Un Default

What Un-Default MCP server does

The Un-Default MCP server lets an AI client inspect written content for language patterns that may encode racist defaults, sexist assumptions, ableist metaphors, or documented dogwhistles. Findings include an explanation of what was detected and, where appropriate, a clearer alternative. The analyzer is intended for copy, documentation, UI strings, and live-page content.

Matching is rule-based and does not require an AI service or user account. Rules are open and can be adjusted for a project. Context still matters: ambiguous or quoted matches are advisory rather than automatically treated as defects.

How it works

Launch the MCP entry point with npx -y anti-default mcp. An MCP-compatible host starts the process over standard input and output, then can call the exposed tools. The same underlying analyzer is also used by the command-line interface and web application.

The available workflow separates detection, correction, and context. An agent can scan content, request safe one-to-one fixes, and provide feedback when a match is intentional or acceptable in context. This makes the Un-Default MCP server suitable for an editing loop in which text is checked again after changes.

Setup and configuration

Add the following server definition to an MCP client configuration:

{
  "mcpServers": {
    "un-default": {
      "command": "npx",
      "args": ["-y", "anti-default", "mcp"]
    }
  }
}

Cursor can use .cursor/mcp.json or its MCP settings. Claude Desktop uses its developer configuration file, while Claude Code can use the repository setup created by init, the marketplace plugin, or claude mcp add. Running npx -y anti-default init can create MCP configuration files along with project skills, hooks, scripts, and an ignore file; existing files are not overwritten.

Tools and capabilities

The MCP tool names are:

• un_default_scan — inspect content and return findings.
• un_default_fix — request safe one-to-one autofixes.
• un_default_feedback — record contextual feedback, including cases marked acceptable.

Outside MCP, the package can scan paths, changed files, and batches of URLs. It can emit JSON or SARIF for automation, create baselines, and honor .undefaultignore entries. The repository also provides a GitHub Action for changed-file checks and a Chrome extension that runs the bundled rules offline.

Limitations and notes

The analyzer is not a substitute for human judgment. Quoted language, ambiguous matches, and intentional usage may remain advisory, and suggestions are not presented as mandatory changes. Safe fixes are limited to supported one-to-one replacements; a scan after fixing may still produce findings that require review.

The MCP process uses the local npm package and its rule set. The provided material does not describe remote MCP transport, authentication, hosted account features, or environment variables required by the MCP command. The former anti-default package and command name remain supported as aliases, while the project is now named Un-Default.