@astrojs/ vercel

This adapter allows Astro to deploy your hybrid or server rendered site to Vercel.

If you’re using Astro as a static site builder, you don’t need an adapter.

Learn how to deploy your Astro site in our Vercel deployment guide.

Why Astro Vercel

Vercel is a deployment platform that allows you to host your site by connecting directly to your GitHub repository. This adapter enhances the Astro build process to prepare your project for deployment through Vercel.

Installation

Astro includes an astro add command to automate the setup of official integrations. If you prefer, you can install integrations manually instead.

Add the Vercel adapter to enable SSR in your Astro project with the following astro add command. This will install @astrojs/vercel and make the appropriate changes to your astro.config.mjs file in one step.

npx astro add vercel

pnpm astro add vercel

yarn astro add vercel

Manual Install

First, add the @astrojs/vercel adapter to your project’s dependencies using your preferred package manager:

npm install @astrojs/vercel

pnpm add @astrojs/vercel

yarn add @astrojs/vercel

Then, add the adapter and your desired on-demand rendering mode to your astro.config.* file:

import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';

export default defineConfig({
  // ...
  output: 'server',
  adapter: vercel(),
});

Choosing a Target

You can deploy to different targets:

serverless: SSR inside a Node.js function.
static: generates a static website following Vercel’s output formats, redirects, etc.

You can change where to target by changing the import:

import vercel from '@astrojs/vercel/serverless';
import vercel from '@astrojs/vercel/static';

Usage

Find out more about deploying your project to Vercel.

You can deploy by CLI (vercel deploy) or by connecting your new repo in the Vercel Dashboard. Alternatively, you can create a production build locally:

astro build
vercel deploy --prebuilt

Configuration

To configure this adapter, pass an object to the vercel() function call in astro.config.mjs:

Web Analytics

Type: VercelWebAnalyticsConfig
Available for: Serverless, Static

Added in: @astrojs/vercel@3.8.0

You can enable Vercel Web Analytics by setting webAnalytics: { enabled: true }. This will inject Vercel’s tracking scripts into all of your pages.

import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';

export default defineConfig({
  // ...
  output: 'server',
  adapter: vercel({
    webAnalytics: {
      enabled: true,
    },
  }),
});

imagesConfig

Type: VercelImageConfig
Available for: Serverless, Static

Added in: @astrojs/vercel@3.3.0

Configuration options for Vercel’s Image Optimization API. See Vercel’s image configuration documentation for a complete list of supported parameters.

The domains and remotePatterns properties will automatically be filled using the Astro corresponding image settings.

import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/static';

export default defineConfig({
  // ...
  output: 'static',
  adapter: vercel({
    imagesConfig: {
      sizes: [320, 640, 1280],
    },
  }),
});

imageService

Type: boolean
Available for: Serverless, Static

Added in: @astrojs/vercel@3.3.0

When enabled, an Image Service powered by the Vercel Image Optimization API will be automatically configured and used in production. In development, the image service specified by devImageService will be used instead.

import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/static';

export default defineConfig({
  // ...
  output: 'static',
  adapter: vercel({
    imageService: true,
  }),
});

---
import { Image } from 'astro:assets';
import astroLogo from '../assets/logo.png';
---

<!-- This component -->
<Image src={astroLogo} alt="My super logo!" />

<!-- will become the following HTML -->
<img
  src="/_vercel/image?url=_astro/logo.hash.png&w=...&q=..."
  alt="My super logo!"
  loading="lazy"
  decoding="async"
  width="..."
  height="..."
/>

devImageService

Type: 'sharp' | 'squoosh' | string
Available for: Serverless, Static

Added in: @astrojs/vercel@3.8.0

Default: ‘sharp’

Allows you to configure which image service to use in development when imageService is enabled. This can be useful if you cannot install Sharp’s dependencies on your development machine, but using another image service like Squoosh would allow you to preview images in your dev environment. Build is unaffected and will always use Vercel’s Image Optimization.

It can also be set to any arbitrary value in order to use a custom image service instead of Astro’s built-in ones.

import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';

export default defineConfig({
  // ...
  output: 'server',
  adapter: vercel({
    imageService: true,
    devImageService: 'squoosh',
  }),
});

includeFiles

Type: string[]
Available for: Serverless

Use this property to force files to be bundled with your function. This is helpful when you notice missing files.

import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';

export default defineConfig({
  // ...
  output: 'server',
  adapter: vercel({
    includeFiles: ['./my-data.json'],
  }),
});

excludeFiles

Type: string[]
Available for: Serverless

Use this property to exclude any files from the bundling process that would otherwise be included.

import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';

export default defineConfig({
  // ...
  output: 'server',
  adapter: vercel({
    excludeFiles: ['./src/some_big_file.jpg'],
  }),
});

maxDuration

Type: number
Available for: Serverless

Use this property to extend or limit the maximum duration (in seconds) that Serverless Functions can run before timing out. See the Vercel documentation for the default and maximum limit for your account plan.

import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';

export default defineConfig({
// ...
  output: "server",
  adapter: vercel({
    maxDuration: 60
  }),
});

Function bundling configuration

The Vercel adapter combines all of your routes into a single function by default.

You also have the option to split builds into a separate function for each route using the functionPerRoute option. This reduces the size of each function, meaning you are less likely to exceed the size limit for an individual function. Also, code starts are faster.

Verify that your Vercel plan includes an appropriate number of functions before enabling functionPerRoute. For example, Vercel’s free tier limits each deployment to no more than 12 functions. If your Vercel plan is insufficient for the number of routes in your project, you will receive an error message during deployment.

import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';

export default defineConfig({
  // ...
  output: 'server',
  adapter: vercel({
    functionPerRoute: true,
  }),
});

Vercel Edge Middleware

You can use Vercel Edge middleware to intercept a request and redirect before sending a response. Vercel middleware can run for Edge, SSR, and Static deployments. You may not need to install this package for your middleware. @vercel/edge is only required to use some middleware features such as geolocation. For more information see Vercel’s middleware documentation.

Add a middleware.js file to the root of your project:

export const config = {
  // Only run the middleware on the admin route
  matcher: '/admin',
};

export default function middleware(request) {
  const url = new URL(request.url);
  // You can retrieve IP location or cookies here.
  if (url.pathname === '/admin') {
    url.pathname = '/';
  }
  return Response.redirect(url);
}

While developing locally, you can run vercel dev to run middleware. In production, Vercel will handle this for you.

Vercel Edge Middleware with Astro middleware

The @astrojs/vercel/serverless adapter can automatically create the Vercel Edge middleware from an Astro middleware in your code base.

This is an opt-in feature, and the edgeMiddleware option needs to be set to true:

import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';

export default defineConfig({
  // ...
  output: 'server',
  adapter: vercel({
    edgeMiddleware: true,
  }),
});

Optionally, you can create a file recognized by the adapter named vercel-edge-middleware.(js|ts) in the srcDir folder to create Astro.locals.

Typings requires the @vercel/edge package.

/**
 *
 * @param options.request {Request}
 * @param options.context {import("@vercel/edge").RequestContext}
 * @returns {object}
 */
export default function ({ request, context }) {
  // do something with request and context
  return {
    title: "Spider-man's blog",
  };
}

If you use TypeScript, you can type the function as follows:

import type { RequestContext } from '@vercel/edge';

export default function ({ request, context }: { request: Request; context: RequestContext }) {
  // do something with request and context
  return {
    title: "Spider-man's blog",
  };
}

The data returned by this function will be passed to Astro middleware.

The function:

must export a default function;
must return an object;
accepts an object with a request and context as properties;
request is typed as Request;
context is typed as RequestContext;

Limitations and constraints

When you opt in to this feature, there are few constraints to note:

The Vercel Edge middleware will always be the first function to receive the Request and the last function to receive Response. This an architectural constraint that follows the boundaries set by Vercel.
Only request and context may be used to produce an Astro.locals object. Operations like redirects, etc. should be delegated to Astro middleware.
Astro.locals must be serializable. Failing to do so will result in a runtime error. This means that you cannot store complex types like Map, function, Set, etc.

Node.js Version Support

The @astrojs/vercel adapter supports specific Node.js versions for deploying your Astro project on Vercel. To view the supported Node.js versions on Vercel, click on the settings tab for a project and scroll down to “Node.js Version” section.