/**
 * Default settings for position-based context pruning.
 *
 * These are merged with user-provided overrides so any subset can be customized.
 */
export interface ContextPruningSettings {
    /** Whether position-based pruning is enabled. Default: false (opt-in). */
    enabled: boolean;
    /** Number of recent assistant turns to protect from pruning. Default: 3 */
    keepLastAssistants: number;
    /** Age ratio (0-1) at which soft-trim fires. Default: 0.3 */
    softTrimRatio: number;
    /** Age ratio (0-1) at which hard-clear fires. Default: 0.5 */
    hardClearRatio: number;
    /** Minimum tool result size (chars) before pruning applies. Default: 50000 */
    minPrunableToolChars: number;
    softTrim: {
        /** Maximum total chars after soft-trim. Default: 4000 */
        maxChars: number;
        /** Head portion to keep. Default: 1500 */
        headChars: number;
        /** Tail portion to keep. Default: 1500 */
        tailChars: number;
    };
    hardClear: {
        /** Whether hard-clear is enabled. Default: true */
        enabled: boolean;
        /** Placeholder text for hard-cleared content. */
        placeholder: string;
    };
}
export declare const DEFAULT_CONTEXT_PRUNING_SETTINGS: ContextPruningSettings;
/**
 * Merges user-provided partial overrides with the defaults.
 */
export declare function resolveContextPruningSettings(overrides?: Partial<{
    enabled?: boolean;
    keepLastAssistants?: number;
    softTrimRatio?: number;
    hardClearRatio?: number;
    minPrunableToolChars?: number;
    softTrim?: Partial<ContextPruningSettings['softTrim']>;
    hardClear?: Partial<ContextPruningSettings['hardClear']>;
}>): ContextPruningSettings;