The cons of this approach are that a new request needs to be made every time the user wants / needs to fetch new data, which would cause extra bandwidth usage. In addition, some data may be lost between requests, as only one request can be made per second and data can be updated up to 3x per second.
The REST API is recommended for users who are looking for an easy implementation and who may lose price peaks.
The Streaming API (built with socket.io) can be accessed through any of the Node.js or PHP libraries.
The advantage of this approach is that only a single long-lasting connection is established with the server, and then the prices are sent automatically, saving many resources and bandwidth. Because the server always sends updated data to the client, there is no risk of losing peaks of currency between requests.
The Streaming API is recommended for advanced users who are looking for efficiency in their applications / solutions and can not lose a single PIP.
If you have doubts regarding what is the best approach for your case, contact our support center