-ai/
│       ├── SKILL.md                        Canonical skill instructions
│       └── reference/
│           ├── profile.md
│           ├── vocabulary.md
│           ├── mechanical-tells.md
│           ├── why-word-swapping-fails.md
│           └── research-sources.md
│   └── tools/
│       ├── gate.py                       Portable, genre-aware validation CLI
│       └── not_ai_core/                  Shared deterministic gate logic
│
├── assets/                                 Screenshots and logo
├── scripts/                                Python measurement tools
├── examples/                               6 worked before/after pairs
│   ├── linkedin-post/
│   ├── personal-essay/
│   ├── academic-abstract/
│   ├── technical-passage/
│   ├── gen-ai-article/
│   └── already-natural/
├── benchmarks/                             Evaluation framework
├── tests/                                  Gate, wrapper, and payload regression tests
├── README.md
└── LICENSE

Research basis

Study	Finding used
Reinhart et al., PNAS 2025	Grammatical and rhetorical differences across model variants and genres
Jiang & Hyland, 2025	Reader engagement in student and ChatGPT argumentative essays
Wikipedia: Signs of AI Writing	A changing, context-specific field guide whose signs are not proof
Kobak et al., Science Advances 2025	Corpus-level excess vocabulary in biomedical abstracts
Liang et al., Patterns 2023	Detector false positives affecting non-native English writers

What Not Ai will not do

Add random typos to seem human
Force slang into the wrong register
Invent memories, emotions, or opinions
Fabricate facts, citations, or statistics
Optimize for a detector score
Rewrite everything when selective edits are enough
Assert that a given text was machine-written

Contributing

Most useful contributions:

Genre profiles for contexts not yet covered
Before/after benchmark pairs in any genre
Consented source packs with purpose, audience, and protected facts
Blinded human reviews of fidelity, clarity, restraint, and reader usefulness
Better parsers only when an annotated evaluation shows that they improve useful editorial review

The plugin skill is canonical. After editing it, update the local Claude copy with python3 scripts/sync_skill.py; CI checks that the two copies match.

License

MIT. See LICENSE.

"Remove the machine's generic habits. Preserve the person's voice."

Navigation Menu

Repository files navigation

Not Ai

Install in one command

Why it's different

Star History

How it works

1. Editorial contract and source model

2. Deterministic pre-output gate

3. Regression and packaging checks

Why this exists

Pre-output validation

Nine genre profiles

Vocabulary review

Install

Method 1: skills.sh (recommended, works on all agents)

Method 2: Claude Marketplace (for Claude.ai)

Method 2: Claude Skills (ZIP upload) (for Claude.ai Skills)

Method 3: Codex Marketplace (for OpenAI Codex)

Method 4: Claude Code (terminal)

Method 5: ZIP file, manual copy (no git, works everywhere)

Method 6: Other agents (Cursor, Windsurf, Aider, Gemini CLI)

Usage

Measurement scripts

Repository structure

Research basis

What Not Ai will not do

Contributing

License

About

Releases

Packages

Contributors

Languages

Name		Name	Last commit message	Last commit date
.agents/plugins		.agents/plugins
.claude-plugin		.claude-plugin
.claude/skills		.claude/skills
.github/workflows		.github/workflows
assets		assets
benchmarks		benchmarks
docs		docs
examples		examples
plugins/not-ai		plugins/not-ai
scripts		scripts
tests		tests
.gitignore		.gitignore
LICENSE		LICENSE
README.md		README.md
SESSION_FAILURES.md		SESSION_FAILURES.md
package-lock.json		package-lock.json
pyproject.toml		pyproject.toml

Latest commit

History

Folders and files

Repository files navigation

Not Ai

Install in one command

Why it's different

Star History

How it works

1. Editorial contract and source model

2. Deterministic pre-output gate

3. Regression and packaging checks

Why this exists

Pre-output validation

Nine genre profiles

Vocabulary review

Install

Method 1: skills.sh (recommended, works on all agents)

Method 2: Claude Marketplace (for Claude.ai)

Method 2: Claude Skills (ZIP upload) (for Claude.ai Skills)

Method 3: Codex Marketplace (for OpenAI Codex)

Method 4: Claude Code (terminal)

Method 5: ZIP file, manual copy (no git, works everywhere)

Method 6: Other agents (Cursor, Windsurf, Aider, Gemini CLI)

Usage

Measurement scripts

Repository structure

Research basis

What Not Ai will not do

Contributing

License

About

Topics

Resources

Stars

Watchers

Forks

Releases

Packages

Contributors

Languages