/** OpenAI chat content-delta SSE chunk. */
export declare function noticeChunk(text: string): string;
/** Terminal SSE chunk that marks the turn as failed, followed by [DONE]. */
export declare function errorEvent(message: string): string;
/** Terminal SSE chunk carrying a normal finish reason. */
export declare function finishChunk(reason: string): string;
/** Reasoning-only OpenAI chat SSE chunk. */
export declare function reasoningChunk(text: string): string;
/** Wrap a static SSE string as a text/event-stream response. */
export declare function sseResponse(body: string): Response;