Workers - Workers Builds now uses newer versions of Node.js, Python, Go, Bun, and more

Your builds now run on newer versions of Node.js, Python, Ruby, Go, Bun, Yarn, and Python package managers by default, so you get the latest fixes and features without changing your build configuration.

Runtimes

Runtime	Previous version	New version	Override with
Node.js	24.18.0	24.21.0	NODE_VERSION
Python	3.13.3	3.14.8	PYTHON_VERSION
Ruby	3.4.7	3.4.11	RUBY_VERSION
Go	1.24.3	1.27.2	GO_VERSION

Tools and package managers

Tool	Previous version	New version	Override with
Bun	1.2.15	1.4.3	BUN_VERSION
Yarn	4.9.1	4.18.1	YARN_VERSION
pip	25.1.1	26.2.1
pipx	1.7.1	1.17.2
Poetry	2.1.3	2.4.3
uv	0.7.13	0.12.10

Bun 1.4.3 supports both v1 (bun.lockb) and v2 (bun.lock) lockfiles, so existing Bun projects continue to install without changes.

If your project already sets a version through an environment variable or a version file (such as .nvmrc, .node-version, .python-version, or .ruby-version), your builds continue to use that version. To keep using a previous default, add the matching environment variable to your build configuration. For example, set PYTHON_VERSION to 3.13.3.

For more information, refer to Override default versions and the build image policy.