ERC-5643

ERC-5643, also known as Token State, is an Ethereum Request for Comment (ERC) that defines a standard interface for non-fungible tokens (NFTs) to manage time-based, recurring state changes. At its core, it enables a token's properties or access rights to expire and automatically renew based on a predefined subscription period, such as monthly or annually. This is implemented through a mandatory expiresAt function that returns a UNIX timestamp for when the current state ends, and an renewSubscription function to extend it. The standard is minimal and opinionated, focusing solely on the state management logic and leaving payment mechanics and tokenomics to the implementing contract.

The primary innovation of ERC-5643 is moving subscription logic on-chain and making it a native property of the token itself. Unlike traditional SaaS models where subscription status is stored in a centralized database, here the state is verifiable and enforceable by the smart contract. This enables new use cases for NFTs, transforming them from static digital collectibles into dynamic membership passes, software licenses, or content access keys that require active renewal. For example, a streaming service could issue an NFT that grants access only while the subscription is paid up, with the NFT effectively becoming inactive—or "soulbound"—if the subscription lapses.

Implementing ERC-5643 requires careful design of the renewal mechanism. The standard does not specify how payment is collected; the renewSubscription function could transfer ERC-20 tokens, native ETH, or even trigger a cross-chain action. This flexibility allows developers to build complex subscription economies. A key technical consideration is managing the state expiration. Contracts must handle queries for expired tokens and may implement hooks to notify other systems or alter metadata when a subscription renews or lapses, enabling dynamic visual changes in associated artwork or attributes.

The standard promotes interoperability by providing a common interface that wallets, marketplaces, and explorers can universally understand. A decentralized application (dApp) can trustlessly check the expiresAt value of any ERC-5643-compliant NFT to determine if a user's access is valid. This solves a significant problem in Web3 where subscription status is often managed off-chain, breaking composability. By standardizing this pattern, ERC-5643 paves the way for a new class of recurring revenue models and utility-based NFTs that are integral to the growing decentralized physical infrastructure (DePIN) and service networks.

ERC-5643 is an Ethereum Improvement Proposal (EIP) that defines a standard interface for Non-Fungible Tokens (NFTs) with expirable ownership, commonly referred to as subscription NFTs. The term's origin is purely functional: 'ERC' denotes an Ethereum Request for Comments, a standard format for proposing application-level conventions, while '5643' is its unique, sequential identifier assigned within the EIP repository. This naming follows the established pattern for all ERC standards, such as ERC-20 and ERC-721, which are defined by their proposal number.

The proposal was authored by William Schwab, Lucas Henne, and Michael Elliot, and was formally entered into the EIP process as Draft status in March 2023. Its creation was driven by the need to formalize a pattern for NFTs that encode a temporal access right, moving beyond the perpetual ownership model of standard NFTs. The core concept—stateful expiration—was designed to enable use cases like software licenses, media subscriptions, and time-bound memberships directly on-chain, providing a native mechanism for access to lapse without manual revocation.

The technical nomenclature within the standard is precise. The key function expiresAt(uint256 tokenId) returns a Unix timestamp for when the token's ownership expires, anchoring the mechanism in a globally consistent time standard. The proposal builds upon the foundational ERC-721 metadata and enumeration extensions, ensuring compatibility with existing NFT infrastructure. By standardizing this pattern, ERC-5643 provides a common language and predictable behavior for developers building subscription-based economies, allowing wallets and marketplaces to uniformly display and interact with time-bound tokens.

ERC-5643, also known as Tokenized Subscriptions, is an Ethereum token standard that introduces a stateful subscription mechanism directly into non-fungible tokens (NFTs). It extends the widely adopted ERC-721 and ERC-1155 standards by adding a core function, expiresAt(uint256 tokenId), which returns a UNIX timestamp for when the token's subscription period ends. This function allows smart contracts and user interfaces to programmatically check a token's active status, enabling automated access control and recurring billing logic without requiring manual renewal checks or off-chain validation.

The core subscription logic is managed through two primary functions: renewSubscription and cancelSubscription. When a user calls renewSubscription, they must send the required payment (often in a native token like ETH or an ERC-20) to extend the token's expiry timestamp. This payment is typically routed to a predefined beneficiary address, such as the original creator or a DAO treasury. Conversely, cancelSubscription stops the automatic renewal process for a token, though the access granted by the token remains valid until its current expiry time. This design cleanly separates the financial transaction from the access state.

A key innovation of ERC-5643 is its minimal and permissionless design. The standard does not enforce how payments are made or who can renew a subscription; it only provides the interface to update the expiry state. This allows for immense flexibility in implementation. For example, a project could build a subscription NFT that renews monthly with ETH, annually with a stablecoin, or even via a custom token-gated system. The state change—the updated expiresAt timestamp—is the single source of truth for an application to grant or deny access to a service, content, or physical good.

From a developer's perspective, integrating ERC-5643 involves listening for the SubscriptionUpdate event, which is emitted whenever a token's expiry changes. Front-end applications can use this event to update user interfaces in real-time, showing subscription status or prompting for renewal. Smart contracts that provide gated services would query the expiresAt function in their own logic, often within a modifier like onlyValidSubscription(tokenId), to restrict function calls to only holders with active tokens. This creates a robust, on-chain system for managing recurring relationships.

Practical use cases for this mechanism are extensive. They include software-as-a-service (SaaS) licenses, premium content platforms, membership DAOs, time-limited in-game items, and physical asset rentals. For instance, a music streaming dApp could mint an NFT that serves as a monthly pass; the user's access to high-fidelity streams is automatically revoked the moment block.timestamp exceeds the token's stored expiry, unless a renewal transaction is submitted. This transforms static NFTs into dynamic, utility-bearing assets with enforceable, time-based economics directly embedded in the token's state.

The ERC-5643 standard, also known as Token State or Subscription NFT, defines a minimal smart contract interface that enables a non-fungible token (NFT) to have an expiration date and a renewal mechanism. This interface introduces the expiresAt(uint256 tokenId) function, which returns a Unix timestamp indicating when the token's current state or subscription period ends. A return value of 0 signifies the token is in a permanent, non-expiring state. This core function allows wallets, marketplaces, and other smart contracts to programmatically check a token's active status, enabling new utility models beyond static ownership.

The standard's primary innovation is its statefulness over time, transforming an NFT from a static record of ownership into a dynamic asset with a lifecycle. This is achieved without mandating a specific renewal logic, granting developers flexibility. Common implementations might tie renewal to a payment, a governance vote, or the completion of a task. The interface is intentionally minimal, comprising only the state query function (expiresAt) and a required StateUpdate event that must be emitted whenever a token's expiration timestamp changes. This design ensures broad compatibility and easy integration with existing ERC-721 and ERC-1155 NFT infrastructures.

Practical applications for ERC-5643 are extensive, particularly in software licensing, subscription-based content, and membership programs. For instance, a software company could issue an NFT that grants access to a premium application, where the expiresAt value dictates the subscription's end date. A decentralized autonomous organization (DAO) might use it for time-bound voting rights or committee memberships. The standard also facilitates automated expiration handling, where external systems can listen for the StateUpdate event to trigger actions like revoking access or displaying a renewal prompt, creating a more seamless user experience.

From a technical perspective, implementing ERC-5643 requires careful consideration of access control and state management. The contract must define who is authorized to update a token's expiration—typically the token owner or a designated admin contract. Developers must also decide whether expiration leads to the token being burned, rendered inert, or placed into a locked state. It's crucial that the StateUpdate event is emitted for all state changes, including renewals and cancellations, to maintain a reliable public record. This event-driven architecture is key for building responsive off-chain indexers and user interfaces.

The ERC-5643 standard represents a significant step toward more complex and useful on-chain relationships. By adding a simple temporal dimension to NFT ownership, it unlocks models for recurring revenue, temporary access, and phased benefits. Its lightweight design ensures it can be composed with other standards, such as ERC-2981 for royalties or ERC-5192 for soulbound tokens, to create sophisticated digital asset ecosystems. As the blockchain space evolves, interfaces like ERC-5643 provide the foundational primitives for building the next generation of dynamic, utility-driven applications.