The Irish midfielder came through the Cobh Ramblers’ academy, a side that currently play in the Irish First Division.
The 19-year-old was part of a squad that won the Munster Senior Cup in the 2022/23 season.
He was snapped up by League One Exeter City in January of this year after impressing on trial in a friendly match against Southampton.
Cummins also spent the conclusion of last season on loan at Mousehole AFC.
Manager Steve Tully said: “Delighted to get Charlie on board, he’s the right type of character and will add quality to our midfield.”
Welcome Charlie!