import type { Attributes } from '@opentelemetry/api';
/**
 * Max nesting levels (3). Both formats use 3.
 * - Array format: event_data.{object}.{key}.{level1}.{level2}.{level3}
 * - Legacy data format (without object property): event_data.{property}.{level1}.{level2}.{level3}
 */
type OtelAttributeValue = string | number | boolean;
export declare function toSnakeCase(str: string): string;
export declare function isNonNullish<T>(value: T | null | undefined): value is T;
export declare function isOtelAttributeValue(value: unknown): value is OtelAttributeValue;
/**
 * Flattens an object's properties into OTEL attributes with a given prefix.
 */
export declare function flattenToAttributes(data: Record<string, unknown>, prefix: string, attributes: Attributes, useSnakeCase?: boolean, keysToOmit?: readonly string[]): void;
/**
 * Flattens nested object properties (one level deep) into OTEL attributes.
 * Processes string, number, and boolean primitives. Skips null, undefined, and nested objects.
 */
export declare function flattenNestedObject(obj: Record<string, unknown>, prefix: string, attributes: Attributes): void;
/**
 * Flattens nested object into OTEL attributes with configurable max levels.
 * Output: prefix.{level1}.{level2}... Deeper nesting is dropped.
 * Prefix may have trailing dot; it is normalized.
 */
export declare function flattenWithMaxDepth(obj: Record<string, unknown>, prefix: string, attributes: Attributes, options?: {
    currentDepth?: number;
    useSnakeCase?: boolean;
    maxNestingLevels?: number;
}): void;
export {};