feat: add HTTP server transport for MCP

Adds src/http-server.ts - a Node.js HTTP entry point that exposes the
MCP implementation via Streamable HTTP transport (POST/GET /mcp) per
the MCP 2025-11-25 specification.

- Uses StreamableHTTPServerTransport (stateless mode) from the MCP SDK
- Port configurable via MCP_PORT env var (default: 3000)
- ObsidianMCPServer.connect() now accepts an optional Transport param
  so both stdio (existing) and HTTP (new) modes reuse the same server
- Added 'npm run server' script to start the HTTP server

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

package.json

@@ -6,6 +6,7 @@
   "main": "dist/index.js",
   "scripts": {
     "build": "tsc",
+    "server": "node dist/http-server.js",
     "validate-manifest": "mcpb validate manifest.json",
     "pack": "npm run build && mcpb pack",
     "test": "jest",

src/http-server.ts

@@ -0,0 +1,114 @@
+/**
+ * HTTP Entry Point for Obsidian MCP Server
+ * Exposes the MCP implementation over Streamable HTTP transport
+ * per the MCP 2025-11-25 specification.
+ *
+ * Endpoint: POST/GET /mcp
+ * Port: MCP_PORT env var (default: 3000)
+ */
+
+import http, { IncomingMessage } from 'node:http';
+import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
+import { ObsidianMCPServer } from './server.js';
+import { registerAllTools } from './tools/index.js';
+import { logger } from './utils/logger.js';
+
+const PORT = parseInt(process.env.MCP_PORT ?? '3000', 10);
+
+/**
+ * Read and parse the JSON body from an incoming HTTP request.
+ */
+function readBody(req: IncomingMessage): Promise<unknown> {
+  return new Promise((resolve, reject) => {
+    const chunks: Buffer[] = [];
+    req.on('data', (chunk: Buffer) => chunks.push(chunk));
+    req.on('end', () => {
+      const raw = Buffer.concat(chunks).toString('utf8');
+      if (!raw) {
+        resolve(undefined);
+        return;
+      }
+      try {
+        resolve(JSON.parse(raw));
+      } catch {
+        reject(new Error('Invalid JSON body'));
+      }
+    });
+    req.on('error', reject);
+  });
+}
+
+async function main(): Promise<void> {
+  const vaultName = process.env.OBSIDIAN_VAULT;
+  if (!vaultName) {
+    logger.error('OBSIDIAN_VAULT environment variable not set');
+    process.exit(1);
+  }
+
+  logger.info('Starting Obsidian MCP HTTP server', { vault: vaultName, port: PORT });
+
+  // Create and configure the MCP server
+  const mcpServer = new ObsidianMCPServer();
+  await registerAllTools(mcpServer);
+
+  // Stateless transport: no session management, each request is self-contained.
+  // Use sessionIdGenerator: () => randomUUID() for stateful/multi-client mode.
+  const transport = new StreamableHTTPServerTransport({
+    sessionIdGenerator: undefined,
+  });
+
+  await mcpServer.connect(transport);
+
+  const httpServer = http.createServer(async (req, res) => {
+    // Only serve the /mcp endpoint
+    if (req.url !== '/mcp') {
+      res.writeHead(404, { 'Content-Type': 'application/json' });
+      res.end(JSON.stringify({ error: 'Not Found. Use POST /mcp' }));
+      return;
+    }
+
+    try {
+      let body: unknown;
+      if (req.method === 'POST') {
+        body = await readBody(req);
+      }
+      await transport.handleRequest(req, res, body);
+    } catch (error) {
+      logger.error('Error handling MCP request', {
+        error: error instanceof Error ? error.message : String(error),
+      });
+      if (!res.headersSent) {
+        res.writeHead(500, { 'Content-Type': 'application/json' });
+        res.end(JSON.stringify({ error: 'Internal server error' }));
+      }
+    }
+  });
+
+  httpServer.listen(PORT, () => {
+    logger.info(`MCP HTTP server ready`, { url: `http://localhost:${PORT}/mcp` });
+  });
+
+  // Graceful shutdown
+  const shutdown = async (signal: string) => {
+    logger.info(`Received ${signal}, shutting down`);
+    httpServer.close(async () => {
+      try {
+        await mcpServer.close();
+        logger.info('Server closed');
+        process.exit(0);
+      } catch {
+        process.exit(1);
+      }
+    });
+  };
+
+  process.on('SIGINT', () => shutdown('SIGINT'));
+  process.on('SIGTERM', () => shutdown('SIGTERM'));
+}
+
+main().catch((error) => {
+  logger.error('Fatal error', {
+    error: error instanceof Error ? error.message : String(error),
+  });
+  process.exit(1);
+});

src/server.ts

@@ -6,6 +6,7 @@
 
 import { Server } from '@modelcontextprotocol/sdk/server/index.js';
 import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
+import { Transport } from '@modelcontextprotocol/sdk/shared/transport.js';
 import {
   CallToolRequestSchema,
   ListToolsRequestSchema,
@@ -119,12 +120,12 @@ export class ObsidianMCPServer {
   }
 
   /**
-   * Connect to stdio transport
+   * Connect using the provided transport, or stdio if none is given
    */
-  async connect(): Promise<void> {
-    const transport = new StdioServerTransport();
-    await this.server.connect(transport);
-    logger.info('MCP server connected to stdio transport');
+  async connect(transport?: Transport): Promise<void> {
+    const t = transport ?? new StdioServerTransport();
+    await this.server.connect(t);
+    logger.info('MCP server connected', { transport: transport ? 'custom' : 'stdio' });
   }
 
   /**