import type { PromptHistoryEntry, PromptLabel, PromptStore, PromptVersion } from '../types/prompts.js';
import { type PostgresLikeClient } from './client.js';
/** Options for the Postgres prompt store. */
export interface PostgresPromptStoreOptions {
    /** Table name prefix, optionally schema-qualified. Defaults to `nexus_prompt`, for `nexus_prompt_versions` and so on. */
    table?: string;
}
/** The schema for the prompt store, as statements. */
export declare function promptStoreMigration(options?: PostgresPromptStoreOptions): string[];
/**
 * Prompt versions, labels, and history in Postgres.
 *
 * Label compare-and-set is a single statement — an insert that does nothing on conflict, or an update
 * that matches only the expected version — so two workers promoting at once cannot both win.
 */
export declare class PostgresPromptStore implements PromptStore {
    private readonly client;
    private readonly options;
    private readonly versions;
    private readonly labels;
    private readonly history;
    constructor(client: PostgresLikeClient, options?: PostgresPromptStoreOptions);
    /** Creates the prompt tables if they do not exist. Never runs implicitly. */
    migrate(): Promise<void>;
    /** Stores a version, unless one with the same content version exists. */
    saveVersion(version: PromptVersion): Promise<void>;
    /** Reads a version. */
    getVersion(name: string, version: string): Promise<PromptVersion | undefined>;
    /** Versions of a prompt, newest first. Defaults to 50. */
    listVersions(name: string, options?: {
        limit?: number;
    }): Promise<PromptVersion[]>;
    /** Reads a label. */
    getLabel(name: string, label: string): Promise<PromptLabel | undefined>;
    /** Every label of a prompt, sorted by name. */
    listLabels(name: string): Promise<PromptLabel[]>;
    /** Writes a label when it still points at `expected`, in one statement. */
    setLabel(label: PromptLabel, expected?: string | null): Promise<boolean>;
    /** Removes a label. Resolves true when it existed. */
    deleteLabel(name: string, label: string): Promise<boolean>;
    /** Records a change. */
    appendHistory(entry: PromptHistoryEntry): Promise<void>;
    /** A prompt's history, newest first, optionally for one label. Defaults to 100. */
    listHistory(name: string, options?: {
        label?: string;
        limit?: number;
    }): Promise<PromptHistoryEntry[]>;
    /** Every prompt name, sorted. */
    listNames(): Promise<string[]>;
}