Developers in modern general-purpose programming languages cre-ate reusable code libraries by encapsulating them in Applications Programming Interfaces (APIs). Domain-specific languages (DSLs) can be developed as an al-ternative method for code abstraction and distribution, sometimes preferable to APIs because of their expressivity and tailored development environment. How-ever the cost of implementing a fully functional development environment for a DSL is generally higher. In this paper we propose DSLit, a prototype-tool that, given an existing API, reduces the cost of developing a corresponding DSL by analyzing the API, automatically generating a semantically equivalent DSL with its complete development environment, and allowing for user customization. To build this bridge between the API and DSL technical spaces we make use of exist-ing Model-Driven Engineering (MDE) techniques, further promoting the vision of MDE as a unifying technical space.