This article extends tail-call optimisation by applying it to asynchronous calls. We first introduce TMA, a novel code transformation for asynchronous tail recursive functions that prevents the creation of unnecessary tasks. We then show how to combine TMA with the existing TMC optimisation; we obtain an optimisation able to turn a recursive function with multiple tail calls under constructors into a parallel version of the function, also optimised in space. We formalise both optimisations over representative calculi, and prove them correct through backward simulations. Finally, we provide a proof-of-concept implementation as an OCaml syntax extension and evaluate it experimentally, showing our approach optimises both memory and execution time

@article{paperbot3646,
  title = {Tail Modulo Async-Await},
  author = {Emma Nardino and Ludovic Henrio and Gabriel Radanne and Yannick Zakowski},
  journal = {Proceedings of the ACM on Programming Languages},
  volume = {10},
  number = {ICFP},
  year = {2026},
  doi = {10.1145/3828684}
}