Dev Containers: What's New

Three improvements have shipped for dev containers: instant code previews, a long-standing sign-in redirect bug fixed, and automatic idle pausing. Here’s what changed and what (if anything) you need to do.

Live Previews With HMR

New dev containers now use Hot Module Replacement. Changes to your code appear in the browser almost instantly, without a full rebuild. If you’ve been working through the old flow (edit, wait, reload, check) this is the improvement you’ll notice most.

Existing containers don’t get this automatically. If you want it, ask Amber to rebuild your dev container. Your project files are preserved — only the container setup is refreshed.

Sign-In No Longer Loops

If your container runs an application with its own sign-in page (Clerk, Auth.js, a custom login form), you’ve likely hit this: clicking sign in dumps you back at the Amber dashboard instead of your app. The platform’s authentication layer was intercepting the redirect before the container’s login could complete.

That’s fixed. Container sign-in pages now load directly, and post-login redirects stay within your container. No rebuild needed — this applies to all existing and new containers immediately.

Automatic Idle Pausing

Containers that sit idle for one hour will now pause automatically to free up resources. They restart the moment you return — no data is lost, and the restart is fast enough that you’re unlikely to notice it.

Memory and CPU limits have also been tuned. If your container was occasionally crashing unexpectedly, this is probably why it’s now more stable.

Summary

Change	New containers	Existing containers
Live previews (HMR)	Enabled by default	Rebuild to get it
Sign-in fix	Applies automatically	Applies automatically
Idle pause after 1hr	Enabled by default	Enabled by default
Tuned resource limits	Enabled by default	Enabled by default

If you want live previews, ask Amber to rebuild. Everything else is already in effect.