A measurement of the electroweak (EW) production of two jets in association with a $\mathrm {Z} $ boson in proton-proton collisions at $\sqrt{s}=13,\text {TeV} $ is presented, based on data recorded in 2016 by the CMS experiment at the LHC corresponding to an integrated luminosity of 35.9 $,\text {fb}^{\text {--}1}$ . The measurement is performed in the $\ell \ell \mathrm {jj}$ final state with $\ell $ including electrons and muons, and the jets j corresponding to the quarks produced in the hard interaction. The measured cross section in a kinematic region defined by invariant masses $m_{\ell \ell } >50,\text {GeV} $ , $m_{\mathrm {jj}} >120,\text {GeV} $ , and transverse momenta $p_{\mathrm {T j}} > 25,\text {GeV}$ is $\sigma \mathrm {EW}(\ell \ell \mathrm {jj})= 534 \pm 20,\text {(stat)} \pm 57,\text {(syst) fb} $ , in agreement with leading-order standard model predictions. The final state is also used to perform a search for anomalous trilinear gauge couplings. No evidence is found and limits on anomalous trilinear gauge couplings associated with dimension-six operators are given in the framework of an effective field theory. The corresponding 95% confidence level intervals are $-2.6< c{WWW}/\varLambda ^2 < 2.6,\text {TeV}^{-2}$ and $-8.4< c_{W}/\varLambda ^2 < 10.1,\text {TeV}^{-2}$ . The additional jet activity of events in a signal-enriched region is also studied, and the measurements are in agreement with predictions.