ERC-1155 Maturity is an implementation of ERC-1155 that reduces the token balance size to uint224 (from uint256) and adds an uint32 maturity time.

The maturity feature creates a soft-lock effect for newly minted token balances. Once the maturity time has elapsed, the balance becomes matured and fully fungible. However, until that time, the balance is only partly fungible and subject to the following rules:

• A zero balance is a fully matured balance.
• A balance with a maturity time equal to or older than block.timestamp is a fully matured balance.
• A maturing balance can be divided into smaller balances with the same maturity time.
• A less matured balance cannot be transferred or merged into a more mature balance.
• A more mature balance can be transferred to and merged into a less matured balance, resulting in a balance with a later maturity time.

The maturity time can be queried using the IERC1155Maturity interface:

interface IERC1155Maturity is IERC1155 {
    /**
     * @dev Returns the maturity time of tokens of token type `id` owned by `account`.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function maturityOf(address account, uint256 id) external view returns (uint256);

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {maturityOf}.
     *
     * Requirements:
     *
     * - `accounts` and `ids` must have the same length.
     */
    function maturityOfBatch(address[] calldata accounts, uint256[] calldata ids)
        external
        view
        returns (uint256[] memory);
}