A method for debugging client-side code includes a client receiving an application file set from a server in response to the client requesting an application. A singleton is generated on the client by executing a script in the application file set. The singleton monitors a data event generated by an application programming interface. The singleton writes a client data record to a cache memory in response to the application programming interface generating the data event. The client data record records an application event. The singleton flushes the contents of the cached memory in response to a flush event, and transfers the contents to the server for persistent storage.