cpp-mcp/IMPLEMENTATION_SUMMARY.md

# MCP Framework Implementation Summary

## Overview

This implementation provides a complete C++ framework for the Model Context Protocol (MCP), designed for easy extension to agent workflows. The framework follows a modular architecture with clear separation of concerns, making it straightforward to customize and extend.

## Directory Structure

```
/MCP/
├── mcp_protocol.h/cpp      - Core protocol definitions
├── mcp_server.h/cpp        - Server implementation
├── mcp_client.h/cpp        - Client implementation
├── mcp_resource.h          - Resource definitions
├── mcp_tools.h/cpp         - Tool and workflow system implementation
├── mcp_workflow_resource.h/cpp - Workflow resource implementation
├── mcp_agent_resource.cpp  - Agent resource implementation
├── CMakeLists.txt          - Build system configuration
├── README.md               - Project documentation
└── examples/               - Example implementations
    ├── custom_agent.h/cpp  - Custom agent implementations
    ├── server_example.cpp  - Server example
    ├── client_example.cpp  - Client example
    └── host_example.cpp    - Host example
```

## Key Components

### 1. Core Protocol (mcp_protocol.h/cpp)

Defines the fundamental structures of the MCP protocol:

- `request` and `response` structures
- Error handling with `error_code` and `mcp_exception`
- Resource interface (`resource` base class)
- Tool definition structure (`tool`)

### 2. Server (mcp_server.h/cpp)

Provides an HTTP server that exposes MCP resources and tools:

- Register resources at specific paths
- Register tools with handlers
- Process incoming HTTP requests
- Route requests to appropriate resources

### 3. Client (mcp_client.h/cpp)

Implements a client for connecting to MCP servers:

- Connect to servers
- Discover available resources and tools
- Make requests to resources
- Call tools with parameters

### 4. Resource System (mcp_resource.h)

Defines various resource types:

- `file_resource`: Access to the file system
- `directory_resource`: Directory operations
- `api_resource`: Custom API endpoints
- `image_resource`: Image handling

### 5. Tool System (mcp_tools.h/cpp) - New Implementation

Provides tool-related functionality:

- `tool_registry`: Central registry for tools
- `tool_builder`: Fluent API for tool creation
- `workflow_step`: Single step in a workflow
- `workflow`: Define and execute sequences of tool calls
- `agent`: Base class for agents

### 6. Workflow Resources (mcp_workflow_resource.h/cpp, mcp_agent_resource.cpp) - New Implementation

Implements resources for workflow and agent management:

- `workflow_resource`: Create, manage, and execute workflows
- `agent_resource`: Register and manage agents

## Usage Examples

### 1. Creating a Server

```cpp
// Create and configure the server
mcp::server server("localhost", 8080);
server.set_name("Example Server");

// Register a tool
mcp::tool time_tool = mcp::tool_builder("get_time")
    .with_description("Get the current time")
    .build();

server.register_tool(time_tool, get_time_handler);

// Register a resource
auto file_resource = std::make_shared<mcp::file_resource>("./files");
server.register_resource("/files", file_resource);

// Start the server
server.start(true);
```

### 2. Connecting with a Client

```cpp
// Create a client
mcp::client client("localhost", 8080);

// Call a tool
mcp::json result = client.call_tool("get_time");

// Make a request to a resource
mcp::response res = client.get("/files/example.txt");
```

### 3. Creating and Using Workflows

```cpp
// Create a workflow
mcp::workflow workflow("data_processing", "Process data");

// Add steps
workflow.add_tool_call("get_data", {{"source", "database"}});
workflow.add_tool_call("process_data", {{"filter", "recent"}});

// Execute the workflow
mcp::json result = workflow.execute();
```

### 4. Implementing Custom Agents

```cpp
// Create a custom agent
class custom_agent : public mcp::agent {
public:
    explicit custom_agent(const std::string& name) : mcp::agent(name) {}
    
    void initialize(const mcp::json& config) override {
        // Initialize from config
    }
    
    mcp::json process(const mcp::json& input) override {
        // Process the input
        mcp::json output = call_tool("some_tool", input);
        return output;
    }
};
```

## Agent Workflow Extension

The framework is specifically designed to support agent workflows with:

1. **Workflow Engine**: Define sequences of tool calls with data passing
2. **Agent Base Class**: Easily create custom agents
3. **Tool Registry**: Centralized tool management
4. **Resource APIs**: RESTful interfaces for workflow and agent management

## Custom Agent Examples

Three example agent implementations are provided:

1. **Echo Agent**: Simple agent that echoes back input with optional processing
2. **Workflow Agent**: Executes predefined workflows
3. **Chain Agent**: Chains multiple tools together with data mapping

## Host Integration

The host example demonstrates how to:

1. Combine server and client functionality
2. Manage connections to other MCP servers
3. Create workflows that span multiple servers
4. Register and manage agents

## Building the Project

Use the provided CMakeLists.txt:

```bash
mkdir build && cd build
cmake ..
make
```

## Extending the Framework

### Adding New Tools

```cpp
// Define a new tool
mcp::tool my_tool = mcp::tool_builder("my_tool")
    .with_description("My custom tool")
    .with_string_param("input", "Input string")
    .build();

// Implement the tool handler
mcp::json my_tool_handler(const mcp::json& params) {
    std::string input = params["input"];
    // Process the input
    return {{"output", "Processed: " + input}};
}

// Register with the server
server.register_tool(my_tool, my_tool_handler);
```

### Creating New Resource Types

```cpp
class custom_resource : public mcp::resource {
public:
    resource_type type() const override {
        return resource_type::custom;
    }
    
    json metadata() const override {
        return {{"name", "Custom Resource"}};
    }
    
    response handle_request(const request& req) override {
        // Handle the request
        response res;
        res.set_json_body({{"status", "success"}});
        return res;
    }
};
```

### Implementing New Agent Types

```cpp
class my_agent : public mcp::agent {
public:
    explicit my_agent(const std::string& name) : mcp::agent(name) {}
    
    void initialize(const mcp::json& config) override {
        // Initialize from config
    }
    
    mcp::json process(const mcp::json& input) override {
        // Custom processing logic
        return result;
    }
};
```

## Conclusion

This MCP Protocol framework provides a robust foundation for building agent-based systems. It offers:

- **Standardized Communication**: Common protocol for all components
- **Extensible Design**: Easy to add new tools, resources, and agents
- **Workflow Support**: Define and execute complex workflows
- **Agent Framework**: Create specialized agents for different tasks

The implementation uses lower_line_naming_style as requested and provides comprehensive examples of customized host, client, and server configurations.