/**
 * Edge-runtime / serverless email validator.
 *
 * No Node.js APIs (no `node:net`, no `node:dns`) — DNS is delegated to a
 * caller-supplied `DNSResolver`, so the same code runs on Cloudflare Workers,
 * Vercel Edge, Lambda@Edge, and Deno Deploy.
 *
 * Shares data with the main validator: `commonEmailDomains` and the typo map
 * are imported from `src/data/`, so we never drift between the two surfaces.
 */
import type { DomainSuggesterOptions, EmailValidationResult, ValidateEmailOptions } from '../types';
/** Compact LRU/TTL cache. One Map, expiry stamp per entry, batched eviction. */
export declare class EdgeCache<T> {
    private readonly maxSize;
    private readonly ttl;
    private readonly cache;
    constructor(maxSize?: number, ttl?: number);
    get(key: string): T | undefined;
    set(key: string, value: T): void;
    clear(): void;
    size(): number;
    private evict;
}
export declare const validationCache: EdgeCache<EmailValidationResult>;
export declare const mxCache: EdgeCache<string[]>;
/**
 * Common email domains — re-exported so callers (Vercel Edge, etc.) can pass a
 * custom subset via `DomainSuggesterOptions.customDomains`.
 */
export declare const COMMON_DOMAINS: readonly string[];
/** DNS resolver contract — caller-supplied so we don't import `node:dns`. */
export interface DNSResolver {
    resolveMx(domain: string): Promise<Array<{
        exchange: string;
        priority: number;
    }>>;
    resolveTxt(domain: string): Promise<string[]>;
}
/** No-op resolver for environments where DNS isn't available. */
export declare class StubDNSResolver implements DNSResolver {
    resolveMx(): Promise<Array<{
        exchange: string;
        priority: number;
    }>>;
    resolveTxt(): Promise<string[]>;
}
/**
 * DNS-over-HTTPS resolver — works in any runtime with `fetch` (Cloudflare
 * Workers, Vercel Edge, Deno, browsers, Node 18+). Defaults to Cloudflare's
 * 1.1.1.1 endpoint; pass `endpoint` to use Google (8.8.8.8), NextDNS, or
 * a self-hosted resolver.
 *
 * Compatible with [`cf-doh`](https://www.npmjs.com/package/cf-doh) — if you
 * already use that, drop it in directly. This built-in keeps the package
 * zero-dep so the same code works on every edge runtime without an extra
 * install step.
 */
export interface DoHResolverOptions {
    /** DoH endpoint URL. Default: https://cloudflare-dns.com/dns-query */
    endpoint?: string;
    /** Per-query request timeout, ms. Default: 5000 */
    timeoutMs?: number;
    /** Custom fetch (e.g. to add headers / proxy). Default: globalThis.fetch */
    fetch?: typeof fetch;
}
export declare class DoHResolver implements DNSResolver {
    private readonly endpoint;
    private readonly timeoutMs;
    private readonly fetchFn;
    constructor(options?: DoHResolverOptions);
    resolveMx(domain: string): Promise<Array<{
        exchange: string;
        priority: number;
    }>>;
    resolveTxt(domain: string): Promise<string[]>;
    private query;
}
/**
 * Suggest a corrected domain. Returns the canonical for a known typo,
 * otherwise the closest match within the threshold, otherwise null.
 */
export declare function suggestDomain(domain: string, options?: DomainSuggesterOptions): string | null;
/**
 * Validate one email — syntax / typo / disposable / free / MX (if a resolver
 * is supplied). Each step is independently flag-gated so callers pay only for
 * what they use.
 */
export declare function validateEmailCore(email: string, options?: ValidateEmailOptions & {
    dnsResolver?: DNSResolver;
}): Promise<EmailValidationResult>;
export declare function validateEmailBatch(emails: string[], options?: ValidateEmailOptions & {
    dnsResolver?: DNSResolver;
}): Promise<EmailValidationResult[]>;
export declare function clearCache(): void;
export type { DomainSuggesterOptions, EmailValidationResult, ValidateEmailOptions } from '../types';