Abstract: Methods and apparatus for application agnostic federation service to facilitate cross connectivity of messaging and communications platforms are described. In an embodiment, a method is provided for operating a cross-messaging platform to communicate messages between a first user registered on a first messaging platform and a second user registered on a second messaging platform. The method includes registering the first user, receiving a request from the first user to connect with the second user, and sending an invitation to the second user to connect with the first user. The method also includes registering the second user if the second user accepts the invitation, and establishing a communication channel between the first messaging platform and the second messaging platform so that communication between the first and second users occur using the communication channel.