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. Thanks to the atomic composition combined with the use of the same native token, 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. Thus, they could be called "Etherlink nodes" by now, but we keep calling them "EVM nodes" because the corresponding executable is still called octez-evm-node.
• 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.