Invoker

The Invoker contract enables users to trigger cross-chain borrowing and collateral removal actions using the native token of any chain, not just the chain where the selected Controller contract resides.

This addresses a key UX challenge: operations like borrow or removeCollateral are initiated in the Controller, which may reside on a different chain from the involved SToken chain. Without the Invoker, users would need to pay gas fees in the Controller’s native token, creating unnecessary friction in cross-chain interactions.

Why It Matters

Imagine a user with assets on Polygon who wants to borrow using a Controller contract on Ethereum:

• Without the Invoker: They must pay gas fees in ETH, even though their funds are on Polygon.
• With the Invoker: They can initiate the borrow from Polygon and pay in POL.

The Invoker adds an extra cross-chain message to the process, which slightly increases fees and latency, but offers maximum flexibility and better UX.

Architecture

The Invoker integrates with:

• The Router on the same chain to send the message
• The Controller on a remote chain to initiate the operation

It acts as a secure gateway for abstracting away the complexities of where Controllers reside, letting users interact from anywhere.

Summary

The Invoker contract is a powerful tool for enhancing UX in a multi-chain DeFi environment. It enables:

• Decoupled operations: Call borrow or removeCollateral from any chain.

• Fee flexibility: Pay gas in the native token of your current chain.

• Router integration: Routes cross-chain calls to the correct Controller.

• Admin controls: Restrict supported Soul contracts with ACL roles.

By introducing a thin abstraction between the user and the Controller, the Invoker offers a smooth cross-chain experience, especially for dApps built on top of Soul.