TanStack Query (React Query) v5

Last Updated: 2025-11-28 Versions: @tanstack/react-query@5.90.11, @tanstack/react-query-devtools@5.90.2 Requires: React 18.0+ (useSyncExternalStore), TypeScript 4.7+ (recommended)

---

Quick Setup

npm install @tanstack/react-query@latest
npm install -D @tanstack/react-query-devtools@latest

Step 2: Provider + Config

// src/main.tsx
import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
import { ReactQueryDevtools } from '@tanstack/react-query-devtools'

const queryClient = new QueryClient({
  defaultOptions: {
    queries: {
      staleTime: 1000 * 60 * 5, // 5 min
      gcTime: 1000 * 60 * 60, // 1 hour (v5: renamed from cacheTime)
      refetchOnWindowFocus: false,
    },
  },
})

<QueryClientProvider client={queryClient}>
  <App />
  <ReactQueryDevtools initialIsOpen={false} />
</QueryClientProvider>

Step 3: Query + Mutation Hooks

// src/hooks/useTodos.ts
import { useQuery, useMutation, useQueryClient, queryOptions } from '@tanstack/react-query'

// Query options factory (v5 pattern)
export const todosQueryOptions = queryOptions({
  queryKey: ['todos'],
  queryFn: async () => {
    const res = await fetch('/api/todos')
    if (!res.ok) throw new Error('Failed to fetch')
    return res.json()
  },
})

export function useTodos() {
  return useQuery(todosQueryOptions)
}

export function useAddTodo() {
  const queryClient = useQueryClient()
  return useMutation({
    mutationFn: async (newTodo) => {
      const res = await fetch('/api/todos', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(newTodo),
      })
      if (!res.ok) throw new Error('Failed to add')
      return res.json()
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['todos'] })
    },
  })
}

// Usage:
function TodoList() {
  const { data, isPending, isError, error } = useTodos()
  const { mutate } = useAddTodo()

  if (isPending) return <div>Loading...</div>
  if (isError) return <div>Error: {error.message}</div>
  return <ul>{data.map(todo => <li key={todo.id}>{todo.title}</li>)}</ul>
}

---

Critical Rules

Always Do

✅ Use object syntax for all hooks

// v5 ONLY supports this:
useQuery({ queryKey, queryFn, ...options })
useMutation({ mutationFn, ...options })

✅ Use array query keys

queryKey: ['todos']              // List
queryKey: ['todos', id]          // Detail
queryKey: ['todos', { filter }]  // Filtered

✅ Configure staleTime appropriately

staleTime: 1000 * 60 * 5 // 5 min - prevents excessive refetches

✅ Use isPending for initial loading state

if (isPending) return <Loading />
// isPending = no data yet AND fetching

✅ Throw errors in queryFn

if (!response.ok) throw new Error('Failed')

✅ Invalidate queries after mutations

onSuccess: () => {
  queryClient.invalidateQueries({ queryKey: ['todos'] })
}

✅ Use queryOptions factory for reusable patterns

const opts = queryOptions({ queryKey, queryFn })
useQuery(opts)
useSuspenseQuery(opts)
prefetchQuery(opts)

✅ Use gcTime (not cacheTime)

gcTime: 1000 * 60 * 60 // 1 hour

Never Do

❌ Never use v4 array/function syntax

// v4 (removed in v5):
useQuery(['todos'], fetchTodos, options) // ❌

// v5 (correct):
useQuery({ queryKey: ['todos'], queryFn: fetchTodos }) // ✅

❌ Never use query callbacks (onSuccess, onError, onSettled in queries)

// v5 removed these from queries:
useQuery({
  queryKey: ['todos'],
  queryFn: fetchTodos,
  onSuccess: (data) => {}, // ❌ Removed in v5
})

// Use useEffect instead:
const { data } = useQuery({ queryKey: ['todos'], queryFn: fetchTodos })
useEffect(() => {
  if (data) {
    // Do something
  }
}, [data])

// Or use mutation callbacks (still supported):
useMutation({
  mutationFn: addTodo,
  onSuccess: () => {}, // ✅ Still works for mutations
})

❌ Never use deprecated options

// Deprecated in v5:
cacheTime: 1000 // ❌ Use gcTime instead
isLoading: true // ❌ Meaning changed, use isPending
keepPreviousData: true // ❌ Use placeholderData instead
onSuccess: () => {} // ❌ Removed from queries
useErrorBoundary: true // ❌ Use throwOnError instead

❌ Never assume isLoading means "no data yet"

// v5 changed this:
isLoading = isPending && isFetching // ❌ Now means "pending AND fetching"
isPending = no data yet // ✅ Use this for initial load

❌ Never forget initialPageParam for infinite queries

// v5 requires this:
useInfiniteQuery({
  queryKey: ['projects'],
  queryFn: ({ pageParam }) => fetchProjects(pageParam),
  initialPageParam: 0, // ✅ Required in v5
  getNextPageParam: (lastPage) => lastPage.nextCursor,
})

❌ Never use enabled with useSuspenseQuery

// Not allowed:
useSuspenseQuery({
  queryKey: ['todo', id],
  queryFn: () => fetchTodo(id),
  enabled: !!id, // ❌ Not available with suspense
})

// Use conditional rendering instead:
{id && <TodoComponent id={id} />}

---

Known Issues Prevention

This skill prevents 8 documented issues from v5 migration and common mistakes:

Issue #1: Object Syntax Required

Error: useQuery is not a function or type errors Source: v5 Migration Guide Why It Happens: v5 removed all function overloads, only object syntax works Prevention: Always use useQuery({ queryKey, queryFn, ...options })

Before (v4):

useQuery(['todos'], fetchTodos, { staleTime: 5000 })

After (v5):

useQuery({
  queryKey: ['todos'],
  queryFn: fetchTodos,
  staleTime: 5000
})

Issue #2: Query Callbacks Removed

Error: Callbacks don't run, TypeScript errors Source: v5 Breaking Changes Why It Happens: onSuccess, onError, onSettled removed from queries (still work in mutations) Prevention: Use useEffect for side effects, or move logic to mutation callbacks

Before (v4):

useQuery({
  queryKey: ['todos'],
  queryFn: fetchTodos,
  onSuccess: (data) => {
    console.log('Todos loaded:', data)
  },
})

After (v5):

const { data } = useQuery({ queryKey: ['todos'], queryFn: fetchTodos })
useEffect(() => {
  if (data) {
    console.log('Todos loaded:', data)
  }
}, [data])

Issue #3: Status Loading → Pending

Error: UI shows wrong loading state Source: v5 Migration: isLoading renamed Why It Happens: status: 'loading' renamed to status: 'pending', isLoading meaning changed Prevention: Use isPending for initial load, isLoading for "pending AND fetching"

Before (v4):

const { data, isLoading } = useQuery(...)
if (isLoading) return <div>Loading...</div>

After (v5):

const { data, isPending, isLoading } = useQuery(...)
if (isPending) return <div>Loading...</div>
// isLoading = isPending && isFetching (fetching for first time)

Issue #4: cacheTime → gcTime

Error: cacheTime is not a valid option Source: v5 Migration: gcTime Why It Happens: Renamed to better reflect "garbage collection time" Prevention: Use gcTime instead of cacheTime

Before (v4):

useQuery({
  queryKey: ['todos'],
  queryFn: fetchTodos,
  cacheTime: 1000 * 60 * 60,
})

After (v5):

useQuery({
  queryKey: ['todos'],
  queryFn: fetchTodos,
  gcTime: 1000 * 60 * 60,
})

Issue #5: useSuspenseQuery + enabled

Error: Type error, enabled option not available Source: GitHub Discussion #6206 Why It Happens: Suspense guarantees data is available, can't conditionally disable Prevention: Use conditional rendering instead of enabled option

Before (v4/incorrect):

useSuspenseQuery({
  queryKey: ['todo', id],
  queryFn: () => fetchTodo(id),
  enabled: !!id, // ❌ Not allowed
})

After (v5/correct):

// Conditional rendering:
{id ? (
  <TodoComponent id={id} />
) : (
  <div>No ID selected</div>
)}

// Inside TodoComponent:
function TodoComponent({ id }: { id: number }) {
  const { data } = useSuspenseQuery({
    queryKey: ['todo', id],
    queryFn: () => fetchTodo(id),
    // No enabled option needed
  })
  return <div>{data.title}</div>
}

Issue #6: initialPageParam Required

Error: initialPageParam is required type error Source: v5 Migration: Infinite Queries Why It Happens: v4 passed undefined as first pageParam, v5 requires explicit value Prevention: Always specify initialPageParam for infinite queries

Before (v4):

useInfiniteQuery({
  queryKey: ['projects'],
  queryFn: ({ pageParam = 0 }) => fetchProjects(pageParam),
  getNextPageParam: (lastPage) => lastPage.nextCursor,
})

After (v5):

useInfiniteQuery({
  queryKey: ['projects'],
  queryFn: ({ pageParam }) => fetchProjects(pageParam),
  initialPageParam: 0, // ✅ Required
  getNextPageParam: (lastPage) => lastPage.nextCursor,
})

Issue #7: keepPreviousData Removed

Error: keepPreviousData is not a valid option Source: v5 Migration: placeholderData Why It Happens: Replaced with more flexible placeholderData function Prevention: Use placeholderData: keepPreviousData helper

Before (v4):

useQuery({
  queryKey: ['todos', page],
  queryFn: () => fetchTodos(page),
  keepPreviousData: true,
})

After (v5):

import { keepPreviousData } from '@tanstack/react-query'

useQuery({
  queryKey: ['todos', page],
  queryFn: () => fetchTodos(page),
  placeholderData: keepPreviousData,
})

Issue #8: TypeScript Error Type Default

Error: Type errors with error handling Source: v5 Migration: Error Types Why It Happens: v4 used unknown, v5 defaults to Error type Prevention: If throwing non-Error types, specify error type explicitly

Before (v4 - error was unknown):

const { error } = useQuery({
  queryKey: ['data'],
  queryFn: async () => {
    if (Math.random() > 0.5) throw 'custom error string'
    return data
  },
})
// error: unknown

After (v5 - specify custom error type):

const { error } = useQuery<DataType, string>({
  queryKey: ['data'],
  queryFn: async () => {
    if (Math.random() > 0.5) throw 'custom error string'
    return data
  },
})
// error: string | null

// Or better: always throw Error objects
const { error } = useQuery({
  queryKey: ['data'],
  queryFn: async () => {
    if (Math.random() > 0.5) throw new Error('custom error')
    return data
  },
})
// error: Error | null (default)

---

Key Patterns

Dependent Queries (Query B waits for Query A):

const { data: posts } = useQuery({
  queryKey: ['users', userId, 'posts'],
  queryFn: () => fetchUserPosts(userId),
  enabled: !!user, // Wait for user
})

Parallel Queries (fetch multiple at once):

const results = useQueries({
  queries: ids.map(id => ({ queryKey: ['todos', id], queryFn: () => fetchTodo(id) })),
})

Prefetching (preload on hover):

queryClient.prefetchQuery({ queryKey: ['todo', id], queryFn: () => fetchTodo(id) })

Infinite Scroll (useInfiniteQuery):

useInfiniteQuery({
  queryKey: ['todos', 'infinite'],
  queryFn: ({ pageParam }) => fetchTodosPage(pageParam),
  initialPageParam: 0, // Required in v5
  getNextPageParam: (lastPage) => lastPage.nextCursor,
})

Query Cancellation (auto-cancel on queryKey change):

queryFn: async ({ signal }) => {
  const res = await fetch(`/api/todos?q=${search}`, { signal })
  return res.json()
}

Data Transformation (select):

select: (data) => data.filter(todo => todo.completed)

Avoid Request Waterfalls: Fetch in parallel when possible (don't chain queries unless truly dependent)

---

Official Docs: https://tanstack.com/query/latest | v5 Migration: https://tanstack.com/query/latest/docs/framework/react/guides/migrating-to-v5 | GitHub: https://github.com/TanStack/query | Context7: /websites/tanstack_query