Function createMcpFastifyApp

createMcpFastifyApp(options?: CreateMcpFastifyAppOptions): FastifyInstance
Creates a Fastify application pre-configured for MCP servers.

When the host is '127.0.0.1', 'localhost', or '::1' (the default is '127.0.0.1'), DNS rebinding protection is automatically applied via an onRequest hook to protect against DNS rebinding attacks on localhost servers.

Fastify parses JSON request bodies by default, so no additional middleware is required for MCP Streamable HTTP endpoints.
Parameters
- options: CreateMcpFastifyAppOptions = {}
  Configuration options
Returns FastifyInstance
A configured Fastify application
Example: Basic usage - defaults to 127.0.0.1 with DNS rebinding protection
```
const app = createMcpFastifyApp();
```
Example: Custom host - DNS rebinding protection only applied for localhost hosts
```
const appOpen = createMcpFastifyApp({ host: '0.0.0.0' }); // No automatic DNS rebinding protection
const appLocal = createMcpFastifyApp({ host: 'localhost' }); // DNS rebinding protection enabled
```
Example: Custom allowed hosts for non-localhost binding
```
const app = createMcpFastifyApp({ host: '0.0.0.0', allowedHosts: ['myapp.local', 'localhost'] });
```
- Defined in fastify.ts:56