--- id: useMutationState title: useMutationState --- `useMutationState` is a hook that gives you access to all mutations in the `MutationCache`. You can pass `filters` to it to narrow down your mutations, and `select` to transform the mutation state. **Example 1: Get all variables of all running mutations** ```tsx import { useMutationState } from '@tanstack/react-query' const variables = useMutationState({ filters: { status: 'pending' }, select: (mutation) => mutation.state.variables, }) ``` **Example 2: Get all data for specific mutations via the `mutationKey`** ```tsx import { useMutation, useMutationState } from '@tanstack/react-query' const mutationKey = ['posts'] // Some mutation that we want to get the state for const mutation = useMutation({ mutationKey, mutationFn: (newPost) => { return axios.post('/posts', newPost) }, }) const data = useMutationState({ // this mutation key needs to match the mutation key of the given mutation (see above) filters: { mutationKey }, select: (mutation) => mutation.state.data, }) ``` **Example 3: Access the latest mutation data via the `mutationKey`** Each invocation of `mutate` adds a new entry to the mutation cache for `gcTime` milliseconds. To access the latest invocation, you can check for the last item that `useMutationState` returns. ```tsx import { useMutation, useMutationState } from '@tanstack/react-query' const mutationKey = ['posts'] // Some mutation that we want to get the state for const mutation = useMutation({ mutationKey, mutationFn: (newPost) => { return axios.post('/posts', newPost) }, }) const data = useMutationState({ // this mutation key needs to match the mutation key of the given mutation (see above) filters: { mutationKey }, select: (mutation) => mutation.state.data, }) // Latest mutation data const latest = data[data.length - 1] ``` **Options** - `options` - `filters?: MutationFilters`: [Mutation Filters](../../guides/filters.md#mutation-filters) - `select?: (mutation: Mutation) => TResult` - Use this to transform the mutation state. - `queryClient?: QueryClient`, - Use this to use a custom QueryClient. Otherwise, the one from the nearest context will be used. **Returns** - `Array` - Will be an Array of whatever `select` returns for each matching mutation.