Product Details is a public JSON API which contains release information for Firefox (desktop and mobile) and Thunderbird. The data is managed by the Release Management team through Ship-it and exported available at this domain:

https://product-details.mozilla.org/

Each branch corresponds to an environment:

• master branch -> development environment -> used locally for development
• staging branch -> staging environment -> https://product-details.staging.mozilla-releng.net
• testing branch -> testing environment -> https://product-details.testing.mozilla-releng.net

• production branch -> production environment ->

  https://product-details.mozilla.org

More about product details you can read on the wiki: https://wiki.mozilla.org/Release_Management/Product_details