/**
 * Defensive schema-drift guards for GIS tools that rely on external
 * ArcGIS/API field names. Validates expected fields exist in API responses
 * before parsing, so upstream renames fail loudly instead of silently
 * returning bad data.
 */
/**
 * Validate that an ArcGIS feature response contains the expected fields.
 * Checks the first feature's `attributes` object. Skips validation when
 * the features array is empty (no data is not a schema problem).
 *
 * @throws Error with provider name and missing field when validation fails.
 */
export declare function guardArcGisFields(features: Array<{
    attributes: Record<string, unknown>;
}>, expectedFields: readonly string[], provider: string): void;
/**
 * Validate that a JSON object has the expected top-level keys.
 *
 * @throws Error with provider name and missing field when validation fails.
 */
export declare function guardJsonFields(data: Record<string, unknown>, expectedFields: readonly string[], provider: string): void;