# MCPTransport Documentation

## Overview
The `MCPTransport` module provides the communication infrastructure for the Model Context Protocol (MCP), enabling agents to communicate over HTTP and Server-Sent Events (SSE). It implements robust networking capabilities with error handling, reconnection logic, and message queuing.

## Core Components

### MCPTransport (Abstract Base Class)
- Defines the base interface for transport implementations
- Abstract methods:
  - `send_message`: Send messages to other agents
  - `receive_message`: Receive messages from other agents

### HTTPTransport Class
Implements the MCPTransport interface using HTTP and SSE protocols.

#### Key Features
1. **Dual Operation Modes**
   - Server Mode: Runs local HTTP server
   - Client Mode: Connects to remote server

2. **Communication Protocols**
   - HTTP REST API for message exchange
   - SSE support for real-time updates
   - Robust message queuing system

3. **Connection Management**
   - Automatic reconnection handling
   - Connection lifecycle management
   - Session persistence

4. **Error Handling**
   - Network error recovery
   - Message deduplication
   - Timeout management

## Key Components

### Initialization
```python
class HTTPTransport:
    def __init__(self, host="localhost", port=8000):
        # Initialize server/client settings
        # Setup FastAPI application
        # Configure message queue
```

### Core Methods

1. **Message Polling**
   - `_poll_for_messages`: Background task for message retrieval
   - Handles:
     - Message deduplication
     - Error recovery
     - Connection management

2. **Connection Management**
   - `connect`: Establishes remote server connection
   - `disconnect`: Graceful connection termination
   - `start_polling`: Initiates message polling

3. **Message Handling**
   - `send_message`: Sends messages to other agents
   - `receive_message`: Processes incoming messages
   - `_handle_message`: Internal message processing

### Error Handling
1. **Network Errors**
   - Automatic retry mechanisms
   - Exponential backoff
   - Connection recovery

2. **Message Validation**
   - Schema validation
   - Required field checking
   - Message ID tracking

3. **Session Management**
   - Session cleanup
   - Resource management
   - Memory leak prevention

## Best Practices

1. **Connection Management**
   - Always use proper connection/disconnection methods
   - Handle session cleanup appropriately
   - Monitor connection health

2. **Error Handling**
   - Implement proper error recovery
   - Log important events
   - Handle edge cases

3. **Message Processing**
   - Validate message format
   - Handle message ordering
   - Implement idempotency

## Usage Examples

```python
# Server Mode
transport = HTTPTransport(host="localhost", port=8000)
await transport.start()

# Client Mode
transport = HTTPTransport.from_url("https://remote-server.com")
await transport.connect(agent_name="agent1", token="auth_token")

# Send Message
await transport.send_message(target="agent2", message={"type": "request"})

# Receive Message
message, sender = await transport.receive_message()
```

## Configuration Options

1. **Server Settings**
   - Host configuration
   - Port selection
   - SSL/TLS setup

2. **Client Settings**
   - Authentication tokens
   - Polling intervals
   - Timeout configurations

3. **Message Options**
   - Batch processing
   - Priority handling
   - Delivery guarantees

## Security Considerations

1. **Authentication**
   - Token-based auth
   - Session management
   - Access control

2. **Data Protection**
   - SSL/TLS encryption
   - Message validation
   - Input sanitization

3. **Resource Protection**
   - Rate limiting
   - Request validation
   - Resource cleanup