Caerus Chain

The project Caerus, addresses a prominent issue within the current Ethereum Virtual Machine (EVM) environment, specifically regarding data accessibility limitations. In the existing EVM infrastructure, both developers and users face challenges in efficiently querying historical or past data on-chain.

Prior solutions, such as The Graph, Covalent, and Dune, offered decentralized API services to address centralization issues but still posed challenges as contracts had to rely on centralized oracle services.

Caerus was conceptualized as a solution to this problem, aiming to improve the EVM by enabling direct access to historical data through smart contracts.

Core Features

Caerus is designed on a Layer2 basis, with a notable addition of "Archive Storage" to its architecture. This Archive Storage is implemented to store historical data that can be directly accessed from the EVM, thus resolving the aforementioned limitations.

Modifications have been made to Op Geth, resulting in the ability to access past data within contracts through new Caerus commands in the EVM.

Caerus introduces a new read-only keyword "caerus" in the Solidity language. Developers can leverage this keyword to interact directly with historical data.

Practical Use Cases

Caerus presents practical applications in various scenarios, demonstrating its ability to resolve multiple issues within the blockchain domain.

For instance, Time-Weighted Average Price (TWAP) can now be more efficiently calculated and updated with a single query, spanning from past to present data.

In Airdrop scenarios, historical data can be verified to facilitate token airdrops.

Other applications include reputation systems, APR calculations, indicating the versatile nature of Caerus in addressing diverse blockchain challenges.

When building the Caerus project, our team dived deep into the intricate components of blockchain technology, especially for Ethereum Virtual Machine (EVM).

Technology Stack

Caerus Ethereum Virtual Machine

• Modified to integrate with Caerus functionalities, allowing direct access to historical data.

Solidity Compiler

• Adapted from version 0.8.21.
• Modified to support the new "caerus" keyword and its functionalities.

Development

• Modifying EVM: The core of Caerus revolved around modifying the EVM. We delved into the internals of the EVM and added new opcodes and functionalities that enabled smart contracts to query historical data directly.

• Solidity Enhancements: The addition of the "caerus" keyword in Solidity was a significant milestone. This required a deep understanding of the Solidity language and its compiler, Solc. We modified the compiler to recognize and compile the new keyword, enabling developers to interact with historical data seamlessly.