/**
 * Token storage primitives for OAuth grant and access tokens.
 *
 * @remarks
 * Defines the {@link TokenStore} interface and a default in-memory
 * implementation. Persistent backends (e.g., browser storage, secure
 * keychains) are intentionally not provided here — consumers can implement
 * the interface for their environment.
 *
 * @category Auth
 * @module auth/token-store
 */
/**
 * A persisted token record.
 */
export interface TokenRecord {
    /** The opaque token value. */
    token: string;
    /** Optional expiration as a Unix timestamp in seconds. */
    expiresAt?: number;
}
/**
 * Async key/value store for token records.
 */
export interface TokenStore {
    /**
     * Returns the record for `key`, or `null` if missing or expired.
     */
    get(key: string): Promise<TokenRecord | null>;
    /**
     * Stores `record` under `key`, overwriting any existing entry.
     */
    set(key: string, record: TokenRecord): Promise<void>;
    /**
     * Removes the entry for `key`. No-op if `key` is absent.
     */
    delete(key: string): Promise<void>;
    /**
     * Removes all entries.
     */
    clear(): Promise<void>;
}
/**
 * In-memory {@link TokenStore} implementation.
 *
 * @remarks
 * Expired entries are evicted lazily on read. Records are shallow-copied on
 * `set` and `get` so caller mutations do not leak into stored state.
 */
export declare class InMemoryTokenStore implements TokenStore {
    #private;
    get(key: string): Promise<TokenRecord | null>;
    set(key: string, record: TokenRecord): Promise<void>;
    delete(key: string): Promise<void>;
    clear(): Promise<void>;
    /**
     * Returns the number of stored entries (including any not yet
     * lazily evicted). Intended for tests and diagnostics.
     */
    get size(): number;
}