Telemedicine is used to assist and support remote medical care for patients. Our objective was to build up a REST Webservices alert engine that receives clinical parameters from patients of vital signs and basic laboratories to monitor patients remotely. We built a REST API using FHIR, so it can interoperate with other applications, send data to be processed, and receive a response. If the API detects a health risk situation, it sends an alert about the medical parameters that are controlled. The results of the processed data, news and alert, can return synchronously or asynchronously, at the same time that the data to be processed is being sent. The alerts generated can be automatically sent to a web service, mail or WhatsApp of the physician. The alert message comes out as normal, low, medium and high risk. The presented approach establishes communication that enables timely health information exchange. We conducted an experiment (with fictitious data) where we sent several queries by Postman. Finally, we evaluated the communication to be successful by manual checking. The use of the API significantly improves the monitoring of chronic patients. Many works show the effectiveness of telemedicine to improve the control of certain chronic diseases. In addition, telemedicine interventions were also found to significantly improve other health outcomes. Our API enables us to transfer data and produce alerts successfully. This gives us hope that a future with ubiquitous healthcare information interoperability is possible using our system.