Avail: Architecture and Use Cases — Anurag Arjun

Published in

Cumulo.pro

5 min readJul 28, 2023

Anurag Arjun, co-founder of Polygon and now a member of the Avail team, takes us through a deep dive into the architecture and use cases of Avail.

The Origin of Avail: A Journey from Polygon to Independence

Avail is a data availability layer that started within Polygon in November 2020 and was recently spun off in March 2023 to become an independent entity.

This change did not mean a complete break with Polygon, as the entire Polygon team decided to join Avail, bringing their experience and expertise to the new project. This transition is a crucial part of Avail’s history, and one can see how the background and previous experience of Anurag and his team has influenced the direction and focus of the project.

What we do here, preamble

In today’s blockchain landscape, rollups are rapidly emerging as the main form of execution. Looking at the rise of rollups on Ethereum and the intense activity happening on layers such as Polygon, Arbitrum or Optimism, it is evident that rollups are now considered the best way to perform execution.

With rollups becoming the way forward and blockchain developments becoming more and more modular as they grow, a crucial question arises: what are these rollups really looking for? What do they crave so fervently? The answer is simple: they want a large amount of data availability. This is the main reason why Avail is being worked on.

A bold statement can be made: every blockchain base layer in the future will be a data availability layer (DA layer). Even Ethereum is already pivoting towards a rollup-centric roadmap, where the base layer will become a data availability layer and all execution will move to rollups on top.

It is in this context that Avail should be placed. Avail is a base layer that provides scalability and rollup capability, preparing for the future of blockchain.

The Avail Core: A Base Layer for Rollups

Avail is a modular layer that focuses on data availability. It does not perform any execution, but accepts rollup transactions and makes them accessible. This is achieved through a combination of Erasure coding, polynomial commitments KGZ and data sampling. Avail sorts the transactions it receives and provides them to a Light Land Network. It works similarly to Ethereum by providing a layer for Rollups, which perform execution on Layer 2.

Avail supports a variety of rollup execution environments, which can include the Ethereum Virtual Machine (EVM), more complex environments such as SVM, and other specific blockchains. Offloading block data is facilitated by USP data sampling, which allows offloading with a few random samples.

Data Availability Layer Internal Functionality

Rollups are the main consumers of Avail, these rollups send transactions, each corresponding to a specific application, identified by an application ID. These transactions can be sent to the same base layer, allowing multiple rollups to upload data to Avail. In the process that follows, commitments of the data are created and packaged into blocks.

The incentive mechanism is based on a Nominated Proof of Stake system, which allows for a broad and fair distribution of stake. Instead of delegating to a single validator, participants delegate to a pool that is distributed equally among several validators. This allows for a ranked choice of validators and encourages a decentralised pool of up to 1,000 validators.

Lifeline Network Optimisation for Block Verification

The Avail team has developed an efficient network, known as a lifeline, using a Substrate platform. This network allows for rapid analysis of data blocks to identify any potential problems. To verify the integrity of the data, Avail generates specific tests within its data matrix. This allows them, with sufficient samples, to confirm that a block of data is correct.

As the number of nodes in the network increases, they can also handle larger data blocks. Despite handling data blocks of up to 128MB, they can generate and verify data within their 20-second block time target.

The main idea is to design a rollup-centric blockchain ecosystem, with rollup and infrastructure developers as its main customers, through different types of solutions, such as Sovereign Rollups, Validiums, Optimistic chains and specific applications.

Next Steps

Avail has been in development for two and a half years and is currently in its second long-term testnet, named Cartier, after one of the researchers behind the Polynomial Commitments Keys.

They already have a strong set of external validators on the testnet and plan to reach 200 next month. In addition, they aim to scale to 5000 thin clients in the near future. This quarter, Avail plans to launch an incentivised testnet.

Their main goal is to launch the mainnet by the end of Q4 or early Q1.