"I have recently added you..." : "Te he agregado/añadido " + "hace poco" / "hace un rato" / "el otro día" ... "I have recently added him..." : "Lo he agregado/añadido" + "hace poco" / ... "I have just added you..." : "Te acabo de agregar/añadir"

to he agregado recientemente .....

If you want to mean "I have just added...", it is " (Yo) acabo de añadir" or "...de agregar" If the action is not just passed (next to the present) and it is anyway very near to the present, so you should translate it as "Hace poco he añadido..." (past perfect), or longer in the past "Hace poco añadí...". Hope I could help you. Bye.