/**
 * @module
 * Unified error hierarchy for sently transports and SMTP.
 */
/** Stable machine-readable error codes shared across providers. */
export type SentlyErrorCode = "INVALID_CONFIG" | "SMTP_AUTH_FAILED" | "RATE_LIMITED" | "TIMEOUT" | "CONNECTION_FAILED" | "PROVIDER_ERROR" | "BAD_REQUEST";
/** Options for constructing a {@link SentlyError}. */
export interface SentlyErrorOptions {
    /** HTTP status code when the failure originated from an HTTP transport. */
    statusCode?: number;
    /** Original error or response payload. */
    cause?: unknown;
    /** Provider identifier (e.g. `"smtp"`, `"resend"`). */
    provider?: string;
}
/**
 * Base error class for all sently transport and protocol failures.
 *
 * Subclasses may shadow {@link code} with provider-specific or numeric values
 * (e.g. SMTP response codes). Use {@link sentlyCode} for the stable machine-readable
 * code in those cases.
 */
export declare class SentlyError extends Error {
    /**
     * Stable machine-readable error code.
     * Preserved even when a subclass shadows {@link code}.
     */
    readonly sentlyCode: SentlyErrorCode;
    /** HTTP status code when applicable. */
    readonly statusCode?: number;
    /** Provider identifier when applicable. */
    readonly provider?: string;
    /**
     * Error code — machine-readable string on {@link SentlyError}, or a legacy
     * provider/SMTP-specific value on subclasses (numeric SMTP codes, Brevo/SES API codes).
     */
    code: string | number;
    /** Creates a sently error with a machine-readable code and optional metadata. */
    constructor(message: string, sentlyCode: SentlyErrorCode, options?: SentlyErrorOptions);
}
/**
 * Map an HTTP status code to a stable sently error code.
 *
 * @param status - HTTP response status code
 * @returns Machine-readable error code
 */
export declare function httpStatusToSentlyCode(status: number): SentlyErrorCode;
/**
 * Map an SMTP response code and command to a stable sently error code.
 *
 * @param smtpCode - Three-digit SMTP response code (0 for local/parse errors)
 * @param command - SMTP command that failed
 * @returns Machine-readable error code
 */
export declare function smtpCodeToSentlyCode(smtpCode: number, command: string): SentlyErrorCode;