This paper proposes to create a monitor of digital business ecosystems so that it provides agents with information to improve the behaviour of the ecosystem in terms of stability. This work proposes that, in digital ecosystems, monitor techniques can provide fundamental services and information. The final goal is to run the monitor algorithms, generate recommendation strategies and test them. A set of evaluation metrics must be defined as well. We want to provide an outline of some global indicators, such as heterogeneity and diversity, and establish relationships between agent behaviour and these global indicators of system performance.