Environment Variables Now Available at Sandbox Creation

Vercel has enhanced its Sandbox SDK and CLI with support for setting environment variables at sandbox creation time. This feature streamlines workflows that involve multiple sequential commands requiring the same environment configuration.

What Changed

When creating a Sandbox instance, developers can now pass environment variables via the env parameter:

await using sandbox = await Sandbox.create({
  env: { HELLO: "world", DEBUG: "true" },
});

These environment variables are automatically inherited by every subsequent runCommand call, eliminating the need to redeclare them for each step.

Flexibility and Override Support

While environment variables are inherited from sandbox creation, the feature maintains flexibility:

• Inheritance: All environment variables passed to Sandbox.create() are available to every command
• Per-command overrides: Individual runCommand calls can still override specific environment variable values when needed

Getting Started

Developers can update to the latest version with:

npm install @vercel/sandbox

This enhancement is particularly useful for multi-step processes like installing dependencies, building projects, or starting development servers, where maintaining consistent configuration across steps is critical.