Axelar Contracts MultiversX

Before diving into these contracts, it is important to have a basic high level understanding of how the Axelar protocol works by first checking the below resources:

• https://docs.axelar.dev/learn
• https://docs.axelar.dev/learn/network/flow

CGP (Cross-chain Gateway Protocol) Contracts

The MultiversX CGP contracts are based on the Axelar CGP (Cross-Chain Gateway Protocol) spec:

• https://github.com/axelarnetwork/cgp-spec

The following contracts were written starting from the referance Solidity implementation:

• Gateway Contract - main GMP contract which handles inbound execution of cross-chain commands from Axelar Network Validators and outbound cross-chain transactions
• Gas Service Contract - handles cross-chain gas payments

Also take a look at the full Axelar Cross-Chain Gateway Protocol Specification MultiversX if interested, although the README files in this project should contain most of the information from there.

Interchain Governance Contract

The Governance contract enables cross-chain governance proposals on top of the CGP protocol.

This contract will be used instead of a multisig to manage the other contracts, so they can remain upgradable but will be managed only by cross-chain governance proposals.

Interchain Token Service (ITS) Contracts

ITS is a comprised of a set of contracts which enable token transfers on top of the CGP protocol.

It is based on the Axelar ITS Solidity implementation available at the time of writing: (v1.2.4)

• https://github.com/axelarnetwork/interchain-token-service/blob/v1.2.4/DESIGN.md

It consists of the following contracts:

• Interchain Token Service - main contract which handles transferring of tokens, registering & deploying of token managers
• Interchain Token Factory - a wrapper over the Interchain Token Service which allows easier deployment of interchain tokens
• Token Manager - Token Manager implementation which either locks/unlocks tokens from the contract or mints/burns them directly

There is also a module used by the Token Manager & Interchain Token Service contracts:

• Operatable module - holds details regarding the operator (pseudo owner) of a contract as well as roles management

For testing there is also the Ping Pong Interchain contract, which is an implementation of the Ping Pong contract compatible with ITS.

Axelar Amplifier

These contracts work together with the Axelar Amplifier in order to facilitate GMP (General Message Passing) calls between MultiversX and other chains.

The Axelar Amplifier require multiple CosmWASM contracts to be deployed on Axelar network:

• Voting Verifier contract
• Gateway contract
• Multisig Prover contract

Axelar Devnet

• source chain - multiversx
• Voting Verifier contract - axelar1sejw0v7gmw3fv56wqr2gy00v3t23l0hwa4p084ft66e8leap9cqq9qlw4t
• Gateway contract - axelar1gzlxntvtkatgnf3shfcgc8alqqljjtmx75vezqrt97cpw5mpeasqlc0j84
• Multisig Prover contract - axelar1x3wz8zzretn0dp5qxf0p8qynkpczv6hc2x0r8v2guray3t3573hqflslxd

Testing

Ethereum Sepolia HelloWorld contract: - 0x8b77c570ba9edf17d2d24a99602f645adaeb3ff8 (code)