Operation Based Bridge

The “Operation Based Bridge” mission is focused on catalyzing the mass migration of NFTs from Ethereum Mainnet to the Superchain Ecosystem: Optimism, Base, Zora, etc… using a Based Bridge (BB) token.

Problem

Each Optimism rollup includes a canonical ERC721 bridging smart contract.

But to date there has been very little activity on these canonical smart contracts: Optimism, Base and Zora all have little to no transactions originating to/from these smart contracts.

But… why?

First, no application exists that makes bridging NFT easy for the average user.

Second, there is no incentive for users to bridge Ethereum NFTs to the Superchain ecosystem.

Solution

About a month ago Jesse Pollak (Base Contributor #001) posted about the need for an ERC721 Bridging application that utilizes the native/canonical ERC721 bridging smart contracts.

https://warpcast.com/jessepollak/0x19e16123

Shortly after that post was made the Emerald team started digging into logistics of creating such an application. A prototype was built - Based Bridged - that allows for the creation of bridgable NFT collections and the actual bridging of NFTs by users.

A relatively simply application that includes the minimum amount of features required to help users bridge ERC721 tokens to various Superchain rollups.

However during the development of this application we came to the realization that even if this application was launched and promoted, there would still be a lack of incentives that would drive users towards the bridging NFTs to the Superchain.

For The Culture

There is something special about NFTs.

For some it's about the potential financial upside. But for many others it's about the culture.

There is a certain "magic" to owning a piece of onchain history. It means something.

NFTs represent an opportunity to express your values, join new communities and be part of something bigger than yourself. Contrasted with DeFi, which tends to be about playing the onchain game in a single player mode, the NFT experience is about playing the onchain game in multi-player mode.

Why is that worth mentioning?

Because any incentives program that focuses on NFTs, should take that into account and offer an experience that reflects those unique values.

Can users be financially compensated for bridging there NFT collections to the Superchain? Yes, of course… but that doesn't mean it's the only way, nor is it neccesarily the best way.

Ethereum is a Storytelling Canvas

Ethereum, from the very beginning has always been rich in culture. From the silly badger dances at early conferences, to the recently released Delivery at Dawn short film celebrating the launch of EIP-4844, the Ethereum community is rich in culture.

With roots that tap deeply into values of freedom, collaboration and self-expression.

A great space to invite artist, creators and storytellers.

Growing The Onchain Creator Ecosystem

Anyone familiar with permaculture might have heard of the term "function stacking" before.

The goal of function stacking to create synergies that enhance the efficiency and productivity of the underlying system. By ensuring that each element performs more than one role, resources are used more efficiently, waste is minimized, and the overall resilience and sustainability of the system is increased.

In essence it's a methodology used to maximize the efficiency and resiliance of a complex system, by bringing together different protocols to support each other in long-term and sustainble growth.

O.K… but what does that have to do with bridging NFTs to the Superchain ecosystem?

On one hand bridging an NFT can be thought of as isolated action: signing a transaction, paying the gas costs and voila, a token is magically teleported to a new blockchain.

But that's kinda of boring…

The game pieces have only been shifted around a bit.

Nothing of value was created during that energy shift.

For all intents and purposes a wasted effort.

Function Stack The Art

What would it look like if we "function stacked" NFT bridging?

What if bridging OG NFTs (art and culture) from Etheruem resulted in the proliferation of even more onchain creators in the emerging Superchain ecosystem?

Connecting Holders & Artists

A bit of a trope, but still well established truth is that a "two-sided market" is a great framework for SaaS companies to drive immediate engagement and long-term growth.

With the recent completition of the Optimism "We Love the Artist" contest we can conclude there is a now an established (and likely growing) community of artists orbiting in the Superchain ecosystem.

And we also know there is a substantial number of people holding a variety of NFT collections on Ethereum mainnet - with both financial and sentinmental value.

From a purely heuristic perspective we can start to see a "two-sided market" beginning to take form. At a minimum we know there is one group of people who care about onchain art and another group discovering how they can participate in the onchain art economy.

It begs the question.

How can these two groups be connected in a more meaningful way?

What is the bridge that will bring them together 😉

Based Bridge (BB) Protocol Tokens

Tokens.

The lifeblood of blockchains. They keep our digital worlds going round.

What if the canonical Superchain ERC721 bridges had a token?

An incentive designed to strenghten the relationships between collectors and creators.

And in effect also helping users bridge into the emerging Superchain ecosystem - avoiding the impending "state lock-in" that will occur as Ethereum L1 continues to complete milestones in its public roadmap.

Step 1 - Reward Action

The first step (obviously) starts with incentivizing the desired action: bridging NFTs from Ethereum mainnet into the Superchain ecosystem.

Based Bridge (BB) tokens will be issued for bridging whitelisted NFT collections.

The issuance should happen with minimal governance. Ideally no governance if possible.

And thus is required to be completely transparent in the rules from the start: no owners or admins can change issuance rules upon launch. The "game" is designed to be a short-lived campaign that incentives taking time-sensitive actions and creating relationships in a new creator marketplace.

Trying to create a token that lives outside those bounds complicates the experience.

Step 2 - Create Space

Both Optimism and Base have demonstrated a unique ability, in the world of Ethereum rollups, to "create space" for others to grow. Whether it's through retro-active public goods or actively championing for artists, there is large community of people who resonate with that vision and want to help champion those ideals.

It has opened up a natural opportunity to invite these people, and ask them to help shape that vision even further. To expand the "mythos" that first attracted them and provide them with an opportunity to share it with others.

Giving a platform for artists and storytellers to create.

The Delivery at Dawn short film serves as a great demonstration of what's possible. A symbol of what it means to be part of the Superchain story.

The next step is inviting storytellers to build out this imagined world.

To create the "artifacts" that represent Ethereum's next evolution - The Superchain Era.

Step 3 - Connect the People

The final, and most critical step, is connecting collectors and creators. Creating a marketplace where Based Bridged (BB) tokens can be spent to purchase limited edition NFTs.

Users who migrated NFTs from Ethereum mainnet to the Superchain ecosystem are rewarded with exclusive access to Superchain themed art(ifacts) drops.

Product Experience

Operation Based Bridge consists of 3 core major components:

• Native ERC721 Bridging - Optimism Smart Contracts & Open Source Frontend
• Rewards & Recommendations - Emerald
• Superchain Art Marketplace - Superchain Patrons DAO?

Native ERC721 Bridging

The Native ERC721 Bridging application will be made available as a stand-alone and Open Source application. Anyone can review, audit and improve the code.

Initial mockups are available on Figma and available for anyone to preview.

Rewards & Recommendations

Core to Operation Based Bridge experience is rewards and recommendation, in addition to the core ERC721 bridging experience, that helps users discover what NFTs are eligible for rewards.

Technical Overview

Operation Based Bridge includes multiple technical components. Below is an overview of these major parts, potential problem areas and remaining work.

Bridging

Let's talk about the bridging smart contracts:

• L1ERC721Bridge
• L2ERC721Bridge
• OptimismMintableERC721
• OptimismMintableERC721Factory

The set of contract responsible for mangaging the bridging of ERC721 tokens between Ethereum mainnet and a target Optimism rollup. A few details worth mentioning:

• Each rollup has a unique L1ERC721Bridge deployment on mainnet.
• All rollups share a canoncical address for the L2ERC721Bridge deployment.
  • 0x4200000000000000000000000000000000000017
• The OptimismMintableERC721Factory contract uses CREATE2 to deterministically generate a new OptimismMintableERC721 deployment from the original address, but also uses mutable name and symbol fields, which means there is certain degree of "social consensus" required on which OptimismMintableERC721 contract is the "official" one, becase multiple versions could be created with minor differences in the name and symbol.

The L1ERC721Bridge and L2ERC721Bridge smart contract don't allow for arbitrary function execution during message passing. This makes it slightly more difficult for a user, because it requires a "claim" function to be subsequentially called after bridging.

Potential Problem Areas

The OptimismMintableERC721 contract uses EIP-681 to generate a reference to the mainnet storage object, which contains the original tokens tokenURI metadata.

// Creates a base URI in the format specified by EIP-681:
// https://eips.ethereum.org/EIPS/eip-681
baseTokenURI = string(
    abi.encodePacked(
        "ethereum:",
        Strings.toHexString(uint160(_remoteToken), 20),
        "@",
        Strings.toString(_remoteChainId),
        "/tokenURI?uint256="
    )
);

It is unknown as to what extent applications/services support this standard. It's worth investigating where this more obscure EIP might impact the user experience.