Operator Allowlist

The Operator Allowlist restricts which addresses can transfer your tokens, ensuring royalties are enforced by only allowing transfers through compliant marketplaces like Immutable’s Orderbook.

Contracts Repository

View the Operator Allowlist source code

Why It’s Required

The Operator Allowlist protects game studios from:

Vampire attacks: Unauthorized marketplaces bypassing royalties
Protocol fee evasion: Trading outside Immutable’s ecosystem
Revenue loss: Transactions that don’t pay creator royalties

Mandatory Compliance: All ERC-721 and ERC-1155 collections on Immutable Chain must implement the Operator Allowlist.

Non-Compliance Consequences

Forfeit any token grants received
Passport users see warnings that your collection may be counterfeit
Exclusion from ecosystem marketplaces (TokenTrove, GameStop NFT, etc.)

How It Works

The allowlist is a registry of approved operator addresses:

Address Type	Example
Contract Address	Seaport settlement contract
Bytecode Hash	Smart contract wallet implementations
Implementation Address	Proxy contract targets

Enforcement Flows

Approvals (approve, setApprovalForAll):

Scenario	Allowed
Target is an EOA (user wallet)	✅
Target has approved bytecode	✅
Target has approved address	✅
Unapproved smart contract	❌

Transfers (transferFrom, safeTransferFrom):

Scenario	Allowed
Caller is an EOA	✅
Caller is approved marketplace	✅
Unapproved contract	❌

Implementation

Using Preset Contracts

All Immutable preset contracts and contracts deployed via Hub include Operator Allowlist protection by default.

Custom Contracts

For custom contracts, inherit from OperatorAllowlistEnforced.sol:

import "@imtbl/contracts/contracts/allowlist/OperatorAllowlistEnforced.sol";

contract MyNFT is ERC721, OperatorAllowlistEnforced {
    constructor(address allowlist) {
        _setOperatorAllowlistRegistry(allowlist);
    }
    
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal override {
        // Check operator allowlist for transfers
        if (from != address(0) && to != address(0)) {
            require(
                _isAllowlisted(msg.sender),
                "Operator not allowlisted"
            );
        }
        super._beforeTokenTransfer(from, to, tokenId);
    }
}