Cannot get API specs with Flask Blueprints and Swagger UI

I know this thread is old, but I ran into this exact problem today, trying to use flask-restful-swagger with my (somewhat) modern flask + python3 app that uses blueprints. Same problem, no errors, just no spec available no matter what i tried.

I finally abandoned this package (as it seems like it hasn't been very active anyway), even though I like the markup better with this package.

I chose Flasgger, which seemed to be updated more recently. In 10 minutes I had it up and running. Code and short tutorial are here: https://github.com/rochacbruno/flasgger

It looks like you're just not hitting the right URL. Because your blueprint url_prefix is "/test", the Swagger spec url should be at:

localhost:5000/test/api/spec