Add VIP: Support CCIP for Connex

vips/VIP-Connex-CCIP-Support.md

@@ -0,0 +1,55 @@
+---
+Title: Support CCIP for Connex
+Description: CCIP adds trusted off-chain-sources
+Author: Mario Micklisch (@ifavo)
+Discussions: https://vechain.discourse.group/t/add-vip-support-ccip-for-connex/85
+Category:  Core
+Status: Idea
+CreatedAt: 2023-12-07
+
+---
+
+## Overview
+
+[ERC-3668: CCIP Read: Secure offchain data retrieval](https://eips.ethereum.org/EIPS/eip-3668) suggests a mechanism that is used widely on the ETH ecosystem to allow a contract to fetch external data.
+Providing the functionality as option for connex based interactions with VechainThor improves data access.
+
+## Rationale
+
+Short lived data or data available at places not accessable via contracts (other chains, web, etc.) is made accessable using CCIP reading.
+By supporting ERC-3668 Connex will improve developer experience, following a widely used standard and simplify the process of accessing off-chain-information.
+
+With CCIP support off-chain-sources can be shared between different platforms, potentially opening new potentials for dApp developers.
+
+## Specification
+
+Connex has an option to enable CCIP as feature.
+
+**When enabled**, it checks errors from contract calls for the signature of:
+
+```sol
+error OffchainLookup(address sender, string[] urls, bytes callData, bytes4 callbackFunction, bytes extraData)
+```
+
+If detected, it follows the ERC-3668 process to lookup the data and continue with the contract call.
+
+**When disabled**, it will pass on the error without additional processing.
+
+
+## Test Cases
+
+1. Create a Connex instance
+3. Deploy test contract: https://github.com/smartcontractkit/ccip-read/blob/master/packages/ethers-ccip-read-provider/contracts/Token.sol
+4. Set URLs to a custom resolving
+5. With Disabled CCIP-Reading: When `balanceOf` is called, Then an error is thrown
+6. With Enabled CCIP-Reading: When `balanceOf` is called, Then the CCIP process is followed And `balanceOfWithSig` returns successful
+
+## Reference Implementation
+
+
+## Security Considerations
+
+- If the contracts follow the verification of data, security on the blockchain side will not have an impact.
+- Contracts and dApps could forward users to access backends using Connex. This could also happen with regular fetch requests in a dApp. It will expose client information (User-Agent, IP) to a configured backend.
+
+Copyright and related rights waived via [CC0](./LICENSE.md).