vite-plugin-vercel

Vercel adapter for Vite.

Bundle your Vite application as supported by Vercel Output API.

Install

npm i -D vite-plugin-vercel

yarn add -D vite-plugin-vercel

pnpm add -D vite-plugin-vercel

bun add -D vite-plugin-vercel

Features

• [x] SSG/Static files
  • see prerender config
• [x] SSR/Serverless functions
  • .[jt]s files under the <root>/api folder of your project are automatically bundled as Serverless functions under .vercel/output/functions/api/*.func
  • see additionalEndpoints config
• [x] ISR/Prerender functions
  • see isr config. Also see implementation of vike for example
• [x] Edge functions
• [x] Edge middleware
• [ ] Images optimization
• [ ] Preview mode
• [x] Advanced config

Simple usage

Install this package as a dev dependency and add it to your Vite config:

// vite.config.ts
import { defineConfig } from 'vite';
import vercel from 'vite-plugin-vercel';
import { getVercelEntries } from "vite-plugin-vercel";

const entries = await getVercelEntries("endpoints/api", {
  // Auto mapping examples:
  //   endpoints/api/page.ts -> /api/page
  //   endpoints/api/name/[name].ts -> /api/name/*
  destination: "api",
});

export default defineConfig({
  plugins: [vercel({
    entries,
  })],
});

[!NOTE] @vercel/build forces the building of files in the /api folder, with no way to disable this behavior. It's recommended to place your files in a different folder.

Configure endpoints

Endpoints added via getVercelEntries can be configured by exporting values from the endpoint file:

// file: endpoints/api/endpoint.ts

// Should run on edge runtime
export const edge = true;

// Always add those header to this endpoint
export const headers = {
  'Some-Header': 'some value',
};

// Stream the response
export const streaming = true;

// Enable Incremental Static Regeneration for this endpoint
export const isr = {
  expiration: 30,
};

export default async function handler() {
  return new Response('Edge Function: OK', {
    status: 200,
  });
}

Edge middleware

You can use Edge middleware as describe in the official documentation (i.e. with a middleware.ts file at the root of your project).

Advanced settings

// vite.config.ts
import { defineConfig } from 'vite';
import vercel from 'vite-plugin-vercel';

export default defineConfig({
  plugins: [vercel({
    // All the followings are optional

    /**
     * How long Functions should be allowed to run for every request, in seconds.
     * If left empty, default value for your plan will be used.
     */
    defaultMaxDuration: 30,
    /**
     * Enable streaming responses by default for all Serverless Functions
     */
    defaultSupportsResponseStreaming: true,
    /**
     * Default expiration time (in seconds) for prerender functions.
     * Defaults to 86400 seconds (24h).
     */
    expiration: 86400,

    /**
     * See https://vercel.com/docs/projects/project-configuration#rewrites
     */
    rewrites: [{ source: '/about', destination: '/about-our-company.html' }],
    /**
     * @see {@link https://vercel.com/docs/projects/project-configuration#headers}
     */
    headers: [
      {
        "source": "/service-worker.js",
        "headers": [
          {
            "key": "Cache-Control",
            "value": "public, max-age=0, must-revalidate"
          }
        ]
      }
    ],
    /**
     * See https://vercel.com/docs/projects/project-configuration#redirects
     */
    redirects: [
      { source: '/me', destination: '/profile.html', permanent: false },
    ],
    /**
     * See https://vercel.com/docs/projects/project-configuration#cleanurls
     */
    cleanUrls: true,
    /**
     * See https://vercel.com/docs/projects/project-configuration#trailingslash
     */
    trailingSlash: true,
    /**
     * Use `getVercelEntries` for mapping your filesystem routes to entries.
     * If you are interfacing this plugin with a framework, entries can also be added through the {@link https://github.com/photon-js/universal-deploy | universal-deploy} API
     */
    entries: {
      root: {
        id: 'src/routes/root.ts',
        name: 'root',
        route: '/'
      }
    },
    /**
     * Advanced configuration to override .vercel/output/config.json
     * See https://vercel.com/docs/build-output-api/v3/configuration#configuration
     */
    config: {
      // routes?: Route[];
      // images?: ImagesConfig;
      // wildcard?: WildcardConfig;
      // overrides?: OverrideConfig;
      // cache?: string[];
      // crons?: CronsConfig;
    },
    /**
     * Defaults to `.vercel/output`. Mostly useful for testing purpose
     */
    outDir: '.vercel/output',
  })]
});

FAQ

What does ISR do in dev mode?

Nothing. It's a production-only feature

What does edge: true target do in dev mode?

Nothing (yet?). If you have a use-case where an actual Edge runtime would be necessary in dev, please open a discussion

I don't see Vercel specific headers in dev mode

This is not yet supported. Please open an issue if you need this (PR welcome).

Related documentation: https://vercel.com/docs/edge-network/headers/request-headers

Migrations

• Migration from v9 to v11

Demo

https://vite-plugin-vercel-demo-roan.vercel.app/