Pep Guardiola’s side will pay Fluminense an initial £8.5million with add-ons to follow which could take the eventual transfer fee to around £15million.
Fluminense will also receive a percentage of any future sales of the player.
Kayky will join up with Man City’s youth set-up when he arrives in England next year.
The 17-year-old signed a five-year deal with the Premier League leaders.
This was disclosed by football transfer expert, Fabrizio Romano, on Monday night.
Romano wrote on Twitter, “Brazilian gem Kayky will join Manchester City, confirmed and here-we-go.
“The agreement is already at the “signing stage”.
“Kayky will join #MCFC in June 2022 – personal terms agreed for 5 years.
“Fluminense will receive €10M + add ons + % future sale.”
Kayky has scored two goals in six first-team appearances for Fluminense this year.
The forward has drawn comparisons with Paris Saint-Germain’s Neymar.
