Topup

Topup Action Handlers Fee Handler

Overview

  • Interface containing required methods for performing collateral top ups on a lending protocol

  • This needs to be implemented by each protocol-specific top up handler (e.g. Aave Handler, Compound Handler)

Overview

  • LP token holders can register a position on a supported protocol for top up

  • Positions can get updated or removed at any time

  • Keepers can execute collateral top ups

  • Top-ups are executed through pre-registered top-up handlers

Overview

  • Handles fees charged on top up amount

Integrating Protocols for Top Ups

There is a number of protocols for which Mero supports collateral top ups.

Currently the following protocols are supported:

We aim to add support to various other protocols. Please reach out if you are interested in integrating with Mero by emailing info@mero.finance.

This section outlines how protocols can be integrated with Mero. Note that in the future integration will be subject to approval from the Mero DAO.

Getting Started: Top Up Handlers

Integrating a new protocol can be relatively straightforward. The top up logic is mostly abstracted away and handled by the TopUpAction contract. This contract handles the registration/deletion/updating of positions, while also containing a list of all supported Top up handlers. A top up handler is a contract which contains the top up logic for a specific protocol. Hence, integrating a new protocol requires to create a new top up handler for it.

A top up handler contains the following interface.

function topUp(bytes32 account, address underlying, uint256 amount, bytes memory extra) external payable

Tops up the account for the protocol

  • account: Account to be topped up

  • underlying: Underlying currency to be used for top up

  • amount: Amount to be topped up

  • extra: Arbitrary data that can be passed to the handler

TopUpHandler.getUserFactor(address account, bytes memory extra) external returns (uint256)

Returns a factor for the user which should always be >= 1 for sufficiently colletaralized positions and should get closer to 1 when collaterization level decreases

  • account: Account for which to get the factor

  • extra: Arbitrary data that can be passed to the handler

An example implementation of a top up handler is given by the Top Up Handler for Compound.

Adding A Top Up Handler

Once a new protocol top up handler has been implemented it only needs to be added to the TopUpAction contract. This can be done via the following method:

updateTopUpHandler(bytes32 protocol, address handlerAddress) external

Update an existing or add a new top up handler.

  • protocol: Name of the protocol as bytes32

  • handlerAddress: Address of the handler