The BaseRewardPool.sol contract is used as the main reward contract for all LP pools.
//sample convex reward contracts interface
interface IConvexRewards{
//get balance of an address
function balanceOf(address _account) external returns(uint256);
//withdraw to a convex tokenized deposit
function withdraw(uint256 _amount, bool _claim) external returns(bool);
//withdraw directly to curve LP token
function withdrawAndUnwrap(uint256 _amount, bool _claim) external returns(bool);
//claim rewards
function getReward() external returns(bool);
//stake a convex tokenized deposit
function stake(uint256 _amount) external returns(bool);
//stake a convex tokenized deposit for another address(transfering ownership)
function stakeFor(address _account,uint256 _amount) external returns(bool);

Token Type of Reward

Use baseRewardPool.rewardToken() to determine what token is rewarded

Balance of an Account

Use baseRewardPool.balanceOf(address) to see how much an address has staked.

Total Staked Amount

Use baseRewardPool.totalSupply() to see how much is currently staked on the reward contract

Current Earned Rewards

Use baseRewardPool.earned(address) to see how much rewards an address will receive if they claim their rewards now.

Claim Rewards

Use baseRewardPool.getReward() or baseRewardPool.getReward( address, bool ) to claim rewards for your address or an arbitrary address. The bool is an option to also claim extra incentive tokens (ex. snx) which is defaulted to true in the non-parametrized version. More information on extra rewards below.

Stake/Deposit Tokens

Use baseRewardPool.stake( amount ) to stake a given amount for your address Use baseRewardPool.stakeAll() to stake all tokens for your address Use baseRewardPool.stakeFor( address, amount ) to stake on behalf of another address (*This transfers ownership of the tokens!)

Unstake/Withdraw Tokens

Use baseRewardPool.withdraw( amount, bool ) to withdraw a specific amount. bool is to also claim while withdrawing Use baseRewardPool.withdrawAll( bool ) to withdraw all tokens staked. bool is to also claim while withdrawing Use baseRewardPool.withdrawAndUnwrap( amount, bool ) to withdraw a specific amount of tokens AND also unwrap the tokens back into the underlying LP tokens. bool is to also claim while withdrawing Use baseRewardPool.withdrawAllAndUnwrap(bool claim) to withdraw all tokens AND also unwrap the tokens back into the underlying LP tokens. bool is to also claim while withdrawing

Extra Rewards

The BaseRewardPool has an array of child reward contracts called extraRewards. You can query the number of extra rewards via baseRewardPool.extraRewardsLength(). This array holds a list of VirtualBalanceRewardPool contracts which are similar in nature to the base reward contract but without actual control of staked tokens. This means that if a pool has CRV rewards as well as SNX rewards, the pool's main reward contract(BaseRewardPool) will distribute the CRV and the child contract(VirtualBalanceRewardPool) will distribute the SNX.

Other Information

The reward contract mechanics are that of popular synthetix style reward contract. Some important parameters for determining things like APY could be: duration: The reward contract cycle length periodFinish: When the current cycle is planned to finish rewardRate: How many tokens are distributed per second