CPV & CKM in kaon and light flavour: status and prospects

$V_{us}$ and $V_{ud}$ are the most accurately known elements of the CKM matrix. The status of CKM first-row unitarity shows a discrepancy of $\sim 3\sigma$ with respect to the Standard Model prediction. In this proceeding the current state and the future prospects of the experimental measurements that contribute to the determination of $V_{us}$ and $V_{ud}$ are summarized.