MCP PHPCS Server

A Model Context Protocol server that brings PHP_CodeSniffer into your AI coding workflow — lint PHP against your coding standard and auto-fix violations, straight from any MCP client.

Implemented in pure PHP with zero Composer dependencies. Drop it into any project or run it standalone — it speaks JSON-RPC 2.0 over stdio and works with Claude Desktop, Claude Code, Cursor, and any other MCP-compatible client.

Tools

Tool	Description
phpcs_check	Runs PHP_CodeSniffer against a file or directory and returns a readable report of violations.
phpcbf_fix	Runs PHP Code Beautifier and Fixer (phpcbf) to automatically fix fixable violations.

Both tools take a single required path (absolute or project-relative file/directory).

Requirements

• PHP 8.1+
• phpcs and phpcbf binaries available (via PHP_CodeSniffer, e.g. a project's vendor/bin or a global install)

Quick start

1. Clone the repository (or copy it into your project):

   git clone https://github.com/larspohlmann/mcp-phpcs-server.git

2. Make the entrypoint executable:

   chmod +x mcp-phpcs-server/bin/mcp-phpcs

3. Register it with your MCP client (see below).

Configuration

Configure via environment variables or config/config.json. Environment variables take precedence.

Variable	config.json key	Description	Default
MCP_PHPCS_PATH	phpcsPath	Path to the phpcs binary	phpcs on PATH
MCP_PHPCBF_PATH	phpcbfPath	Path to the phpcbf binary	phpcbf on PATH
MCP_PHPCS_RULESET	rulesetPath	Path to a coding-standard ruleset	auto-discovered

If no ruleset is provided, the server searches upward from the current working directory for one of phpcs.xml, phpcs.xml.dist, or ruleset.xml.

Client setup

Claude Desktop / Claude Code

Add the server to your MCP config:

{
  "mcpServers": {
    "phpcs": {
      "command": "/absolute/path/to/mcp-phpcs-server/bin/mcp-phpcs",
      "env": {
        "MCP_PHPCS_PATH": "/usr/local/bin/phpcs",
        "MCP_PHPCBF_PATH": "/usr/local/bin/phpcbf",
        "MCP_PHPCS_RULESET": "/path/to/your/phpcs.xml"
      }
    }
  }
}

Then ask your assistant something like "Run phpcs on src/Service/UserService.php and fix what you can."

Example tool call

{
  "name": "phpcs_check",
  "arguments": { "path": "src/Service/UserService.php" }
}

Architecture

The server follows a light Domain-Driven Design layout:

• src/Domain — tool contracts and result value objects
• src/Application — JSON-RPC MCP server and tool registry
• src/Infrastructure — process runner, config, ruleset discovery, tool implementations
• bin/mcp-phpcs — stdio entrypoint

It implements the MCP methods initialize, tools/list, and tools/call.

Notes

• STDOUT carries only JSON-RPC messages; all logs go to STDERR.
• A non-zero exit code from phpcs means violations were found — it is reported as findings, not treated as a fatal error.

License

MIT