Foundation Mission Request: ERC-7683 Integration with Native Interoperability [TECHNICAL]

[opjulian]

Proposed Foundation Mission Request: ERC-7683 Integration with Native Interoperability

Season 7 Intent: A set of interoperable Stage 1 chains doing $250m per month in cross-chain asset transfer

Total grant amount: 26k OP

Should this Foundation Mission be fulfilled by one or multiple teams: One

OP Labs or Optimism Unlimited Sponsor: zainbacchus

Reviewing Body: Developer Advisory Board Foundation Mission Team

Submit by: April 16th

Selection by: April 25th

Start date: April 28th (Please note Missions must be completed within 12 months (i.e. marked as done)

Any questions? You can reach the DAB via the new #dab-general channel in the Optimism Superchain Devs discord: https://discord.gg/QSdZHfHq

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Develop and deploy an ERC-7683-compliant settlement system that leverages Superchain's native interoperability for secure and efficient cross-chain transactions. This system will standardize cross-chain intents, enabling seamless interactions across the Superchain ecosystem.

What is required to execute this Mission:

1. ERC-7683 Implementation:
   • Develop a settlement system adhering to the ERC-7683 standard for cross-chain intents.
   • Ensure compatibility with ERC-7683 order structures, including GaslessCrossChainOrder and OnchainCrossChainOrder.
   • Implement settlement interfaces IOriginSettler and IDestinationSettler as defined in the standard.
2. Superchain Interoperability Integration:
   • Utilize Superchain's native message relaying via IL2ToL2CrossDomainMessenger for cross-chain intent verification.
3. End-to-End Process Validation:
   • Develop a comprehensive flow to validate the full settlement process on testnet environments.
   • Operate a filler on testnet to test and confirm the complete settlement workflow.

Solution Criteria:

• User Deposit & Order Creation:

  Users create a compliant OnchainCrossChainOrder or GaslessCrossChainOrder and escrow tokens by invoking open or openFor on the IOriginSettler contract, thereby locking funds and defining the cross-chain intent.

• Filler Initiation on Destination Chain:

  A filler detects the escrowed deposit and credits the user's account on the destination chain by calling the fill function on the IDestinationSettler contract.

• Interchain Settlement Messaging:

  Post-filling, the filler invokes a function on the destination settler, triggering a fill confirmation sent to the origin settler contract via Superchain's native interoperability.

• Atomicity:

  Provide fillers the option to execute the fill and message initiation within a single transaction or separately, ensuring flexibility.

• Batching:

  Implement an option for fillers to batch fill confirmations into a single message to optimize gas costs on both chains. If immediate batching support is unfeasible, design interfaces to accommodate future batching capabilities.

• Verification & Filler Repayment:

  Upon receiving and verifying one or more messages, the origin settler should release the depositor’s escrowed funds to the filler.

Security & Reliability:

• Superchain Native Interoperability:

  Leverage Superchain's native interoperability to facilitate trust-minimized settlements.

• ERC-7683 Compliance:

  Ensure all order structures and settlement contracts conform to the ERC-7683 standard.

• Robust Security Measures:

  Incorporate proof validation, replay protection, and settler logic to prevent unauthorized fund releases.

Milestones & Deliverables:

1. Specification & Design:
   • Develop a detailed implementation plan, including design approach and system architecture.
2. Development & Open-Source Repository:
   • Establish an open-source code repository to track progress and facilitate community collaboration.
3. Testnet Deployment:
   • Deploy the system on testnets (e.g., Unichain Sepolia and OP Sepolia).
   • Demonstrate successful cross-chain intent fulfillment on testnet environments.
4. Audits:
   • Conduct comprehensive security audits to ensure system robustness and reliability.
5. Mainnet Deployment:
   • Deploy the audited system on mainnets (e.g., Unichain and OP Mainnet).
   • Validate successful cross-chain intent fulfillment on mainnet environments.

Impact Assessment:

• Testnet Demonstration:

  Successful execution of ERC-7683 cross-chain intents secured by Superchain's native interoperability on testnets.

• Open-Source Contribution:

  Availability of the ERC-7683 implementation as an open-source resource for the broader community, facilitating future development.

• Economic Activity:

  Achievement of a target volume (e.g., $XYZ) in transactions between Unichain and OP Mainnet using the settlement contract.

Go-to-Market Strategy:

Upon successful audit and testnet validation, the Superchain settlement contract will be adopted by protocols such as Across to facilitate cross-chain orders between OP Mainnet and Unichain Mainnet upon the launch of interoperability features.

Resources:

• [ERC-7683 Specification](https://www.erc7683.org/spec)
• [Superchain Interoperability Explainer](https://docs.optimism.io/stack/interop/explainer)

This mission aims to enhance the Superchain ecosystem's decentralization, interoperability, and resilience by integrating ERC-7683 with native interoperability features, thereby providing a standardized framework for secure and efficient cross-chain transactions.

Note - please leverage the [Superchain Dev Docs](https://docs.optimism.io/stack/interop/explainer) and [[Superchain Devnet](https://docs.optimism.io/stack/interop/tools/devnet)](https://docs.optimism.io/stack/interop/tools/devnet) to prototype the Superchain interop integration.

Application Instructions

To apply for this Foundation Mission, please complete the form in the expandable section below and leave your response as a comment on this issue thread. Submissions will be open until April 11th*, at which time the Foundation will review all submissions and select individuals/teams to complete the work defined here.*

Submission Form

Copy the entire application below and leave a comment on this issue with your answers completed. A representative from the Optimism Foundation or the Developer Advisory Board may reach out using the contact info provided to request more information as necessary.

Foundation Mission Application

Please verify that your team members below:

• Team Lead: Please specify the best point of contact for your team
• Contact info:
• L2 recipient address:
• Please list the members of your team and link to any previous work:

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What makes your team best-suited to execute this Mission?

• [...]
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Please describe your proposed solution based on the above Solution Criteria (if applicable):

• [...]
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Please outline your step-by-step plan to execute this Mission, including expected deadlines to complete each piece of work:

• [...]
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Please define the [critical milestone(s)](https://gov.optimism.io/t/collective-grant-policies/5833#p-25088-critical-milestones-and-clawback-8) that should be used to determine whether you’ve executed on this proposal:

• [...]
• [...]

Please list any additional support your team would require to execute this mission (financial, technical, etc.):

• [...]
• [...]

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Please check the following to make sure you understand the terms of the Optimism Foundation Mission program:

• I understand my grant for completing this Foundation Mission will be locked for one year from the date of proposal acceptance.
• I understand that I will be required to provide additional KYC information to the Optimism Foundation to receive this grant
• I understand my locked grant may be clawed back for failure to execute on critical milestones, as outlined in the [Collective Grant Policies](https://gov.optimism.io/t/collective-grant-policies/5833#p-25088-critical-milestones-and-clawback-8)
• I confirm that I have read and understand the [Collective Grant Policies](https://gov.optimism.io/t/collective-grant-policies/5833#p-25088-critical-milestones-and-clawback-8)

[Sednaoui]

Foundation Mission Application

Please verify that your team members below:

• Team Lead: @Sednaoui
• Contact info: marc@candidelabs.com
• L2 recipient address: 0xe40A924AFAAe6Dc03F685edBF4CDF9154987363f
• Please list the members of your team and link to any previous work:

  • Team

    • Andrew Wahid – Co-Founder (@andrewwahid)
      Andrew leads engineering efforts on Candide’s InstaGas, building our core paymaster api from head to toe.

    • Marc Sednaoui – Co-Founder (@Sednaoui])
      Marc spearheads technical documentation and actively engages with the developer community, ensuring our tools are seamlessly integrated and widely adopted.

    • Sherif Ahmed – Co-Founder @sherifahmed990
      Sherif is the driving force behind Candide's Bundler and AbstractionKit, building core infrastructure to streamline UserOperations and optimize wallet transaction processes.

  • Previous Work

    • Voltaire Bundler: A lightning-fast Bundler for Ethereum's Account Abstraction, developed in Python and Rust.
    • AbstractionKit: A fast growing open-source Ethereum utility library for creating smart wallets.
    • InstaGas: A paymaster solution offering easy access to gas sponsorship through policies and gas payments in ERC-20 tokens.
    • Smart Account Contacts: Audited and formally verified smart account contracts**.**
    • Candide Wallet: The first ERC-4337 open-source consumer mobile wallet

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What makes your team best-suited to execute this Mission?

ERC-7683 is a chain abstraction standard specific for cross-chain trade executions. It achieves optimal synergy when coupled with a settlement system integrated with Account Abstraction. As per the spec:

Ideally, 7683 orders containing Messages can be combined with smart contract wallets like implementations of ERC-4337 or EIP-7702 to allow complete cross-chain delegated execution.

Candide has a proven track record of delivering Account Abstraction developer tooling and pushing the boundaries for Ethereum UX improvements for real-world use cases. This mission requires not only a deep understanding of intent system mechanics and protocol-level communication, but also the capability to architect a user-centric design paradigm, placing the needs and experiences of end-users at the forefront, rather than the underlying technology.

Please describe your proposed solution based on the above Solution Criteria (if applicable):

We propose to develop the ERC-7683 settlement system that leverages the Superchain's inherent interoperability to enable cross-chain intents. The system comprises two principal components: the standard-compliant smart contracts and a filler, also known as the relayer. The smart contracts inherit the Superchain's native interoperability L2ToL2CrossDomainMessenger contract to relay messages with replay protection and domain binding. We will explore the possibility of harnessing erc-4337 paymasters as relayers to compete in fulfilling users' orders to provide standard approaches for smart accounts.

Please outline your step-by-step plan to execute this Mission, including expected deadlines to complete each piece of work:

Milestone 1: Specification & Design (Delivery date: 2 weeks)

• Research the latest specifications for ERC-7683 cross-chain trades and the new Superchain native interoperability system.
• Develop a detailed implementation plan, including a design approach and system architecture.
• Engage with the relevant stakeholders to gather feedback and validate the proposed design.

Milestone 2: Smart Contract Development (3 weeks)

• Develop the ERC-7683 settlement smart contracts that inherits L2ToL2CrossDomainMessenger
  • Develop a compliant origin settler contract implementation
    • Implements the IOriginSettler interface.
    • Allow users to create compliant OnchainCrossChainOrder or GaslessCrossChainOrder, escrow tokens by invoking the open or openFor functions, and thereby lock funds and define the cross-chain intent.
  • Develop a compliant destination settlement contract
    • Implements the IDestinationSettler interface.
    • This contract will be invoked by the filler to credit the user's account on the destination chain by calling the fill function.
  • Implement Interchain Settlement Messaging:
    • Develop the functionality for fillers to trigger a confirmation message, which will be sent to the origin settler contract via the Superchain's native interoperability L2ToL2CrossDomainMessenger contract.
    • This will ensure reliable and secure cross-chain communication between the origin and destination chains.
  • Provide Flexible Execution Options for fillers:
    • Implement the capability for fillers to execute the message initiation within a single transaction or separately, as per their preference.
    • Similarly, develop the option for fillers to batch fill confirmations into a single message to optimize gas costs on both chains.
  • Implement Verification and Filler Repayment:
    • Develop the logic to receive and verify one or more messages received from the destination chain.
    • Upon successful verification, release the depositor's escrowed funds to the filler, ensuring a seamless and trustless settlement process.

Milestone 3: Unit Tests and Testnet Deployments (Delivery date: 2 weeks)

In this milestone, we will focus on developing a comprehensive suite of unit tests to ensure the reliability and correctness of the settlement system.

• Testnet Deployments:
  • Deploy the fully developed ERC-7683 settlement system on testnet environments: Unichain Sepolia and OP Sepolia.
• Unit Tests:
  • Test the Compliant Destination Settlement Contract
  • Test the Interchain Settlement Messaging
  • Test the Flexible Execution Options
  • Test the Verification and Filler Repayment
  • Test the Filler Component

Milestone 4: Security Audits (Delivery date: 4 weeks)

• Engage with Multiple Reputable Security Auditing Firms
  • Identify and evaluate firms with relevant experience.
  • Obtain detailed proposals, including timelines and costs.
• Evaluate Proposals and Select Auditing Firm
  • Review and compare proposals based on expertise, methodology, and cost.
  • Select the most suitable firm.
• Present Proposal to Optimism Fnd
• Conduct the Security Audit
• Incorporate Audit Findings and Recommendations
  • Review the audit report and implement necessary changes to address any identified vulnerabilities.

Milestone 5: Mainnet Deployment (Delivery date: 1 week)

• Deploy the audited and hardened ERC-7683 settlement system to Unichain and OP Mainnet.
• Validate the system's performance and reliability in a live, production-ready setting.
• Monitor the system's operation and address any issues that may arise during the initial mainnet deployment phase.
• Achieve a targeted volume of 100k in USD equivalent after 4 weeks of Mainnet deployment

Please define the critical milestone(s) that should be used to determine whether you’ve executed on this proposal:

Milestone	Deliverable Source of Truth	Timeline
Specification & Design	We will established a new repository to Candide’s github organization	2 weeks
Smart Contract Development	Candide’s Github repo	3 weeks
Unit Tests and Testnet Deployments	Candide’s Github repo and Unichain and OP Sepolia	2 weeks
Security Audits	Candide’s Github repo	4 weeks
Milestone 5: Mainnet Deployment	Unichain and OP Mainnet	1 week

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Please check the following to make sure you understand the terms of the Optimism Foundation Mission program:

• I understand my grant for completing this Foundation Mission will be locked for one year from the date of proposal acceptance.
• I understand that I will be required to provide additional KYC information to the Optimism Foundation to receive this grant.
• I understand my locked grant may be clawed back for failure to execute on critical milestones, as outlined in the Collective Grant Policies
• I confirm that I have read and understand the [Collective Grant Policies](https://gov.optimism.io/t/collective-grant-policies/5833#p-25088-critical-milestones-and-clawback-8)

[0xvoidmain]

Foundation Mission Application

Please verify that your team members below:

Team Lead: Tung Hoang, https://github.com/0xvoidmain
Contact info: Telegram: https://t.me/@tunghoang91 | Email: tunghoang@ancient8.gg
L2 recipient address: 0xf1cEa1A3301fE0c4B59A7B367d7214f0A782C238

Please list the members of your team and link to any previous work:

My team: Ancient8 team

• Tung Hoang: 6 years of experience in blockchain development, especially on the Ethereum platform. Participated in DeFi, NFT games, and bridge projects. I previously worked on wallet development at TomoChain (now known as Viction). Currently, I work at Ancient8, where I focus on researching new blockchain technologies, particularly Optimism's interoperability.
• Thanh: 3 years of experience in blockchain development. He is a backend developer.

Previous Work:

• Very.fun: https://very.fun/
  Very.fun is your go-to spot to launch custom memecoin or tokens under the SuperchainERC20 standard from Optimism, powered by Ancient8. Built on the robust Superchain infrastructure, Very.fun leverages the Superchain’s interoperability, scalability, and SuperchainERC20 standard to allow all tokens deployed to be interoperable across OP Stack Chains (Ancient8, OP Mainnet, Base, opBNB, Mode, etc.) once the Superchain Mainnet is live.

• Ancient8 SuperApp: https://app.ancient8.gg/
  A web application for the Ancient8 ecosystem. I managed the project and developed products such as Ancient8 Swap, Bridge, NFT Marketplace, and Vesting Vault.

• Cyball NFT Game: https://docs.cyball.com
  A football card collection game, where each player card has unique skills. Users build teams using these cards and compete against others. Cards can be upgraded and newly minted from existing ones. All features operate fully on-chain via smart contracts. I developed the smart contracts and backend system, including the NFT marketplace.

• Space3: https://space3.gg/
  A mission system where users complete tasks to earn rewards. Thanh is the tech lead for this product.

• TomoWallet:
  A mobile application for iOS and Android that helps users manage their funds on networks such as TomoChain, Ethereum, Binance Smart Chain, etc. Through this project, I gained extensive experience in designing UI/UX for blockchain applications, including both wallets and future dApps.

What makes your team best-suited to execute this Mission?

We are part of the Ancient8 Chain team, a gaming-focused Ethereum Layer 2 based on the OP Stack. Our focus is building user-centered products. ERC-7683 and Superchain Interop are promising technologies to deliver seamless user experiences. At Ancient8, we have already invested significant time in researching and experimenting with ERC-7683 and Superchain Interop. ERC-7683 standardizes cross-chain messaging and simplifies cross-chain app development. Combined with the SuperchainERC20 and Interop standards, it enhances reliability and smoothness in cross-chain swaps.

We design smart contracts and related libraries with a focus on usability, stability, and flexibility, enabling developers to concentrate solely on application-specific logic.

Moreover, prior to the creation of this mission, I developed a smart contract that integrates ERC-7683 with Superchain Interop. You can check it out here:

• https://github.com/ancient8-gg/superchain-settler-opstack.git

A cross-chain swap web app demo for our research will be available soon. And this is our demo for crosschain swap with interop. That base on example about SuperchainERC20

• https://ancient8-gg.github.io/crossswap-op-interop-demo/

Please describe your proposed solution based on the above Solution Criteria (if applicable):

First, we aim to use the ERC-7683 and Interop standards to enhance user experience and developer-friendliness. We will not modify any interfaces defined in ERC-7683. Instead, we inherit from IOriginSettler and IDestinationSettler to create a base contract called SuperchainSettlerERC7683. Developers can inherit this base contract for both the origin and destination chains.

SuperchainSettlerERC7683 will provide core functions for sending and receiving cross-chain messages through L2ToL2CrossDomainMessenger. Additionally, with the auto.interop feature setup in nodes (Superism and Alpha Testnet), some functions will execute automatically without filler intervention.

L2ToL2CrossDomainMessenger is also used to send critical messages back to the source chain, confirming that the order has been fully filled. This simplifies and secures functions like "repay for filler" or "refund."

SuperchainERC20 is a vital standard within Superchain. Therefore, our system is designed to support both ERC20 and SuperchainERC20. Supporting SuperchainERC20 solves the issue of filler funding—fillers no longer need a large capital reserve to operate across chains, reducing costs and improving user experience.

Please outline your step-by-step plan to execute this Mission, including expected deadlines to complete each piece of work:

Milestone 1: Architecture Design (3 weeks)

• Design the architecture of both the smart contract system and the filler system
• Gather feedback from the community and stakeholders

Milestone 2: Development & Unit Tests (5 weeks)

• Smart Contract Development: Must support both SuperchainERC20 and ERC20
  • ISuperChainSettler interface
  • Base SuperChainSettler contract implementing core functions, extendable by application contracts
• Filler System Development:
  • A system to listen for cross-chain messages and fill transactions for dApps
  • Export as a library so developers can easily integrate
  • Listen to OpenOrder event
  • Execute Fill function
  • Relay message if necessary
• Unit testing for both smart contracts and filler system
• Collect feedback from stakeholders and the OP Dev team

Milestone 3: Testnet Deployment (3 weeks)

• Deploy the system on OP Sepolia and A8 testnet
• Test the full system and user experience
• Provide a cross-chain swap web demo using Uniswap V2 as the AMM

Milestone 4: Security Audits (4 weeks)

• Conduct audits to ensure security and reliability
  • Select an audit team
  • Receive stakeholder feedback
  • Address and fix any issues

Milestone 5: Documentation & Testnet Demo Deployment (3 weeks)
From a developer’s perspective, clear and complete documentation and examples are crucial for easy adoption and reduced learning curve—ultimately promoting faster and more sustainable ecosystem growth.

• Demo GaslessCrossChainOrder/OnChainCrossChainOrder with ERC20 and UniSwapV2
• Demo GaslessCrossChainOrder/OnChainCrossChainOrder with SuperchainERC20 and UniSwapV2
• Deploy demo on OP Superchain Testnet
• Provide detailed documentation and tutorials for SuperChainSettler and Filler systems
• Gather feedback from the community and stakeholders

Milestone 6: Release (1 week)

• Release code publicly
• Publish documentation

Milestone 7: Mainnet Deployment
Since the system depends on Interop, it will be deployed on mainnet after Interop is officially released.

Please define the [critical milestone(s)] should be used to determine whether you’ve executed on this proposal:

Milestone	Description	Success Criteria	Timeline
1	Architecture Design	Completion of system architecture design and feedback incorporation from stakeholders.	3 weeks
2	Development & Unit Tests	Smart contracts and filler system developed, unit tested, and reviewed by stakeholders.	5 weeks
3	Testnet Deployment	Successful deployment on OP Sepolia and A8 testnet with a functional cross-chain swap demo.	3 weeks
4	Security Audits	Completion of security audits, feedback addressed, and system verified as stable and secure.	4 weeks
5	Documentation & Deployment	Comprehensive documentation and tutorials provided, demo deployed on OP Superchain Testnet.	3 weeks
6	Release	Public release of code and documentation.	1 week
7	Mainnet Deployment	Successful deployment on mainnet after Interop release.

Please list any additional support your team would require to execute this mission (financial, technical, etc.):

None for now

Please check the following to make sure you understand the terms of the Optimism Foundation Mission program:

• I understand my grant for completing this Foundation Mission will be locked for one year from the date of proposal acceptance.

• I understand that I will be required to provide additional KYC information to the Optimism Foundation to receive this grant

• I understand my locked grant may be clawed back for failure to execute on critical milestones, as outlined in the [Collective Grant Policies]

• I confirm that I have read and understand the [Collective Grant Policies]

[zainbacchus]

Hi @0xvoidmain I think you're missing a link re:

Moreover, prior to the creation of this mission, I developed a smart contract that integrates ERC-7683 with Superchain Interop. You can check it out here: ...
A cross-chain swap web app demo for our research will be available soon.

[0xvoidmain]

Hi @zainbacchus. Yeah, that’s my bad. I’ve updated the form above.Thank you!

[0xludobianco]

Team Lead: Please specify the best point of contact for your team

Ludovico Bianco

Contact info:

Tg handle: @ludobianco
Mail: ludovico@substancelabs.xyz

L2 recipient address:

0x2e125385273F057Cb1d2ec55Af4Bd656e07b0387

Please list the members of your team and link to any previous work:

Substance Labs brings deep, hands-on experience in building secure, modular infrastructure for cross-chain communication, with a focus on public goods and protocol-agnostic standards. Over the past decade, the team has been involved in foundational interoperability initiatives—from pioneering oracle systems to developing frameworks for trust-minimized cross-chain state verification

Our core contributions include (in chronological order):

• Oraclize / Provable – One of the first oracle services on Ethereum, enabling real-world data to be securely delivered on-chain.
• pNetwork – A cross-chain interoperability protocol that facilitated billions in value transfer through secure bridges.
• Sygma – A modular interoperability layer for cross-chain messaging, enabling composability across ecosystems.
• Hashi – An oracle aggregator that enhances security by validating cross-chain messages through multiple independent oracles.
• State Sharing Network (SSN) – A trust-minimized block header relaying system enabling verified state access across any-to-any chains.
• Safe Crosschain – A framework enabling Safe accounts to verify and execute actions on remote chains using trustless state proofs.
• Aztec Confidential Cross-chain Bridging - (WIP) Building a privacy-preserving, trust-minimized cross-chain bridge between Aztec and Optimism.

Substance Labs Team

Some of our core team members follow:

• Thomas Bertani – A blockchain entrepreneur since 2012, Thomas has pioneered oracles, bridges, and blockchain co-processors since 2014. He founded Oraclize/Provable, one of the earliest oracle services bringing real-world data on-chain, and later founded pNetwork, a cross-chain interoperability protocol that facilitated over $1.2 billion in cross-chain volumes.​
• Georgios Gontikas – A blockchain expert since 2017, Georgios led Hashi’s development from its inception and played a key role in the zk Bridge for Gnosis Chain. He was previously leading the Sygma interoperability protocol at ChainSafe. Later, he served as Head of Bridges at Gnosis, overseeing cross-chain integrations and bridge security enhancements​.
• Alessandro Manfredi - A prolific blockchain developer and architect, who has built a range of complex blockchain protocols since 2017.

What makes your team best-suited to execute this Mission?

Substance Labs brings deep technical expertise in delivering secure, modular cross-chain infrastructure across the Ethereum ecosystem. The team has been actively involved in the development of oracle systems, interoperability protocols, and standardized cross-chain primitives.

More recently, we have led the development of Hashi, a modular and credibly neutral framework for validating cross-chain messages through multiple oracle pathways. Hashi has been recognized by Uniswap’s bridge assessment and is securing live deployments on chains such as Gnosis and Lukso. We also operate the State Sharing Network, a system for trust-minimized block header relaying across EVM chains, which underpins reliable state access for applications.

Our team is also a contributor to the Ethereum Foundation’s Interoperability Working Group, and a collaborator in the design of emerging standards such as ERC-7683 and RRC-7755. These efforts have informed the work on the Open Intents Framework (OIF)—a public good initiative supported by the EF that standardizes intent-based cross-chain interactions. The system proposed in this application will be designed to plug into OIF, ensuring wide composability and visibility from the broader Ethereum and Superchain ecosystems.

Please describe your proposed solution based on the above Solution Criteria (if applicable):

We propose to build an ERC-7683-compliant settlement system that leverages Superchain’s native interoperability for secure, efficient, and trust-minimized cross-chain intent fulfillment. This system will serve as a core settlement layer for protocols adopting ERC-7683 and will be designed from the ground up to integrate with the Open Intent Framework (OIF).
The system will support both GaslessCrossChainOrder and OnchainCrossChainOrder structures and fully implement the IOriginSettler and IDestinationSettler interfaces defined by ERC-7683. Users will create intents by escrowing assets on the origin chain, with fillers executing settlements on the destination chain and sending back fill confirmations.
Interoperability will be powered by the Superchain’s native L2-to-L2 messaging stack (IL2ToL2CrossDomainMessenger), ensuring trust-minimized message relaying without relying on third-party bridges or off-chain relayers.

In line with ERC-7683’s design goals and OIF’s modular vision, the system will include:

• Support for atomic and non-atomic fill flows, enabling fillers to choose between immediate and deferred settlement.

• Interface-level support for batching, allowing fillers to combine multiple fill confirmations into a single cross-chain message, with room for expanded batching infra in future releases.

• Secure, replay-protected messaging, validated on-chain through the Superchain interop stack.

• Robust settler logic to guarantee correct fund release only after verified settlement.

This system will be directly compatible with the Open Intent Framework, a public good initiative supported by the Ethereum Foundation. By adhering to ERC-7683 and exposing standard interfaces, the settlement layer will serve as a plug-and-play backend for OIF-based protocols, enabling seamless fulfillment of intents across OP Stack chains. This will help bootstrap adoption, bring standardization to filler settlement flows, and provide shared infra for composable intent execution.

The full implementation will be open source and extensible, offering a foundation not only for intent protocols like OIF and Across, but also for any application seeking to standardize and simplify cross-chain value transfer in the Superchain ecosystem.

Please outline your step-by-step plan to execute this Mission, including expected deadlines to complete each piece of work:

Phase 1 – Specification & Architecture (Weeks 1–2)

• Finalize technical specifications and architecture for the ERC-7683 settlement system.
• Define system flow diagrams, core interfaces, and cross-chain message structures.
• Outline how the system integrates with the Open Intent Framework (OIF) and supports modular extensions.

Phase 2 – Development & Integration (Weeks 3–5)

• Implement core contracts (IOriginSettler, IDestinationSettler) to support both GaslessCrossChainOrder and OnchainCrossChainOrder.
• Integrate Superchain-native L2-to-L2 messaging (IL2ToL2CrossDomainMessenger) for fill confirmation.
• Build a test filler client for simulating full intent settlement flows across chains.
• Implement atomic and non-atomic fill logic, with interface-level batching support.

Phase 3 – Testnet Deployment & End-to-End Validation (Weeks 6–8)

• Deploy contracts to OP Sepolia and Unichain Sepolia.
• Validate complete cross-chain flows: order creation, destination fill, and origin-side fund release.
• Operate a filler to simulate real usage scenarios.
• Gather metrics and prepare the system for audit submission.

Phase 4 – Audit Preparation & Support (Weeks 9–10)

• Submit the full codebase for review through OP-sponsored audit channels.
• Support the audit team throughout the process and address all findings.
• Implement recommended fixes and improvements, and finalize the code for mainnet use.

Phase 5 – Mainnet Deployment & Monitoring (Weeks 11–12)

• Deploy audited contracts to OP Mainnet and Unichain Mainnet.

Please define the [critical milestone(s)](https://gov.optimism.io/t/collective-grant-policies/5833#p-25088-critical-milestones-and-clawback-8) that%C2%A0that) should be used to determine whether you’ve executed on this proposal:

Deployment of ERC-7683 Settlement Contracts to OP Sepolia and Unichain Sepolia

• Smart contracts implementing IOriginSettler and IDestinationSettler are deployed and publicly verifiable on both testnets.
• Deployment addresses and verification metadata will be shared via public repositories.

Successful End-to-End Cross-Chain Settlement Demonstration Using Superchain Messaging

• A complete settlement flow—from intent creation to cross-chain fill and origin-side fund release—is executed on testnet using IL2ToL2CrossDomainMessenger.
• Public transaction links will be published as proof of execution.

Mainnet Deployment of the ERC-7683 Settlement System on OP Mainnet and Unichain

• Final version of the contracts is deployed to both mainnets.
• Addresses and metadata are published to ensure transparency and reproducibility.

Please list any additional support your team would require to execute this mission (financial, technical, etc.):

We do not expect to need specific assistance but will not hesitate to communicate with Optimism to point out and address any possible blockers.

Please check the following to make sure you understand the terms of the Optimism Foundation Mission program:

• I understand my grant for completing this Foundation Mission will be locked for one year from the date of proposal acceptance.
• I understand that I will be required to provide additional KYC information to the Optimism Foundation to receive this grant
• I understand my locked grant may be clawed back for failure to execute on critical milestones, as outlined in the [Collective Grant Policies]
• I confirm that I have read and understand the [Collective Grant Policies]

[KENILSHAHH]

@0xvoidmain does your crosschain swap web app use 7683 standard to do the bridging ?

[0xvoidmain]

@0xvoidmain does your crosschain swap web app use 7683 standard to do the bridging ?

Hi @KENILSHAHH, in my cross-chain swap demo, I used SuperchainERC20, so I didn’t use ERC-7683 for bridging. In the next demo, which will support ERC20, I will use ERC-7683 for both bridging and swapping.

[opmxwell]

Thanks everyone for the submissions! The applications are now closed and the team(s) will be selected by April 25th.

[wildmolasses]

Thank you for your applications and interest in this Mission.

The DAB has decided to move forward with the proposal made by:

• @0xludobianco

We will be reaching out early next week re: next steps.

For those who were not selected this time around, we would encourage you to keep an eye on future Foundation Missions and get in touch with us in the #dab-general channel in the Optimism Superchain Devs discord, as we'd love to collab together in the future.

[0xludobianco]

We’re happy to share that we’ve successfully deployed the ERC-7683 settlement system on a devnet and executed initial end-to-end tests.

Here are three test transactions demonstrating the core cross-chain settlement logic:

1. Order -> https://optimism-interop-alpha-0.blockscout.com/tx/0x2e26f5dc94cfde0007cda886f4e9e023f7619aafa411c18f5674b046512c691f?tab=logs

2. Fill -> https://optimism-interop-alpha-1.blockscout.com/tx/0xe06a5a73a6a9e7bbda004674bae70326c0999701176789e852b64872c306d39c

3. Settle -> https://optimism-interop-alpha-1.blockscout.com/tx/0x2291a4216169d5068cb79dd4d47e4c61c1b79b73725ce36dff2cfe5b732ac60e

At this stage, we’re temporarily pausing progression to testnet and mainnet deployments because we are waiting for the deployment of L2ToL2CrossDomainMessenger contract by Optimism.
Latest update by the OP team on Discord stated that deployment is scheduled for Q3 2025.

We’ll continue providing updates here, and the community can follow ongoing development and track progress on our GitHub: https://github.com/substance-labs/op-intents-framework