import type { ExistsResult, ExistsOptions } from './npm.js';
interface PurlObject {
    name: string;
    namespace?: string | undefined;
    qualifiers?: Record<string, string> | undefined;
    subpath?: string | undefined;
    type?: string | undefined;
    version?: string | undefined;
}
/**
 * Normalize Composer package URL.
 * Lowercases both namespace and name.
 */
export declare function normalize(purl: PurlObject): PurlObject;
/**
 * Check if a Composer package exists on Packagist.
 *
 * Queries Packagist.org API to verify package existence and retrieve
 * the latest version. Composer packages have vendor/package format.
 *
 * @param name - Package name (e.g., 'http-foundation')
 * @param namespace - Vendor name (e.g., 'symfony')
 * @param version - Optional version to validate (e.g., 'v6.3.0')
 * @param options - Optional configuration including cache
 * @returns Promise resolving to existence result with latest version
 *
 * @example
 * ```typescript
 * // Check if package exists
 * const result = await packagistExists('http-foundation', 'symfony')
 * // -> { exists: true, latestVersion: 'v6.3.0' }
 *
 * // Validate specific version
 * const result = await packagistExists('http-foundation', 'symfony', 'v6.3.0')
 * // -> { exists: true, latestVersion: 'v6.3.0' }
 *
 * // Non-existent package
 * const result = await packagistExists('fake-package', 'vendor')
 * // -> { exists: false, error: 'Package not found' }
 * ```
 */
export declare function packagistExists(name: string, namespace?: string, version?: string, options?: ExistsOptions): Promise<ExistsResult>;
export {};