MCP PHP SDK

The official PHP SDK for Model Context Protocol (MCP). It provides a framework-agnostic API for implementing MCP servers in PHP.

Important

Currently, we are still in the process of merging Symfony's MCP SDK and PHP-MCP components. Not all code paths are fully tested, complete, or this package may contain duplicate functionality or dead code.

If you want to help us stabilize the SDK, please see the issue tracker.

This project is a collaboration between the PHP Foundation and the Symfony project. It adopts development practices and standards from the Symfony project, including Coding Standards and the Backward Compatibility Promise.

Until the first major release, this SDK is considered experimental.

🚧 Roadmap

Features

• Bring back PHP-MCP examples
• Glue handler, registry and reference handlers
• Revive ServerBuilder
• Revive transports
  • Streamable Transport modelcontextprotocol#7
  • Http/SSE-based Transport modelcontextprotocol#8
• Support pagination
• Support Schema validation
• Support multiple versions of the MCP specification modelcontextprotocol#14
• (Re-)Implement missing Notification & Request Handlers modelcontextprotocol#9

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Examples working

• 01-discovery-stdio-calculator
• 02-discovery-http-userprofile
• 03-manual-registration-stdio
• 04-combined-registration-http
• 05-stdio-env-variables
• 06-custom-dependencies-stdio
• 07-complex-tool-schema-http
• 08-schema-showcase-streamable
• 09-standalone-cli

Installation

composer require mcp/sdk

Since this package has no tagged releases yet, it is required to extend your composer.json:

"minimum-stability": "dev",
"prefer-stable": true

⚡ Quick Start: Stdio Server with Discovery

This example demonstrates the most common usage pattern - a stdio server using attribute discovery.

1. Define Your MCP Elements

Create src/CalculatorElements.php:

<?php

namespace App;

use Mcp\Capability\Attribute\McpTool;

class CalculatorElements
{
    #[McpTool(name: 'add_numbers')]
    public function add(int $a, int $b): int
    {
        return $a + $b;
    }
}

2. Create the Server Script

Create mcp-server.php:

#!/usr/bin/env php
<?php

declare(strict_types=1);

require_once __DIR__ . '/vendor/autoload.php';

use Mcp\Server;
use Mcp\Server\Transport\StdioTransport;

Server::make()
    ->withServerInfo('Stdio Calculator', '1.1.0', 'Basic Calculator over STDIO transport.')
    ->withDiscovery(__DIR__, ['.'])
    ->build()
    ->connect(new StdioTransport());

3. Configure Your MCP Client

Add to your client configuration (e.g., mcp.json):

{
    "mcpServers": {
        "php-calculator": {
            "command": "php",
            "args": ["/absolute/path/to/your/mcp-server.php"]
        }
    }
}

4. Test the Server

Your AI assistant can now call:

• add_numbers - Add two integers

Documentation

• SDK documentation
• Model Context Protocol documentation
• Model Context Protocol specification
• Officially supported servers

Examples of MCP Tools that use this SDK

• https://github.com/pronskiy/mcp

Contributing

We are passionate about supporting contributors of all levels of experience and would love to see you get involved in the project. See the contributing guide to get started before you report issues and send pull requests.

Credits

The starting point for this SDK was the PHP-MCP project, initiated by Kyrian Obikwelu. We are grateful for the work done by Kyrian and other contributors to that repository, which created a solid foundation for this SDK.

License

This project is licensed under the MIT License - see the LICENSE file for details.