Richards had been in Munich on loan with their U-19s since July but will now be solely in the hands of the reigning Bundesliga champions after signing a four-and-a-half-year deal through June 2023.
Richards had already seen plenty of game time while on loan, logging over 1,700 minutes across 20 matches. He made his first appearance during his first month with the club, seeing first-team action while Bayern were on their summer tour.
The transfer highlights the growing partnership between the two clubs, which created a player development program last February. Details of the transfer are kept confidential by the club, but Goal.com reported two weeks ago that the fee was around $1.5 million, with a chance it could swell to $2 million.