How to include a library module dependency in an Android Studio project?

Android Studio works on project-modules concept,All your modules should be inside a root directory(Your Project Directory). One module can be depended on other module/modules. Your libraries are considered as different modules under same project and your main module(app in your case) depends on them.

Change your project structure a little bit :

Project Root
+-- libs
    +-- PullToRefresh (my lib project)
+-- app
|   +-- builds
|   +-- src
|   |   +-- main (java code and resources)
    +-- .....
+--settings.gradle

Include this line in your settings.gradle

include ':libs:PullToRefresh'

Your build.gradle looks fine. I suggest you to change your directory name from libs to library because use libs for your jar dependency not for module dependencies.

and keep this in your main module’s build.gradle file :

dependencies {
    compile project(":libs:PullToRefresh")
}