  While the observation of nucleon decay would be a smoking gun of Grand
Unified Theories (GUTs) in general, the ratios between the decay rates of the
various channels carry rich information about the specific GUT model
realization. To investigate this fingerprint of GUT models in the context of
supersymmetric (SUSY) GUTs, we present the software tool \texttt{SusyTCProton},
which is an extension of the module \texttt{SusyTC} to be used with the
\texttt{REAP} package. It allows to calculate nucleon decay rates from the
relevant dimension five GUT operators specified at the GUT scale, including the
full loop-dressing at the SUSY scale. As an application, we investigate the
fingerprints of two example GUT toy models with different flavor structures,
performing an MCMC analysis to include the experimental uncertainties for the
charged fermion masses and CKM mixing parameters. While both toy models provide
equally good fits to the low energy data, we show how they could be
distinguished via their predictions of ratios for nucleon decay rates. Together
with \texttt{SusyTCProton} we also make the additional module
\texttt{ProtonDecay} public. It can be used independently from \texttt{REAP}
and allows to calculate nucleon decay rates from given $D=5$ and $D=6$ operator
coefficients (accepting the required SUSY input for the $D=5$ case in SLHA
format). The $D=6$ functionality can also be used to calculate nucleon decay in
non-SUSY GUTs.
