contentful
https://app.contentful.com is one of the very few not open source tools, that we use / support.
gocontentful
https://github.com/foomo/gocontentful
gocontentful is a command line utility and a go librabry.
contentfulproxy
https://github.com/foomo/contentfulproxy
Is a caching reserve proxy that allows you to save money, when using contentful.