Pion and Kaon structure function measurements at Jefferson Lab 12 GeV and the Electron-Ion Collider

The lightest mesons, Pions and Kaons play a fundamental role in the understanding of hadronic mass. The 12 GeV JLab will address some questions, but to ultimately understand the role of sea quarks and gluons in pion and kaon masses the wide kinematic reach in the longitudinal momentum fraction as well as in the four-momentum transfer, as enabled by the Electron-Ion Collider (EIC) is needed. In this talk, we present the current status of and projections for measurements of pion and kaon structure functions in the Jefferson Laboratory 12 GeV era and at the EIC.