ERC-6900 (Modular Smart Contract Accounts)

ERC-6900 organizes a smart account's logic into well-defined types. Validation functions decide whether an action is authorized, for example when validating an ERC-4337 UserOperation. Execution functions hold the business logic. Hooks run before or after, under strict ordering rules. So each module gets its own storage space without colliding with others, it mandates ERC-7201 namespacing. The result is an extensible account: spending limits, social recovery, session keys or multisig install as reusable, auditable modules.

It is the piece that makes account abstraction genuinely extensible. ERC-6900 competes with ERC-7579, its minimalist alternative. ERC-6900 is more prescriptive, splitting validation into dedicated functions and ordered hooks, and requiring namespacing. ERC-7579 leaves more decisions to the implementer and prioritizes one module working across many different wallets. As a rule of thumb, a complex permission system with lifecycle hooks fits ERC-6900; a single reusable module fits ERC-7579.

The reference implementation is Alchemy's Modular Account, from the team leading the standard. Circle has built smart accounts on ERC-6900. As of June 2026 the standard is still iterating (version 0.8, aligned with ERC-4337 v0.7), so it should be cited as a specification in development, not finalized.