@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 only need this adapter if you are using additional Vercel services (e.g. Vercel Web Analytics, Vercel Image Optimization). Otherwise, you do not need an adapter to deploy your static site.

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:

`webAnalytics`

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',
  }),
});

`isr`

Type: boolean | VercelISRConfig
Available for: Serverless

Added in: @astrojs/vercel@7.2.0

Default: false

Allows your project to be deployed as an ISR (Incremental Static Regeneration) function, which caches your on-demand rendered pages in the same way as prerendered pages after first request.

To enable this feature, set isr to true in your Vercel adapter configuration in astro.config.mjs:

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

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

Note that ISR function requests do not include search params, similar to requests in static mode.

ISR cache invalidation

By default, an ISR function caches for the duration of your deployment. You can further control caching by setting an expiration time, or by excluding particular routes from caching entirely.

Time-based invalidation

You can change the length of time to cache routes this by configuring an expiration value in seconds:

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

export default defineConfig({
  // ...
  output: 'server',
  adapter: vercel({
    isr: {
      // caches all pages on first request and saves for 1 day
      expiration: 60 * 60 * 24,
    },
  }),
});

Excluding paths from caching

To implement Vercel’s Draft mode, or On-Demand Incremental Static Regeneration (ISR), you can create a bypass token and provide it to the isr config along with any routes to exclude from caching:

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

export default defineConfig({
    output: "server",
    adapter: vercel({
        isr: {
            // A secret random string that you create.
            bypassToken: "005556d774a8",
            // Paths that will always be served fresh.
            exclude: [ "/api/invalidate", "/posts/[...slug]" ]
        }
    })
})

`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,
  }),
});

Running Astro middleware on Vercel Edge Functions

The @astrojs/vercel/serverless adapter can create an edge function from an Astro middleware in your code base. When edgeMiddleware is enabled, an edge function will execute your middleware code for all requests including static assets, prerendered pages, and on-demand rendered pages.

For on-demand rendered pages, the context.locals object is serialized using JSON and sent in a header for the serverless function, which performs the rendering. As a security measure, the serverless function will refuse to serve requests with a 403 Forbidden response unless they come from the generated edge function.

This is an opt-in feature. To enable it, set edgeMiddleware to true:

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

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

The edge middleware has access to Vercel’s RequestContext as ctx.locals.vercel.edge. If you’re using TypeScript, you can get proper typings by updating src/env.d.ts to use EdgeLocals:

/// <reference path="../.astro/types.d.ts" />
/// <reference types="astro/client" />

type EdgeLocals = import('@astrojs/vercel').EdgeLocals

declare namespace App {
  interface Locals extends EdgeLocals {
    // ...
  }
}

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.