To include Bun in your service's environment, you must do at least one of the following:

• Set your service's Bun version using one of the methods below.
• Include a bun.lock or bun.lockb file in your service's root directory.

Otherwise, your service's environment will not include Bun.

Set your service's Bun version in any of the following ways (in descending order of precedence):

1. Set the BUN_VERSION environment variable for your service in the Render Dashboard:

   

2. Add a file named .bun-version to the root of your repo. This file contains a single line with the version to use:

You can specify either a semantic version number (such as 1.3.4) or use latest to always use the most recent version of Bun with every deploy.

History of default Bun versions

If you don't set a Bun version for your service, Render's default version depends on when you originally created the service: