MCP Lambda Server
A Node.js package that provides MCP (Model Context Protocol) server infrastructure for AWS Lambda functions with SSE support.
Features
- Adapts the MCP TypeScript SDK to work with AWS Lambda
- Supports Server-Sent Events (SSE) through Lambda response streaming
- Handles CORS and HTTP method validation
- TypeScript support
Important Notes
- Lambda response streaming only works with Function URLs. It does not work with API Gateway or Application Load Balancer.
- Only Node.js runtime is officially supported for response streaming.
Installation
npm install @markvp/mcp-lambda-layer
Usage
Create your Lambda function and import the package:
import { MCPHandlerFactory } from '@markvp/mcp-lambda-layer';
import { z } from 'zod';
// Create MCP handler factory with your configuration
const factory = new MCPHandlerFactory({
tools: {
summarize: {
params: {
text: z.string(),
},
handler: async ({ text }) => {
// Your implementation here - could be any service/model/API
const summary = await yourSummarizeImplementation(text);
return {
content: [{ type: 'text', text: summary }],
};
},
},
},
prompts: {
generate: {
description: 'Generate content based on a prompt',
handler: async extra => {
// Your implementation here - could be any service/model/API
const result = await yourGenerateImplementation(extra.prompt);
return {
content: [{ type: 'text', text: result }],
};
},
},
},
});
// Export the handler directly
export const handler = factory.getHandler();
Required Lambda Configuration
- Runtime: Node.js 18.x or later
- Handler: index.handler
- Memory: 128 MB minimum (adjust based on your needs)
- Timeout: 120 seconds recommended
- Function URL: Required and must have response streaming enabled
- API Gateway/ALB: Not supported with streaming
Package Contents
This package provides:
- MCP Server implementation with SSE transport
- Protocol handling (JSON-RPC)
- Streaming response support
- Type definitions and interfaces
Your Lambda function provides:
- Tool and prompt implementations
- Business logic
- Any necessary API clients or services
- Configuration
License
MIT
