Skip to content

Interoperability

The Porto Stack provides native cross-chain interoperability through a comprehensive settlement system, enabling trustless multi-chain operations and secure token escrow capabilities.

Overview

Porto's interoperability layer consists of three main components that work together to facilitate cross-chain transactions:

Settlement System

The settlement system enables cross-chain transaction finality through merkle signature verification and messaging protocols. Porto supports multiple settlement mechanisms:

  • SimpleSettler: Signature-based settlement for trusted environments
  • LayerZeroSettler: Cross-chain messaging using LayerZero v2 protocol for decentralized settlement

Escrow

The escrow system provides secure token holding with configurable settlement conditions and automatic refunds. Key features include:

  • Multi-token support with native and ERC20 tokens
  • Configurable refund amounts and deadlines
  • Integration with any settlement provider
  • Atomic settlement verification

Cross-Chain Execution

The Porto Account includes native support for multi-chain operations:

  • Multichain Nonces: Special nonce prefix (0xc1d0) enables signature replay across chains
  • Merkle Signature Verification: Built-in support for merkle proofs in multi-chain executions
  • Cross-Chain Fund Transfers: Secure token transfers with strictly ordered addresses

Funder Interface

The Funder interface enables cross-chain execution funding, allowing relayers and third parties to sponsor transactions across multiple chains.

Interface

interface IFunder {
    struct Transfer {
        address token;
        uint256 amount;
    }
    
    function fund(
        bytes32 digest,
        Transfer[] memory transfers, 
        bytes memory funderSignature
    ) external;
}

SimpleFunder Implementation

Porto provides a reference implementation that demonstrates:

  • Pull-based funding model: Authorized relayers can pull funds on-demand
  • Signature verification: Ensures only authorized funding requests are processed
  • Risk management: Separate controls for token and native currency withdrawals
  • Multi-chain support: Coordinates funding across different chains for interop operations

The SimpleFunder serves as both a production-ready contract and a template for custom funder implementations tailored to specific use cases.

Architecture Benefits

Trustless Operations

  • No dependency on centralized bridges
  • Cryptographic verification of cross-chain messages
  • Automatic fallback mechanisms with time-based refunds

Flexibility

  • Pluggable settlement providers
  • Support for multiple messaging protocols
  • Customizable escrow conditions

Security

  • Atomic settlement guarantees
  • Protected refund mechanisms
  • Signature verification at every step

Use Cases

Cross-Chain DeFi

Execute swaps and provide liquidity across multiple chains with guaranteed settlement or automatic refunds.

Multi-Chain NFT Purchases

Purchase NFTs on one chain using tokens from another, with escrow protection ensuring delivery.

Cross-Chain Subscriptions

Manage recurring payments across different chains with automatic settlement verification.

Interchain Governance

Participate in governance across multiple chains with unified signature schemes.

Getting Started

Explore the detailed documentation for each component:

For implementation examples and integration guides, refer to the test suite in the account repository.