import type { PromptHistoryEntry, PromptLabel, PromptStore, PromptVersion } from '../types/prompts.js';
/** Options for the in-memory prompt store. */
export interface MemoryPromptStoreOptions {
    /** History entries kept per prompt before the oldest are dropped. Defaults to 1,000. */
    maxHistory?: number;
}
/**
 * Prompt versions, labels, and history in process memory.
 *
 * The registry's default, and enough for tests and for a single process that defines its prompts in
 * code. Every read returns a copy, so a caller cannot change a stored version by mutating what it got.
 */
export declare class MemoryPromptStore implements PromptStore {
    private readonly versions;
    private readonly labels;
    private readonly history;
    private readonly maxHistory;
    constructor(options?: MemoryPromptStoreOptions);
    /** Stores a version, unless one with the same content version exists. */
    saveVersion(version: PromptVersion): void;
    /** Reads a version. */
    getVersion(name: string, version: string): PromptVersion | undefined;
    /** Versions of a prompt, newest first. Defaults to 50. */
    listVersions(name: string, options?: {
        limit?: number;
    }): PromptVersion[];
    /** Reads a label. */
    getLabel(name: string, label: string): PromptLabel | undefined;
    /** Every label of a prompt, sorted by name. */
    listLabels(name: string): PromptLabel[];
    /** Writes a label when it still points at `expected`. */
    setLabel(label: PromptLabel, expected?: string | null): boolean;
    /** Removes a label. Returns true when it existed. */
    deleteLabel(name: string, label: string): boolean;
    /** Records a change. */
    appendHistory(entry: PromptHistoryEntry): void;
    /** A prompt's history, newest first, optionally for one label. Defaults to 100. */
    listHistory(name: string, options?: {
        label?: string;
        limit?: number;
    }): PromptHistoryEntry[];
    /** Every prompt name, sorted. */
    listNames(): string[];
}