Hooks

Inspired by unbuild, tsdown supports a flexible hooks system that allows you to extend and customize the build process. While we recommend using the plugin system for most build-related extensions, hooks provide a convenient way to inject Rolldown plugins or perform additional tasks at specific stages of the build lifecycle.

Usage

You can define hooks in your configuration file in two ways:

Passing an Object

Define your hooks as an object, where each key is a hook name and the value is a function:

tsdown.config.ts

import { defineConfig } from 'tsdown'

export default defineConfig({
  hooks: {
    'build:done': async () => {
      await doSomething()
    },
  },
})

Passing a Function

Alternatively, you can pass a function that receives the hooks object, allowing you to register hooks programmatically:

tsdown.config.ts

import { defineConfig } from 'tsdown'

export default defineConfig({
  hooks(hooks) {
    hooks.hook('build:prepare', () => {
      console.log('Hello World')
    })
  },
})

For more details on how to use the hooks, refer to the hookable documentation.

Available Hooks

For detailed type definitions, see src/features/hooks.ts.

build:prepare

Invoked before each tsdown build starts. Use this hook to perform setup or preparation tasks.

build:before

Invoked before each Rolldown build. For dual-format builds, this hook is called for each format. Useful for configuring or modifying the build context before bundling.

build:done

Invoked after each tsdown build completes. Use this hook for cleanup or post-processing tasks.