/**
 * Session compression — trim old messages or summarize via LLM.
 */
export interface CompressResult {
    originalMessages: number;
    compressedMessages: number;
    method: 'trim' | 'llm';
    backupPath: string;
}
/**
 * Trim a session to keep only the last N messages.
 * Creates a backup of the original session first.
 */
export declare function trimSession(sessionId: string, keepLast?: number): Promise<CompressResult>;
/**
 * Compress a session using the LLM to generate a summary.
 * Replaces all messages with [summary + last N messages].
 */
export declare function compressSessionWithLLM(sessionId: string, proxyUrl: string, model: string, keepLast?: number): Promise<CompressResult>;
