diff --git a/integration/templates/fastify-vite/src/client/main.ts b/integration/templates/fastify-vite/src/client/main.ts
index 7dcc4eb0a36..26861ff1e42 100644
--- a/integration/templates/fastify-vite/src/client/main.ts
+++ b/integration/templates/fastify-vite/src/client/main.ts
@@ -9,6 +9,7 @@ document.addEventListener('DOMContentLoaded', async function () {
   await clerk.load({
     ui: { ClerkUI },
   });
+  window.Clerk = clerk;
 
   if (clerk.isSignedIn) {
     document.getElementById('app')!.innerHTML = `
diff --git a/integration/tests/fastify/machine.test.ts b/integration/tests/fastify/machine.test.ts
new file mode 100644
index 00000000000..9396d2df912
--- /dev/null
+++ b/integration/tests/fastify/machine.test.ts
@@ -0,0 +1,175 @@
+import { test } from '@playwright/test';
+
+import { appConfigs } from '../../presets';
+import type { MachineAuthTestAdapter } from '../../testUtils/machineAuthHelpers';
+import {
+  registerApiKeyAuthTests,
+  registerM2MAuthTests,
+  registerOAuthAuthTests,
+} from '../../testUtils/machineAuthHelpers';
+
+const createMainFile = () => `
+import 'dotenv/config';
+
+import express from 'express';
+import Fastify from 'fastify';
+import ViteExpress from 'vite-express';
+import { machineRoutes } from './routes/machine';
+
+async function start() {
+  const fastify = Fastify();
+
+  await fastify.register(machineRoutes);
+
+  await fastify.listen({ port: 0, host: '127.0.0.1' });
+  const fastifyAddress = fastify.server.address();
+  const fastifyPort = typeof fastifyAddress === 'object' ? fastifyAddress?.port : 0;
+
+  const expressApp = express();
+
+  expressApp.use('/api', async (req: any, res: any) => {
+    const url = \`http://127.0.0.1:\${fastifyPort}\${req.url}\`;
+    const headers: Record<string, string> = {};
+    for (const [key, value] of Object.entries(req.headers)) {
+      if (typeof value === 'string') {
+        headers[key] = value;
+      } else if (Array.isArray(value)) {
+        headers[key] = value.join(', ');
+      }
+    }
+
+    const response = await fetch(url, {
+      method: req.method,
+      headers,
+      body: ['GET', 'HEAD'].includes(req.method) ? undefined : req,
+      // @ts-expect-error duplex needed for streaming request bodies
+      duplex: ['GET', 'HEAD'].includes(req.method) ? undefined : 'half',
+      redirect: 'manual',
+    });
+
+    res.status(response.status);
+    response.headers.forEach((value: string, key: string) => {
+      res.setHeader(key, value);
+    });
+    const body = await response.arrayBuffer();
+    res.send(Buffer.from(body));
+  });
+
+  const port = parseInt(process.env.PORT as string) || 3002;
+  ViteExpress.listen(expressApp, port, () => console.log(\`Server is listening on port \${port}...\`));
+}
+
+start();
+`;
+
+const adapter: MachineAuthTestAdapter = {
+  baseConfig: appConfigs.fastify.vite,
+  apiKey: {
+    path: '/api/me',
+    addRoutes: config =>
+      config
+        .addFile(
+          'src/server/routes/machine.ts',
+          () => `
+import { clerkPlugin, getAuth } from '@clerk/fastify';
+import type { FastifyInstance } from 'fastify';
+
+export const machineRoutes = async (fastify: FastifyInstance) => {
+  await fastify.register(clerkPlugin, {
+    publishableKey: process.env.VITE_CLERK_PUBLISHABLE_KEY,
+  });
+
+  fastify.get('/me', async (request, reply) => {
+    const { userId, tokenType } = getAuth(request, { acceptsToken: 'api_key' });
+
+    if (!userId) {
+      return reply.code(401).send('Unauthorized');
+    }
+
+    return reply.send({ userId, tokenType });
+  });
+
+  fastify.post('/me', async (request, reply) => {
+    const authObject = getAuth(request, { acceptsToken: ['api_key', 'session_token'] });
+
+    if (!authObject.isAuthenticated) {
+      return reply.code(401).send('Unauthorized');
+    }
+
+    return reply.send({ userId: authObject.userId, tokenType: authObject.tokenType });
+  });
+};
+        `,
+        )
+        .addFile('src/server/main.ts', () => createMainFile()),
+  },
+  m2m: {
+    path: '/api/m2m',
+    addRoutes: config =>
+      config
+        .addFile(
+          'src/server/routes/machine.ts',
+          () => `
+import { clerkPlugin, getAuth } from '@clerk/fastify';
+import type { FastifyInstance } from 'fastify';
+
+export const machineRoutes = async (fastify: FastifyInstance) => {
+  await fastify.register(clerkPlugin, {
+    publishableKey: process.env.VITE_CLERK_PUBLISHABLE_KEY,
+  });
+
+  fastify.get('/m2m', async (request, reply) => {
+    const { subject, tokenType, machineId } = getAuth(request, { acceptsToken: 'm2m_token' });
+
+    if (!machineId) {
+      return reply.code(401).send('Unauthorized');
+    }
+
+    return reply.send({ subject, tokenType });
+  });
+};
+        `,
+        )
+        .addFile('src/server/main.ts', () => createMainFile()),
+  },
+  oauth: {
+    verifyPath: '/api/oauth-verify',
+    callbackPath: '/api/oauth/callback',
+    addRoutes: config =>
+      config
+        .addFile(
+          'src/server/routes/machine.ts',
+          () => `
+import { clerkPlugin, getAuth } from '@clerk/fastify';
+import type { FastifyInstance } from 'fastify';
+
+export const machineRoutes = async (fastify: FastifyInstance) => {
+  await fastify.register(clerkPlugin, {
+    publishableKey: process.env.VITE_CLERK_PUBLISHABLE_KEY,
+  });
+
+  fastify.get('/oauth-verify', async (request, reply) => {
+    const { userId, tokenType } = getAuth(request, { acceptsToken: 'oauth_token' });
+
+    if (!userId) {
+      return reply.code(401).send('Unauthorized');
+    }
+
+    return reply.send({ userId, tokenType });
+  });
+
+  fastify.get('/oauth/callback', async (_request, reply) => {
+    return reply.send({ message: 'OAuth callback received' });
+  });
+};
+        `,
+        )
+        .addFile('src/server/main.ts', () => createMainFile()),
+  },
+};
+
+test.describe('Fastify machine authentication @machine', () => {
+  registerApiKeyAuthTests(adapter);
+  registerM2MAuthTests(adapter);
+  registerOAuthAuthTests(adapter);
+});