ERC (Ethereum Request for Comments)

An Ethereum Request for Comments (ERC) is a formal proposal document that defines a technical standard for applications, tokens, or protocols on the Ethereum blockchain, analogous to an Internet RFC. These standards are managed through the Ethereum Improvement Proposal (EIP) process, where ERC-20 and ERC-721 are specific, widely adopted standards that originated as EIPs. The term ERC has become the common vernacular for any application-level standard on Ethereum, providing a blueprint for interoperability and consistency across the ecosystem.

The process begins when a developer authors an Ethereum Improvement Proposal (EIP), which is the overarching framework for all changes to Ethereum, including core protocol upgrades and application standards. If the EIP proposes a standard for the application layer—such as a token format or a wallet interface—it is assigned an ERC number (e.g., EIP-20 becomes the ERC-20 standard). The proposal undergoes community review, discussion, and finalization by Ethereum core developers before being accepted as a standard that other projects can implement.

Prominent examples include ERC-20 for fungible tokens (like DAI or USDC), ERC-721 for non-fungible tokens (NFTs), and ERC-1155 for multi-token contracts. These standards specify a set of required functions (like transfer or balanceOf) and events that a smart contract must implement, ensuring that wallets, exchanges, and other smart contracts can interact with them predictably. This interoperability is fundamental to Ethereum's composability, allowing decentralized applications (dApps) to build upon and integrate with each other seamlessly.

For developers, adhering to an ERC standard is not enforced by the protocol but is a critical social and technical convention. Using a standard like ERC-20 guarantees that a new token will be compatible with the vast majority of existing infrastructure, including decentralized exchanges (DEXs) like Uniswap and wallets like MetaMask. This dramatically reduces development overhead and risk, as the contract's behavior is well-understood and audited by the community, though developers must still ensure their specific implementation is secure.

The evolution of ERC standards reflects the needs of the ecosystem, with newer proposals like ERC-4337 (account abstraction) and ERC-6900 (modular smart accounts) aiming to solve complex problems like user experience and wallet flexibility. As the primary mechanism for establishing shared rules at the application layer, the ERC process is central to Ethereum's innovation, ensuring that progress is coordinated and decentralized applications remain interoperable in a trustless environment.

The Ethereum Request for Comments (ERC) naming convention was adopted to formalize the process for proposing and standardizing technical specifications on the Ethereum blockchain. It is a direct homage to the Internet Engineering Task Force's (IETF) RFC process, which has been used since 1969 to define foundational internet protocols like TCP/IP and HTTP. This naming choice signals Ethereum's roots in open-source, collaborative development and its goal of establishing robust, community-vetted standards for decentralized applications and infrastructure.

The ERC process begins when a developer authors an EIP (Ethereum Improvement Proposal), which is a formal design document. If the EIP's scope is an application-level standard—such as a token interface, a library format, or a wallet convention—it is assigned an ERC number. This distinction separates core protocol upgrades (EIPs) from application standards (ERCs). The first widely adopted standard, ERC-20, was proposed by Fabian Vogelsteller and Vitalik Buterin in November 2015, establishing the blueprint for fungible tokens that would become the foundation of the initial coin offering (ICO) boom.

The evolution of ERC standards reflects the maturation of the Ethereum ecosystem. Early standards like ERC-20 and ERC-721 (for non-fungible tokens) solved fundamental problems of digital asset representation. Later proposals, such as ERC-1155 (multi-token standard) and ERC-4337 (account abstraction), address more complex use cases like gaming and user experience. Each ERC number represents a specific, immutable snapshot of a proposed standard at a point in its development lifecycle, from Draft and Review to Final status.

The ERC namespace is managed through the Ethereum Magicians forum and GitHub repositories, where proposals undergo rigorous technical debate and peer review. This open process ensures that standards are secure, interoperable, and widely supported before implementation. The success of an ERC is ultimately determined by voluntary adoption by developers, wallet providers, and exchanges, making it a powerful example of decentralized, bottom-up standardization in action.

An Ethereum Request for Comments (ERC) begins as a formal proposal, authored by a community member and submitted as an EIP (Ethereum Improvement Proposal). The author drafts a document following the EIP template, which must include a clear technical specification, rationale, and backward compatibility analysis. This draft is assigned a number and enters the "Draft" status on the official Ethereum GitHub repository, opening it for initial community feedback and discussion.

The proposal then moves to the "Review" phase, where it is scrutinized by relevant subject matter experts and Ethereum client developers. For core protocol changes, this review happens in the All Core Devs meetings. For application-level standards like token interfaces (e.g., ERC-20, ERC-721), specialized ERC working groups conduct the review. This stage involves rigorous technical debate, security analysis, and iterative refinements to the proposal based on feedback.

Once consensus is reached and the specification is finalized, the proposal advances to "Final" status. A finalized ERC represents a stable, peer-reviewed standard that developers can implement with confidence. It is not automatically part of the Ethereum protocol; instead, it serves as a blueprint. Widespread adoption occurs when wallet providers, block explorers, and dApp developers independently integrate support for the new standard, making it a de facto part of the ecosystem.

The entire process is governed by the principle of rough consensus, meaning no single entity has veto power. While the Ethereum Foundation facilitates the process, ultimate authority rests with the network's users, node operators, and developers who choose to adopt the standard. This open, collaborative model has been instrumental in Ethereum's evolution, producing foundational standards that define everything from fungible tokens to non-fungible tokens (NFTs) and decentralized identity.

The ERC process began as an informal, community-driven effort inspired by the Internet's RFC (Request for Comments) model, where developers would publish technical proposals for peer review on the Ethereum Magicians forum or GitHub. This early phase was characterized by ad-hoc discussions, with proposals like ERC-20 and ERC-721 gaining adoption through widespread implementation rather than a formal approval process. The lack of a central authority meant that "standards" emerged organically based on utility and network effects, leading to some fragmentation and confusion.

To address this, the Ethereum community, led by the Ethereum Improvement Proposal (EIP) editors, formalized the process. An ERC is now a specific category of EIP focused on application-level standards. The formal journey involves several stages: Draft, Review, Last Call, and Final. Proposals must undergo rigorous technical review, security audits, and community consensus before being finalized. This structured pipeline, managed through the Ethereum GitHub repository, ensures interoperability, reduces risk, and provides a clear path for innovation to become a ratified standard.

Key evolutionary milestones include the establishment of ERC-20 for fungible tokens, which became the foundational DeFi primitive, and ERC-721 for non-fungible tokens (NFTs), which created an entirely new digital asset class. Later, more complex standards like ERC-1155 (multi-token standard) and ERC-4337 (account abstraction) emerged, demonstrating the process's ability to handle sophisticated smart contract interactions. The process continues to evolve, with recent efforts focusing on improving efficiency (e.g., ERC-6900 for modular smart accounts) and formalizing roles like ERC Editors to shepherd proposals.