import express from 'express';
import dotenv from 'dotenv';
// Load environment variables
dotenv.config();
const DEFAULT_PORT = 3000;
export async function startHttpServer(port: number = DEFAULT_PORT): Promise<void> {
const app = express();
// Middleware
app.use(express.json({ limit: '50mb' }));
app.use(express.raw({ type: 'application/octet-stream', limit: '50mb' }));
// CORS middleware for MCP
app.use((_req, res, next) => {
res.header('Access-Control-Allow-Origin', _req.headers.origin || '*');
res.header('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');
res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization, Accept, Mcp-Session-Id');
res.header('Access-Control-Expose-Headers', 'Mcp-Session-Id');
if (_req.method === 'OPTIONS') {
res.sendStatus(200);
return;
}
next();
});
// Health check endpoint
app.get('/health', (_req, res) => {
res.json({ status: 'ok', transport: 'http', version: '0.2.0' });
});
// MCP endpoint for Streamable HTTP
app.post('/mcp', async (req, res) => {
try {
// Validate Accept header
const acceptHeader = req.headers.accept;
if (!acceptHeader || (!acceptHeader.includes('application/json') && !acceptHeader.includes('text/event-stream'))) {
res.status(400).json({
error: 'Invalid Accept header. Must include application/json or text/event-stream'
});
return;
}
// Extract session ID if present
const sessionId = req.headers['mcp-session-id'] as string;
// Set response headers
res.setHeader('Content-Type', 'application/json');
if (sessionId) {
res.setHeader('Mcp-Session-Id', sessionId);
}
// Process JSON-RPC request
const jsonRpcRequest = req.body;
if (!jsonRpcRequest || typeof jsonRpcRequest !== 'object') {
res.status(400).json({
jsonrpc: '2.0',
error: { code: -32600, message: 'Invalid Request' },
id: null
});
return;
}
// Handle the request through MCP server
// Note: This is a simplified implementation
// In a full implementation, you'd need to properly integrate with the MCP server's request handling
if (jsonRpcRequest.method === 'tools/list') {
const tools = [
{
name: 'parse_document',
description: 'Parse a document using Upstage AI\'s document digitization API.',
inputSchema: {
type: 'object',
properties: {
file_path: { type: 'string' },
output_formats: { type: 'array', items: { type: 'string' } }
},
required: ['file_path']
}
},
{
name: 'extract_information',
description: 'Extract structured information from documents using Upstage Universal Information Extraction.',
inputSchema: {
type: 'object',
properties: {
file_path: { type: 'string' },
schema_path: { type: 'string' },
schema_json: { type: 'string' },
auto_generate_schema: { type: 'boolean', default: true }
},
required: ['file_path']
}
}
];
res.json({
jsonrpc: '2.0',
result: { tools },
id: jsonRpcRequest.id
});
return;
}
// For other methods, return method not found
res.json({
jsonrpc: '2.0',
error: { code: -32601, message: 'Method not found' },
id: jsonRpcRequest.id
});
} catch (error: any) {
console.error('Error processing MCP request:', error);
res.status(500).json({
jsonrpc: '2.0',
error: { code: -32603, message: 'Internal error', data: error.message },
id: req.body?.id || null
});
}
});
// Server-Sent Events endpoint (GET /mcp for streaming)
app.get('/mcp', (req, res) => {
// Validate Accept header for SSE
const acceptHeader = req.headers.accept;
if (!acceptHeader || !acceptHeader.includes('text/event-stream')) {
return res.status(400).json({
error: 'Invalid Accept header. Must include text/event-stream for SSE'
});
}
// Set SSE headers
res.setHeader('Content-Type', 'text/event-stream');
res.setHeader('Cache-Control', 'no-cache');
res.setHeader('Connection', 'keep-alive');
// Send initial connection event
res.write('event: connected\n');
res.write('data: {"type":"connection","status":"connected"}\n\n');
// Handle client disconnect
req.on('close', () => {
res.end();
});
// Keep connection alive
return;
});
// Start the server
app.listen(port, '127.0.0.1', () => {
console.log(`\nMCP Server with HTTP Streamable transport running at:`);
console.log(`🌐 HTTP: http://127.0.0.1:${port}/mcp`);
console.log(`🏥 Health: http://127.0.0.1:${port}/health`);
console.log(`\nAdd to Claude Desktop config:`);
console.log(`{`);
console.log(` "mcpServers": {`);
console.log(` "upstage-http": {`);
console.log(` "command": "npx",`);
console.log(` "args": ["mcp-upstage-server", "--http", "--port", "${port}"],`);
console.log(` "env": {`);
console.log(` "UPSTAGE_API_KEY": "your-api-key"`);
console.log(` }`);
console.log(` }`);
console.log(` }`);
console.log(`}`);
});
}
export default startHttpServer;
