type SpanAttributeValue = string | number | boolean;
/**
 * Builds a `{ attributes }` object for use in `tracer.startSpan()` options,
 * prefixing each key with `cqrs.<prefix>`.
 * Entries with non-primitive values (not string/number/boolean) are omitted.
 * An optional `keys` array limits which properties are included.
 *
 * @example
 * tracer.startSpan('send', spanAttributes('command', cmd, ['type', 'aggregateId']), ctx)
 */
export declare function spanAttributes<T extends Record<any, any>>(prefix: string, attrs: T, keys?: Array<keyof T>): {
    attributes: Record<string, SpanAttributeValue>;
};
export {};