  We present an interface between the multipurpose NLO Monte Carlo tool
MadGraph5_aMC@NLO and the automated one-loop amplitude generator GoSam. As a
first application of this novel framework, we compute the NLO corrections to
$pp \to t\bar{t}H$ and $pp \to t\bar{t}\gamma\gamma$ matched to a parton
shower. In the phenomenological analyses of these processes, we focus our
attention on observables which are sensitive to the polarisation of the top
quarks.
