Service-based systems are software systems composed of autonomous components or services pro-vided by different vendors, deployed on remote machines and accessible through the web. One of the challenges of modern software engineering is to ensure that such a system behaves as intended by its designer. The Reo coordination language is an extensible notation for formal modeling and execu-tion of service compositions. Services that have no prior knowledge about each other communicate through advanced channel connectors which guarantee that each participant, service or client, re-ceives the right data at the right time. Each channel is a binary relation that imposes synchronization and data constraints on input and output messages. Furthermore,...