The present invention enables capturing API level calls using a combination of dynamic instrumentation and library overriding. The invention allows event level tracing of API function calls and returns, and is able to generate an execution trace. The instrumentation is lightweight and relies on dynamic library/shared library linking mechanisms in most operating systems. Hence we need no source code modification or binary injection. The tool can be used to capture parameter values, and return values, which can be used to correlate traces across API function calls to generate transaction flow logic.