Overview of the η/η' physics at BESIII and KLOE-2

As the mixing states of the pseudoscalar singlet and octet, η/η' offer an important laboratory to test the fundamental symmetries and to search for new physics beyond the Standard Model. In this talk, I will give an overview of the recent related progress and insights on η/η' decays at BESIII, KLOE/KLOE2. In addition, I will also include the prospect in η/η' decays tthat could be achieved with the proposed Super Tau Charm Factory (STCF) at a e⁺e^- collider and Huizhou Hadron Spectrometer (HHaS) proposed at the High Intensity Heavy-ion Accelerator Facility (HIAF).