import { SentlyError } from "../core/errors.js";
import type { MailOptions, SendResult, Transport, VerifyResult } from "../core/types.js";
/** Header for a per-message SNDR template ID (`template_id`). */
export declare const SNDR_TEMPLATE_ID_HEADER = "x-sndr-template-id";
/** SNDR API configuration. */
export interface SndrConfig {
    /**
     * SNDR API key (starts with `sndr_live_` or `sndr_test_`).
     * Store in environment variables — never hardcode.
     */
    apiKey: string;
    /** API base URL. Default: `https://api.sndr.sh`. */
    baseUrl?: string;
    /**
     * Default SNDR template ID when not set per message via
     * {@link SNDR_TEMPLATE_ID_HEADER}.
     */
    defaultTemplateId?: string;
}
/** Error thrown when the SNDR API returns a non-success response. */
export declare class SndrError extends SentlyError {
    readonly statusCode: number;
    readonly apiError: unknown;
    /** Creates an SNDR API error with status code and response payload. */
    constructor(message: string, statusCode: number, apiError: unknown);
}
/**
 * SNDR HTTP API transport.
 */
export declare class SndrTransport implements Transport {
    readonly provider = "sndr";
    private readonly apiKey;
    private readonly baseUrl;
    private readonly defaultTemplateId?;
    /** Creates an SNDR transport with the given API key. */
    constructor(config: SndrConfig);
    /** Sends an email via `POST /v1/send`. */
    send(options: MailOptions): Promise<SendResult>;
    /** Verifies the API key by listing domains (`GET /v1/domains`). */
    verify(): Promise<VerifyResult>;
}