How vibeflow knows what your AI agent is doing

Wed, 17 Jun 2026 08:00:00 -0400

vibeflow is an open-source Linux terminal that shows, per tab, whether the program inside is working or waiting on you. This article details how the detection works: the open protocol, the heuristic fallback, and other key components.

A regular terminal emulator renders a grid of characters coming out of a pty. It has no notion of what the program on the other end is doing, which was never a problem because a human was typing every command and already knew. The terminal is essentially modeled after a typewriter, and how often has anyone worked at two typewriters at once, much less five? AI coding agents break that assumption. They run for minutes (for periods getting longer all the time), then stop and wait for input, and from the terminal’s point of view “thinking hard” and “waiting for you” are the same thing: a quiet pty.

OSC 1338 on Brian Hengen

How vibeflow knows what your AI agent is doing