# usePending \[The status value behind Pending] The hook behind [`Pending`](/react/pending), for when you need the status value rather than rendered UI. It subscribes to any `ObservableLike` (an `Observable` or a plain value) and returns the current `IWrapped`, narrowed to `PENDING` / `FULFILLED` / `REJECTED`, never `IDLE`. Pass `getDefaultValue` to start `FULFILLED` instead of `PENDING`. :::tip\[Prefer `Pending` for rendering] To render UI per status, reach for the [`Pending`](/react/pending) component, not this hook — it keeps the unwrap at the render edge ([late unwrapping](/core-concepts/late-unwrapping)) and holds the last fulfilled value across a background reload. Use `usePending` only when you genuinely need the `IWrapped` value itself (e.g. a count or a derived label), not to gate a subtree. ::: ```tsx import { usePending, useStateData } from "rxfy-react"; import { StatusEnum } from "rxfy"; import { fetchTodos, todosState } from "./todos"; function TodoCount({ params }: { params: object }) { const { data$ } = useStateData({ state: todosState, fetchFn: fetchTodos, params }); const wrapped = usePending(data$); if (wrapped.type === StatusEnum.PENDING) return …; if (wrapped.type === StatusEnum.REJECTED) return error; return {wrapped.value.todos.length} todos; } ``` ```ts function usePending( source$: ObservableLike, getDefaultValue?: () => T, ): IWrapped; type ObservableLike = Observable | T; ``` The `IWrapped` it returns is the async-status discriminated union, narrowed to the `K` cases: ```ts type IWrapped = { [StatusEnum.IDLE]: { type: StatusEnum.IDLE }; [StatusEnum.PENDING]: { type: StatusEnum.PENDING }; [StatusEnum.FULFILLED]: { type: StatusEnum.FULFILLED; value: T }; [StatusEnum.REJECTED]: { type: StatusEnum.REJECTED; error: unknown }; }[K] & { type: K }; ``` The matching `createIdle` / `createPending` / `createFulfilled` / `createRejected` constructors are exported from `rxfy` for building these values directly. :::warning `source$` must be referentially stable across renders; wrap inline-created sources in `useMemo`. :::