Etherlink's architecture

Seamless integration

To enable the seamless integration of the two ecosystems (EVM and Michelson) in a single blockchain, Etherlink provides Native Atomic Composability (sometimes shortened as NAC): smart contracts in one interface can call contracts in the other within a single atomic transaction. From an economical perspective, the interface used to interact with the chain doesn't matter, it becomes only a technical detail. Thanks to the atomic composition, Etherlink can be seen as unified execution layer, constituting a single economical space.

Each interface is implemented by a dedicated runtime exposing a standard RPC endpoint.

Interface	Runtime	RPC standard
EVM	EVM runtime	Ethereum JSON-RPC
Michelson	Michelson runtime	Tezos RPC

The goal for each interface is to stay as compatible as possible with the original ecosystem it supports — Ethereum for the EVM interface, and Tezos Layer 1 for the Michelson interface. Where differences exist, they are documented in the respective interface sections.

Network architecture

Etherlink is powered by a Tezos Smart Rollup. The key components of the Etherlink architecture are:

• Sequencer — elected by Tezos Layer 1 bakers, the sequencer orders and batches operations from all interfaces into blueprints, which it publishes to the L1 rollup inbox. It targets a block time of around 500 ms, and offers pre-confirmations in about 50ms.
• Rollup nodes — apply blueprints (including operations from all interfaces) to produce Etherlink blocks and maintain the chain state. Each rollup node derives a per-interface block from each Etherlink block.
• EVM nodes — expose the two JSON-RPC APIs, backed respectively by the EVM runtime state and Michelson runtime state.
• Tezos nodes — expose the Tezos Layer 1 RPC API.

Operations submitted via either interface to the corresponding runtime are collected by the sequencer, interleaved in first-in-first-out order, and included in the next blueprint.