A method and system of measuring performance and capacity of a network includes monitoring network activity using an application programming interfaces (API) monitoring system with a web services definition language (WSDL) file and a probe. The WSDL file provides instructions to a probe control system in the API monitoring system and the probe control system provides regular expressions to the probe. Performance data are collected using the probe. The performance data includes a collection of performance information. Using the probe, performance data are transmitted between the network and the API monitoring system. The API monitoring system stores the performance data in a database of performance data monitored and analyzes the performance data to determine performance and capacity of the network. The API monitoring system reports information on performance and capacity of the network to a network operations center dashboard.