/**
 * Message Reducer Utility
 *
 * Handles the accumulation of streaming chunks from LLM responses,
 * merging deltas into a complete message structure including
 * content and tool calls.
 */
/**
 * Reduces a new streaming chunk into the previous accumulated message.
 *
 * @param previous - The previously accumulated message state
 * @param chunk - The new chunk from the stream
 * @returns The updated accumulated message state
 */
export declare function reduceStreamChunk(previous: Record<string, unknown>, chunk: unknown): Record<string, unknown>;
