/**
 * API Key Authentication Provider
 *
 * Handles API key authentication with support for:
 * - Custom header names (default: X-API-Key)
 * - Custom prefix (e.g., "Bearer ")
 * - Header or query param location
 */
import { AuthProvider, AuthResult, APIKeyAuthConfig } from './index.js';
export declare class APIKeyProvider implements AuthProvider<APIKeyAuthConfig> {
    readonly type: "api_key";
    authenticate(config: APIKeyAuthConfig): Promise<AuthResult>;
    clear(config: APIKeyAuthConfig): Promise<void>;
    validate(config: APIKeyAuthConfig): Promise<boolean>;
    private getCacheKey;
}