I have been working on a side project that needed a well developed API. While I have written API's at work in the past, I wanted to get something built up that was a bit more manageable and had proper testing. I also really wanted to use Marshmallow and RESTPlus with a SQLalchemy backend.
I spent the better part of this week building and researching to finally hit my head against the wall too many times to count. FINALLY, I found AJ Pryor's blog post that shows how he integrated all three beautifully, and he had an example repo setup.
Thanks to AJ for figuring it out and writing flask-accepts, I think that without it, I'd still be banging my head against a wall or migrating to a different framework.