Setting your Bun Version
| Current default Bun version |
|---|
|
Services created before 2025-08-18 have a different default version. See below. |
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.lockorbun.lockbfile 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):
-
Set the
BUN_VERSIONenvironment variable for your service in the Render Dashboard:
-
Add a file named
.bun-versionto 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 1.3.1) 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:
| Service Creation Date | Default Bun Version |
|---|---|
2025-08-18 and later | 1.2.20 |
Before 2025-08-18 | 1.1.0 |