HTTP server transport layer for MCP protocol. Handles JSON-RPC routing, session management, SSE integration, and protocol compliance.

Core Purpose

• Route JSON-RPC requests to handlers
• Manage client sessions
• Enable SSE streaming
• Handle protocol initialization

Key Components

HttpServerTransport Class

export class HttpServerTransport {
    // Dependencies
    private resourceHandler: ResourceHandler
    private toolHandler: ToolHandler
    private promptHandler: PromptHandler
    private sseTransport: SSETransport
    private sessions: Map<string, Session>
    
    // Main methods
    handleRequest(): Routes and processes requests
    handleSSEConnection(): Manages SSE streams
}

Request Routing

Supported Methods

Method	Handler	Purpose
resources/list	ResourceHandler	List resources
resources/read	ResourceHandler	Read resource
tools/list	ToolHandler	List tools
tools/call	ToolHandler	Execute tool
prompts/list	PromptHandler	List prompts
prompts/get	PromptHandler	Get prompt
initialize	Internal	Protocol init
ping	Internal	Health check

Integration in Application

• Used By: Express server endpoints
• Handlers: Resources, Tools, Prompts
• Protocol: JSON-RPC 2.0 compliant
• Streaming: Optional SSE support

Request Flow

1. Receive JSON-RPC request
2. Validate method and params
3. Route to appropriate handler
4. Execute handler logic
5. Return JSON-RPC response

Session Management

Session Headers

• Request: Mcp-Session-Id
• Response: Mcp-Session-Id

Session Features

• UUID-based identification
• Client tracking
• SSE connection association

Protocol Features

Initialization Response

{
    protocolVersion: "2024-11-05",
    capabilities: {
        resources: { read: true, list: true },
        tools: { list: true, call: true },
        prompts: { list: true, get: true }
    },
    serverInfo: { name, version }
}

Resource Templates

{
    uriTemplate: "airs://scan-results/{scanId}",
    name: "Scan Results",
    description: "Retrieve scan by ID"
}

Error Handling

JSON-RPC Error Codes

• -32600: Invalid Request
• -32601: Method not found
• -32602: Invalid params
• -32603: Internal error

Error Integration

• Sentry exception capture
• Structured logging
• Generic client responses

SSE Support

Stream Detection

• Check Accept header for text/event-stream
• Identify streamable methods
• Initialize SSE connection

Streaming Flow

1. Detect SSE capability
2. Create/retrieve session
3. Initialize SSE transport
4. Send response via events
5. Clean up connection

Key Features

Request Validation

• Method presence check
• Parameter type validation
• JSON-RPC structure verification

Performance

• Efficient method routing
• Session caching
• Minimal async overhead

Security

• Session isolation
• Error sanitization
• Input validation

Usage Example

// Handle incoming request
await transport.handleRequest(req, res);

// Establish SSE connection
transport.handleSSEConnection(req, res);

// Request automatically routed to:
// - ResourceHandler for resources/*
// - ToolHandler for tools/*
// - PromptHandler for prompts/*

Related Modules

• SSE Transport - Streaming implementation
• Resource Handler - Resource operations
• Tool Handler - Tool execution
• Transport Types - Type definitions