/**
 * Helper functions for creating aggregation metrics.
 * These functions return objects that describe the aggregation to perform.
 */
export type AggregationHelper<TField extends string = string, TAggregation extends string = string> = {
    field: TField;
    aggregation: TAggregation;
};
/**
 * Creates a count aggregation for the specified field.
 * @param field - The field name to count.
 * @returns An aggregation helper object.
 *
 * @example
 * ```typescript
 * count('id')
 * ```
 */
export declare function count<TField extends string>(field: TField): AggregationHelper<TField, 'count'>;
/**
 * Creates an average aggregation for the specified field.
 * @param field - The field name to average.
 * @returns An aggregation helper object.
 *
 * @example
 * ```typescript
 * avg('age')
 * ```
 */
export declare function avg<TField extends string>(field: TField): AggregationHelper<TField, 'average'>;
/**
 * Creates a sum aggregation for the specified field.
 * @param field - The field name to sum.
 * @returns An aggregation helper object.
 *
 * @example
 * ```typescript
 * sum('age')
 * ```
 */
export declare function sum<TField extends string>(field: TField): AggregationHelper<TField, 'sum'>;
/**
 * Creates a median aggregation for the specified field.
 * @param field - The field name to calculate median for.
 * @returns An aggregation helper object.
 */
export declare function median<TField extends string>(field: TField): AggregationHelper<TField, 'median'>;
/**
 * Creates a min aggregation for the specified field.
 * @param field - The field name to find minimum for.
 * @returns An aggregation helper object.
 */
export declare function min<TField extends string>(field: TField): AggregationHelper<TField, 'min'>;
/**
 * Creates a max aggregation for the specified field.
 * @param field - The field name to find maximum for.
 * @returns An aggregation helper object.
 */
export declare function max<TField extends string>(field: TField): AggregationHelper<TField, 'max'>;
/**
 * Creates a range aggregation for the specified field.
 * @param field - The field name to calculate range for.
 * @returns An aggregation helper object.
 */
export declare function range<TField extends string>(field: TField): AggregationHelper<TField, 'range'>;
/**
 * Creates a standard deviation aggregation for the specified field.
 * @param field - The field name to calculate standard deviation for.
 * @returns An aggregation helper object.
 */
export declare function stdDev<TField extends string>(field: TField): AggregationHelper<TField, 'standardDeviation'>;
/**
 * Creates a unique count aggregation for the specified field.
 * @param field - The field name to count unique values for.
 * @returns An aggregation helper object.
 */
export declare function unique<TField extends string>(field: TField): AggregationHelper<TField, 'unique'>;
