Container Corral by ima-hima

Container Corral keeps your Firefox tabs organized around Multi-Account Containers, using Firefox's built-in native tab groups.

Group tabs by container
Every container gets its own tab group. Open a tab in your "Work" container and it joins the "Work" group; open one in "Shopping" and it joins "Shopping." Tab groups can't span windows, so a tab is moved to whichever window already holds its container's group — keeping every tab in a container together, even across multiple windows.

Inherit the container for new tabs (optional)
Turn this on and a blank new tab — from Ctrl+T, the + button, or a link opened from outside Firefox — opens in the same container as the tab you were just on, instead of defaulting to no container.

Tab right-click menu
Move a tab into its container's group, or reopen it without a container.

Container Corral doesn't manage per-site "always open this in a container" rules — use Multi-Account Containers' own "Always Open in This Container" feature for that.

Requires Firefox 142+ (for native tab groups). Source: https://github.com/ima-hima/container-corral