ERC-1155 interaction

ERC-1155 is the multi-token standard. A single contract can hold both fungible tokens (like gold coins in a game) and non-fungible tokens (like unique items). The standard also has efficient batch operations built in. Standard ERC-1155 contracts work on Sei without modification.

Try it: deploy an ERC-1155

Compile and deploy a real ERC-1155 to Sei Testnet from the browser. The Remix sandbox preloads an OpenZeppelin-based DemoMultiToken with a public mint(id, amount) function. Then use the read and write patterns below with your deployed address. First, add Sei Testnet to your wallet: In Remix, compile the contract on the Solidity Compiler tab. Then deploy it from the Deploy & Run tab with Environment set to Injected Provider - MetaMask.

Setup

import { createPublicClient, createWalletClient, http, parseAbi } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import { sei } from 'viem/chains';

const client = createPublicClient({ chain: sei, transport: http() });
const account = privateKeyToAccount('0xYourPrivateKey');
const walletClient = createWalletClient({ account, chain: sei, transport: http() });

const ERC1155_ABI = parseAbi([
  'function balanceOf(address account, uint256 id) view returns (uint256)',
  'function balanceOfBatch(address[] accounts, uint256[] ids) view returns (uint256[])',
  'function isApprovedForAll(address account, address operator) view returns (bool)',
  'function setApprovalForAll(address operator, bool approved)',
  'function safeTransferFrom(address from, address to, uint256 id, uint256 amount, bytes data)',
  'function safeBatchTransferFrom(address from, address to, uint256[] ids, uint256[] amounts, bytes data)',
  'function uri(uint256 id) view returns (string)',
  'event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value)',
  'event TransferBatch(address indexed operator, address indexed from, address indexed to, uint256[] ids, uint256[] values)',
]);

const CONTRACT = '0xContractAddress';

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider('https://evm-rpc.sei-apis.com');
const wallet = new ethers.Wallet('0xYourPrivateKey', provider);

const ERC1155_ABI = [
  'function balanceOf(address account, uint256 id) view returns (uint256)',
  'function balanceOfBatch(address[] accounts, uint256[] ids) view returns (uint256[])',
  'function isApprovedForAll(address account, address operator) view returns (bool)',
  'function setApprovalForAll(address operator, bool approved)',
  'function safeTransferFrom(address from, address to, uint256 id, uint256 amount, bytes data)',
  'function safeBatchTransferFrom(address from, address to, uint256[] ids, uint256[] amounts, bytes data)',
  'function uri(uint256 id) view returns (string)',
  'event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value)',
  'event TransferBatch(address indexed operator, address indexed from, address indexed to, uint256[] ids, uint256[] values)',
];

const CONTRACT = '0xContractAddress';
const readContract = new ethers.Contract(CONTRACT, ERC1155_ABI, provider);
const writeContract = new ethers.Contract(CONTRACT, ERC1155_ABI, wallet);

Reading a single balance

const balance = await client.readContract({
  address: CONTRACT,
  abi: ERC1155_ABI,
  functionName: 'balanceOf',
  args: ['0xOwnerAddress', 1n], // token ID 1
});

const balance = await readContract.balanceOf('0xOwnerAddress', 1n);

Batch balance query

balanceOfBatch fetches the balances for multiple owner and ID pairs in one call. This is the most efficient way to load a user’s inventory:

const owners = ['0xOwner', '0xOwner', '0xOwner'] as const;
const ids = [1n, 2n, 3n];

const balances = await client.readContract({
  address: CONTRACT,
  abi: ERC1155_ABI,
  functionName: 'balanceOfBatch',
  args: [owners, ids],
});
// balances[0] = balance of token 1, balances[1] = token 2, etc.

const owners = ['0xOwner', '0xOwner', '0xOwner'];
const ids = [1n, 2n, 3n];

const balances = await readContract.balanceOfBatch(owners, ids);

Reading token metadata URI

viem

const uri = await client.readContract({
  address: CONTRACT,
  abi: ERC1155_ABI,
  functionName: 'uri',
  args: [1n],
});
// URI often contains {id} — replace it with the hex token ID per ERC-1155 spec
const resolvedUri = uri.replace('{id}', (1n).toString(16).padStart(64, '0'));

Transferring a single token

const hash = await walletClient.writeContract({
  address: CONTRACT,
  abi: ERC1155_ABI,
  functionName: 'safeTransferFrom',
  args: [account.address, '0xRecipient', 1n, 5n, '0x'], // transfer 5 of token ID 1
});

const receipt = await client.waitForTransactionReceipt({ hash });

const tx = await writeContract.safeTransferFrom(wallet.address, '0xRecipient', 1n, 5n, '0x');
const receipt = await tx.wait();

Batch transfer

Send multiple token IDs in a single transaction:

const hash = await walletClient.writeContract({
  address: CONTRACT,
  abi: ERC1155_ABI,
  functionName: 'safeBatchTransferFrom',
  args: [
    account.address,
    '0xRecipient',
    [1n, 2n, 3n],     // token IDs
    [5n, 10n, 1n],    // amounts
    '0x',
  ],
});

const tx = await writeContract.safeBatchTransferFrom(
  wallet.address,
  '0xRecipient',
  [1n, 2n, 3n],
  [5n, 10n, 1n],
  '0x',
);

Operator approval

// Grant an operator permission to transfer all tokens
const hash = await walletClient.writeContract({
  address: CONTRACT,
  abi: ERC1155_ABI,
  functionName: 'setApprovalForAll',
  args: ['0xOperatorAddress', true],
});

// Check approval status
const isApproved = await client.readContract({
  address: CONTRACT,
  abi: ERC1155_ABI,
  functionName: 'isApprovedForAll',
  args: ['0xOwnerAddress', '0xOperatorAddress'],
});

const tx = await writeContract.setApprovalForAll('0xOperatorAddress', true);

const isApproved = await readContract.isApprovedForAll('0xOwnerAddress', '0xOperatorAddress');

Watching transfer events

Watch new events over the WebSocket endpoint. Watchers that poll the public HTTP endpoint can miss events or report them twice. For details, see Listen to events.

import { webSocket } from 'viem';

const wsClient = createPublicClient({ chain: sei, transport: webSocket('wss://evm-ws.sei-apis.com') });

// Watch single transfers
const unwatch = wsClient.watchContractEvent({
  address: CONTRACT,
  abi: ERC1155_ABI,
  eventName: 'TransferSingle',
  onLogs: (logs) => {
    logs.forEach(({ args }) => {
      console.log(`Token ${args.id}: ${args.from} → ${args.to}, amount: ${args.value}`);
    });
  },
});

// Watch batch transfers
const unwatchBatch = wsClient.watchContractEvent({
  address: CONTRACT,
  abi: ERC1155_ABI,
  eventName: 'TransferBatch',
  onLogs: (logs) => {
    logs.forEach(({ args }) => {
      console.log(`Batch from ${args.from} → ${args.to}:`, args.ids, args.values);
    });
  },
});

const wsProvider = new ethers.WebSocketProvider('wss://evm-ws.sei-apis.com');
const wsContract = new ethers.Contract(CONTRACT, ERC1155_ABI, wsProvider);

wsContract.on('TransferSingle', (operator, from, to, id, value) => {
  console.log(`Token ${id}: ${from} → ${to}, amount: ${value}`);
});

wsContract.on('TransferBatch', (operator, from, to, ids, values) => {
  console.log(`Batch from ${from} → ${to}:`, ids, values);
});

Overview

Client Setup

Accounts and Transactions

Tokens

Contracts

Sei Features

ERC-1155 Interaction

ERC-1155 interaction

Try it: deploy an ERC-1155

Setup

Reading a single balance

Batch balance query

Reading token metadata URI

Transferring a single token

Batch transfer

Operator approval

Watching transfer events

​ERC-1155 interaction

​Try it: deploy an ERC-1155

​Setup

​Reading a single balance

​Batch balance query

​Reading token metadata URI

​Transferring a single token

​Batch transfer

​Operator approval

​Watching transfer events

ERC-1155 interaction

Try it: deploy an ERC-1155

Setup

Reading a single balance

Batch balance query

Reading token metadata URI

Transferring a single token

Batch transfer

Operator approval

Watching transfer events