rpc text stream

const chatCompletion = await openai.chat.completions.create({
            model: 'gpt-4o',
            messages: messages,
            stream: true,
        });
        let { readable, writable } = new TransformStream()
        const writer = writable.getWriter();
        const encoder = new TextEncoder();

        (async () => {
            try {
                    for await (const chunk of stream) {
                            const content = chunk['choices'][0].delta.content;
                            const encodedMessage = encoder.encode(content);
                            writer.write(encodedMessage);
                    }
                    writer.close();
            } catch (e) {
                    console.error(e);
                    // writer.abort(e);
                    return new Response('bad bad error', {
                            headers: headerCode
                    });
            }
    })();
    return readable;