API gateways - Is it possible to create API gateways with streaming response support?

API Gateway does support streaming responses, but the implementation depends on the type of API you're using. For your use case of streaming responses from an LLM service, WebSocket APIs would be the most suitable option.

WebSocket APIs in API Gateway allow for real-time, two-way communication between clients and servers. This is ideal for streaming responses, as it enables your backend to push data to connected clients as it becomes available, without the need for complex polling mechanisms.

To implement this:

1. Create a WebSocket API in API Gateway.
2. Set up the necessary routes for your API, including a route for initiating the streaming response.
3. Integrate your backend LLM service with the API Gateway.
4. Use the persistent connection provided by the WebSocket API to stream responses back to the client.

Some key benefits of using WebSocket APIs for streaming include:

• Real-time data transfer
• Reduced latency compared to traditional HTTP polling
• Efficient use of resources, as the connection is maintained

However, there are some considerations:

• WebSocket APIs may have higher costs compared to HTTP APIs due to the persistent connection.
• You'll need to manage connection state and implement reconnection logic on the client side.
• There may be limitations on the duration of idle connections, so you might need to implement keep-alive mechanisms.

API Gateway provides features like monitoring and throttling of connections and messages, which can help you manage your API's performance and costs.

For your LLM service, this approach would allow you to start generating and streaming the response as soon as the model begins producing output, similar to how OpenAI's API works. This can significantly improve the perceived responsiveness of your service, especially for longer responses.

Sources
API Gateway use cases - Amazon API Gateway
About Amazon API Gateway - Security Overview of Amazon API Gateway

Hi,

Read this article: https://amlanscloud.com/llmstreampost/

It provides all the details to implement LLM response streaming with API gateway: https://amlanscloud.com/llmstreampost/

Best,

Didier