ERC

An ERC (Ethereum Request for Comments) is a formal proposal document that describes a new standard for the Ethereum ecosystem, covering everything from token interfaces to wallet formats and contract libraries. The process is modeled after the internet's RFC (Request for Comments) system, where developers submit proposals (EIPs or Ethereum Improvement Proposals) for community review and consensus. Once finalized and widely adopted, an EIP that defines an application-level standard is assigned an ERC number, such as ERC-20 for fungible tokens or ERC-721 for non-fungible tokens (NFTs). These standards ensure interoperability, allowing different applications and smart contracts to interact seamlessly.

The lifecycle of an ERC begins as an Ethereum Improvement Proposal (EIP). An author drafts the proposal, which is then discussed and refined in the Ethereum community, primarily on GitHub and in developer forums. For a proposal to become a standard, it must go through a rigorous process: Draft, Review, Last Call, and finally Final. Key criteria include technical soundness, backward compatibility, and clear security considerations. The most influential ERCs are often those that define token standards, which have become the foundational building blocks for decentralized finance (DeFi), digital collectibles, and governance systems on Ethereum and other EVM-compatible chains.

Beyond the famous token standards, ERCs cover a wide range of functionalities. ERC-165 standardizes how contracts publish and detect the interfaces they implement, while ERC-1155 creates a multi-token standard for managing both fungible and non-fungible assets in a single contract. Other examples include ERC-4337 for account abstraction and ERC-4626 for tokenized vaults. This ecosystem of standards reduces development risk, enhances security by providing vetted code patterns, and fosters innovation by creating a common language for developers. The collective adoption of ERCs is a primary reason for Ethereum's network effects and its position as a leading platform for decentralized applications.

The acronym ERC stands for Ethereum Request for Comments. This naming convention was directly inspired by the internet's RFC (Request for Comments) process, established by the Internet Engineering Task Force (IETF). In the IETF, an RFC is a formal document that proposes a new standard, protocol, or procedure, which is then reviewed and debated by the community. Ethereum's founders adopted this model to foster a transparent, collaborative, and community-driven approach to protocol improvement. The first use of the term in the Ethereum ecosystem can be traced to early GitHub repositories and forum discussions around 2015, as developers sought a structured way to propose enhancements beyond the core protocol.

The ERC process begins when a developer drafts an Ethereum Improvement Proposal (EIP), which is the overarching category for all changes to Ethereum. If an EIP specifically defines application-level standards—such as token interfaces, name registries, or library formats—it is assigned an ERC number. For example, the famous token standard ERC-20 began its life as EIP-20. This bifurcation creates a clear taxonomy: EIPs govern the core blockchain and consensus rules, while ERCs define standards for the application layer where smart contracts and dApps operate. The Ethereum community, particularly the Ethereum Magicians forum and later the EIP Editors, reviews, debates, and ultimately finalizes these proposals.

The choice of "Request for Comments" was a deliberate philosophical stance. It signaled that Ethereum's development was not top-down but a permissionless innovation platform where anyone could contribute. The most successful ERCs, like ERC-20 for fungible tokens and ERC-721 for non-fungible tokens (NFTs), achieved their status through widespread adoption and utility, not by executive decree. This organic, market-driven standardization is a key feature of Ethereum's ecosystem strength. The term has since become synonymous with Ethereum's interoperability blueprint, enabling thousands of developers to build composable applications knowing that contracts adhering to the same ERC will work together seamlessly.

EIP (Ethereum Improvement Proposal) is the formal, overarching process for proposing changes to the Ethereum protocol, while ERC (Ethereum Request for Comment) is a specific category of EIP focused on defining application-level standards. All ERCs are EIPs, but not all EIPs are ERCs. This relationship is codified in the EIP process itself, where an EIP is assigned a type—Core, Networking, Interface, or ERC—upon submission. An ERC is therefore an EIP with the explicit goal of establishing a standard for smart contracts, tokens, wallets, and other high-level components of the Ethereum ecosystem.

The distinction is functional. Core EIPs involve consensus-critical changes to the Ethereum protocol, such as the transition to Proof-of-Stake (EIP-3675) or gas fee adjustments. In contrast, ERC standards provide blueprints for interoperability. For example, ERC-20 (EIP-20) defines a fungible token interface, and ERC-721 (EIP-721) defines a non-fungible token (NFT) interface. These standards are not enforced by the protocol but are adopted by developers to ensure their smart contracts can interact seamlessly with wallets, exchanges, and other contracts, creating a composable and predictable application layer.

The lifecycle of an ERC follows the standard EIP process: it begins as a draft, moves to review, and, if accepted by the community, achieves final status. Key ERCs are often discussed and developed within specialized community forums like the Ethereum Magicians. This rigorous process ensures that widely adopted standards like ERC-20 and ERC-721 are robust, secure, and well-specified before becoming the foundation for billions of dollars in economic activity, demonstrating how the formal EIP framework enables decentralized coordination and innovation at the application level.

An ERC begins as an EIP (Ethereum Improvement Proposal) focused on application-level standards, not core protocol changes. The process is community-driven: a proposer drafts a specification, opens it for peer review on forums like Ethereum Magicians, and iterates based on feedback. Key stages include Draft, Review, Last Call, and finally Final. A proposal reaches Final status once it has been widely reviewed, tested, and implemented, often requiring multiple independent implementations to demonstrate robustness and interoperability.

The most influential standard is ERC-20, which defines a common interface for fungible tokens, enabling seamless interaction between wallets, exchanges, and dApps. Other foundational standards include ERC-721 for non-fungible tokens (NFTs), ERC-1155 for multi-token contracts, and ERC-4337 for account abstraction. Each standard solves a specific interoperability problem, creating a predictable framework that reduces development risk and fosters composability—the ability for different applications to seamlessly work together, which is a cornerstone of DeFi and the broader Web3 stack.

Beyond tokens, the ERC process standardizes a wide range of functionalities. This includes ERC-165 for interface detection, ERC-725 for blockchain identities, and ERC-4626 for yield-bearing vault tokens. The process ensures that these specifications are technically sound, secure, and backward-compatible where possible. By providing a clear path from idea to adoption, the ERC framework is critical for Ethereum's evolution, allowing innovation to flourish within a stable, predictable environment that developers and users can trust.