The prop, who celebrates his 25th birthday next week, trained with the Ireland squad during the GUINNESS Series in November.
Archer has penned a two-year deal with Munster as has the 25-year-old Ian Keatley, who deputised at out-half for Ronan O'Gara in the province's memorable Heineken Cup bonus point win over Racing Metro 92 last Sunday.
It was the Dubliner's 39th competitive appearance for the men in red since his move from Connacht in the summer of 2011.
Keatley has been in fine form for Munster in the RaboDirect PRO12 this season, converting 28 of his 31 kicks at goal for a very impressive 90.32% average.
He is the fourth top points scorer in this season's league after 13 rounds of matches. His 88-point haul includes tries against Edinburgh and the Newport Gwent Dragons in September.
Keatley was capped twice during Ireland's 2009 summer tour to Canada and the USA. He was recently named in the extended training squad for the upcoming RBS 6 Nations and is set to play for the O2 Ireland Wolfhounds against England Saxons on Friday night.
Meanwhile, Munster hooker Sean Henry will return to his native Connacht at the end of this season.