added sse http support

src/index.ts

@@ -6,6 +6,10 @@ import { z } from "zod";
 import { searchLibraries, fetchLibraryDocumentation } from "./lib/api.js";
 import { formatSearchResults } from "./lib/utils.js";
 import dotenv from "dotenv";
+import { createServer } from "http";
+import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { SSEServerTransport } from "@modelcontextprotocol/sdk/server/sse.js";
+import { parse } from "url";
 
 // Load environment variables from .env file if present
 dotenv.config();
@@ -23,19 +27,23 @@ if (process.env.DEFAULT_MINIMUM_TOKENS) {
   }
 }
 
-// Create server instance
-const server = new McpServer({
+// Store SSE transports by session ID
+const sseTransports: Record<string, SSEServerTransport> = {};
+
+// Function to create a new server instance with all tools registered
+function createServerInstance() {
+  const server = new McpServer({
     name: "Context7",
     description: "Retrieves up-to-date documentation and code examples for any library.",
-  version: "1.0.6",
+    version: "1.0.7",
     capabilities: {
       resources: {},
       tools: {},
     },
-});
+  });
 
-// Register Context7 tools
-server.tool(
+  // Register Context7 tools
+  server.tool(
     "resolve-library-id",
     `Resolves a package/product name to a Context7-compatible library ID and returns a list of matching libraries.
 
@@ -111,9 +119,9 @@ ${resultsText}`,
         ],
       };
     }
-);
+  );
 
-server.tool(
+  server.tool(
     "get-library-docs",
     "Fetches up-to-date documentation for a library. You must call 'resolve-library-id' first to obtain the exact Context7-compatible library ID required to use this tool, UNLESS the user explicitly provides a library ID in the format '/org/project' or '/org/project/version' in their query.",
     {
@@ -160,12 +168,98 @@ server.tool(
         ],
       };
     }
-);
+  );
+
+  return server;
+}
 
 async function main() {
+  const transportType = process.env.MCP_TRANSPORT || "stdio";
+
+  if (transportType === "http" || transportType === "sse") {
+    const port = process.env.PORT ? parseInt(process.env.PORT, 10) : 3000;
+    const httpServer = createServer(async (req, res) => {
+      const url = parse(req.url || "").pathname;
+
+      // Set CORS headers for all responses
+      res.setHeader('Access-Control-Allow-Origin', '*');
+      res.setHeader('Access-Control-Allow-Methods', 'GET,POST,OPTIONS,DELETE');
+      res.setHeader('Access-Control-Allow-Headers', 'Content-Type, MCP-Session-Id, mcp-session-id');
+
+      // Handle preflight OPTIONS requests
+      if (req.method === 'OPTIONS') {
+        res.writeHead(200);
+        res.end();
+        return;
+      }
+
+      try {
+        // Create new server instance for each request
+        const requestServer = createServerInstance();
+
+        if (url === "/mcp") {
+          const transport = new StreamableHTTPServerTransport({
+            sessionIdGenerator: undefined
+          });
+          await requestServer.connect(transport);
+          await transport.handleRequest(req, res);
+        } else if (url === "/sse" && req.method === "GET") {
+          // Create new SSE transport for GET request
+          const sseTransport = new SSEServerTransport("/messages", res);
+          // Store the transport by session ID
+          sseTransports[sseTransport.sessionId] = sseTransport;
+          // Clean up transport when connection closes
+          res.on("close", () => {
+            delete sseTransports[sseTransport.sessionId];
+          });
+          await requestServer.connect(sseTransport);
+        } else if (url === "/messages" && req.method === "POST") {
+          // Get session ID from query parameters
+          const parsedUrl = parse(req.url || "", true);
+          const sessionId = parsedUrl.query.sessionId as string;
+          
+          if (!sessionId) {
+            res.writeHead(400);
+            res.end("Missing sessionId parameter");
+            return;
+          }
+
+          // Get existing transport for this session
+          const sseTransport = sseTransports[sessionId];
+          if (!sseTransport) {
+            res.writeHead(400);
+            res.end(`No transport found for sessionId: ${sessionId}`);
+            return;
+          }
+
+          // Handle the POST message with the existing transport
+          await sseTransport.handlePostMessage(req, res);
+        } else if (url === "/ping") {
+          res.writeHead(200, { 'Content-Type': 'text/plain' });
+          res.end('pong');
+        } else {
+          res.writeHead(404);
+          res.end("Not found");
+        }
+      } catch (error) {
+        console.error("Error handling request:", error);
+        if (!res.headersSent) {
+          res.writeHead(500);
+          res.end("Internal Server Error");
+        }
+      }
+    });
+
+    httpServer.listen(port, () => {
+      console.error(`Context7 Documentation MCP Server running on ${transportType.toUpperCase()} at http://localhost:${port}/mcp and legacy SSE at /sse`);
+    });
+  } else {
+    // Stdio transport - this is already stateless by nature
+    const server = createServerInstance();
     const transport = new StdioServerTransport();
     await server.connect(transport);
     console.error("Context7 Documentation MCP Server running on stdio");
+  }
 }
 
 main().catch((error) => {