import type { ProviderConfig } from '../types.js';
import { DoHProvider } from './doh.js';
import type { Quad9Transport } from './quad9-transport.js';
/**
 * Quad9 DNS-over-HTTPS provider. Quad9 uses the RFC 8484 binary wire format
 * rather than the JSON representation used by the other DoH providers.
 */
export declare class Quad9Provider extends DoHProvider {
    private readonly baseUrl;
    protected requestTransport: Quad9Transport;
    constructor(config?: ProviderConfig);
    private encodeDNSQuery;
    private assertAvailable;
    private readName;
    private readCharacterString;
    /**
     * Decode every record type exposed by Zynor. Unknown types can appear in
     * ANY/authority/additional sections (for example RRSIG or OPT); those are
     * explicitly skipped instead of being mislabeled as hex-encoded records.
     */
    private decodeRData;
    private request;
}