In this article we explore the existence, uniqueness, and stability for a coupled system of sequential fractional integrodifferential equations involving $\psi$–Hilfer fractional derivative with multi–point boundary conditions. For the uniqueness result we use Banach fixed point theorem, and the Leray–Schauder alternative to obtain the existence result. Further, we investigate various kinds of stability such as Hyers–Ulam stability. Examples are provided to verify our results.