I built BeforeRunIt: A live explanation line under your Linux prompt

vishwa thilina — Fri, 23 Oct 2026 05:55:06 +0000

Have you ever typed a terminal command and paused because you weren't completely sure what it would do?

I built BeforeRunIt, an open-source tool that adds a live, plain-English explanation underneath your Linux shell prompt while you type.

It currently supports Bash, Zsh and Fish.

The idea is simple:

KNOWN — a recognized, low-risk command.

CAUTION — a command that deserves a closer look.

DANGER — a potentially destructive or risky command.

UNKNOWN — a command the built-in rules don't recognize.

It works with built-in rules and also supports optional AI explanations for unfamiliar commands. The rule-based mode works locally without requiring an AI service.

I wanted to make command awareness part of the terminal workflow, instead of relying on users to remember every flag or look up every command before running it.

This is an early open-source project, not a security sandbox or a guarantee that commands are safe. I'm looking for feedback from Linux users and developers, especially on rule accuracy, false positives, shell compatibility and commands that should be covered next.

Repository: https://github.com/vishwathilina/BeforeRunIt

I'd appreciate technical feedback, bug reports and contributions from people who want to help improve it.

DEV Community: vishwa thilina

I built BeforeRunIt: A live explanation line under your Linux prompt