firefox@beta

Install command: 
brew install --cask firefox@beta

Name: Mozilla Firefox Beta

Web browser

https://www.mozilla.org/firefox/channel/desktop/#beta

Cask JSON API: /api/cask/firefox@beta.json

Cask code: firefox@beta.rb on GitHub

Current version: 145.0b4

Requirements: macOS >= 10.15

Conflicts with casks:

firefox 144.0 Web browser Mozilla Firefox
firefox@cn 116.0 Chinese version of Firefox firefox-cn
firefox@esr 140.4.0 Web browser Mozilla Firefox ESR

Analytics:

Installs (30 days)
firefox@beta 79
Installs (90 days)
firefox@beta 267
Installs (365 days)
firefox@beta 1,307