Domain Architecture

Reference Implementation for ERC-8110: Domain Architecture for Diamonds.

Benchmark and demonstration of the following sections:

• Subdomains and Layout-Sensitive State

• Isolated Domains

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⚠️ Important Notice: The smart contract code provided in this repo serves only as an illustrative example.

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Abstract

ERC-8110 (Domain Architecture for Diamonds) introduces a storage management architecture for contracts implementing a Diamond-based system.

Building on the namespaced storage identifier mechanism defined in ERC-8042 (Diamond Storage), this proposal organizes contract state into domains and sub-domains. Each domain owns a dedicated storage layout and identifier, enabling consistent naming, deterministic storage positions, and a structured directory model that separates storage ownership from facet-level logic.

By formalizing domain boundaries and identifier conventions, this pattern reduces the risk of storage collisions and human error, while improving auditability and enabling better tooling for complex, multi-facet systems.

ERC-8110 defines only how storage is organized within Diamond-based architectures. It does not mandate a specific execution, upgrade, or facet model. Any system compatible with the Diamond architecture may adopt this Domain Architecture to manage and evolve its storage safely.

Benchmark

Ideas

This repository provides a reference implementation and gas benchmarks comparing the original AppStorage pattern with Domain and Isolated Domain architectures.

• AppStorage (AS Broken) - src/appStorage/
  The original storage pattern commonly used in Diamonds.
  In this benchmark, the storage packing is intentionally broken to simulate a realistic upgrade scenario where layout changes over time.

• AppStoragePacked (AS Packed) - src/appStoragePacked/
  The original AppStorage pattern with an optimized and tightly packed storage layout.
  This variant is included to provide a fair baseline comparison against ERC-8110–based approaches.

• ERC7201Packed (ERC-7201) - src/ERC7201Storage/
  Implements the ERC-7201 storage pattern using inheritance, a widely adopted approach for proxy-safe storage management.
  The layout is also tightly packed to provide a fair baseline when comparing against ERC-8110–based approaches.

• Domain - src/domainStorage/
  An ERC-8110–compliant approach that separates storage identifiers by domain and sub-domain, improving clarity and providing a consistent and safer upgrade path for storage.

• Isolated Domain - src/isolatedDomainStorage/
  An ERC-8110–compliant approach that moves the data access layer from facets into the domain by introducing explicit getters and setters.
  This fully isolates storage management code from business logic, while keeping runtime gas costs comparable.

Run test

    forge test --gas-report -vv

Result Benchmark

Function / Metric	AS Broken	AS Packed	ERC-7201	Domain	Isolated Domain
Deployment Gas	586,452	592,233	592,185	581,778	666,034
Bytecode Size	2,496	2,526	2,526	2,478	2,868
readAllValue	11,476	9,375	9,375	9,375	9,499
readAndWritePackedValue	24,676	24,676	24,676	24,652	24,509
readAndWriteUnpackedValue	26,818	24,719	24,719	24,695	24,563
readPackedValue	2,386	2,386	2,386	2,386	2,446
readUnpackedValue	4,523	2,431	2,431	2,431	2,491
writeAllValue	134,501	112,418	112,418	112,418	112,500
writePackedBools	44,157	44,157	44,157	44,157	44,127
writeUnpackedBools	66,305	44,201	44,201	44,201	44,171