🚀 Symfony MCP Server 1.2.0 Release

[klapaudius]

🍾 Symfony MCP Server 1.2.0 is here !

We're excited to announce this release ! It brings significant enhancements to the Model Context Protocol implementation, introducing streaming capabilities and real-time progress notifications that align with the MCP specification 2025-03-26.

🎯 Key Features

Streamable HTTP Transport Support

In addition to Server-Sent Events (SSE), we now support the Streamable HTTP transport protocol. This dual-transport approach allows:

• Flexibility in deployment scenarios
• Better compatibility with various LLM clients
• Seamless fallback options for different environments
• Both transports can be active simultaneously, ensuring backward compatibility

Streaming Tool Support with Progress Notifications

Tools can now provide real-time feedback during long-running operations:

• Progress Tracking: Tools implementing StreamableToolInterface can send progress updates
• Live Updates: Users see real-time progress with current/total values and descriptive messages
• Error Resilience: Operations continue even if progress notifications fail
• MCP Compliant: Fully implements the notifications/progress specification

Structured Tool Results

A new result system provides type-safe responses:

• TextToolResult - For text-based responses
• ImageToolResult - For image data with MIME types
• AudioToolResult - For audio data with MIME types
• ResourceToolResult - For referencing external resources
• CollectionToolResult - For combining multiple tool results into a single response

🔧 Migration Guide

Tool Interface Updates

The ToolInterface is now deprecated in favor of StreamableToolInterface:

// Old approach (deprecated)
class MyTool implements ToolInterface {
    public function execute(array $args = []): string {
        return "Result";
    }
}

// New approach
class MyTool implements StreamableToolInterface {
    
    public function execute(array $args = []): ToolResultInterface {
        return new TextToolResult("Lorem Ipsum dolor sit amet [...]");
    }
    
    public function isStreaming(): bool {
        return false; // disable streaming support
    }
    
    public function setProgressNotifier(ProgressNotifierInterface $progressNotifier): void {
        // Nothing here is needed since it is a not streaming tool
    }
}

Configuration Changes

Update your configuration to use the new plural form:

# Old (deprecated but still supported)
klp_mcp_server:
    server_provider: 'sse'

# New
klp_mcp_server:
    server_providers: ['sse', 'streamable_http']

📈 Performance & Developer Experience

Enhanced Testing Tools

• mcp:test-tool command now supports progress visualization
• Real-time feedback during tool development
• Better debugging capabilities for streaming operations

Example: Streaming Data Tool

class StreamingDataTool implements StreamableToolInterface {
    private ?ProgressNotifierInterface $progressNotifier = null;

    public function execute(array $args = []): ToolResultInterface {
        $totalItems = 10;
        
        for ($i = 1; $i <= $totalItems; $i++) {
            // Process item...
            
            // Send progress update
            $this->progressNotifier?->notify(
                progress: $i,
                total: $totalItems,
                message: "Processing item $i of $totalItems"
            );
            
            usleep(500000); // Simulate work
        }
        
        return new TextToolResult("Processed $totalItems items successfully!");
    }

    public function setProgressNotifier(ProgressNotifierInterface $progressNotifier): void {
        $this->progressNotifier = $progressNotifier;
    }
}

🚦 Backward Compatibility

This release maintains full backward compatibility:

• Existing tools continue to work without modification
• Deprecation warnings guide the migration process
• Both old and new configuration formats are supported
• Clients using older protocol versions can still connect

📚 Documentation

We've significantly expanded our documentation:

• Comprehensive streaming tool implementation guide
• Progress notification best practices
• Updated examples demonstrating all new features
• Migration paths clearly documented

📦 Installation

Update your composer dependency:

composer require klapaudius/symfony-mcp-server:^1.2

📋 Full Changelog

For a complete list of changes : 1.1.0...1.2.0.

🔗 Resources

• Documentation
• Building Tools Guide
• MCP Specification

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Happy coding! 🎉

If you encounter any issues or have suggestions, please open an issue on our GitHub repository.