WXT

Appearance

Upgrading WXT ​

Overview ​

To upgrade WXT to the latest major version:

  1. Install it, skipping scripts so wxt prepare doesn't run - it will probably throw an error after a major version change (we'll run it later).

    sh
    pnpm i wxt@latest --ignore-scripts

  2. Follow the upgrade steps below to fix any breaking changes.

  3. Run wxt prepare. It should succeed and type errors will go away afterwards.

    sh
    pnpm wxt prepare

  4. Manually test to make sure both dev mode and production builds work.

For minor or patch version updates, there are no special steps. Just update it with your package manager:

sh
pnpm i wxt@latest

Listed below are all the breaking changes you should address when upgrading to a new version of WXT.

Currently, WXT is in pre-release. This means changes to the second digit, v0.X, are considered major and have breaking changes. Once v1 is released, only major version bumps will have breaking changes.

v0.20.0 → v0.21.0 ​

This release focuses on trimming WXT's install footprint and simplifying project configuration.

TIP

Read through all the changes once before updating your code.

Install Footprint ​

When installing wxt v0.20, it downloaded 98 MB and 366 packages to your node_modules. v0.21 cuts this down to 64 MB / 320 packages - that's 65.3% the previous size! This is a good improvement, but frankly, not good enough. Why?

  • wxt init is slow for new developers trying it out
  • Less exposure to supply chain attacks
  • More compute and storage used by servers hosting the package and clients downloading it degrades hardware and shortens their life-cycle

If you want to explore WXT's dependencies and why it's so large, here's a few links:

We'll continue working on minimizing WXT's install footprint.

Minimum Node.js, Vite, and TypeScript Versions ​

ToolOld requirementNew requirement
Node.js>=20.12.0>=22
Vite^5.4.19 || ^6.3.4 || ^7.0.0^6.3.4 || ^7.0.0 || ^8.0.0-0
TypeScriptNot enforced>=5.4

Vite 5 support was dropped as part of moving WXT's dev server off vite-node and onto Vite's native ModuleRunner/Environment API, which requires Vite ≥6.3.4.

vite, web-ext, and typescript Are Now Peer Dependencies ​

Previously, WXT installed its own copies of vite and web-ext for you (you never had to add them to your package.json). Now, all three are declared as peerDependencies instead of regular dependencies, so your project controls the exact version that gets used, and WXT's install size shrinks.

  • vite is a required peer, add it to your devDependencies.
  • web-ext and typescript are optional peers, only needed if you use the corresponding features (see below for web-ext).
sh
pnpm add -D vite typescript

Opt Into Opening the Browser During Dev Mode ​

In v0.21, web-ext is now an optional peer dependency - if it's installed, the browser will be opened automatically. If not, the feature is disabled.

  • To continue opening the browser automatically: Install web-ext as a dependency

    sh
    pnpm add -D web-ext

  • If you don't use this feature: Don't install it and you can delete any web-ext.config.ts options and/or remove any webExt.enabled: false config

You can still disable this behavior by setting webExt.enabled: false in your wxt.config.ts file or web-ext.config.ts file if the package is present.

Projects created with wxt init will include web-ext in their package.json, opting new projects into this feature by default.

.wxt/tsconfig.json Compiler Option Changes ​

The generated .wxt/tsconfig.json was updated to match Vite's current recommended TypeScript settings, and now requires TypeScript ≥5.4.

jsonc
{
  "compilerOptions": {
    "lib": ["ESNext", "DOM", "DOM.Iterable"], 
    "target": "ESNext",
    "module": "ESNext", 
    "module": "Preserve", 
    "moduleDetection": "force", 
    "moduleResolution": "Bundler",
    "allowImportingTsExtensions": true, 
    "verbatimModuleSyntax": true, 
    "noEmit": true,
    "esModuleInterop": true, 
    "forceConsistentCasingInFileNames": true, 
    "resolveJsonModule": true, 
    "strict": true,
    "skipLibCheck": true,
    "noFallthroughCasesInSwitch": true, 
    "noUncheckedIndexedAccess": true, 
    "noImplicitOverride": true, 
  },
}

If these changes do cause problems, verbatimModuleSyntax and noUncheckedIndexedAccess are the two most likely culprits. It's recommended you fix the issues and leave the new settings enabled.

However, if you want to revert the config back and upgrade to the recommended options at a later time, you can add the following to your wxt.config.ts file:

ts
export default defineConfig({
  hooks: {
    'prepare:tsconfig': (_, { tsconfig }) => {
      // Reverts TSConfig back to WXT v0.20
      // - https://wxt.dev/guide/resources/upgrading.html#wxttsconfigjson-compiler-option-changes
      delete tsconfig.lib;
      tsconfig.module = 'ESNext';
      delete tsconfig.moduleDetection;
      delete tsconfig.allowImportingTsExtensions;
      delete tsconfig.verbatimModuleSyntax;
      tsconfig.esModuleInterop = true;
      tsconfig.forceConsistentCasingInFileNames = true;
      tsconfig.resolveJsonModule = true;
      delete tsconfig.noFallthroughCasesInSwitch;
      delete tsconfig.noUncheckedIndexedAccess;
      delete tsconfig.noImplicitOverride;
    },
  },
});

url: Imports Removed ​

The url: import feature (importing and bundling remote code by URL, e.g. import 'url:https://code.jquery.com/jquery.js') has been removed due to the supply-chain risk of a compromised CDN silently injecting code into your build.

There is no config flag to restore this behavior. If you relied on it:

  • Prefer an NPM package if one exists for the library you need.
  • Vendor the file: download it once, commit it to your repo, and import it locally like any other file. This lets you review the code and track changes via version control, instead of trusting a URL to never change.
Why was this removed?

See https://github.com/wxt-dev/wxt/issues/2262 and https://github.com/wxt-dev/wxt/issues/2229 for the full discussion. A proposal to restore this behind a mandatory integrity hash is being tracked in #2514; if there's enough demand, it may come back as a separate, opt-in WXT module instead of core.

Zip Filename Template Changes ​

The default filename templates for zip.artifactTemplate and zip.sourcesTemplate changed, and the {{version}} template variable's meaning changed:

  • {{version}} now always resolves to manifest.version (previously it resolved to manifest.version_name ?? manifest.version).
  • A new {{versionName}} variable was added with the old {{version}} behavior (manifest.version_name ?? manifest.version).
  • A new {{packageVersion}} variable was added, resolving to your package.json's version.
  • A new {{modeSuffix}} variable was added (-dev for development builds, '' for production).

The defaults themselves changed to use these new variables:

diff
- artifactTemplate: '{{name}}-{{version}}-{{browser}}.zip'
+ artifactTemplate: '{{name}}-{{packageVersion}}-{{browser}}{{modeSuffix}}.zip'

- sourcesTemplate: '{{name}}-{{version}}-sources.zip'
+ sourcesTemplate: '{{name}}-{{packageVersion}}-sources{{modeSuffix}}.zip'

  • If you don't customize artifactTemplate/sourcesTemplate: your production zip filenames will not change, but dev and other build modes will be output to separate directories.

    If you previously install the dev version of your extension in your browser, note that the output directory has changed and you'll need to re-install it next time you run the dev command.

  • If you have a custom template: replace any {{version}} usage with {{versionName}} to keep the old value, or explicitly opt back into the old defaults:

    wxt.config.ts
    ts
    export default defineConfig({
  zip: {
    artifactTemplate: '{{name}}-{{versionName}}-{{browser}}.zip',
    sourcesTemplate: '{{name}}-{{versionName}}-sources.zip',
  },
});

For more info on the difference between manifest.version and manifest.version_name, see the Manifest Config docs.

Sources ZIP: includeSources/excludeSources Now Behave Like a Standard Allowlist ​

Previously, includeSources/excludeSources behaved counterintuitively: all files - excludeSources + includedSources = zipped files. This is not the standard behavior for allowlist/blocklists.

As of v0.21, these options behave as expected: includedSources - excludeSources = zipped files.

Additionally, a new zip.dotSources option (default false) was added to control whether hidden files/directories can be included in the zip.

This will likely be the biggest pain point of the upgrade. You will need to rebuild your included and excluded sources lists from scratch. Luckily, it's simpler than before!

  1. Do you need any hidden files? If so, set zip.dotSources to true
  2. Add base files and directories that need to be in the ZIP to zip.includeSources
  3. Run wxt zip -b firefox and confirm all the files you need are included
  4. Remove files from the zip by adding them to zip.excludeSources
  5. Run wxt zip -b firefox and confirm only the files you need are in the zip

TIP

wxt zip -b firefox now prints every file included in the sources ZIP. This will help you identify missing or unwanted files more quickly.

Here's an example configuration:

ts
// wxt.config.ts
export default defineConfig({
  srcDir: 'src',
  zip: {
    // Say I have a .tool-versions file I want to include
    dotSources: true,
    // Specify base folders and files to include
    includeSources: [
      'src',
      'public',
      'package.json',
      'bun.lock',
      'README.md',
      '.tool-versions',
    ],
    // Exclude any folders inside the base folders that are not needed, like test data
    excludeSources: ['**/__fixtures__'],
  },
});

createShadowRootUi DOM Changes ​

@webext-core/isolated-element was upgraded from v1 to v3. The only breaking change relevant to WXT projects is that the internal structure of the shadow root's is simpler:

html
<html>
  <head>
    <style>
      ...
    </style>
  </head>
  <body>
    ...your app
  </body>
</html>
html
<style>
  ...
</style>
<div>...your app</div>

Historically, CSS frameworks haven't had good support for shadow roots, so we needed a full <html> structure for styles to be applied correctly. But that has change this past few years, frameworks have started to include the host: selector alongside root: (which is required for base styles to be applied to the shadow root's host element):

css
:root { 
:root, :host { 
    /* base styles... */
}

If you use createShadowRootUi, see if your UI looks the same after this update without any changes.

If the styles are broken, you can continue using the full <html> structure by installing the v1 of @webext-core/isolated-element - WXT will respect whatever version of the package is listed in your package.json.

sh
pnpm add @webext-core/isolated-element@^1

In the next major version, support for @webext-core/isolated-element v1 will be dropped, so you have some time to migrate.

Content & Unlisted Script globalName Now Defaults to false ​

Content scripts and unlisted scripts are built as an IIFE. Previously, WXT generated a global variable to hold the IIFE's return value for all scripts by default. Now, no global variable is generated by default, producing a smaller, anonymous IIFE that prevents variable collisions with the page.

If you rely on the return value of your script, for example when injecting it with browser.scripting.executeScript and reading InjectionResult.result, set globalName: true to restore the old behavior:

ts
export default defineUnlistedScript({
  globalName: true, 
  main() {
    return 'some value';
  },
});

This applies per-entrypoint, to both defineContentScript and defineUnlistedScript.

ESLint Auto-Import Config Now Detects Your Installed ESLint Version ​

Setting imports.eslintrc.enabled: true used to always assume you wanted the legacy ESLint 8 config format, regardless of which ESLint version you actually had installed.

Now, true behaves the same as 'auto': WXT detects your installed ESLint version and generates the matching file automatically (ESLint 9+ → eslint-auto-imports.mjs, ESLint ≤8 → eslintrc-auto-import.json).

  • If you're on ESLint 9+ but never explicitly set enabled: 9, you'll now get the new flat-config file instead of the legacy one.
  • To force the old ESLint 8 format regardless of your installed version, set enabled: 8 explicitly.

See the ESLint config docs for the full set of options and how to wire up the generated file.

Deprecated APIs Removed From v0.21 ​

APIs deprecated in v0.20 have been removed:

  • wxt.config.runner / ExtensionRunnerConfig / defineRunnerConfig → use wxt.config.webExt / defineWebExtConfig instead.

  • dev.server.hostname → use dev.server.host instead.

  • The wxt/testing barrel export → import from the specific submodule instead:

    ts
    import { fakeBrowser, WxtVitest } from 'wxt/testing'; 
import { fakeBrowser } from 'wxt/testing/fake-browser'; 
import { WxtVitest } from 'wxt/testing/vitest-plugin';

  • The clean(root: string) JS API overload → Pass a root like this instead clean({ root: './my-extension' })

CWS v2 API Support ​

publish-browser-extension was upgraded to v5, which adds support for the new Chrome Web Store v2 API to wxt submit! Instead of using a refresh token for auth, it uses a service account, which is much easier to setup and never expires. It also supports a few other features: https://developer.chrome.com/blog/cws-api-v2

To setup your project to use v2, run wxt submit init and go through the setup process for the CWS, selecting v2 when prompted.

v1 will stop working 15th October 2026, so you have a few months to migrate.

@webext-core/fake-browser v2 ​

If you use wxt/testing/fake-browser (or @webext-core/fake-browser directly) in unit tests, note that its types now match @wxt-dev/browser instead of webextension-polyfill. This is the same change WXT's own browser went through in v0.20.

Most notably, mocking browser.runtime.onMessage listeners that return a promise no longer works, use sendResponse instead:

ts
fakeBrowser.runtime.onMessage.addListener(async () => { 
  return await someAsyncWork(); 
fakeBrowser.runtime.onMessage.addListener((_message, _sender, sendResponse) => { 
  someAsyncWork().then(sendResponse); 
  return true; 
});

If you use use a messaging library, it will likely continue working as-is.

New Deprecations in v0.20 ​

Deprecated APIs will be removed in the next major release.

  • useAppConfig deprecated in favor of getAppConfig - same function, just renamed. This avoids react linters mistaking it as a hook.

v0.19.0 → v0.20.0 ​

v0.20 is a big release! There are lots of breaking changes because this version is intended to be a release candidate for v1.0. If all goes well, v1.0 will be released with no additional breaking changes.

TIP

Read through all the changes once before updating your code.

webextension-polyfill Removed ​

WXT's browser no longer uses the webextension-polyfill!

Why?

See https://github.com/wxt-dev/wxt/issues/784

To upgrade, you have two options:

  1. Stop using the polyfill

    • If you're already using extensionApi: "chrome", then you're not using the polyfill and there is nothing to change!

    • Otherwise there is only one change: browser.runtime.onMessage no longer supports using promises to return a response:

      ts
      browser.runtime.onMessage.addListener(async () => { 
  const res = await someAsyncWork(); 
  return res; 
browser.runtime.onMessage.addListener(async (_message, _sender, sendResponse) => { 
  someAsyncWork().then((res) => { 
    sendResponse(res); 
  }); 
  return true; 
});

  2. Continue using the polyfill - If you want to keep using the polyfill, you can! One less thing to worry about during this upgrade.

    • Install webextension-polyfill and WXT's new polyfill module:

      sh
      pnpm i webextension-polyfill @wxt-dev/webextension-polyfill

    • Add the WXT module to your config:

      wxt.config.ts
      ts
      export default defineConfig({
  modules: ['@wxt-dev/webextension-polyfill'],
});

The new browser object (and types) is backed by WXT's new package: @wxt-dev/browser. This package continues WXT's mission of providing useful packages for the whole community. Just like @wxt-dev/storage, @wxt-dev/i18n, @wxt-dev/analytics, it is designed to be easy to use in any web extension project, not just those using WXT, and provides a consistent API across all browsers and manifest versions.

extensionApi Config Removed ​

The extensionApi config has been removed. Before, this config provided a way to opt into using the new browser object prior to v0.20.0.

Remove it from your wxt.config.ts file if present:

wxt.config.ts
ts
export default defineConfig({
  extensionApi: 'chrome', 
});

Extension API Type Changes ​

With the new browser introduced in v0.20, how you access types has changed. WXT now provides types based on @types/chrome instead of @types/webextension-polyfill.

These types are more up-to-date with MV3 APIs, contain less bugs, are better organized, and don't have any auto-generated names.

To access types, use the new Browser namespace from wxt/browser:

ts
import type { Runtime } from 'wxt/browser'; 
import type { Browser } from 'wxt/browser'; 

function getMessageSenderUrl(sender: Runtime.MessageSender): string { 
function getMessageSenderUrl(sender: Browser.runtime.MessageSender): string { 
  // ...
}

If you use auto-imports, Browser will be available without manually importing it.

Not all type names will be the same as what @types/webextension-polyfill provides. You'll have to find the new type names by looking at the types of the browser.* API's you use.

public/ and modules/ Directories Moved ​

The default location for the public/ and modules/ directories have changed to better align with standards set by other frameworks (Nuxt, Next, Astro, etc). Now, each path is relative to the project's root directory, not the src directory.

  • If you follow the default folder structure, you don't need to make any changes.
  • If you set a custom srcDir, you have two options:

    1. Move the your public/ and modules/ directories to the project root:

      html
       📂 {rootDir}/
    📁 modules/ 
    📁 public/ 
    📂 src/
       📁 components/
       📁 entrypoints/
       📁 modules/ 
       📁 public/ 
       📁 utils/
       📄 app.config.ts
    📄 wxt.config.ts

    2. Keep the folders in the same place and update your project config:

      wxt.config.ts
      ts
      export default defineConfig({
  srcDir: 'src',
  publicDir: 'src/public', 
  modulesDir: 'src/modules', 
});

Import Path Changes and #imports ​

The APIs exported by wxt/sandbox, wxt/client, or wxt/storage have moved to individual exports under the wxt/utils/* path.

Why?

As WXT grows and more utilities are added, any helper with side-effects will not be tree-shaken out of your final bundle.

This can cause problems because not every API used by these side-effects is available in every type of entrypoint. Some APIs can only be used in the background, sandboxed pages can't use any extension API, etc. This was leading to JS throwing errors in the top-level scope, preventing your code from running.

Splitting each util into it's own module solves this problem, making sure you're only importing APIs and side-effects into entrypoints they can run in.

Refer to the updated API Reference to see the list of new import paths.

However, you don't need to memorize or learn the new import paths! v0.20 introduces a new virtual module, #imports, that abstracts all this away from developers. See the blog post for more details about how this module works.

So to upgrade, just replace any imports from wxt/storage, wxt/client, and wxt/sandbox with an import to the new #imports module:

ts
import { storage } from 'wxt/storage'; 
import { defineContentScript } from 'wxt/sandbox'; 
import { ContentScriptContext, useAppConfig } from 'wxt/client'; 
import { storage } from '#imports'; 
import { defineContentScript } from '#imports'; 
import { ContentScriptContext, getAppConfig } from '#imports';

You can combine the imports into a single import statement, but it's easier to just find/replace each statement.

ts
import { storage } from 'wxt/storage'; 
import { defineContentScript } from 'wxt/sandbox'; 
import { ContentScriptContext, useAppConfig } from 'wxt/client'; 
import {
  storage, 
  defineContentScript, 
  ContentScriptContext, 
  getAppConfig, 
} from '#imports';

TIP

Before types will work, you'll need to run wxt prepare after installing v0.20 to generate the new TypeScript declarations.

createShadowRootUi CSS Changes ​

WXT now resets styles inherited from the webpage (visibility, color, font-size, etc.) by setting all: initial inside the shadow root.

WARNING

This doesn't effect rem units. You should continue using postcss-rem-to-px or an equivalent library if the webpage sets the HTML element's font-size.

If you use createShadowRootUi:

  1. Remove any manual CSS overrides that reset the style of specific websites. For example:

    entrypoints/reddit.content/style.css
    css
    body { 
  /* Override Reddit's default "hidden" visibility on elements */
  visibility: visible !important; 
}

  2. Double check that your UI looks the same as before.

If you run into problems with the new behavior, you can disable it and continue using your current CSS:

ts
const ui = await createShadowRootUi({
  inheritStyles: true, 
  // ...
});

Default Output Directories Changed ​

The default value for the outDirTemplate config has changed. Now, different build modes are output to different directories:

  • --mode production → .output/chrome-mv3: Production builds are unchanged
  • --mode development → .output/chrome-mv3-dev: Dev mode now has a -dev suffix so it doesn't overwrite production builds
  • --mode custom → .output/chrome-mv3-custom: Other custom modes end with a -[mode] suffix

To use the old behavior, writing all output to the same directory, set the outDirTemplate option:

wxt.config.ts
ts
export default defineConfig({
  outDirTemplate: '{{browser}}-mv{{manifestVersion}}', 
});

WARNING

If you've previously loaded the extension into your browser manually for development, you'll need to uninstall and re-install it from the new dev output directory.

Deprecated APIs Removed ​

  • entrypointLoader option: WXT now uses vite-node for importing entrypoints during the build process.

    This was deprecated in v0.19.0, see the v0.19 section for migration steps.

  • transformManifest option: Use the build:manifestGenerated hook to transform the manifest instead:
    wxt.config.ts
    ts
    export default defineConfig({
  transformManifest(manifest) { 
  hooks: { 
    'build:manifestGenerated': (_, manifest) => { 
       // ...
    }, 
  },
});

New Deprecations ​

runner APIs Renamed ​

To improve consistency with the web-ext.config.ts filename, the "runner" API and config options have been renamed. You can continue using the old names, but they have been deprecated and will be removed in a future version:

  1. The runner option has been renamed to webExt:

    wxt.config.ts
    ts
    export default defineConfig({
  runner: { 
  webExt: { 
    startUrls: ["https://wxt.dev"],
  },
});

  2. defineRunnerConfig has been renamed to defineWebExtConfig:

    web-ext.config.ts
    ts
    import { defineRunnerConfig } from 'wxt'; 
import { defineWebExtConfig } from 'wxt';

  3. The ExtensionRunnerConfig type has been renamed to WebExtConfig

    ts
    import type { ExtensionRunnerConfig } from 'wxt'; 
import type { WebExtConfig } from 'wxt';

v0.18.5 → v0.19.0 ​

vite-node Entrypoint Loader ​

The default entrypoint loader has changed to vite-node. If you use any NPM packages that depend on the webextension-polyfill, you need to add them to Vite's ssr.noExternal option:

wxt.config.ts
ts
export default defineConfig({
  vite: () => ({ 
    ssr: { 
      noExternal: ['@webext-core/messaging', '@webext-core/proxy-service'], 
    }, 
  }), 
});

Read the full docs for more information.

This change enables:

Importing variables and using them in the entrypoint options:

entrypoints/content.ts
ts
import { GOOGLE_MATCHES } from '~/utils/constants'

export default defineContentScript({
  matches: [GOOGLE_MATCHES],
  main: () => ...,
})

Using Vite-specific APIs like import.meta.glob to define entrypoint options:

entrypoints/content.ts
ts
const providers: Record<string, any> = import.meta.glob('../providers/*', {
  eager: true,
});

export default defineContentScript({
  matches: Object.values(providers).flatMap(
    (provider) => provider.default.paths,
  ),
  async main() {
    console.log('Hello content.');
  },
});

Basically, you can now import and do things outside the main function of the entrypoint - you could not do that before. Still though, be careful. It is recommended to avoid running code outside the main function to keep your builds fast.

To continue using the old approach, add the following to your wxt.config.ts file:

wxt.config.ts
ts
export default defineConfig({
  entrypointLoader: 'jiti', 
});

WARNING

entrypointLoader: "jiti" is deprecated and will be removed in the next major version.

Drop CJS Support ​

WXT no longer ships with Common JS support. If you're using CJS, here's your migration steps:

  1. Add "type": "module" to your package.json.
  2. Change the file extension of any .js files that use CJS syntax to .cjs, or update them to use EMS syntax.

Vite also provides steps for migrating to ESM. Check them out for more details: https://vitejs.dev/guide/migration#deprecate-cjs-node-api

v0.18.0 → v0.18.5 ​

When this version was released, it was not considered a breaking change... but it should have been.

New modules/ Directory ​

WXT now recognizes the modules/ directory as a folder containing WXT modules.

If you already have <srcDir>/modules or <srcDir>/Modules directory, wxt prepare and other commands will fail.

You have two options:

  1. [Recommended] Keep your files where they are and tell WXT to look in a different folder:

    wxt.config.ts
    ts
    export default defineConfig({
  modulesDir: 'wxt-modules', // defaults to "modules"
});

  2. Rename your modules directory to something else.

v0.17.0 → v0.18.0 ​

Automatic MV3 host_permissions to MV2 permissions ​

Out of an abundance of caution, this change has been marked as a breaking change because permission generation is different.

If you list host_permissions in your wxt.config.ts's manifest and have released your extension, double check that your permissions and host_permissions have not changed for all browsers you target in your .output/*/manifest.json files. Permission changes can cause the extension to be disabled on update, and can cause a drop in users, so be sure to double check for differences compared to the previous manifest version.

v0.16.0 → v0.17.0 ​

Storage - defineItem Requires defaultValue Option ​

If you were using defineItem with versioning and no default value, you will need to add defaultValue: null to the options and update the first type parameter:

ts
const item = storage.defineItem<number>("local:count", { 
const item = storage.defineItem<number | null>("local:count", { 
defaultValue: null, 
  version: ...,
  migrations: ...,
})

The defaultValue property is now required if passing in the second options argument.

If you exclude the second options argument, it will default to being nullable, as before.

ts
const item: WxtStorageItem<number | null> =
  storage.defineItem<number>('local:count');
const value: number | null = await item.getValue();

Storage - Fix Types In watch Callback ​

If you don't use TypeScript, this isn't a breaking change, this is just a type change.

ts
const item = storage.defineItem<number>('local:count', { defaultValue: 0 });
item.watch((newValue: number | null, oldValue: number | null) => { 
item.watch((newValue: number, oldValue: number) => { 
  // ...
});

v0.15.0 → v0.16.0 ​

Output Directory Structure Changed ​

JS entrypoints in the output directory have been moved. Unless you're doing some kind of post-build work referencing files, you don't have to make any changes.

plaintext
.output/
  <target>/
    chunks/
      some-shared-chunk-<hash>.js
      popup-<hash>.js // [!code --]
    popup.html
    popup.html
    popup.js // [!code ++]

v0.14.0 → v0.15.0 ​

Renamed zip.ignoredSources to zip.excludeSources ​

wxt.config.ts
ts
export default defineConfig({
  zip: {
    ignoredSources: [
      /*...*/
    ], 
    excludeSources: [
      /*...*/
    ], 
  },
});

Renamed Undocumented Constants ​

Renamed undocumented constants for detecting the build config at runtime in #380. Now documented here: https://wxt.dev/guide/essentials/config/environment-variables.html#built-in-environment-variables

  • __BROWSER__ → import.meta.env.BROWSER
  • __COMMAND__ → import.meta.env.COMMAND
  • __MANIFEST_VERSION__ → import.meta.env.MANIFEST_VERSION
  • __IS_CHROME__ → import.meta.env.CHROME
  • __IS_FIREFOX__ → import.meta.env.FIREFOX
  • __IS_SAFARI__ → import.meta.env.SAFARI
  • __IS_EDGE__ → import.meta.env.EDGE
  • __IS_OPERA__ → import.meta.env.OPERA

v0.13.0 → v0.14.0 ​

Content Script UI API changes ​

createContentScriptUi and createContentScriptIframe, and some of their options, have been renamed:

  • createContentScriptUi({ ... }) → createShadowRootUi({ ... })
  • createContentScriptIframe({ ... }) → createIframeUi({ ... })
  • type: "inline" | "overlay" | "modal" has been changed to position: "inline" | "overlay" | "modal"
  • onRemove is now called before the UI is removed from the DOM, previously it was called after the UI was removed
  • mount option has been renamed to onMount, to better match the related option, onRemove.

v0.12.0 → v0.13.0 ​

New wxt/storage APIs ​

wxt/storage no longer relies on unstorage. Some unstorage APIs, like prefixStorage, have been removed, while others, like snapshot, are methods on the new storage object. Most of the standard usage remains the same. See https://wxt.dev/guide/storage and https://wxt.dev/api/reference/wxt/storage/ for more details (#300)

v0.11.0 → v0.12.0 ​

API Exports Changed ​

defineContentScript and defineBackground are now exported from wxt/sandbox instead of wxt/client. (#284)

  • If you use auto-imports, no changes are required.

  • If you have disabled auto-imports, you'll need to manually update your import statements:

    ts
    import { defineBackground, defineContentScript } from 'wxt/client'; 
import { defineBackground, defineContentScript } from 'wxt/sandbox';

v0.10.0 → v0.11.0 ​

Vite 5 ​

You will need to update any other Vite plugins to a version that supports Vite 5.

v0.9.0 → v0.10.0 ​

Extension Icon Discovery ​

WXT no longer discovers icons other than .png files. If you previously used .jpg, .jpeg, .bmp, or .svg, you'll need to convert your icons to .png files or manually add them to the manifest inside your wxt.config.ts file.

v0.8.0 → v0.9.0 ​

Removed WebWorker Types by Default ​

Removed "WebWorker" types from .wxt/tsconfig.json. These types are useful for MV3 projects using a service worker.

To add them back to your project, add the following to your project's TSConfig:

json
{
  "extends": "./.wxt/tsconfig.json",
  "compilerOptions": {
    "lib": ["ESNext", "DOM", "WebWorker"] 
  } 
}

v0.7.0 → v0.8.0 ​

defineUnlistedScript ​

Unlisted scripts must now export default defineUnlistedScript(...).

BackgroundDefinition Type ​

Rename BackgroundScriptDefintition to BackgroundDefinition.

v0.6.0 → v0.7.0 ​

Content Script CSS Output Location Changed ​

Content script CSS used to be output to assets/<name>.css, but is now content-scripts/<name>.css to match the docs.

v0.5.0 → v0.6.0 ​

Require a Function for vite Config ​

The vite config option must now be a function. If you were using an object before, change it from vite: { ... } to vite: () => ({ ... }).

v0.4.0 → v0.5.0 ​

Revert Move Public Directory ​

Change default publicDir to from <rootDir>/public to <srcDir>/public.

v0.3.0 → v0.4.0 ​

Update Default Path Aliases ​

Use relative path aliases inside .wxt/tsconfig.json.

v0.2.0 → v0.3.0 ​

Move Public Directory ​

Change default publicDir to from <srcDir>/public to <rootDir>/public.

Improve Type Safety ​

Add type safety to browser.runtime.getURL.

v0.1.0 → v0.2.0 ​

Rename defineBackground ​

Rename defineBackgroundScript to defineBackground.