Gateway Contract

The Gateway Contract is the core component of Mugen’s cross-chain bridging mechanism, handling the order state flow, token whitelisting, and fee structure. It ensures secure, decentralized, and efficient asset transfers across multiple blockchain ecosystems.

Order State Flow

The order state in the Gateway Contract flows through the following steps:

1. Order Creation

Users initiate the bridging process by creating an order. This involves defining:

• Source Token: The token being bridged from the source chain.

• Target Chain: The destination blockchain where the asset will be delivered.

• Target Recipient: The wallet address receiving the asset on the target chain.

• Target Token: (Optional) If a swap is required, the desired token on the target chain.

Orders can be submitted via the Gateway Contract interface or supported dApps, ensuring a seamless and transparent user experience. The creation process validates the user’s inputs, and checks the token whitelist.

2. Order Execution

Once an order is created:

• Solver Selection: Solvers are incentivized to execute orders by providing the best quotes and timely delivery.

• Token Transfer: The solver initiates the transfer of tokens to the recipient’s address on the destination chain. During this process, solvers may leverage the Settlement Layer to finalize quotes and ensure optimal execution.

• Proof of Execution: Solvers provide proofs to verifiers for validation, including transaction details and cryptographic signatures.

3. Order Unlock

After the order execution is validated:

• Verification by Quorum: Verifiers collaborate to validate the solver’s proof and ensure the transaction aligns with the original intent.

• Unlock Mechanism: If the quorum reaches consensus, the tokens are unlocked and transferred to the target recipient on the destination chain. This ensures decentralized trust in the bridging process.

• Security Layers: Additional measures, such as timestamp checks and delay mechanisms, are applied to mitigate risks.

4. Order Refund

In cases where the order cannot be completed due to invalid inputs, network errors, or solver failures:

• Verification by Quorum: Verifiers assess the refund request and confirm its validity.

• Refund Execution: The tokens, minus applicable fees, are returned to the user’s address on the source chain.

• Buffer Tokens: A reserve buffer ensures timely refunds, even during network congestion or unforeseen delays.

This structured order flow ensures that every transaction is secure, efficient, and transparent, providing users with a seamless cross-chain experience.

Verifier Role and Quorum Mechanism

The verifier role is integral to maintaining the trust and security of the Gateway Contract. It works in conjunction with a quorum mechanism to validate transactions.

• Why Verifier Role?

• • Ensures that a trusted and decentralized group of participants verifies transactions.

  • Prevents unauthorized or malicious activity within the system.

• How the Quorum Works:

• • A predefined number of verifiers must validate a transaction before it is approved.

  • This decentralized consensus ensures the integrity of the bridge operations.

Token Whitelisting

The Gateway Contract implements a token whitelisting system:

• Source Token Validation: Only pre-approved tokens can be bridged. This ensures compatibility and prevents unsupported tokens from being used.

• Permissionless Order Creation: While token whitelisting ensures security, the contract allows anyone to create intents, providing flexibility for users.

Fee Structure

The Gateway Contract charges a flat fee for bridging:

• Fee Rate: A flat fee of 0.25% of the input token amount is charged, irrespective of the token type or value.

• Uniform Fee Application: The same fee structure applies to all token types, including ERC20 tokens.

Future Improvements: While this flat fee model is effective for the current version, Version 3 (v3) might introduce a more optimized fee structure.