Modular Node

The core principle of a modular node is the separation of the monolithic node stack into distinct, interoperable layers. This allows for:

• Independent scaling: Each layer (e.g., execution) can scale without affecting others.
• Specialized hardware: Optimize hardware (CPU, storage) for specific tasks like consensus or data retrieval.
• Flexible deployment: Operators can run only the components their service requires, reducing resource overhead.

A modular node can interface with multiple execution clients (e.g., Geth, Erigon, Nethermind) without being tied to a single implementation. This provides:

• Reduced client centralization risk: Promotes ecosystem diversity and resilience.
• Best-of-breed performance: Operators can choose the client that best fits their needs for speed, resource usage, or features.
• Easier upgrades: Swapping or updating the execution layer does not require overhauling the entire node software.

Modular nodes natively support or can easily integrate light clients and zero-knowledge proofs for efficient state verification. This enables:

• Trust-minimized access: Devices like phones or browsers can securely interact with the chain without syncing the full state.
• Scalable data availability: Relies on data availability sampling to verify block data is published without downloading it entirely.
• Bridge and oracle security: Provides cryptographic guarantees for cross-chain communication and off-chain data feeds.

Presents a single, consistent JSON-RPC interface to downstream applications (wallets, dApps, explorers), abstracting the complexity of the underlying modular components. This ensures:

• Developer familiarity: Works with existing Ethereum tooling and standards.
• Operational simplicity: Applications don't need to manage connections to multiple specialized services.
• Reliability: The API layer can route requests and load balance across redundant backend services.

Incorporates advanced systems for Maximal Extractable Value (MEV) protection and transaction ordering. Features include:

• Private transaction pools: Submit transactions directly to builders or sequencers to avoid frontrunning.
• Bundle simulation: Safely simulate complex transaction bundles before submission.
• Fair ordering: Integrate with protocols that mitigate the negative externalities of MEV, providing a more equitable user experience.

Designed to natively support a multi-chain environment, including Layer 2 rollups (Optimistic, ZK) and other modular chains. This allows the node to:

• Serve multiple chains: Act as a unified gateway for an ecosystem of interconnected blockchains.
• Validate state proofs: For ZK-rollups, verify validity proofs submitted to the settlement layer.
• Bridge verification: Securely verify messages and assets moving between the modular stack's layers.

This comparison highlights the operational shift brought by modular architecture.

Monolithic Full Node (e.g., Bitcoin Core):

• Runs consensus, execution, data availability, and settlement as a single unit.
• Requires downloading and verifying the entire blockchain history.

Modular Node (e.g., Celestia Light Node):

• Runs a specialized function (e.g., DA sampling).
• Resource-efficient; can sync in minutes using data availability sampling (DAS).
• Enables horizontal scaling as different node types specialize in different tasks.

Modular nodes achieve horizontal scaling by adding more specialized nodes (e.g., more sequencers, more data availability layers) rather than requiring each node to process everything. This decouples transaction throughput from the computational limits of a single machine.

• Example: A rollup can scale by adding more sequencer nodes to batch transactions, independent of the execution layer's capacity.

By specializing in a single function, modular nodes can be optimized for cost-efficiency. Operators don't need to run expensive, full-featured hardware for every component.

• Resource Optimization: A data availability node can run on high-storage, low-CPU hardware, while an execution node prioritizes CPU/RAM.
• Example: Running a Celestia light node for data sampling is significantly cheaper than running a full Ethereum node.

Components can be upgraded, replaced, or configured independently without forking the entire network. This enables sovereignty and rapid innovation.

• Swap Components: A rollup can change its data availability layer from one provider to another.
• Independent Upgrades: An execution environment (like an EVM) can be upgraded without consensus changes to the settlement or DA layer.

Security responsibilities are partitioned, allowing each layer to focus on its core guarantee. This creates defense-in-depth and can reduce the attack surface of any single component.

• Settlement Layer: Focuses on consensus and finality.
• Data Availability Layer: Guarantees data is published and retrievable.
• Execution Layer: Isolated for smart contract logic, with faults contained to that layer.

Developers can launch application-specific chains (appchains or rollups) by composing best-in-class modular components without building a monolithic stack from scratch.

• Lego-like Composition: Choose a settlement layer (e.g., Ethereum), a DA layer (e.g., Celestia), and a virtual machine (e.g., WASM).
• Faster Iteration: Test and deploy new execution environments without forking the base layer.

Modular architecture reduces redundant computation and storage across the network. Light clients and fraud/validity proofs allow for secure verification without full node replication.

• Light Nodes: Can securely verify chain state by sampling small data chunks from a data availability layer.
• Proof Systems: ZK-proofs or fraud proofs offload verification work, making resource requirements for validators more predictable.

The component of a blockchain responsible for processing transactions and executing smart contract code. In a modular stack, this layer is often separated from consensus and data availability. A modular node may be dedicated to execution.

• Function: Computes state transitions (e.g., balance changes, contract deployments).
• Modular Context: Rollups (Optimistic or ZK) are pure execution layers that post results to a separate settlement layer.

The foundational blockchain layer that provides finality, dispute resolution, and a canonical home for assets. It acts as the "court of appeals" for other layers, especially for fraud proofs in optimistic rollups.

• Core Role: Establishes the ultimate, immutable record of state and handles bridging between execution layers.
• Example: Ethereum is often used as the settlement layer for L2 rollups, providing security guarantees.

The mechanism by which network participants (nodes) agree on the canonical order and validity of transactions. In modular designs, consensus is often separated from execution.

• Function: Uses algorithms (e.g., Tendermint, HotStuff) to achieve agreement on the state of the ledger.
• Separation: A modular node may run consensus logic independently, allowing the execution layer to be swapped or upgraded.

The traditional architecture where a single blockchain handles all core functions: execution, consensus, data availability, and settlement. This contrasts directly with the modular approach.

• Characteristics: Tightly coupled layers (e.g., Bitcoin, pre-modular Ethereum).
• Trade-off: Offers simplicity and strong security coupling but faces inherent scalability limitations, which modular architectures aim to solve.