Skip to main contentA Relay Vault is a smart contract (RelayPool.sol) that
implements the
ERC4626
standard. It is deployed on specific EVM network, for a specific currency,
represented by an ERC20. It is possible to use wrapped tokens (such as WETH) to
handle native currencies (we provide a
Native Gateway for this purpose).
Each vault has a base yield pool, in which funds are instantly deposited and
withdrawn. This pool is typically a lending protocol such as Aave or Morpho, but
it can be any contract that implements the ERC4626 standard. The base yield pool
is used to generate yield for the vault.
Each vault also has origins. Origins are contracts deployed on different
chains. Origins can be treated as “bridging” contracts. When a user sends funds
to a bridge, they can receive the same amount (minus fees) of funds from the
vault on the destination chain. In order to achieve this, the RelayBridge
contracts uses Hyperlane to send a message to the
vault. As soon as the message reaches the vault, the funds are pulled from the
yield pool and sent to the recipient. At the same time, the vault initiates the
transfer of funds using an underlying bridge (e.g. native bridges, … ).
The Relay Vaults can be considered to be an “accelerator” where funds are
“dispersed” without requiring to wait for the full resolution of the bridge,
in exchange for a small fee.
In order to abstract the underlying bridges, we rely on the concept of
BridgeProxy. A BridgeProxy contract is deployed on
both the origin chain and the vault’s chain and implements the specificities of
the underlying bridge.
Each origin has its own fee which represents the “opportunity cost” of the
funds being bridged: shorter bridges should have lower fees than longer ones.
Finally, the vault contract is designed to resist “inflation” attacks. Any yield
generated (thru fees, or extra rewards) is not accrued instantly by the vault,
but streamed over a specific period of time, rendering any attack where funds
deposited and withdrawn in a short period of time ineffective. 
