import type { SSEOutput } from '../x-stream';
import type { MessageStatus } from '../use-x-chat';
import type { XModelMessage } from './types';
export type OpenAITransformInfo<ChatMessage = XModelMessage, Output = SSEOutput> = {
    originMessage?: ChatMessage;
    chunk: Output;
    chunks: Output[];
    status: MessageStatus;
    /** Optional response headers (content-type detection) */
    responseHeaders?: Headers;
};
/**
 * Parse OpenAI-compatible SSE / JSON chunks into cumulative assistant message.
 * Use as `transformMessage` in useXChat for enterprise LLM chat.
 */
export declare function transformOpenAIMessage<ChatMessage extends XModelMessage = XModelMessage, Output extends SSEOutput = SSEOutput>(info: OpenAITransformInfo<ChatMessage, Output>): ChatMessage;
/**
 * Build OpenAI chat messages array from local history + current user message.
 */
export declare function toOpenAIMessages(history: XModelMessage[], userMessage: string | XModelMessage): XModelMessage[];