Firefox Runner CLI

fx-runner is a Node.js command-line interface (CLI) tool developed by Mozilla, designed to control and interact with Firefox browsers programmatically from the terminal. It simplifies tasks such as launching Firefox with specific profiles, passing arguments directly to the browser binary, and managing browser instances for testing or automation purposes. The project is actively maintained, with the latest stable version being 1.4.0, released in January 2024. Releases appear to be ad-hoc, driven by bug fixes and minor feature additions rather than a fixed cadence. Unlike full-fledged browser automation libraries (like Puppeteer or Playwright), `fx-runner` focuses purely on direct CLI interaction, making it particularly suitable for scripting environments, shell-based workflows, and scenarios where a lightweight, non-programmatic JavaScript control is preferred. Its primary differentiator is this direct command-line control over the Firefox binary and its associated profiles.