agent-rules

Agent Rules MCP Server lets AI agents fetch coding rules from a GitHub repository on demand, instead of relying on local rule files. It supports multiple communities and rule formats, including Markdown-based rules with or without metadata, plus special extensions like .chatmode.md, .prompt.md and .instructions.md. You can point the MCP client at a GitHub repository, branch and path, and then use tools like get_rules to retrieve rules for specific domains or list_rules to see available options. This enables consistent, centralized rule access for AI coding agents across projects, without embedding the rule files locally.

To use it, configure an MCP client with the agent-rules server, typically via npx as shown in the default configuration. The tools provided by the server include get_rules, which fetches rule content for one or more domains from the configured GitHub path, and list_rules, which enumerates all available rule domains with descriptions. By supplying environment variables such as GITHUB_OWNER, GITHUB_REPO, GITHUB_PATH, and GITHUB_BRANCH, you can customize where the rules are sourced from (your own repo or community collections).

Prerequisites:

• Node.js (v14+ recommended) and npm installed on your system
• Internet access to fetch packages from npm

Step 1: Install Node.js and npm (if not already installed)

• On macOS: visit https://nodejs.org/ and install the LTS version
• On Windows: use the official installer from nodejs.org
• On Linux: follow your distribution's instructions, e.g., sudo apt-get install nodejs npm

Step 2: Verify npm/npx availability

• node -v
• npm -v
• npx -v

Step 3: Use the MCP server via npx (as intended by the repository)

• The default usage is to run:

npx -y agent-rules-mcp@latest

Step 4: Configure environment variables for your rules source

• Provide GITHUB_OWNER, GITHUB_REPO, GITHUB_PATH, and GITHUB_BRANCH to point to your rules
• Example environment block (adjust values as needed):

GITHUB_OWNER=your-username
GITHUB_REPO=your-rules-repo
GITHUB_PATH=your-rules-folder
GITHUB_BRANCH=main

Step 5: Run the MCP client with the configuration shown in the README to start serving rules to your AI agents.

Tips and notes:

• The server is designed to work with both community collections and your own rules repository. If you modify the rules, ensure the GITHUB_PATH points to the correct folder containing .md/.mdc/.chatmode.md/.prompt.md files.
• Supported file formats include .md, .mdc, .chatmode.md, .prompt.md, and .instructions.md. Missing metadata will be auto-extracted from headings and descriptions.
• For large rule sets, consider using list_rules first to understand available domains before fetching specific rules with get_rules.
• If you encounter GitHub access limitations, verify your repository permissions and network access. Creating a personal access token is typically unnecessary for public repos but may be required for private repos.
• The default environment example in the README uses GITHUB_OWNER=4regab, GITHUB_REPO=agent-rules-mcp, GITHUB_PATH=rules, GITHUB_BRANCH=master; adapt these to your setup when using your own repository.
• The MCP client can be extended with additional domains by adding new rule files following the recommended metadata and naming conventions.