ERC-20 Metadata Facet

@perfect-abstractions/compose/token/ERC20/Metadata/ERC20MetadataFacet.sol

Read-only access to the token name, symbol, and decimals

Storage

PropertyTypeDescriptionSTORAGE_POSITIONbytes32ERC-20 metadata storage position within the diamond (Value: keccak256("erc20.metadata"))

Definition

/** @custom:storage-location erc8042:erc20.metadata */
struct ERC20MetadataStorage {
  string name;
  string symbol;
  uint8 decimals;
}

Returns the descriptive name of the token, for example "My Token".

function name() external view returns (string memory);

Returns:

PropertyTypeDescription-stringThe token name, or an empty string if metadata was never set.

Returns the short ticker of the token, for example "MTK".

function symbol() external view returns (string memory);

Returns:

PropertyTypeDescription-stringThe token symbol, or an empty string if metadata was never set.

Returns how many decimal places wallets and interfaces should use when displaying balances.

function decimals() external view returns (uint8);

Returns:

PropertyTypeDescription-uint8The number of decimals, or 0 if metadata was never set. 18 is the usual choice.

Add this facet together with ERC20DataFacet. Wallets and explorers expect both the balance functions and the metadata functions.
Set all three values once during deployment with ERC20MetadataMod.setMetadata. Reading this facet before that happens returns empty strings and 0.
Choose decimals before launch and leave it alone. Changing it later reinterprets every balance already held.

This facet only reads storage, so it cannot corrupt token state on its own. Two consequences of the shared slot are worth knowing:

Renaming the token invalidates outstanding permit signatures. ERC20PermitFacet hashes the stored name into its EIP-712 domain, both in DOMAIN_SEPARATOR() and again inside permit(). If name changes, previously signed permits no longer verify and integrators that cached the old domain separator will produce failing signatures.
decimals is display only. Nothing in Compose does arithmetic with it. Balances, allowances, and the total supply are raw integers, so treat this value as a hint for user interfaces rather than a unit of account.

Last updated:September 16, 2026

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