Callback

The entry point for protocol callbacks to reenter an Agent in a transaction.

Protocolink blocks reentrancy in the middle of a transaction for security reasons. However, blocking reentrancy stops Protocolink from supporting flash loan protocols. To support them without sacrificing security, Protocolink employs the Callback which is shown below.

Callback Call Flow

The Callback plays the receiver role to flash loan services. When users try to borrow a flash loan within Protocolink, they must provide the corresponding callback address in the callback field.

Currently, the supported callbacks are:

• AaveV2FlashLoanCallback
• AaveV3FlashLoanCallback
• BalancerV2FlashLoanCallback
• RadiantV2FlashLoanCallback

Check how the AaveV2 callback is used in this example.