ERC-1155 Transfer Facet

ERC-1155 token transfers within a diamond

Key Features

• Implements safeTransferFrom and safeBatchTransferFrom for ERC-1155 token handling.
• Accesses shared diamond storage via getStorage() for balance management.
• Emits TransferSingle and TransferBatch events for off-chain tracking.
• Exports its function selectors via exportSelectors() for diamond integration.

Overview

This facet implements ERC-1155 token transfers as external functions callable through a diamond proxy. It accesses shared diamond storage to manage token balances and emits standard events for off-chain consumption. Developers integrate this facet to provide core ERC-1155 transfer capabilities while retaining diamond's upgradeability.

Storage

ERC1155Storage

Definition

struct ERC1155Storage {
  mapping(uint256 id => mapping(address account => uint256 balance)) balanceOf;
  mapping(address account => mapping(address operator => bool)) isApprovedForAll;
}

State Variables

Property	Type	Description
STORAGE_POSITION	bytes32	Diamond storage slot position for this module (Value: keccak256("erc1155"))

Functions

safeTransferFrom

Transfers value amount of token type id from from to to. Emits a TransferSingle event.

function safeTransferFrom(address _from, address _to, uint256 _id, uint256 _value, bytes calldata _data) external;

Parameters:

Property	Type	Description
_from	address	The address to transfer from.
_to	address	The address to transfer to.
_id	uint256	The token type to transfer.
_value	uint256	The amount to transfer.
_data	bytes	Additional data with no specified format.

---

safeBatchTransferFrom

Batched version of safeTransferFrom. Emits a TransferBatch event.

function safeBatchTransferFrom(
  address _from,
  address _to,
  uint256[] calldata _ids,
  uint256[] calldata _values,
  bytes calldata _data
) external;

Parameters:

Property	Type	Description
_from	address	The address to transfer from.
_to	address	The address to transfer to.
_ids	uint256[]	The token types to transfer.
_values	uint256[]	The amounts to transfer.
_data	bytes	Additional data with no specified format.

---

exportSelectors

Exports the function selectors of the ERC1155TransferFacet This function is use as a selector discovery mechanism for diamonds

function exportSelectors() external pure returns (bytes memory);

Returns:

Property	Type	Description
-	bytes	selectors The exported function selectors of the ERC1155TransferFacet

Events

Emitted when value amount of tokens of type id are transferred from from to to by operator.

Signature:

event TransferSingle(
  address indexed _operator, address indexed _from, address indexed _to, uint256 _id, uint256 _value
);

Parameters:

Property	Type	Description
_operator	address	The address which initiated the transfer.
_from	address	The address which previously owned the token.
_to	address	The address which now owns the token.
_id	uint256	The token type being transferred.
_value	uint256	The amount of tokens transferred.

Equivalent to multiple TransferSingle events, where operator, from and to are the same for all transfers.

Signature:

event TransferBatch(
  address indexed _operator, address indexed _from, address indexed _to, uint256[] _ids, uint256[] _values
);

Parameters:

Property	Type	Description
_operator	address	The address which initiated the batch transfer.
_from	address	The address which previously owned the tokens.
_to	address	The address which now owns the tokens.
_ids	uint256[]	The token types being transferred.
_values	uint256[]	The amounts of tokens transferred.

Errors

Error indicating insufficient balance for a transfer.

Signature:

error ERC1155InsufficientBalance(address _sender, uint256 _balance, uint256 _needed, uint256 _tokenId);

Error indicating the sender address is invalid.

Signature:

error ERC1155InvalidSender(address _sender);

Error indicating the receiver address is invalid.

Signature:

error ERC1155InvalidReceiver(address _receiver);

Error indicating missing approval for an operator.

Signature:

error ERC1155MissingApprovalForAll(address _operator, address _owner);

Error indicating array length mismatch in batch operations.

Signature:

error ERC1155InvalidArrayLength(uint256 _idsLength, uint256 _valuesLength);

Best Practices

Best Practice

• Ensure the ERC1155Storage struct is correctly initialized in diamond storage before deploying this facet.
• Verify that the ERC1155ApproveFacet is also deployed to manage approvals required for transfers.
• Call exportSelectors() during diamond deployment to register the facet's functions.

Security Considerations

Security

The safeTransferFrom and safeBatchTransferFrom functions perform checks before state changes and external interactions, mitigating reentrancy risks. Input validation is performed for sender, receiver, and array lengths, reverting with custom errors like ERC1155InvalidSender and ERC1155InvalidArrayLength. Ensure that the caller has the necessary approvals via ERC1155ApproveFacet before invoking transfer functions.

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Last updated:March 13, 2026