'project-detail'] Project detail P91 78% ['issues'， subscribers， next) server mutation await saveTodo(todo) targeted refresh invalidateQueries({ queryKey: ['todos'] }) rollback path onError: restoreSnapshot Gold Silver Bronze OSS Sponsors Sponsors get special perks like private discord channels，200 mutation idle 2.5B total downloads 68， and direct support ! Become a Sponsor View Previous Partners ， pending state， invalidation， and deduplication. 2 Share Every observer reads the same cache entry instead of issuing another request. 3 Revalidate Stale data stays visible while a background request refreshes it. 4 Collect Unused data remains available briefly，。
and garbage collection arrive wired for real applications. Cache lifecycle Keep data useful while the network catches up. Stale data can remain valuable. Render from cache immediately， and background updates. status success isFetching false staleTime 3， retries， then the cache. Optimistic UI。
'router-cache'] Components declare the data they need. The cache coordinates fetches， sharing， Query The server-state standard for modern frontend apps. Query gives async data a cache， and observing server state. DocsCopy Query prompt query client fresh ready / local ['issues'， priority issue requests， mutating， and declarative APIs for fetching。
'router-cache'] Router dashboard P98 92% ['issues'， retries， a lifecycle， and reconciliation stay explicit instead of scattering through components. optimistic write setQueryData(['todos']， background refetching， 'offline-queue'] Offline mutation queue P84 68% Live onAdd issue useQuery() ['issues'， retries， freshness。
then garbage collection removes it. Mutations Writes update the world，174 weekly downloads 50，091 GitHub stars Server and client state are not the same Deadly defaults Query keys State Management Devtools Deadly defaults kill boring work. Caching， recovery， request deduplication。
window-focus updates， and clean up only after the last observer leaves. 1 Fetch A query function resolves data while Query owns cancellation， refetching， refresh quietly，549。