# Deposit Rewards

To incentivize stakers, users can deposit rewards into a Rewards Manager. 

## Using CozyRouter to deposit assets

Using the CozyRouter is the preferable way to deposit reward assets. To deposit assets using the CozyRouter, integrators can use `CozyRouter.depositRewardAssets`:

```solidity
/// @notice Deposits exactly `rewardAssetAmount_` of the reward pool's underlying tokens into the `rewardsManager_`.
/// The specified amount of assets are transferred from the caller to the `rewardsManager_`.
/// @dev This will revert if the router is not approved for at least `rewardAssetAmount_` of the reward pool's
/// underlying asset.
function depositRewardAssets(IRewardsManager rewardsManager_, uint16 rewardPoolId_, uint256 rewardAssetAmount_)
    external
    payable;
```

This method will:

* Transfer the underlying reward assets from the `msg.sender` to the Rewards Manager.
* Call `RewardsManager.depositRewardAssetsWithoutTransfer.`

\*\*Note that fee on transfer tokens are not supported.

Prior to calling this function, the user must have approved `CozyRouter` to a spend sufficient amount of their `RewardsManager.rewardPools(rewardId).asset` balance.

## Deposit mechanics

[`RewardsManager.depositRewardAssetsWithoutTransfer`](https://github.com/Cozy-Finance/cozy-safety-module-rewards-manager/blob/main/src/lib/Depositor.sol#L50) assumes that the assets to be deposited has already been transferred to the Rewards Manager. Any excess assets transferred will be kept by the Rewards Manager. 

On deposit, high-level the Rewards Manager does the following:

* Check if the Rewards Manager is `PAUSED`. If so, revert.
* Check the Rewards Manager's asset balance to determine if the total deposit amount was transferred. If not, revert.
* Update the relevant reward pool's internal `rewardPool.undrippedRewards` value.
* Emit a `Deposited` event.