feat: fetch transport (#1209)

Co-authored-by: Felix Weinberger <[email protected]>

Author: mattzcarey

package-lock.json

@@ -86,6 +86,7 @@
         "client": "tsx scripts/cli.ts client"
     },
     "dependencies": {
+        "@hono/node-server": "^1.19.7",
         "ajv": "^8.17.1",
         "ajv-formats": "^3.0.1",
         "content-type": "^1.0.5",

package.json

@@ -0,0 +1,74 @@
+/**
+ * Example MCP server using Hono with WebStandardStreamableHTTPServerTransport
+ *
+ * This example demonstrates using the Web Standard transport directly with Hono,
+ * which works on any runtime: Node.js, Cloudflare Workers, Deno, Bun, etc.
+ *
+ * Run with: npx tsx src/examples/server/honoWebStandardStreamableHttp.ts
+ */
+
+import { Hono } from 'hono';
+import { cors } from 'hono/cors';
+import { serve } from '@hono/node-server';
+import * as z from 'zod/v4';
+import { McpServer } from '../../server/mcp.js';
+import { WebStandardStreamableHTTPServerTransport } from '../../server/webStandardStreamableHttp.js';
+import { CallToolResult } from '../../types.js';
+
+// Create the MCP server
+const server = new McpServer({
+    name: 'hono-webstandard-mcp-server',
+    version: '1.0.0'
+});
+
+// Register a simple greeting tool
+server.registerTool(
+    'greet',
+    {
+        title: 'Greeting Tool',
+        description: 'A simple greeting tool',
+        inputSchema: { name: z.string().describe('Name to greet') }
+    },
+    async ({ name }): Promise<CallToolResult> => {
+        return {
+            content: [{ type: 'text', text: `Hello, ${name}! (from Hono + WebStandard transport)` }]
+        };
+    }
+);
+
+// Create a stateless transport (no options = no session management)
+const transport = new WebStandardStreamableHTTPServerTransport();
+
+// Create the Hono app
+const app = new Hono();
+
+// Enable CORS for all origins
+app.use(
+    '*',
+    cors({
+        origin: '*',
+        allowMethods: ['GET', 'POST', 'DELETE', 'OPTIONS'],
+        allowHeaders: ['Content-Type', 'mcp-session-id', 'Last-Event-ID', 'mcp-protocol-version'],
+        exposeHeaders: ['mcp-session-id', 'mcp-protocol-version']
+    })
+);
+
+// Health check endpoint
+app.get('/health', c => c.json({ status: 'ok' }));
+
+// MCP endpoint
+app.all('/mcp', c => transport.handleRequest(c.req.raw));
+
+// Start the server
+const PORT = process.env.MCP_PORT ? parseInt(process.env.MCP_PORT, 10) : 3000;
+
+server.connect(transport).then(() => {
+    console.log(`Starting Hono MCP server on port ${PORT}`);
+    console.log(`Health check: http://localhost:${PORT}/health`);
+    console.log(`MCP endpoint: http://localhost:${PORT}/mcp`);
+
+    serve({
+        fetch: app.fetch,
+        port: PORT
+    });
+});