Vercel is rolling out a routing fix for Microfrontends that changes how aliases and branch-assigned domains behave across multi-project deployments.
Two specific behaviors are changing. First, running `vc alias` on a Microfrontends URL now carries the full `microfrontends` routing config to the new alias. Previously it only copied the `deploymentId`, stripping the routing rules entirely. Update to the latest Vercel CLI to get this. Second, a project domain assigned to a git branch now routes to that branch across every project in the Microfrontend that shares the branch name, not just the project that owns the domain.
The fix is narrow but the blast radius of the old behavior was wide: anyone using aliases for staging environments or branch domains for preview workflows was getting silently broken routing. The official Microfrontends documentation has the full details on routing rules, alias behavior, and domain assignment.
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