Subscribers
Subscribers, new in Uniswap v4, allow for liquidity-position owners to opt-in to a contract that receives notifications. The new design is intended to support liquidity mining, additional rewards given to in-range liquidity providers. Through notification logic, position owners do not need to risk their liquidity position and its underlying assets. In Uniswap v3, liquidity mining was supported by fully transferring the liquidity position to an external contract; this old design would give the external contract full ownership and control of the liquidity position.
When a position owner subscribes to a contract, the contract will receive notifcations when:
The position is initially subscribed
The position increases or decreases its liquidity
The position is transferred
The position is unsubscribed