When designing smart contracts, the decision between upgradeable and non-upgradeable contracts often presents a trade-off between flexibility and immutability.While upgradeable contracts can be updated over time, they come at the expense of a trust risk - that no party would be able to change the behavior of the protocol in any way. On the flip side, non-upgradeable contracts provide immutability and certainty, but at the expense of adaptability, which is crucial in the fast-changing Web3 environment.
While designing the Protocol’s escrow mechanism, we wanted to strike a balance and trust, ensuring the protocol can easily support new features & optimizations, while minimizing the trust risk associated with upgradeable contracts.

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How it works:

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Dynamic lookup mechanism

The SCEAContract itself is not upgradeable and does not contain implementation logic. Instead, it relies on a dynamic lookup contract to map to the SCEAImplementationLogic contract where the logic resides, and which is upgradeable. When the escrow contract needs to execute specific logic, it queries the SCEAImplementationLookUp contract to retrieve the corresponding SCEAImplementationLogic contract.

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Proxy execution

The escrow contract then executes the logic retrieved from the implementation contract in the context of its own storage, effectively acting as a proxy. This ensures that updates or modifications are applied to the SCEAImplementationLogic contract rather than the SCEAContract contract, thus making the escrow contract immutable. To further mitigate the trust risk and ensure the integrity of the Onboard Protocol, any upgrades to the implementation logic or any other parts of the protocol would undergo a third-party audit before being released. Upgradeable SCEA

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Code Outline

class Factory implements Ownable {

     storageLocation = 0x020202020202020202020...;
      
     fallback() { 
        address = load(storageLocation); //factory implementation contract
        delegatecall(address, parameters);
     }
}


class SCEAImplementationLookUp implements Ownable {
     storageLocation = 0x020202020202020202020...;
     getSceaImplementationAddress() {
        address = load(storageLocation); //factory implementation contract
        return address;
     }
}


class SCEAContract { // several instances

   fallback() {
      implAddress = SCEAImplementationLookUp().getSceaImplementationAddress();
      delegatecall(implAddress, methodName, ...parameters);
   }

}