Avail is expanding the capabilities of OP Stack to reduce L2 DA costs by 90%

As Avail rapidly approaches mainnet, this series of articles will explore potential integrations between Avail and leading scaling solutions and show how developers can integrate with Avail to take advantage of its secure, decentralized, and low-cost data availability blockchain.

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• Avail is expanding the capabilities of the OP Stack.
• With Avail, developers of the OP Stack can reduce their data availability costs by about 90%.
• L2 built on the OP Stack can leverage Avail for secure, low-cost, and decentralized data availability.
• Avail is moving towards mainnet and recently announced a rewarding testnet.

Check out the first article in the series, “zkEVM Validiums Can Reduce Gas Fees in ETH Shops by 90%!”

OP Stack with Avail

OP Stack has become a popular choice for communities and companies to build their own L2 Rollups. It is used by the OP mainnet and is maintained by the Optimism Collective. It is also a technology stack that developers have begun to expand and modify. One such modification is the use of a purpose-built data availability layer like Avail. In this article, we’ll discuss how you can use OP Stack with Avail as your data availability provider to significantly reduce your ETH transaction fees.

How does OP Stack manage data availability?

OP The DA layer supported by Stack by default is ETH. L2 transactions are submitted to the sequencer, which is responsible for sorting transactions and creating L2 blocks. The transaction batch is sent by the sequencer to the ETH, and the ETH submits the transaction data as calldata.

The advantage of using ETH as a data availability layer (DA layer) is that developers using the OP Stack can inherit the security guarantees of ETH Workshop. Anyone can access L2 transaction data published on ETH Square and use it to derive the correct chain state of L2.

However, this benefit comes at a significant cost. ETH Fang is not designed as a data availability solution and is not optimized for this use case. While efforts are being made to improve this, at the time of writing, up to 90% of what L2 pays ETH Fang is used to manage data availability. High-volume use cases that process large volumes of transactional data can be significantly reduced by using purpose-built data availability solutions like Avail.

How does Avail work with OP Stack?

The Avail team built the Avail OP Stack, a modified version of the OP Stack that sends transaction data to Avail instead of ETH, reducing transaction fees by up to 90%.

Transactions are submitted to sequencer nodes in the Avail OP Stack. The op-batcher then submits the transaction batch to a module called the op-avail, which is added to submit the data to the avail.

The transaction data is then added to the Avail blockchain, and a transaction reference is returned to the op-avail, which is passed to the op-batcher and submitted to the ETH as calldata. Transaction references published on ETH Square contain the Avail block hash, sender address, and nonce of the external transaction.

Chains built with the Avail OP Stack inherit the security guarantees of Avail’s nominated proof-of-stake blockchain network. Avail’s blockchain is built using the Polkadot SDK to reduce the risk of validator centralization and is working to support 1000 external validators. Data published on Avail’s blocks is validated by the Avail network, but not executed. L2 can use the OP Stack with Avail and pay a fraction of the cost of the current implementation, which publishes transaction data to the ETH.

To get a more detailed look at how the Avail OP Stack works for sequencers and validator nodes, you can see a more detailed diagram in the Avail OP Stack repository.

Future improvements

Optimism’s proof-of-fault system, which verifies the correctness of transactions on ETH, is still under development at the time of writing. OP Stack sequencer is still centralized for now, but plans are made to decentralize it. As these improvements are rolled out by the Optimism Collective, the Avail OP Stack will be updated to include these changes.

Several improvements to the Avail OP Stack have been identified and will be implemented soon. Avail’s data roots will be published to the ETH via the Vector Data Proof Bridge. The data root is the root of the Merkle tree, and its leaves are the chunks of data submitted to Avail. This will enable sequencers and other L2 nodes to verify on the ETH that Avail’s validators have reached consensus on the availability of the data.

Once the OP Stack has implemented a valid proof of failure, a DA containing proof can be sent along with Avail’s batch hash and used in OP Stack’s proof-of-failure interactive dispute game.

The Optimism Collective has also announced plans for an interoperable network of L2 chains built using the OP Stack, called Superchains(). All of these future improvements are still in development and will be implemented into the Avail OP stack where possible.

Start trying the Avail OP Stack today!

Check out the Getting Started guide in the Avail OP Stack repository () and get started today! If you have any questions or suggestions on how to improve this build, you can reach out to the team on the Avail forums or Discord.

OP Stack is one of many blockchains that can take advantage of Avail’s secure universal data availability layer. To learn more about integrating Avail with other leading L2 and blockchain ecosystems, check out the Avail Ecosystem series and subscribe to our newsletter.