/**
 * Credential storage abstraction with keyring support and file fallback.
 *
 * Storage priority:
 * 1. If --insecure-storage: use file only
 * 2. Try keyring, fall back to file with warning if unavailable
 */
export interface StagingCache {
    clientId: string;
    apiKey: string;
    fetchedAt: number;
}
export interface Credentials {
    accessToken: string;
    expiresAt: number;
    userId: string;
    email?: string;
    staging?: StagingCache;
    refreshToken?: string;
}
export declare function setInsecureStorage(value: boolean): void;
declare function getCredentialsPath(): string;
export declare function hasCredentials(): boolean;
export declare function getCredentials(): Credentials | null;
export declare function saveCredentials(creds: Credentials): void;
export declare function clearCredentials(): void;
export declare function updateTokens(accessToken: string, expiresAt: number, refreshToken?: string): void;
/**
 * Diagnostic info about credential storage state — for debugging auth failures.
 */
export declare function diagnoseCredentials(): string[];
export { getCredentialsPath };