Rollup L1s: How ABC Stack's Celestia Sovereign Rollup L1s Compare to Avalanche and Cosmos L1 blockchains

Previous articles in this series:

• Gelato's Guide to Avalanche L1s and Native Interoperability
• L1 Blockchain Stacks: Avalanche vs Cosmos

TL;DR

• Rollup L1s (“Sovereign Rollups”) handle execution and settlement while offloading consensus and data availability to Celestia, enabling gigagas-level throughput
• Unlike L2 rollups, ABC Stack Rollups are L1s because they handle settlement internally rather than relying on another chain
• ABC Rollup L1s offer modular bridging so each Rollup L1 can select optimal bridges for specific assets
• Rollup L1s provide flexibility by operating at either extreme of the centralization spectrum as they leverage Celestia's decentralized network or run with a centralized data availability committee (DAC)
• Rollup L1s differ from Avalanche L1s (which target enterprise use with consortium and permissioned chains) and Cosmos L1s  (which require bootstrapping their own proof of stake token based validator networks that have very high costs)
• Upcoming developments include Celestia's LazyBridging and integration with Hyperlane's interoperability solutions

What is the Sovereign Rollup approach?

The Sovereign Rollup approach is an evolutionary shift in blockchain architecture. By combining execution and settlement within the rollup itself while decoupling bridging functionality and leveraging dedicated data availability layers, Sovereign Rollups achieve unprecedented performance while maintaining security and sovereignty. 

Celestia: The Modular Foundation

Sovereign rollups, pioneered by Celestia’s co-founder Mustafa in 2022, separates consensus and data availability from execution, enabling the development of Sovereign Rollups like ABC Stack. As a Celestia-native framework, ABC Stack fully leverages this approach, with Luis from Gelato coining the intuitive term "Rollup L1" to describe these Sovereign Rollups. 

Why does separating consensus and data availability from execution matter?

By specializing in consensus (transaction ordering) and data availability through data availability sampling (DAS), Celestia provides a secure and scalable foundation without enforcing settlement on a base layer like Ethereum.

This design allows Sovereign Rollups to operate independently, maintaining their own state validation and governance while leveraging Celestia for efficient data handling. ABC Stack achieves high scalability by focusing solely on execution and eliminating the overhead of enshrined bridges or settlement layer dependencies. This independence gives developers the flexibility to select optimal bridge providers for specific assets on their rollup rather than being locked into a single bridging solution.

ABC Stack: A Pessimistic Sovereign Rollup L1

What does it mean to be a pessimistic Sovereign Rollup L1? The rollup operates independently (sovereign) and validates all transactions upfront. We assume that all transactions could potentially be invalid and every transaction is validated before including it in the chain.

In the ABC Stack, full nodes independently validate all state transitions according to the rollup's rules. To arrive at the correct rollup state, everyone runs a full node of the rollup (including the Celestia light client) and re-executes the whole chain from genesis to sync up with the current state. 

The key difference from a traditional L1 is that ABC's blockchain is published to Celestia, which serves as the single source of truth for consensus ordering. This ensures that the chain's state is always accurate and consistent without requiring trust in external validators or dispute mechanisms. This operational model is why it's called a Rollup L1. The 'pessimistic' approach means every block undergoes full validation before addition, which ABC handles offchain on full nodes like traditional L1s. 

The architecture achieves gigagas-level throughput (>1000 megagas/sec) through three key optimizations: 

1. Execution layer specialization without settlement layer constraints
2. Celestia's high-throughput data availability sampling
3. Elimination of state synchronization overhead with a slow settlement chain like Ethereum

How does independent settlement ABC Stack an L1 rather than an L2?

For Sovereign Rollup L1s, settlement happens on the rollup itself and not on an external chain. Bridging is an optional module that can be integrated according to the specific needs of an application.

By removing forced bridge dependencies and instead supporting modular interoperability through pre-configured solutions (such as Gelato’s Hyperlane Cluster), it allows developers to maintain full control over their bridging stack.

ABC nodes internally validate state transitions via full execution replay rather than deferring to Ethereum smart contracts. Settlement is “self-contained” and enables the chain rules to evolve through independent governance mechanisms rather than requiring alignment with base layer constraints. 

Rollup L1s vs. L1s

How rollup L1s and validator-based L1s differ

Rollup L1s and validator-based L1s fundamentally differ in how they achieve consensus and ensure state validity. Validator-based L1s rely on dedicated validator networks that maintain the full chain state, process transactions, and reach consensus directly. They handle all blockchain functions (consensus, execution, data availability) within their own independent architectures.

How does independence from settlement layers make ABC Stack an L1 rather than an L2?

ABC Rollup L1s don't have to spin up new validator networks to secure their chain. Instead, ABC rollups publish their blocks on Celestia’s decentralized data availability and consensus network, which is why it's called a "Rollup". Furthermore, ABC Rollup L1s validate state via local transaction re-execution, without reference to a settlement smart contract light client on another chain, like the ones used by Rollup L2s, which is why ABC rollups are considered ' “Rollup L1s”, and not “L2s”. ABC Rollup L1s on Celestia offer superior decentralized consensus guarantees at a fraction of the cost, especially since no new token needs to be created or inflated to pay validators, due to the economies of scale and network effects of Celestia.

Approaches to scalability and decentralization & centralization

Importantly, ABC Rollup L1s offer two polar opposite approaches as they can run on either fully decentralized Celestia or a centralized DA(C) server in the cloud. This allows ABC Rollup L1s to operate on both extreme ends of the spectrum either maximally centralized or maximally decentralized. For the decentralized version of ABC rollups, Celestia provides a high degree of decentralization at a very low cost, thanks to its economies of scale as a blockchain that focuses on sharing its consensus & data availability network with the rollups that publish their blocks on it.

On Avalanche & Cosmos L1s

For a detailed comparison between Cosmos and Avalanche L1s, see our previous article Sovereign Blockchain L1 Stacks: Cosmos vs Avalanche.

Avalanche L1s, particularly those focused on enterprise use cases, occupy a middle ground on the decentralization spectrum. These are often consortium or permissioned chains, where a small to medium set of known participants validate the network. In many cases, such chains opt for Proof of Authority (PoA) instead of Proof of Stake (PoS) to prioritize operational efficiency and regulatory compliance over maximum decentralization.  

It is important to note that ABC Rollup L1s can readily incorporate KYC and other compliance measures at the rollup execution layer, as well as at the data availability (DA) layer when operating on centralized cloud-based DA solutions. However, in scenarios requiring multi-party validator consensus, ABC relies on Celestia's public blockchain for consensus. This reliance may limit the flexibility of implementing customized compliance policies at the consensus layer if such policies become necessary. Technically, while it is feasible to establish a custom multi-validator consensus policy at ABC's centralized layer through a Data Availability Committee (DAC) model, ABC does not currently support this capability, nor does it align with ABC's primary objectives.

Cosmos L1s, on the other hand, use CometBFT (formerly Tendermint) consensus, which is a hybrid of Delegated Proof of Stake (DPoS) and Byzantine Fault Tolerance (BFT). Larger Cosmos chains like dYdX and Osmosis maintain sizable validator sets to maximize decentralization and security, but this model is extremely resource-intensive. Many smaller Cosmos chains struggle to sustain their own decentralized PoS networks due to the costs and complexities of bootstrapping a robust validator set and maintaining a native staking token. As a result, DPoS in Cosmos is often less decentralized in practice, especially on smaller chains. ABC Sovereign Rollup L1s reduce these operational burdens by leveraging Celestia's decentralized data availability layer and shared consensus network, offering an alternative path to achieving decentralization and sovereignty with vastly improved economic efficiency.

Native Interoperability Solutions

ABC Modular Bridging

Modular bridging in the Abundance Stack treats cross-chain communication as an application-specific concern rather than a core protocol primitive (not a native interop solution). It deliberately separates bridging functionality from core rollup operations, allowing developers to implement custom bridging solutions tailored to specific assets or use cases. This flexible architecture facilitates rollups to operate without an enshrined bridge, implement multiple bridge types simultaneously, and upgrade bridging solutions without modifying the underlying rollup. 

Avalanche Warp Messaging (AWM) 

AWM (Avalanche Warp Messaging) facilitates native, trust-minimized communication between Avalanche L1s using BLS multi-signature aggregation for message signing and validator verification via the P-Chain. This eliminates reliance on third-party bridges and ensures trustless interoperability. Built on AWM, Teleporter simplifies cross-chain interactions with an EVM-compatible interface, enabling Solidity developers to trigger contract calls across Avalanche L1.

Inter-Blockchain Communication Protocol (IBC) 

IBC enables cross-chain interoperability by leveraging light clients for state verification and modular layers for transport and application-specific logic. It facilitates permissionless communication between Cosmos-based chains and via additional integrations such as cross-chain bridges, Cosmos-based chains can connect to external ecosystems like Ethereum and Polkadot. IBC requires the establishment of predefined channels and relies on relayers to transfer messages.

How does ABC Modular Bridging Differ

ABC's approach is treating bridging as an application-layer concern, which distinguishes it from more integrated bridging solutions such as AWM and IBC. That is also why Modular Bridging is not a native interoperability solution. Economically, ABC avoids bridge lock-in costs, allowing applications to choose the most cost-effective bridging solution. Avalanche targets enterprise adoption by facilitating customizable L1s with flexible validator and compliance options, while Cosmos focuses on universal connectivity through standardized light clients and IBC. 

Expanding ABC native interoperability with Celestia's LazyBridging and Hyperlane ZK ISMs

Celestia’s Native Interoperability Roadmap 

A central component to Celestia’s roadmap is LazyBridging, which aims to solve modular fragmentation by enabling seamless asset movement across chains. LazyBridging will leverage ZK verification capabilities added natively to the Celestia base layer, allowing rollups to directly bridge assets without third-party multisigs.

This will build upon the foundation established by the Lemongrass upgrade, which introduced key interoperability features like Packet Forward Middleware (PFM) and Interchain Accounts (ICA). With the Lemongrass upgrade having enhanced Celestia's IBC capabilities, LazyBridging will further extend Celestia's native IBC support and provide rollups with access to assets both within and beyond the Celestia ecosystem.

Hyperlane ZK ISMs

Hyperlane ISMs are customizable smart contracts that verify the authenticity of interchain messages on destination chains. As ZKPs mature, Hyperlane's architecture allows replacing multisig validators with ZK light clients/validity proofs (proves correctness). This will one day enable ABC ZK rollups to be built on top of Hyperlane’s modular interoperability stack.

By having native interoperability with Celestia, ABC chains will soon be able to tap into IBC and Hyperlane. 

What does Gelato's Hyperlane Cluster integration offer?

With a single click through Gelato's RaaS platform, developers can deploy a pre-configured bridging solution consisting of Gelato-operated Hyperlane Validators across multiple blockchains. This ready-to-use infrastructure connects to existing Hyperlane mailboxes on chains like Base, Ethereum, and Solana, automatically sets up the necessary contracts and connections, and is maintained by Gelato with support from other trusted validators, eliminating the complexity of manual bridge configuration.

Conclusion

The fundamental differences between traditional L1s and Rollup L1s reveal distinct architectural tradeoffs in blockchain design. ABC Stack excels at either extremes of the blockchain spectrum. It can be configured for maximum decentralization through Celestia's infrastructure while maintaining gigagas-level performance, or it can operate with a centralized DA(C) server for use cases prioritizing efficiency.

Avalanche L1s serve a different market segment. They are tailored for scenarios where institutions need permissioned consortium blockchains with specific governance and validator sets, making them ideal for enterprise use cases such as financial services that want to have maximum control over their whole blockchain operations, due to compliance or similar reasons. ABC Rollup L1s offer flexibility in integrating compliance measures such as KYC at both the execution and centralized DA layers, but reliance on Celestia's public blockchain limits customized compliance options at the consensus layer. Although technically possible, implementing a custom multi-validator consensus policy via a Data Availability Committee is not currently supported or prioritized by ABC.

Cosmos, which pioneered application-specific blockchains, is facing increasing competition from Celestia-based rollups that simplify blockchain development and reduce operational overhead. Interestingly, even Noble, a notable Cosmos chain, has recently announced their own Sovereign Rollup, which signals the growing recognition of the Sovereign Rollup approach's advantages. Cosmos L1s will struggle to maintain their position against Sovereign Rollup L1 architectures that offer vastly superior economics, scalability, and maintenance while preserving security and decentralization guarantees.

In general, both Avalanche and Cosmos L1s have a much higher cost overhead for running a blockchain with even a small degree of decentralization, so projects that are cost-sensitive or want a high degree of consensus decentralization, or no decentralization at all, gain tremendous value from ABC Rollup L1s' cost-effective modular blockchain approaches. At the same time, approaches like Avalanche L1s will likely still play a major role in the institutional and enterprise blockchain landscapes, where maximum control and compliance often matter more than the cost of decentralization.

Coming in Part 2: Deep Dive into L2 Rollup Frameworks

In our next installment, we'll dive deeper into established L2 rollup frameworks, specifically Optimism and Arbitrum. We'll examine the fundamental mechanism and architectural differences between Optimism and Arbitrum in terms of cost and performance, L2 design choices, and the types of applications best suited for each approach.

To try out your own ABC’s Sovereign Rollup L1, deploy it with just one click on: raas.gelato.network.

Definitions

• ABC Stack — a Celestia-native framework for building high-performance Sovereign Rollup L1s  that achieve gigagas-level throughput while maintaining decentralization through Celestia or operating with centralized DA servers.
• Data Availability (DA) Layer — a blockchain layer that specializes in storing and ensuring access to transaction data, allowing other chains to verify state transitions without executing them.
• Data Availability Sampling (DAS) — a technique used by Celestia that enables light clients to verify data availability without downloading the entire blockchain.
• Rollup L1 — a blockchain that operates as its own settlement layer (like an L1) while publishing data to another chain for consensus and data availability (like a rollup).
• Validator-based L1 — a traditional blockchain that relies on a dedicated validator network for all functions: consensus, execution, settlement, and data availability.
• Modular Bridging — an approach that treats cross-chain communication as an application-specific feature rather than a protocol primitive, allowing developers to implement custom bridging solutions.
• Gigagas — a measure of execution throughput representing one billion gas units per second.
• LazyBridging — Celestia's planned native bridging solution that will enable seamless asset movement across chains by leveraging ZK verification capabilities.
• Hyperlane ISMs — customizable smart contracts that verify the authenticity of interchain messages, supporting modular security models including ZK proofs.

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