feat: add sse server support.

Dockerfile.sse

@@ -0,0 +1,41 @@
+# Generated by https://smithery.ai. See: https://smithery.ai/docs/config#dockerfile
+## Stage 1: Builder
+FROM node:lts-alpine AS builder
+
+# Set working directory
+WORKDIR /app
+
+# Copy all files into the container
+COPY . .
+
+# Install dependencies without running scripts
+RUN npm install --ignore-scripts
+
+# Build the TypeScript source code
+RUN npm run build
+
+## Stage 2: Runtime
+FROM node:lts-alpine
+
+WORKDIR /app
+
+# Install Python and other programming languages
+RUN apk add --no-cache \
+    python3 \
+    go \
+    php \
+    ruby
+
+# Copy only the necessary files from the builder stage
+COPY --from=builder /app/dist ./dist
+COPY package*.json ./
+
+# Install only production dependencies
+RUN npm install --production --ignore-scripts
+
+# Use a non-root user for security (optional)
+RUN adduser -D mcpuser
+USER mcpuser
+
+# Set the entrypoint command
+CMD ["node", "./dist/cli.js", "--transport", "sse"]

package.json

@@ -13,7 +13,9 @@
   "scripts": {
     "build": "tsc && shx chmod +x dist/index.js dist/cli.js",
     "watch": "tsc --watch",
-    "start": "node ./dist/cli.js"
+    "start": "node ./dist/cli.js",
+    "start-http": "node ./dist/cli.js --transport=http",
+    "start-sse": "node ./dist/cli.js --transport=sse"
   },
   "files": [
     "dist"

src/cli.ts

@@ -9,8 +9,8 @@ program
   .name('mcp-server-code-runner')
   .description(pkg.description)
   .version(pkg.version)
-  .option('-t, --transport <transport>', 'Transport (stdio or http)', 'stdio')
-  .option('-p, --port <port>', 'Port number for HTTP server')
+  .option('-t, --transport <transport>', 'Transport (stdio, http, or sse)', 'stdio')
+  .option('-p, --port <port>', 'Port number for HTTP/SSE server')
   .action(async (options) => {
     try {
       await startMcpServer(options.transport, { port: parseInt(options.port) });    

src/index.ts

@@ -1,7 +1,8 @@
 import { startStdioMcpServer } from "./stdio.js";
 import { startStreamableHttpMcpServer, McpServerEndpoint } from "./streamableHttp.js";
+import { startSSEMcpServer } from "./sseServer.js";
 
-export type Transport = 'stdio' | 'http';
+export type Transport = 'stdio' | 'http' | 'sse';
 
 export interface HttpServerOptions {
     port?: number;
@@ -12,7 +13,9 @@ export async function startMcpServer(transport: Transport, options?: HttpServerO
         return startStdioMcpServer();
     } else if (transport === 'http') {
         return startStreamableHttpMcpServer(options?.port);
+    } else if (transport === 'sse') {
+        return startSSEMcpServer(options?.port);
     } else {
-        throw new Error('Invalid transport. Must be either "stdio" or "http"');
+        throw new Error('Invalid transport. Must be either "stdio", "http", or "sse"');
     }
 }

src/sseServer.ts

@@ -0,0 +1,125 @@
+import express, { Request, Response } from "express";
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { SSEServerTransport } from "@modelcontextprotocol/sdk/server/sse.js";
+import { createServer } from "./server.js";
+
+export interface McpServerEndpoint {
+  url: string;
+  port: number;
+}
+
+export async function startSSEMcpServer(port?: number): Promise<McpServerEndpoint> {
+  const app = express();
+  app.use(express.json());
+
+  // Store transports by session ID
+  const transports: { [sessionId: string]: SSEServerTransport } = {};
+
+  // SSE endpoint for establishing connection
+  app.get('/sse', async (req: Request, res: Response) => {
+    console.log('Received SSE connection request');
+    try {
+      const server: McpServer = createServer();
+      const transport: SSEServerTransport = new SSEServerTransport('/messages', res);
+
+      // Store the transport by session ID
+      transports[transport.sessionId] = transport;
+
+      // Clean up transport when connection closes
+      transport.onclose = () => {
+        delete transports[transport.sessionId];
+        console.log(`SSE session ${transport.sessionId} closed`);
+      };
+
+      // Connect the server to the transport
+      await server.connect(transport);
+
+      console.log(`SSE session ${transport.sessionId} established`);
+    } catch (error) {
+      console.error('Error establishing SSE connection:', error);
+      if (!res.headersSent) {
+        res.status(500).json({
+          jsonrpc: '2.0',
+          error: {
+            code: -32603,
+            message: 'Internal server error',
+          },
+          id: null,
+        });
+      }
+    }
+  });
+
+  // Messages endpoint for receiving client messages
+  app.post('/messages', async (req: Request, res: Response) => {
+    const sessionId = req.query.sessionId as string;
+    console.log(`Received message for session: ${sessionId}`);
+
+    if (!sessionId || !transports[sessionId]) {
+      console.error(`No transport found for sessionId: ${sessionId}`);
+      res.status(400).json({
+        jsonrpc: '2.0',
+        error: {
+          code: -32000,
+          message: 'Invalid or missing session ID',
+        },
+        id: null,
+      });
+      return;
+    }
+
+    try {
+      const transport = transports[sessionId];
+      await transport.handlePostMessage(req, res, req.body);
+    } catch (error) {
+      console.error('Error handling SSE message:', error);
+      if (!res.headersSent) {
+        res.status(500).json({
+          jsonrpc: '2.0',
+          error: {
+            code: -32603,
+            message: 'Internal server error',
+          },
+          id: null,
+        });
+      }
+    }
+  });
+
+  // Health check endpoint
+  app.get('/health', (req: Request, res: Response) => {
+    res.json({ 
+      status: 'ok', 
+      transport: 'sse',
+      activeSessions: Object.keys(transports).length 
+    });
+  });
+
+  // Start the server
+  const PORT = Number(port || process.env.PORT || 3088);
+
+  return new Promise((resolve, reject) => {
+    const appServer = app.listen(PORT, (error) => {
+      if (error) {
+        console.error('Failed to start server:', error);
+        reject(error);
+        return;
+      }
+      const endpoint: McpServerEndpoint = {
+        url: `http://localhost:${PORT}/sse`,
+        port: PORT
+      };
+      console.log(`Code Runner SSE MCP Server listening at ${endpoint.url}`);
+      console.log(`Messages endpoint: http://localhost:${PORT}/messages`);
+      console.log(`Health check: http://localhost:${PORT}/health`);
+      resolve(endpoint);
+    });
+
+    // Handle server errors
+    appServer.on('error', (error) => {
+      console.error('Server error:', error);
+      reject(error);
+    });
+  });
+}
+