wtf is mqtt-studio?

MQTT Studio is a desktop app for working with MQTT, a messaging system commonly used by smart devices and sensors to send small pieces of data back and forth. It is local first, meaning there is no backend server and no account to sign up for. Every connection you save, along with passwords and recent message history, lives in a local database on your own computer, and passwords are encrypted using your operating system's built in secure storage. The app lets you save multiple broker connections, each with its own host, port, login details, encryption settings, and a color tag so you can tell them apart. Once connected, a live topic explorer shows every topic your broker has seen as a tree, similar to another popular tool called MQTT Explorer, with the newest value shown next to each topic and a brief flash whenever new data arrives. Each topic keeps a short history of recent messages, and if those messages are numbers, MQTT Studio draws a chart of them over time. You can also publish your own messages to any topic, choosing the delivery guarantee level and whether the message should be retained. Other features include pausing and resuming the live view without losing incoming data, replaying a full snapshot of what arrived while paused, and exporting a live stream of incoming messages for chosen topics to a file. The app is built with Electron and packages into installers for macOS, Windows, and Linux. Building it from source requires Node.js 20 or newer, and the underlying stack includes React, TypeScript, Tailwind, and a small SQLite database for local storage. It is released under the MIT license.