import { type ValidationState } from './types.js';
/**
 * Returns a wrapped `emitValidationState` that always merges current custom
 * error messages into every emitted state. Also fires when the set of custom
 * errors changes (added or removed), using `getBaseState` to determine the
 * underlying native/Strato errors at that point.
 * @internal
 */
export declare function useCustomMessageEmitter(emitValidationState: ((state: ValidationState) => void) | undefined, getBaseState?: () => ValidationState | Promise<ValidationState>): (state: ValidationState) => ValidationState;