ERC1155 Pointer Contracts

ERC1155 pointer contracts extend Sei’s interoperability framework to support multi-token standards. They allow interaction between ERC1155 contracts and their Cosmos equivalents. This supports use cases for gaming, collectibles, and complex token economies.

Overview

The ERC1155 standard allows a single contract to manage multiple token types - both fungible and non-fungible tokens. ERC1155 pointers maintain this flexibility while providing cross-environment functionality.

Key Features

Multi-Token Support: Bridge multiple token types in a single pointer contract
Batch Operations: Efficient batch transfers and operations
Flexible Token Types: Support for both fungible and non-fungible tokens
Gas Optimization: Reduced gas costs for complex multi-token operations
Cross-Environment Compatibility: Direct interaction between Cosmos and EVM

Prerequisites

Before deploying ERC1155 pointers, ensure you have:

Sei CLI (seid) installed - Installation Guide
Access to the ERC1155 contract address you want to bridge
Sufficient SEI tokens for transaction fees
Understanding of Pointer Contracts Overview

Checking Existing Pointers

Always verify if a pointer already exists for your ERC1155 contract:


seid q evm pointer ERC1155 [CONTRACT_ADDRESS] --node=https://rpc.sei-apis.com

Example:


seid q evm pointer ERC1155 0x1234567890abcdef1234567890abcdef12345678 --node=https://rpc.sei-apis.com

ERC1155 Pointer Registration

⚠️

Important: CW→ERC registration is disabled for security reasons. Only ERC→CW registration is currently supported.

ERC1155 → CosmWasm Pointer

To create a CosmWasm pointer for an existing ERC1155 contract:


seid tx evm register-pointer ERC1155 $ERC1155_CONTRACT_ADDRESS \
  --from=$SENDER \
  --chain-id=pacific-1 \
  --broadcast-mode=block \
  --gas=300000 \
  --fees=10000usei \
  --node=https://rpc.sei-apis.com

Parameters

ERC1155_CONTRACT_ADDRESS: The address of the ERC1155 contract
--from: Your wallet/key name
--chain-id: Network identifier (pacific-1 for mainnet, atlantic-2 for testnet)
--gas: Gas limit (ERC1155 operations may require more gas)
--fees: Transaction fees in usei

Example Registration


# Set environment variables
export ERC1155_ADDRESS="0xabcdef1234567890abcdef1234567890abcdef12"
export SENDER="my-wallet"
 
# Register the pointer
seid tx evm register-pointer ERC1155 $ERC1155_ADDRESS \
  --from=$SENDER \
  --chain-id=pacific-1 \
  --broadcast-mode=block \
  --gas=350000 \
  --fees=12000usei \
  --node=https://rpc.sei-apis.com

Verification

After registration, confirm the pointer was created successfully:


seid q evm pointer ERC1155 $ERC1155_ADDRESS --node=https://rpc.sei-apis.com

ERC1155 Pointer Usage

Solidity Integration


pragma solidity ^0.8.0;
 
import "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";
import "@openzeppelin/contracts/token/ERC1155/utils/ERC1155Holder.sol";
 
contract ERC1155PointerExample is ERC1155Holder {
    IERC1155 public immutable erc1155Contract;
    
    constructor(address _erc1155Address) {
        erc1155Contract = IERC1155(_erc1155Address);
    }
    
    // Batch transfer multiple token types
    function batchTransferToPointer(
        address to,
        uint256[] memory ids,
        uint256[] memory amounts,
        bytes memory data
    ) external {
        erc1155Contract.safeBatchTransferFrom(
            msg.sender,
            to,
            ids,
            amounts,
            data
        );
    }
    
    // Check balance of specific token ID
    function getTokenBalance(address account, uint256 tokenId) 
        external 
        view 
        returns (uint256) 
    {
        return erc1155Contract.balanceOf(account, tokenId);
    }
    
    // Check multiple token balances
    function getBatchBalances(
        address[] memory accounts,
        uint256[] memory ids
    ) external view returns (uint256[] memory) {
        return erc1155Contract.balanceOfBatch(accounts, ids);
    }
}

CosmWasm Integration


use cosmwasm_std::{
    Addr, Binary, Deps, DepsMut, Env, MessageInfo, Response, StdResult, Uint128,
};
use cw1155::{Cw1155ExecuteMsg, Cw1155QueryMsg, TokensResponse};
 
#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
pub struct InstantiateMsg {
    pub erc1155_pointer: Addr,
}
 
// Execute message to interact with ERC1155 pointer
pub fn execute_transfer_batch(
    deps: DepsMut,
    env: Env,
    info: MessageInfo,
    to: Addr,
    token_ids: Vec<String>,
    amounts: Vec<Uint128>,
) -> Result<Response, ContractError> {
    let erc1155_pointer = ERC1155_POINTER.load(deps.storage)?;
    
    let transfer_msg = Cw1155ExecuteMsg::SendBatch {
        from: Some(info.sender.to_string()),
        to: to.to_string(),
        batch: token_ids.into_iter().zip(amounts.into_iter())
            .map(|(id, amount)| (id, amount, None))
            .collect(),
        msg: None,
    };
    
    let cosmos_msg = CosmosMsg::Wasm(WasmMsg::Execute {
        contract_addr: erc1155_pointer.to_string(),
        msg: to_binary(&transfer_msg)?,
        funds: vec![],
    });
    
    Ok(Response::new()
        .add_message(cosmos_msg)
        .add_attribute("action", "batch_transfer")
        .add_attribute("to", to))
}

Advanced Use Cases

Gaming Assets Bridge


contract GameAssetsBridge {
    IERC1155 public gameAssets;
    mapping(uint256 => string) public assetTypes;
    
    // Token ID ranges
    uint256 constant WEAPONS_START = 1;
    uint256 constant ARMOR_START = 10000;
    uint256 constant CONSUMABLES_START = 20000;
    
    constructor(address _gameAssets) {
        gameAssets = IERC1155(_gameAssets);
    }
    
    function bridgeGameAssets(
        address player,
        uint256[] memory tokenIds,
        uint256[] memory amounts
    ) external {
        // Validate token types
        for (uint256 i = 0; i < tokenIds.length; i++) {
            require(isValidGameAsset(tokenIds[i]), "Invalid game asset");
        }
        
        // Transfer to bridge
        gameAssets.safeBatchTransferFrom(
            player,
            address(this),
            tokenIds,
            amounts,
            ""
        );
        
        // Emit bridge event for off-chain processing
        emit AssetsBridged(player, tokenIds, amounts);
    }
    
    function isValidGameAsset(uint256 tokenId) internal pure returns (bool) {
        return tokenId >= WEAPONS_START;
    }
}

Multi-Token Marketplace


contract MultiTokenMarketplace {
    struct Listing {
        address seller;
        address tokenContract;
        uint256 tokenId;
        uint256 amount;
        uint256 pricePerToken;
        bool active;
    }
    
    mapping(bytes32 => Listing) public listings;
    
    function createListing(
        address tokenContract,
        uint256 tokenId,
        uint256 amount,
        uint256 pricePerToken
    ) external {
        bytes32 listingId = keccak256(
            abi.encodePacked(msg.sender, tokenContract, tokenId, block.timestamp)
        );
        
        // Transfer tokens to marketplace
        IERC1155(tokenContract).safeTransferFrom(
            msg.sender,
            address(this),
            tokenId,
            amount,
            ""
        );
        
        listings[listingId] = Listing({
            seller: msg.sender,
            tokenContract: tokenContract,
            tokenId: tokenId,
            amount: amount,
            pricePerToken: pricePerToken,
            active: true
        });
        
        emit ListingCreated(listingId, msg.sender, tokenContract, tokenId);
    }
    
    function purchaseTokens(bytes32 listingId, uint256 amount) external payable {
        Listing storage listing = listings[listingId];
        require(listing.active, "Listing not active");
        require(amount <= listing.amount, "Insufficient tokens");
        
        uint256 totalPrice = amount * listing.pricePerToken;
        require(msg.value >= totalPrice, "Insufficient payment");
        
        // Transfer tokens to buyer
        IERC1155(listing.tokenContract).safeTransferFrom(
            address(this),
            msg.sender,
            listing.tokenId,
            amount,
            ""
        );
        
        // Update listing
        listing.amount -= amount;
        if (listing.amount == 0) {
            listing.active = false;
        }
        
        // Transfer payment to seller
        payable(listing.seller).transfer(totalPrice);
        
        // Refund excess payment
        if (msg.value > totalPrice) {
            payable(msg.sender).transfer(msg.value - totalPrice);
        }
    }
}

Gas Considerations

ERC1155 operations, especially batch operations, may require higher gas limits:

Operation	Estimated Gas	Use Case
Single Transfer	~45,000	Basic token transfer
Batch Transfer (5 tokens)	~120,000	Multi-token operations
Pointer Registration	~300,000	Initial setup
Complex Multi-Token Operations	~500,000+	Gaming marketplaces

Gas Optimization Tips


contract OptimizedERC1155Operations {
    // Use packed structs for batch operations
    struct BatchTransfer {
        uint128 tokenId;
        uint128 amount;
    }
    
    function optimizedBatchTransfer(
        address to,
        BatchTransfer[] calldata transfers
    ) external {
        uint256 length = transfers.length;
        uint256[] memory ids = new uint256[](length);
        uint256[] memory amounts = new uint256[](length);
        
        // Unpack in a single loop
        for (uint256 i = 0; i < length;) {
            ids[i] = transfers[i].tokenId;
            amounts[i] = transfers[i].amount;
            
            unchecked { ++i; }
        }
        
        IERC1155(tokenContract).safeBatchTransferFrom(
            msg.sender,
            to,
            ids,
            amounts,
            ""
        );
    }
}

Security Considerations

⚠️

Security: Always validate token IDs and amounts in multi-token operations to prevent unauthorized transfers.

Input Validation


contract SecureERC1155Bridge {
    mapping(uint256 => bool) public allowedTokenIds;
    uint256 public maxBatchSize = 100;
    
    modifier validBatch(uint256[] memory ids, uint256[] memory amounts) {
        require(ids.length == amounts.length, "Array length mismatch");
        require(ids.length <= maxBatchSize, "Batch too large");
        
        for (uint256 i = 0; i < ids.length; i++) {
            require(allowedTokenIds[ids[i]], "Token not allowed");
            require(amounts[i] > 0, "Invalid amount");
        }
        _;
    }
    
    function secureBatchTransfer(
        address to,
        uint256[] memory ids,
        uint256[] memory amounts
    ) external validBatch(ids, amounts) {
        // Safe to proceed with transfer
        IERC1155(tokenContract).safeBatchTransferFrom(
            msg.sender,
            to,
            ids,
            amounts,
            ""
        );
    }
}

Troubleshooting

Common Issues

Registration Fails


# Check if pointer already exists
seid q evm pointer ERC1155 $CONTRACT_ADDRESS
 
# Verify contract exists and is ERC1155
# Check gas limits and fees

Transfer Failures

Verify token ownership and approvals
Check for sufficient gas limits
Ensure contract implements ERC1155Receiver if receiving
Validate token IDs exist in the contract

Performance Issues

Use batch operations when possible
Implement pagination for large datasets
Cache frequently accessed data
Optimize struct packing

Debug Commands


# Check pointer status
seid q evm pointer ERC1155 $CONTRACT_ADDRESS --output json
 
# Verify transaction
seid q tx $TX_HASH --output json
 
# Check account balance
seid q bank balances $ADDRESS

Best Practices

Batch Operations: Use batch transfers for multiple tokens
Gas Estimation: Always estimate gas for complex operations
Input Validation: Validate all token IDs and amounts
Error Handling: Implement comprehensive error handling
Events: Emit events for cross-chain tracking
Testing: Thoroughly test on testnet before mainnet deployment

Success: ERC1155 pointers provide multi-token bridging capabilities. Start with simple use cases and expand to complex token economies.