Custom builds

Custom builds are a way for you to customize how your code is compiled, before being processed by Wrangler.

Note

With the release of Wrangler v2, it is no longer necessary to use custom builds to bundle your code via webpack and similar bundlers. Wrangler runs esbuild ↗ by default as part of the dev and publish commands, and bundles your Worker project into a single Worker script. Refer to Bundling.

Configure custom builds

Custom builds are configured by adding a [build] section in your wrangler.toml, and using the following options for configuring your custom build.

• command string optional

  • The command used to build your Worker. On Linux and macOS, the command is executed in the sh shell and the cmd shell for Windows. The && and || shell operators may be used. This command will be run as part of wrangler dev and npx wrangler deploy.

• cwd string optional

  • The directory in which the command is executed.

• watch_dir string | string\[] optional

  • The directory to watch for changes while using wrangler dev. Defaults to the current working directory.

Example:

wrangler.toml

[build]
command = "npm run build"
cwd = "build_cwd"
watch_dir = "build_watch_dir"