English Français العربية

Ghostchars

Official registry Other

Find and remove invisible Unicode: zero-width, tag smuggling, bidi, homoglyphs. Offline.

Source code Website Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

NPM package ghostchars
Claude Code 
claude mcp add ghostchars -- npx -y ghostchars@1.0.2 mcp
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "ghostchars": {
            "command": "npx",
            "args": [
                "-y",
                "ghostchars@1.0.2",
                "mcp"
            ]
        }
    }
}

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. Ghostchars
  2. What is here
  3. Quick start
  4. How the two engines stay identical
  5. Working on it
  6. Issues
  7. Licence

Ghostchars

Ghostchars finds and removes the characters that hide in text: zero-width spaces, bidi overrides, tag characters, soft hyphens, stray variation selectors, noncharacters, and the typography that reads as machine written. It runs offline. Nothing you clean leaves your machine.

This repository is the engine behind ghostchars.com and the free tools built on it. The same cleaner exists twice, in Python and in TypeScript, and one fixture file proves the two agree on every codepoint.

What is here

pathwhat it is
strip_invisible.pyThe reference engine. Stdlib only, one file. See PYTHON.md.
clean_file.py, style_report.pyDocuments (.docx, .odt, .html) and the style report, on the same engine.
web/src/engine/The TypeScript port. The website, the CLI and the MCP server run this.
cli/ghostchars on npm: a Node CLI, a stdio MCP server, and the agent skill, hook and pre-commit files.
tools/The generators for the Unicode tables and the golden fixtures, and the parity gates.
tests/The Python tests.

Quick start

npx -y ghostchars check --bar text        # the gate: exit 1 if the tree is dirty
pbpaste | npx -y ghostchars clean         # clean the clipboard
./strip_invisible.py --show draft.md      # the reference engine, no install

cli/README.md documents every command, the three bars, ghostchars.json and the agent integrations.

How the two engines stay identical

The Python engine is the specification. tools/gen_golden.py runs it over every fixture and records the findings and the cleaned output for each flag combination in web/src/engine/__fixtures__/golden.json. The TypeScript engine replays that file in its test suite, so a port that disagrees with the reference by one codepoint fails its build. The Unicode property tables the port needs are generated from the same unicodedata snapshot by tools/gen_unicode_tables.py. Two commands fail when anything drifts:

python3 tools/gen_golden.py --check
python3 tools/gen_unicode_tables.py --check

Working on it

Python 3.10 or newer for the reference engine and the tools. Node 22 or newer with pnpm for cli/ and the engine tests under web/. The tree holds its own prose to the text bar with its own CLI: ghostchars.json at the root names the surface and its pins, and npx -y ghostchars check from the root runs it.

The Mac app and the Chrome extension are built on this engine and available at ghostchars.com.

Issues

Bugs and questions about the engine or the CLI go to github.com/ghostchars/ghostchars/issues.

Licence

MIT, with the Unicode licence covering the generated character tables. See LICENSE. The npm package carries its own copy with the notices for what it bundles.

Frequently asked questions

What is Ghostchars?

Find and remove invisible Unicode: zero-width, tag smuggling, bidi, homoglyphs. Offline.

How do I install Ghostchars?

It runs on your machine. In Claude Code: claude mcp add ghostchars -- npx -y ghostchars@1.0.2 mcp. For other clients, paste the JSON configuration from this page into their MCP settings.

Does Ghostchars need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is Ghostchars open source?

Its code is public on GitHub, but the repository does not declare a standard license.

Who maintains Ghostchars?

It is published by ghostchars. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.