Hono on Vercel

Hono is a fast and lightweight web application framework built on Web Standards. You can deploy a Hono app to Vercel with zero configuration.

Start with Hono on Vercel by using the following Hono template to deploy to Vercel with zero configuration:

Vercel deployments can integrate with your git provider to generate preview URLs for each pull request you make to your Hono project.

To run a Hono application on Vercel, ensure that the default export of index.ts or src/index.ts is the Hono application router.

import { Hono } from 'hono';
 
const app = new Hono();
 
// ...
 
export default app;

To run your Hono application locally, use Vercel CLI:

vc dev

This ensures that the application will use the default export to run the same as when deployed to Vercel. The application will be available on your localhost.

Hono has the concept of "Middleware" as a part of the framework. This is different from Vercel Routing Middleware, though they can be used together.

In Hono, Middleware runs before a request handler in the framework's router. This is commonly used for loggers, CORS handling, or authentication. The code in the Hono application might look like this:

app.use(logger());
app.use('/posts/*', cors());
app.post('/posts/*', basicAuth());

More examples of Hono Middleware can be found in the Hono documentation.

In Vercel, Routing Middleware executes code before a request is processed by the application. This gives you a way to handle rewrites, redirects, headers, and more, before returning a response. See the Routing Middleware documentation for examples.

When you deploy a Hono app to Vercel, your server routes automatically become Vercel Functions and use Fluid compute by default.

Vercel Functions support streaming which can be used with Hono's stream() function.

app.get('/stream', (c) => {
  return stream(c, async (stream) => {
    // Write a process to be executed when aborted.
    stream.onAbort(() => {
      console.log('Aborted!');
    });
    // Write a Uint8Array.
    await stream.write(new Uint8Array([0x48, 0x65, 0x6c, 0x6c, 0x6f]));
    // Pipe a readable stream.
    await stream.pipe(anotherReadableStream);
  });
});

Learn more about deploying Hono projects on Vercel with the following resources:

• Hono templates on Vercel
• Backend templates on Vercel