/** Composite key for session lookup. */
export type SessionKey = {
    channelId: string;
    userId: string;
    threadId?: string | undefined;
};
/** Stored session entry. */
export type SessionEntry = {
    /** CLI runtime session ID (e.g., Claude session UUID, Codex thread ID). */
    sessionId: string;
    /** Epoch milliseconds of last access (set/get). */
    lastAccessMs: number;
};
/**
 * File-backed session store mapping channel conversations to CLI runtime session IDs.
 *
 * Design decisions:
 * - No in-memory cache: every get/set/delete reads from and writes to disk
 * - Correctness over performance for the expected low-frequency session lookup pattern
 * - Lazy TTL eviction: expired entries are invisible on get(), evicted on next set()
 * - Atomic writes via write-to-temp + rename pattern
 */
export declare class SessionMap {
    #private;
    /**
     * @param directory - Directory where the session file is stored
     * @param ttlMs - Time-to-live in milliseconds (default: 7 days = 604_800_000)
     */
    constructor(directory: string, ttlMs?: number);
    /** Get session ID for a channel conversation. Returns undefined if not found or expired. */
    get(key: SessionKey): Promise<string | undefined>;
    /** Store or update a session ID for a channel conversation. Updates lastAccessMs. */
    set(key: SessionKey, sessionId: string): Promise<void>;
    /** Delete a session entry. No-op if key doesn't exist. */
    delete(key: SessionKey): Promise<void>;
}