/**
 * PKCE error types and error class.
 *
 * @internal This module is not exported from the main package.
 */
/**
 * Error codes for PKCE-related failures.
 */
export type PKCEErrorCode = 'MISSING_VERIFIER' | 'EXPIRED' | 'INVALID';
/**
 * Error class for PKCE-related failures.
 * Uses a code discriminator for programmatic error handling.
 */
export declare class PKCEError extends Error {
    readonly code: PKCEErrorCode;
    readonly cause?: Error;
    constructor(code: PKCEErrorCode, message: string, cause?: Error);
    /**
     * Factory: PKCE verifier cookie not found.
     */
    static missingVerifier(): PKCEError;
    /**
     * Factory: PKCE verifier has expired.
     */
    static expired(): PKCEError;
    /**
     * Factory: PKCE verifier cookie is malformed.
     */
    static invalid(cause?: Error): PKCEError;
}
//# sourceMappingURL=error.d.ts.map