This adapter allows Astro to deploy your SSR site to Vercel.
Learn how to deploy your Astro site in our Vercel deployment guide.
If you're using Astro as a static site builder — its behavior out of the box — you don't need an adapter.
If you wish to use server-side rendering (SSR), Astro requires an adapter that matches your deployment runtime.
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.
Add the Vercel adapter to enable SSR in your Astro project with the following astro add
command. This will install the adapter and make the appropriate changes to your astro.config.mjs
file in one step.
# Using NPM
npx astro add vercel
# Using Yarn
yarn astro add vercel
# Using PNPM
pnpm astro add vercel
If you prefer to install the adapter manually instead, complete the following two steps:
-
Install the Vercel adapter to your project’s dependencies using your preferred package manager. If you’re using npm or aren’t sure, run this in the terminal:
npm install @astrojs/vercel
-
Add two new lines to your
astro.config.mjs
project configuration file.// astro.config.mjs import { defineConfig } from 'astro/config'; + import vercel from '@astrojs/vercel/serverless'; export default defineConfig({ + output: 'server', + adapter: vercel(), });
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';
📚 Read the full deployment guide here.
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
To configure this adapter, pass an object to the vercel()
function call in astro.config.mjs
:
Type: VercelWebAnalyticsConfig
Available for: Serverless, Static
Added in: @astrojs/[email protected]
You can enable Vercel Web Analytics by setting webAnalytics: { enabled: true }
. This will inject Vercel’s tracking scripts into all of your pages.
// astro.config.mjs
import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';
export default defineConfig({
output: 'server',
adapter: vercel({
webAnalytics: {
enabled: true,
},
}),
});
You can enable Vercel Speed Insights by setting speedInsights: { enabled: true }
. This will collect and send Web Vital data to Vercel.
Type: VercelSpeedInsightsConfig
Available for: Serverless, Static
Added in: @astrojs/[email protected]
// astro.config.mjs
import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';
export default defineConfig({
output: 'server',
adapter: vercel({
speedInsights: {
enabled: true,
},
}),
});
Type: VercelImageConfig
Available for: Serverless, Static
Added in: @astrojs/[email protected]
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.
// astro.config.mjs
import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/static';
export default defineConfig({
output: 'static',
adapter: vercel({
imagesConfig: {
sizes: [320, 640, 1280],
},
}),
});
Type: boolean
Available for: Serverless, Static
Added in: @astrojs/[email protected]
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.
// astro.config.mjs
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="..."
/>
Type: 'sharp' | 'squoosh' | string
Available for: Serverless, Static
Added in: @astrojs/[email protected]
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',
}),
});
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.
// astro.config.mjs
import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';
export default defineConfig({
output: 'server',
adapter: vercel({
includeFiles: ['./my-data.json'],
}),
});
Type: string[]
Available for: Serverless
Use this property to exclude any files from the bundling process that would otherwise be included.
// astro.config.mjs
import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';
export default defineConfig({
output: 'server',
adapter: vercel({
excludeFiles: ['./src/some_big_file.jpg'],
}),
});
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.
// astro.config.mjs
import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';
export default defineConfig({
output: "server",
adapter: vercel({
+ maxDuration: 60
}),
});
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.
// astro.config.mjs
import { defineConfig } from 'astro/config';
import vercel from '@astrojs/vercel/serverless';
export default defineConfig({
output: 'server',
adapter: vercel({
functionPerRoute: true,
}),
});
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:// middleware.js 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.
Warning Trying to rewrite? Currently rewriting a request with middleware only works for static files.
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
:
// astro.config.mjs
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.
// src/vercel-edge-middleware.js
/**
*
* @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:
// src/vercel-edge-middleware.ts
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
andcontext
as properties; request
is typed asRequest
;context
is typed asRequestContext
;
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 receiveResponse
. This an architectural constraint that follows the boundaries set by Vercel. - Only
request
andcontext
may be used to produce anAstro.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 likeMap
,function
,Set
, etc.
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.
Check out the Vercel documentation to learn more.
A few known complex packages (example: puppeteer) do not support bundling and therefore will not work properly with this adapter. By default, Vercel doesn't include npm installed files & packages from your project's ./node_modules
folder. To address this, the @astrojs/vercel
adapter automatically bundles your final build output using esbuild
.
For help, check out the #support
channel on Discord. Our friendly Support Squad members are here to help!
This package is maintained by Astro's Core team. You're welcome to submit an issue or PR!
See CHANGELOG.md for a history of changes to this integration.