Understanding Tags and Cache Invalidation in RTK Query
In RTK Query, tags are labels you assign to cached data so that queries and mutations can communicate with each other about when data should be refetched or updated. They make cache management simple, consistent, and automatic.
1. Provides Tags: A query endpoint can provide one or more tags using
providesTags. This marks the cached data with those tags.2. Invalidates Tags: A mutation endpoint can use
invalidatesTagsto specify which tags should be invalidated when it runs.3. Automatic Refetching: When a tag is invalidated, RTK Query automatically refetches any queries that provide that tag — keeping the UI data fresh without manual refetch calls.
In this example, the getPosts query provides the Posts tag. When the addPost mutation runs, it invalidates that tag, triggering an automatic refetch of getPosts. This ensures that the cache and UI stay in sync without extra manual steps.
Tags are an essential feature of RTK Query’s caching system, helping developers manage complex data relationships easily and maintain up-to-date UI data automatically.