/**
 * Authentication helper utilities
 * Handles API key retrieval from multiple sources with proper fallback logic
 */
/**
 * Get API key with proper fallback logic:
 * 1. Environment variable (GROK_API_KEY)
 * 2. User settings file (~/.grok/user-settings.json)
 * 3. Command-line argument (passed explicitly)
 *
 * @param explicitApiKey - API key passed via command-line argument (highest priority)
 * @returns API key or undefined if not found
 */
export declare function getApiKey(explicitApiKey?: string): string | undefined;
/**
 * Get base URL with proper fallback logic:
 * 1. Explicit base URL from command-line argument
 * 2. Environment variable (GROK_BASE_URL)
 * 3. User settings file (~/.grok/user-settings.json)
 * 4. Default value
 *
 * @param explicitBaseURL - Base URL passed via command-line argument (highest priority)
 * @param defaultBaseURL - Default base URL to use if none found (default: https://api.x.ai/v1)
 * @returns Base URL
 */
export declare function getBaseURL(explicitBaseURL?: string, defaultBaseURL?: string): string;
/**
 * Get model with proper fallback logic:
 * 1. Explicit model from command-line argument
 * 2. Environment variable (GROK_MODEL)
 * 3. Project-specific model setting
 * 4. User's default model
 * 5. Default value
 *
 * @param explicitModel - Model passed via command-line argument (highest priority)
 * @param defaultModel - Default model to use if none found (default: grok-code-fast-1)
 * @returns Model name
 */
export declare function getModel(explicitModel?: string, defaultModel?: string): string;
/**
 * Validate that required authentication is present
 * Throws an error with helpful message if API key is missing
 *
 * @param apiKey - API key to validate
 * @throws Error if API key is undefined or empty
 */
export declare function validateApiKey(apiKey: string | undefined): asserts apiKey is string;
/**
 * Get all authentication configuration with proper fallbacks
 * Convenience function that combines all auth-related getters
 *
 * @param options - Optional explicit values from command-line arguments
 * @returns Complete authentication configuration
 */
export declare function getAuthConfig(options?: {
    apiKey?: string;
    baseURL?: string;
    model?: string;
}): {
    apiKey: string | undefined;
    baseURL: string;
    model: string;
};