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

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

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.

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
• 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<TResult>
• Will be an Array of whatever select returns for each matching mutation.