Announcing Optics: A Gas-efficient Interoperability Standard for Cross-chain Communication

How Celo is connecting decentralized ecosystems and improving blockchain interoperability.

Joe Nyzio
Joe Nyzio
Apr 21 · 4 min read

Celo’s mission is to build a financial system that creates the conditions for prosperity for everyone. As a special addition to our Kuneco Community All-Hands, cLabs is proud to announce that we’ve reached an important milestone in this journey.

Kuneco means “togetherness,” and as we bring together our team, community, and supporters, we’re also making connections at the lowest layer — between layer one blockchains. Today, we’re officially announcing Optics, a new gas-efficient bridging standard, and an upcoming deployment connecting Celo to Ethereum. In the spirit of Kuneco, this connection between Celo and Ethereum breaks down the boundaries between these networks and allows the two communities to dream, design, and develop powerful new decentralized applications together.

Building Bridges, Not Walled Gardens

While blockchains like Ethereum and Celo share many similarities, they’re entirely separate and self-contained ecosystems.

Developing methods for cross-chain communication that are fast and affordable is a crucial component of gaining widespread adoption for decentralized applications (dApps). By establishing connections between blockchains, developers can connect the people, services, and technologies that allow everyone to benefit from a more open and connected blockchain ecosystem.

Blockchains are entirely separate ecosystems that cannot communicate with each other.
Blockchains are entirely separate ecosystems that cannot communicate with each other.

Current solutions for building cross-chain communication are complex, expensive, and inaccessible to the average developer. Advances in existing bridging methods have led to incremental improvements, but they don’t allow blockchain interoperability and cross-chain messaging to scale effectively to meet the high demand for dApps.

Ready to meet the challenge, cLabs (a company in the Celo ecosystem) acquired Summa, bringing on a talented team of leaders in cross-chain interoperability. This acquisition began the construction of a gas-efficient interoperability standard for cross-chain communication named Optics. The project is focused on enabling seamless interoperability between layer-one blockchains. This work is part of a broader set of projects, including Cosmos and Polkadot, that focus on developing a future vision for a connected world of blockchains.

Benefits of Optics

Unlike other bridge designs, Optics has a one-to-many relationship — meaning that on each chain, a single message-sending mechanism is used to communicate with all other chains. This enables chains to enter a rich ecosystem of communication between blockchains. It also means that adding additional chains is easy!

Optics has a one-to-many relationship that allows Celo to communicate with all other chains.

Additionally, Optics is designed to minimize gas costs to the users of the system. It is trustless and non-custodial, making it a powerful tool for developers to build decentralized cross-chain applications.

For a more concrete example, this could enable things like buying CELO or cUSD using Ether, or holding DeFi crypto assets in Valora. Also, other chains with less than desirable features such as high transaction fees, a large carbon footprint, or long block confirmation times, could tap into and leverage the benefits of Celo and modern layer ones.

Utilizing Optics: Bridging the Gap to Ethereum

In order to showcase the power and efficiency of Optics, the first communication channel that we’re developing is the Celo to Ethereum bridge. We’re starting with Ethereum because of the overwhelming amount of interest in connecting these ecosystems and the enormous potential of bringing together these large and diverse communities.

While Ethereum brought liquidity and primitives like lending and insurance to dApps, it has become harder to access in light of higher fees and slower transaction times. By utilizing Optics, developers gain access to the best of both blockchains and can build more accessible dApps that reach a wider audience.

The mechanism allows developers to:

  • Permissionlessly build custom cross-chain applications
  • Cheaply move tokens and data between chains
  • Help users reach existing applications on each chain

As we continue our work with Optics, we’ll extend applications across many blockchains, designing a unified and interoperable blockchain network that connects our growing community to fast, low-cost, and accessible DeFi applications.

Get Involved with Optics

While we’re excited about the advances we’ve made in Optics and the Celo to Ethereum bridge, we know that this is only the beginning. This project is part of an ongoing effort to research, design, and develop the best possible solutions for blockchain interoperability and cross-chain communication.

We’re actively looking to collaborate with partners, entrepreneurs, and developers that have an interest in building a more open and connected blockchain ecosystem. If you would like to collaborate, reach out to at any time to join the mission to build a financial system that creates the conditions for prosperity for everyone.

Additional Resources

To get a more technical overview of the design, development, and implementation of Optics read Optics: OPTimistic Interchain Communication.

Learn more about the Celo Protocol in the Celo Developer Documentation and try out Celo on the Alfajores Testnet. You can ask questions and find answers on the Celo Forum, or chat with Celo developers on Discord.


Thanks to James Prestwich, Anna Carroll, Pranay Mohan, Brandy Camacho, Erin Hales, Luke Tchang, and numerous others for leading the research, design, development, implementation, and documentation of both Optics and the Celo to Ethereum Bridge.

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