Add CLAUDE.md with project guidance and usage instructions

- Introduced `CLAUDE.md` to provide comprehensive project overview and developer guidance.
- Documented testing commands, development tools, architecture details, and key components.
- Included notes on protocol implementation, configuration, and code standards for better clarity.

Author: klapaudius

CLAUDE.md

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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is a Symfony bundle that enables developers to seamlessly add a Model Context Protocol (MCP) server to their Symfony applications. The main goal is to provide a production-ready implementation following the official MCP specifications at https://modelcontextprotocol.io/specification/2025-03-26.
+
+The bundle allows Symfony applications to expose tools and resources that can be consumed by Large Language Models (LLMs) through secure transport protocols (SSE and StreamableHTTP), avoiding the security risks of STDIO transport in enterprise environments.
+
+## Commands
+
+### Testing
+```bash
+# Run all tests
+vendor/bin/phpunit
+
+# Run a specific test file
+vendor/bin/phpunit tests/path/to/TestFile.php
+
+# Generate code coverage
+vendor/bin/phpunit --coverage-html build/coverage
+
+# Run PHPStan static analysis
+vendor/bin/phpstan analyse
+```
+
+### Development Tools
+```bash
+# Create a new MCP tool
+php bin/console make:mcp-tool MyCustomTool
+
+# Test a specific MCP tool
+php bin/console mcp:test-tool MyCustomTool
+
+# Test tool with specific input
+php bin/console mcp:test-tool MyCustomTool --input='{"param":"value"}'
+
+# List all available tools
+php bin/console mcp:test-tool --list
+```
+
+### MCP Inspector
+```bash
+# Run the MCP Inspector for visual testing
+npx @modelcontextprotocol/inspector node build/index.js
+```
+
+## Architecture Overview
+
+### Package Structure
+This is a Symfony bundle that implements the Model Context Protocol (MCP) server. It provides:
+
+- **Dual Transport Support**: Both SSE (Server-Sent Events) and StreamableHTTP protocols
+- **Tool System**: Extensible framework for creating MCP tools that LLMs can invoke
+- **Resource System**: Management of resources that can be exposed to LLM clients
+- **Progress Notifications**: Real-time progress updates for long-running operations
+
+### Key Components
+
+#### Transport Layer
+- **SSE Transport**: Uses Server-Sent Events with a pub/sub pattern via adapters (Cache or Redis)
+- **StreamableHTTP Transport**: Direct HTTP-based communication supporting both streaming and non-streaming responses
+- **Adapter System**: Abstraction layer allowing different message brokers (Cache, Redis)
+
+#### Tool System
+- **BaseToolInterface**: Core interface for all tools (deprecated in favor of StreamableToolInterface)
+- **StreamableToolInterface**: Modern interface supporting progress notifications
+- **ToolResultInterface**: Abstraction for different result types (Text, Image, Audio, Resource)
+- **ProgressNotifier**: System for sending real-time progress updates during tool execution
+
+#### Request Handlers
+- Located in `src/Server/Request/`: Handle different MCP protocol methods
+- Each handler implements specific MCP operations (initialize, tools/list, tools/call, etc.)
+
+#### Protocol Implementation
+- **MCPProtocol**: Core protocol implementation handling request/response flow
+- **RequestHandler/NotificationHandler**: Process different message types
+- **MCPServer**: Main server orchestrating all components
+
+### Configuration
+- Main config: `config/packages/klp_mcp_server.yaml`
+- Tools and resources are registered in configuration
+- Supports multiple adapters for SSE transport
+
+## Important Notes
+
+- **Cannot use** `symfony server:start` - requires proper web server (Nginx/Apache + PHP-FPM) for concurrent connections
+- Tools should implement `StreamableToolInterface` for modern features
+- Progress notifications only work with streaming tools (`isStreaming()` returns true)
+- All types should use `string|null` syntax instead of `?string` (null at the end)
+- Follow PSR-12 coding standards and include PHPDoc for all public methods