Writing Style Checker

A tool that detects common writing issues: weasel words, passive voice, duplicate words, long sentences, nominalizations, hedging language, filler adverbs, and AI tells. Available as a web editor, HTTP API, MCP server, CLI tool, and GitHub Action.

Live: wsc.theserverless.dev

Features

Web Editor - Real-time highlighting with inline fix buttons for all 8 detectors
HTTP API - POST text with optional config, get structured JSON results
MCP Server (Remote) - Connect AI assistants via Streamable HTTP transport
MCP Server (Local) - Stdio-based server via wsc-mcp on npm
CLI - Check files from the command line via wsc-cli
GitHub Action - Run checks in CI with ::warning annotations
Configurable - Customize detectors with .wscrc.json files

Detection Rules

Detector	Items	Description
Weasel Words	95 words/phrases	Vague terms like "very", "basically", "arguably", "numerous"
Passive Voice	262 irregular verbs	Auxiliary verbs + past participles (regular `-ed` + irregular)
Duplicate Words	—	Adjacent repeated words across whitespace, case-insensitive
Long Sentences	threshold: 30 words	Sentences exceeding a configurable word count
Nominalizations	230 word pairs	Nouns replaceable with verbs ("utilization" → "use")
Hedging	100 phrases	Phrases that weaken assertions ("I think", "it seems")
Filler Adverbs	140 words	Adverbs adding emphasis without substance ("totally", "utterly")
AI Tells	37 words + 31 phrases	Words/phrases overrepresented in AI-generated text ("delve", "tapestry", "let's dive in")

Word lists sourced from Matt Might's shell scripts and expanded with additional entries. AI tells based on GPTZero corpus analysis and CMU PNAS study.

Configuration

Create a .wscrc.json to customize detectors. All tools (API, MCP, CLI) support it.

{
  "$schema": "https://wsc.theserverless.dev/schema.json",
  "detectors": {
    "weaselWords": {
      "enabled": true,
      "add": ["synergy", "leverage"],
      "remove": ["very"]
    },
    "longSentences": { "maxWords": 25 },
    "adverbs": { "enabled": false }
  }
}

Every field is optional. Missing fields use defaults. JSON Schema provides autocompletion in VS Code.

API Usage

`POST /api/check`

Analyze text for writing style issues. Accepts optional config object.

curl -X POST https://wsc.theserverless.dev/api/check \
  -H "Content-Type: application/json" \
  -d '{"text":"The code was written very quickly."}'

Response:

{
  "summary": {
    "total": 2,
    "weaselWords": 1,
    "passiveVoice": 1,
    "duplicateWords": 0,
    "longSentences": 0,
    "nominalizations": 0,
    "hedging": 0,
    "adverbs": 0
  },
  "issues": {
    "weaselWords": [{ "word": "very", "index": 21, "line": 1, "column": 22, "context": "..." }],
    "passiveVoice": [{ "phrase": "was written", "index": 9, "line": 1, "column": 10, "context": "..." }],
    "duplicateWords": [],
    "longSentences": [],
    "nominalizations": [],
    "hedging": [],
    "adverbs": []
  },
  "meta": { "characterCount": 34, "wordCount": 6, "sentenceCount": 1, "processingTimeMs": 2 }
}

With config:

curl -X POST https://wsc.theserverless.dev/api/check \
  -H "Content-Type: application/json" \
  -d '{"text":"The code was written very quickly.", "config":{"detectors":{"weaselWords":{"enabled":false}}}}'

`GET /api/check`

Returns API documentation as JSON.

`GET /api/detectors`

Returns the list of all 8 detectors with descriptions, configurability, and word counts.

`GET /health`

Runs a smoke test with known text and returns {"status":"healthy"} or 503.

Limits: Max 100,000 characters per request. CORS enabled for all origins.

MCP Server

The Writing Style Checker is available as an MCP server, letting AI assistants check your writing directly.

Tools

Tool	Description
`check_text`	Analyze text for all 8 writing style issues. Accepts optional `config`.
`fix_duplicates`	Remove duplicate adjacent words and return cleaned text
`list_weasel_words`	Return the complete list of weasel words the checker flags
`list_word_lists`	Return info about all detector word lists
`check_file`	(Local only) Read a file from disk and analyze it. Auto-discovers `.wscrc.json`.

Remote MCP Server

Connect any MCP client to the hosted server - no installation required.

{
  "mcpServers": {
    "writing-style-checker": {
      "type": "url",
      "url": "https://wsc.theserverless.dev/mcp"
    }
  }
}

Local MCP Server (stdio)

Install via npm for local usage. Includes check_file for analyzing files on disk with auto-discovery of .wscrc.json.

npx wsc-mcp

Claude Desktop / Claude Code config:

{
  "mcpServers": {
    "writing-style-checker": {
      "command": "npx",
      "args": ["wsc-mcp"]
    }
  }
}

See the wsc-mcp npm page for full documentation.

CLI

Check files from the command line.

# Check all markdown files
npx wsc-cli check "**/*.md"

# Read from stdin
echo "The code was written very quickly." | npx wsc-cli check --stdin

# JSON output for scripting
npx wsc-cli check "**/*.md" --format json

# GitHub Actions annotations
npx wsc-cli check "**/*.md" --format github

# Create a config file
npx wsc-cli init

See the wsc-cli README for full documentation.

GitHub Action

- uses: theserverlessdev/wsc@master
  with:
    files: '**/*.md'
    max-warnings: 20

Input	Default	Description
`files`	`*/.md`	Glob pattern for files to check
`config`	—	Path to `.wscrc.json` config file
`max-warnings`	unlimited	Max warnings before failing
`only-changed`	`false`	Only check files changed in this PR

Privacy

The web editor runs entirely in your browser - text is never sent to any server. The API and MCP endpoints only process text you explicitly send to them.

Project Structure

.
├── src/
│   ├── core/                    # Shared detection engine
│   │   ├── detector.ts          # 8 detection algorithms
│   │   ├── words.ts             # Word/phrase lists (800+ entries)
│   │   ├── config.ts            # Config types, merging, validation
│   │   ├── config-node.ts       # Node-only: file loading, discovery
│   │   ├── analyzer.ts          # Unified analyzeText() entry point
│   │   └── index.ts             # Public API exports
│   ├── docs/                    # Documentation content (Markdown files)
│   ├── mcp/
│   │   └── handler.ts           # MCP JSON-RPC 2.0 handler
│   ├── lib/
│   │   ├── App.svelte           # Main editor page component
│   │   ├── stores/theme.ts      # Theme store (light/dark/system)
│   │   └── components/          # UI components (StatsBar, ConfigPanel, etc.)
│   ├── routes/
│   │   ├── +layout.svelte       # Shared layout (header, nav, footer)
│   │   ├── api/check/+server.ts # HTTP API endpoint
│   │   ├── mcp/+server.ts       # MCP endpoint
│   │   ├── health/+server.ts    # Health check endpoint
│   │   ├── docs/+page.svelte    # Documentation page
│   │   └── words/+page.svelte   # Word library browser
│   └── styles/
│       └── main.scss            # Global styles (light + dark themes)
├── mcp-server/                  # Standalone stdio MCP server (npm: wsc-mcp)
├── cli/                         # CLI tool (npm: wsc-cli)
├── action/                      # GitHub Action (composite)
├── tests/                       # 341 tests across 18 files
├── static/
│   ├── schema.json              # JSON Schema for .wscrc.json
│   ├── llms.txt                 # AI/LLM discovery file
│   └── llms-full.txt            # Detailed LLM context
├── wrangler.toml                # Cloudflare Workers config
└── svelte.config.js             # SvelteKit configuration

Local Development

git clone https://github.com/theserverlessdev/wsc.git
cd wsc
npm install
npm run dev

Visit http://localhost:5173. The API is at /api/check, MCP at /mcp, health at /health.

Commands

Command	Description
`npm run dev`	Start dev server
`npm run build`	Build for production
`npm run check`	Type check with svelte-check
`npm test`	Run all 341 tests
`npm run test:coverage`	Coverage report

Deployment

Deployed as a Cloudflare Worker at wsc.theserverless.dev.

npm run build
npx wrangler deploy

Contributing

See CONTRIBUTING.md for development setup, testing, and pull request guidelines.

For substantial changes, please open an issue first.

Acknowledgements

Matt Might for the original shell scripts
Built with SvelteKit and Svelte 5, deployed on Cloudflare Workers
Logo made with DiffusionBee

License

MIT

Name		Name	Last commit message	Last commit date
Latest commit History 53 Commits
.github/workflows		.github/workflows
action		action
cli		cli
mcp-server		mcp-server
scripts		scripts
src		src
static		static
tests		tests
.gitignore		.gitignore
.npmrc		.npmrc
CLAUDE.md		CLAUDE.md
CONTRIBUTING.md		CONTRIBUTING.md
LICENSE		LICENSE
README.md		README.md
RELEASE-AND-DEPLOYMENT.md		RELEASE-AND-DEPLOYMENT.md
TESTING.md		TESTING.md
_headers		_headers
package-lock.json		package-lock.json
package.json		package.json
svelte.config.js		svelte.config.js
tsconfig.json		tsconfig.json
vite.config.ts		vite.config.ts
vitest.config.ts		vitest.config.ts
wrangler.toml		wrangler.toml

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Writing Style Checker

Features

Detection Rules

Configuration

API Usage

`POST /api/check`

`GET /api/check`

`GET /api/detectors`

`GET /health`

MCP Server

Tools

Remote MCP Server

Local MCP Server (stdio)

CLI

GitHub Action

Privacy

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Writing Style Checker

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GET /api/check

GET /api/detectors

GET /health

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