Piping a API Gateway response to client through Lambda handler - amazon-web-services

Question

I have a REST API using AWS API Gateway. The API is handled by a custom Lambda function. I have a /prompts endpoint in my API, for which the Lambda function will call Open AI API, send it the prompt, and stream the result to the user as it is being generated (which can take a few seconds).
I'm able to stream and handle the response from Open AI's API to my Lambda function.
I would now like to re-stream / pipe that response to the client.
My question is how to do that?
Is there a way to simply pipe the stream being received from Open AI API to my client?
My Lambda function is:
ry {
const res = await openai.createCompletion({
...params,
stream: true,
}, { responseType: 'stream' });
res.data.on('data', data => {
const lines = data.toString().split('\n').filter(line => line.trim() !== '');
for (const line of lines) {
const message = line.replace(/^data: /, '');
if (message === '[DONE]') {
// store the response to DynamoDB
storeRecord(content)
return content
}
try {
const parsed = JSON.parse(message);
content += parsed.choices[0].text
// ****** I want to send content to the front-end client... *******
} catch(error) {
console.error('Could not JSON parse stream message', message, error);
}
}
});
} catch (error) {
if (error.response?.status) {
console.error(error.response.status, error.message);
error.response.data.on('data', data => {
const message = data.toString();
try {
const parsed = JSON.parse(message);
console.error('An error occurred during OpenAI request: ', parsed);
} catch(error) {
console.error('An error occurred during OpenAI request: ', message);
}
});
} else {
console.error('An error occurred during OpenAI request', error);
}
}