Symfony is model independent (there is no βMβ from MVC). Note that Doctrine or Propel are separate projects integrated with Symfony. They are not included in the scope.
I think you just need to implement the client library for your API, which will be separated from the framework (you can even use it in simple php scripts or in other environments).
Step 2 will integrate your library with Symfony. This will likely include the creation of a set and corresponding service definitions. A look at the DoctrineBundle can give you some ideas.
Jakub zalas
source share