Vercel Microfrontends Introduces Missing Configuration Check Feature

Vercel prevents production routing errors through the Microfrontends Config Present deployment check feature. This feature blocks deployment if the microfrontends.json file is not included in the deployment output, preventing service disruption.

This feature is applied by default without separate configuration for apps designated as the default app within a Microfrontends group among projects using Vercel Microfrontends. It works alongside existing Native Deployment Checks such as lint or typecheck.

This check mainly operates when manually promoting an older branch without Microfrontends configuration to production. From the next deployment that includes the configuration file, it passes normally. Related behavior can be adjusted in the project's Build and Deployment Settings.