We're excited to announce our partnership with Avail, the unification layer, to tackle the challenges of fragmentation of liquidity and the silos in the rollup landscape.

Radius enhances the rollup interoperability experience, ensuring decentralization and enabling synchronous composability across multiple rollups.

Together with Avail, we are pushing the boundaries of interoperability and unification, creating a powerful synergy to deliver a seamless, unified experience for cross-rollup interactions.

Our shared vision for a unified Ethereum

Improving the user experience has long been the goal of the community.

Radius and Avail are united in our mission to enhance interoperability and achieve this goal by bringing synchronous composability with cryptographic safety to all rollups, including both optimistic and zk rollups.

Avail Nexus is a proof aggregation/verification layer that enables the unification of rollups with validity proof-based Avail DAS (Data Availability Sampling). When combined with Radius’s mechanism for censorship resistance and trust minimization, we can connect rollups synchronously and atomically with Nexus’s cryptographic guarantees.

In the coming weeks, we’ll focus on achieving secure and efficient cross-rollup interactions through several development phases. As we progress, Radius and Nexus integrations will bring a safe and unified Ethereum.

This opens up exciting opportunities for rollups of various stacks like Polygon CDK, Madara, OP Stack, ZK Stack, and Arbitrum Orbit to interoperate, synchronously and natively, without bridging to L1.

What is synchronous atomic execution and how is it achieved?

Imagine being able to execute multiple transactions from different rollups simultaneously. This is what synchronous atomic execution enables.

Synchronous atomic execution allows for real-time, all-or-nothing execution of cross-rollup transactions without delays or waiting for transactions on different rollups. This is made possible by the shared sequencer of a rollup.

This is how it works:

1. A shared sequencer receives a cross-chain bundle and determines the block order for atomic execution.

2. The rollup executor builds and executes the block as ordered.

This process separates the sequencing and execution. However today, with isolated sequencing, there’s no coordination for users wanting to make transactions across different rollups. Radius addresses this problem by introducing a mechanism that ensures atomic execution through two verifications:

1. The shared sequencer’s commitment to atomic execution of cross-chain bundles.

2. The executor has executed as the shared sequencer committed.

The details of this design will be shared soon.

What will synchronous atomic execution look like?

Let’s see how this works in practice.

This first demo by Radius is a demonstration of synchronous atomic execution showcasing a cross-rollup token transfer between two Polygon CDK chains. In this demo, a user seamlessly transfers 50 wUSDC tokens via a single bundle transaction:

This highlights two significant benefits for users:

• The ability to execute multiple cross-rollup transactions simultaneously, improving the user experience.

• Fast preconfirmation, enabling users to quickly create subsequent transactions.

When is synchronous composability necessary?

Radius’s mechanism allows complex, state-dependent transactions across multiple rollups to execute atomically and predictably. When combined with Nexus, we improve trust minimization in shared sequencers for synchronous composability with faster cryptographic guarantees.

Synchronous composability is especially useful for value-changing transactions where the outcome depends on the state of multiple chains at the time of execution (like swaps and flashloans).

For rollups, this is particularly useful as it provides users with cross-rollup blockspace within the same slot or timeframe. This helps realize the execution users anticipate when initiating the transaction, maximizing the block value.

Radius and Nexus: The Path Forward

This is just the beginning of our efforts to create cross-rollup interoperability seamless and secure. We're confident that Radius and Nexus integrations will dramatically improve the rollup experience over time.

Stay tuned for our upcoming developments as we continue to pave the way for a more unified and efficient rollup ecosystem.