export interface TrajectoryEntry {
    tool: string;
    args_summary: string;
    duration_ms: number;
    ts: number;
}
declare class TrajectoryBuffer {
    private entries;
    record(tool: string, args: Record<string, unknown>, duration_ms: number): void;
    /**
     * Snapshot the last N entries (default = full buffer). Returns a copy
     * so consumers can serialise without holding a reference.
     */
    snapshot(n?: number): TrajectoryEntry[];
    clear(): void;
}
export declare const trajectoryBuffer: TrajectoryBuffer;
export {};