In this guide, we’ll demystify the API resolved without sending a response error, explain its root causes, and provide step-by-step solutions to fix it. We’ll also show you how to implement seamless 3-minute data refresh on the client side—all while ensuring your API routes remain robust. Silent calls aren’t random—they’re a scam tactic. Learn why scammers stay silent and what to do immediately to protect your number. Basically you're not supposed to return anything from your routes, but you can return res.end () for example (or whatever else that has the same signature). Also, my return returnStream.pipe (res) call wasn't correctly typed, and it does not in fact return a NextApiResponse, so this was the culprit. We’ll break down the purpose of PUT, explore arguments for and against returning a response body, outline best practices for “null” or empty responses, and examine real-world examples to help you make informed design decisions. Designing API responses The API response is the most important part of the entire API. Did the API consumer ask a question? They need that answer. Did the API consumer ask to transfer £1,000,000? They need to be confident that went well. Did the API consumer make a mistake? Tell them how to fix it so they can get back to making you money. Creating clear, consistent API responses is crucial. Is there a way to return a response (from make_response () object or similar) with certain properties so that it doesn't render the page again and doesn't do anything else either. My question is, in the case where there are no next messages do I respond with an HTTP 204 (No Response) or should I simply return ? What's the best practice in this situation? Learn how to fix Flask routes that don't return responses. Explore common errors and solutions for ensuring your web application correctly sends data back to the client. Learn how to resolve API errors that cause your application to return no response. This guide covers common causes and provides steps to troubleshoot and fix the issue. Argues that REST APIs should return 204 (No Content) or an empty response instead of 404 (Not Found) when a resource is null, citing reasons like cleaner error logs and simpler client-side handling.