--- id: MutationObserverBaseResult title: MutationObserverBaseResult --- Defined in: [packages/query-core/src/types.ts:1335](https://github.com/TanStack/query/blob/main/packages/query-core/src/types.ts#L1335) The raw state stored on a `Mutation` instance. This is the underlying state that observer results (e.g. `MutationObserverResult`) are derived from. ## Extends - [`MutationState`](MutationState.md)\<`TData`, `TError`, `TVariables`, `TOnMutateResult`\> ## Extended by - [`MutationObserverIdleResult`](MutationObserverIdleResult.md) - [`MutationObserverLoadingResult`](MutationObserverLoadingResult.md) - [`MutationObserverErrorResult`](MutationObserverErrorResult.md) - [`MutationObserverSuccessResult`](MutationObserverSuccessResult.md) ## Type Parameters ### TData `TData` = `unknown` ### TError `TError` = [`DefaultError`](../type-aliases/DefaultError.md) ### TVariables `TVariables` = `void` ### TOnMutateResult `TOnMutateResult` = `unknown` ## Properties ### context ```ts context: TOnMutateResult | undefined; ``` Defined in: [packages/query-core/src/mutation.ts:40](https://github.com/TanStack/query/blob/main/packages/query-core/src/mutation.ts#L40) The value returned by `onMutate`, if defined. Passed to `onSuccess`, `onError` and `onSettled` as the mutation's context. #### Inherited from [`MutationState`](MutationState.md).[`context`](MutationState.md#context) *** ### data ```ts data: TData | undefined; ``` Defined in: [packages/query-core/src/types.ts:1344](https://github.com/TanStack/query/blob/main/packages/query-core/src/types.ts#L1344) The last successfully resolved data for the mutation. #### Overrides [`MutationState`](MutationState.md).[`data`](MutationState.md#data) *** ### error ```ts error: TError | null; ``` Defined in: [packages/query-core/src/types.ts:1353](https://github.com/TanStack/query/blob/main/packages/query-core/src/types.ts#L1353) The error object for the mutation, if an error was encountered. - Defaults to `null`. #### Overrides [`MutationState`](MutationState.md).[`error`](MutationState.md#error) *** ### failureCount ```ts failureCount: number; ``` Defined in: [packages/query-core/src/mutation.ts:53](https://github.com/TanStack/query/blob/main/packages/query-core/src/mutation.ts#L53) The number of times the mutation function has failed for the current attempt. #### Inherited from [`MutationState`](MutationState.md).[`failureCount`](MutationState.md#failurecount) *** ### failureReason ```ts failureReason: TError | null; ``` Defined in: [packages/query-core/src/mutation.ts:57](https://github.com/TanStack/query/blob/main/packages/query-core/src/mutation.ts#L57) The reason the current attempt failed, as reported by the retryer. #### Inherited from [`MutationState`](MutationState.md).[`failureReason`](MutationState.md#failurereason) *** ### isError ```ts isError: boolean; ``` Defined in: [packages/query-core/src/types.ts:1358](https://github.com/TanStack/query/blob/main/packages/query-core/src/types.ts#L1358) A boolean variable derived from `status`. - `true` if the last mutation attempt resulted in an error. *** ### isIdle ```ts isIdle: boolean; ``` Defined in: [packages/query-core/src/types.ts:1363](https://github.com/TanStack/query/blob/main/packages/query-core/src/types.ts#L1363) A boolean variable derived from `status`. - `true` if the mutation is in its initial state prior to executing. *** ### isPaused ```ts isPaused: boolean; ``` Defined in: [packages/query-core/src/mutation.ts:62](https://github.com/TanStack/query/blob/main/packages/query-core/src/mutation.ts#L62) Whether the mutation is currently paused (see network mode), or is waiting for another mutation with the same `scope` to finish. #### Inherited from [`MutationState`](MutationState.md).[`isPaused`](MutationState.md#ispaused) *** ### isPending ```ts isPending: boolean; ``` Defined in: [packages/query-core/src/types.ts:1368](https://github.com/TanStack/query/blob/main/packages/query-core/src/types.ts#L1368) A boolean variable derived from `status`. - `true` if the mutation is currently executing. *** ### isSuccess ```ts isSuccess: boolean; ``` Defined in: [packages/query-core/src/types.ts:1373](https://github.com/TanStack/query/blob/main/packages/query-core/src/types.ts#L1373) A boolean variable derived from `status`. - `true` if the last mutation attempt was successful. *** ### mutate ```ts mutate: MutateFunction; ``` Defined in: [packages/query-core/src/types.ts:1393](https://github.com/TanStack/query/blob/main/packages/query-core/src/types.ts#L1393) The mutation function you can call with variables to trigger the mutation and optionally hooks on additional callback options. #### Param The variables object to pass to the `mutationFn`. #### Param This function will fire when the mutation is successful and will be passed the mutation's result. #### Param This function will fire if the mutation encounters an error and will be passed the error. #### Param This function will fire when the mutation is either successfully fetched or encounters an error and be passed either the data or error. #### Remarks - If you make multiple requests, `onSuccess` will fire only after the latest call you've made. - All the callback functions (`onSuccess`, `onError`, `onSettled`) are void functions, and the returned value will be ignored. *** ### reset() ```ts reset: () => void; ``` Defined in: [packages/query-core/src/types.ts:1397](https://github.com/TanStack/query/blob/main/packages/query-core/src/types.ts#L1397) A function to clean the mutation internal state (i.e., it resets the mutation to its initial state). #### Returns `void` *** ### status ```ts status: MutationStatus; ``` Defined in: [packages/query-core/src/types.ts:1382](https://github.com/TanStack/query/blob/main/packages/query-core/src/types.ts#L1382) The status of the mutation. - Will be: - `idle` initial status prior to the mutation function executing. - `pending` if the mutation is currently executing. - `error` if the last mutation attempt resulted in an error. - `success` if the last mutation attempt was successful. #### Overrides [`MutationState`](MutationState.md).[`status`](MutationState.md#status) *** ### submittedAt ```ts submittedAt: number; ``` Defined in: [packages/query-core/src/mutation.ts:74](https://github.com/TanStack/query/blob/main/packages/query-core/src/mutation.ts#L74) The timestamp for when the mutation was submitted. #### Inherited from [`MutationState`](MutationState.md).[`submittedAt`](MutationState.md#submittedat) *** ### variables ```ts variables: TVariables | undefined; ``` Defined in: [packages/query-core/src/types.ts:1348](https://github.com/TanStack/query/blob/main/packages/query-core/src/types.ts#L1348) The variables object passed to the `mutationFn`. #### Overrides [`MutationState`](MutationState.md).[`variables`](MutationState.md#variables)