Asion

What it is

Asion is a cross-platform productivity and workstation activity tracker for macOS, Linux and Windows. It records which application and window have focus and turns that raw activity into a picture of how time is actually spent. Tools such as Rize.io showed how useful that picture can be; Asion is built on the view that data this personal should stay under its owner’s control, so it is designed privacy-first and with self-hosting in mind.

It is meant for individuals who want an honest record of their working day, for software teams, and for academic time tracking, where researchers and students account for the hours spent on a project. I have been building it since 2024; it is in development, with early access through asion.app. The source code is private.

How it watches without getting in the way

An activity tracker runs all day, so its cost has to be close to zero. Asion listens to native OS event hooks, so each platform reports focus changes as they happen, and a lightweight daemon does the collecting in the background. The native layers are written in C/C++ and Objective-C, alongside Go.

Architecture

Asion is split into several processes, each with one job:

• asion-agent: the background agent. It watches the active window through the operating system’s hooks and collects activity.
• asion-runner: runs the scheduled and long-running work behind the agent.
• asion-ui: the interface where the collected activity is reviewed.
• asion-native-host: the native messaging host that connects browser extensions to the agent.

The components talk to each other over gRPC with Protobuf messages: typed contracts keep inter-process communication efficient and the boundaries between processes explicit. Activity is stored locally in an encrypted SQLCipher database, so the record on disk is unreadable without its key.

Browser integration

Browsers only let an extension reach a local program through native messaging, which frames every message with a 4-byte little-endian length prefix in front of a JSON payload. Asion implements that framing in C++ inside asion-native-host, so the extension and the background agent exchange messages without a network service in between.

Build, test and release automation

Software with native parts on three operating systems has to be built, tested and packaged on each of them, every time it changes. For the Asion ecosystem I built multi-platform CI/CD pipelines on GitHub Actions:

• Multi-platform workflows, with cross-compilation runners producing the native builds.
• Custom automation scripts in Bash, Batch and Python that tie the steps together.
• One-click testing and packaging: a single click runs the tests, packages the components and generates the artifacts for every platform.
• Deployment pipelines that take those multi-platform artifacts through to release.