The reason molten exists is I (@Bogdanp) wanted a modern Python framework for building HTTP APIs that leveraged the support for type annotations added in recent versions of Python 3.

API Star came close to what I wanted but I found certain things off-putting (such as the use of hooks instead of real middleware, lack of support for singleton components or control over component caching and others).

molten’s core principles are as follows:

  • simple and easy to understand core – anyone should be able to read the source code and fully understand it in an afternoon.
  • productivity and stability – we’re going to avoid breaking changes as much as possible.
  • type safety – projects using molten should be able to leverage type annotations for static type checking.

molten has taken a lot of inspiration from API Star and Rocket.