Operators

Operators are a more flexible and powerful version of approvals. While in effect, the operator contract can act on behalf of the specified account. This includes interacting with vaults (i.e. withdrawing/borrowing funds), enabling vaults as collateral, etc. Because of this, it is recommended that only trusted and audited contracts, or EOAs held by a trusted individuals, be installed as operators.

Operators have many use cases. For instance, a user might want to install a modifier such as stop-loss/take-profit/trailing-stop to a position in an account. To accomplish this, a special operator contract that allows a "keeper" to close out the user's position when certain conditions are met can be selected as an operator. Multiple operators can be installed per account. Note however that the operators may implement contradictory logic, so care should be taken when installing multiple operators for a single account.

An operator is similar to a controller, in that an account gives considerable permissions to a smart contract (that presumably has been well audited). However, the important difference is that an account owner can always revoke an operator's privileges at any time, however they can not do so with a controller. Instead, the controller must release its own privileges. Another difference is that controllers can not change the account's collateral or controller sets, whereas an operator can.