Building Reminders for WhatsApp (GPT Online) using QStash

QStash is a task scheduler and message queue system designed for serverless environments, providing developers with the ability to automate workflows without managing state. It's particularly effective for implementing features like the reminder function in GPT Hotline, a WhatsApp-based chatbot similar to ChatGPT with additional capabilities such as image and video search. By using QStash, the author was able to set up a workflow where users can send a message to the bot to receive a reminder at a specified time using a simple command structure. The implementation involves sending a fetch request to QStash with specified parameters including a URL, a message, and timing details, which QStash uses to trigger an API at the set time. The process is simplified by leveraging QStash's REST API and authentication features, allowing seamless integration into the Next.js-based GPT Hotline. The author notes that the ease of using QStash overcame initial hesitations about complexity, recommending it due to its generous free tier and scalability options.