The PerpetualMint contract suite relies on the Chanlink VRF contracts to generate provably-fair random numbers.
The entirety of the PerpetualMint product is split into the contracts which handle minting (PerpetualMintDiamond), and the contracts which handle the $MINT token (TokenDiamond). They are both upgradeable contracts via EIP-2535 (DiamondProxy).
High-level overview of the PerpetualMint contract suite
