ERC-1155 Interaction

Reading and writing ERC-1155 multi-token contracts on Sei with viem and ethers

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), with efficient batch operations built in. Standard ERC-1155 contracts work on Sei without modification.

Setup

viem

import { createPublicClient, createWalletClient, http, parseAbi } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import { sei } from '@sei-js/precompiles/viem';

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';

Reading a Single Balance

viem

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

Batch Balance Query

balanceOfBatch retrieves multiple owner/ID pairs in one call — the most efficient way to load a user’s inventory:

viem

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.

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

viem

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 });

Batch Transfer

Send multiple token IDs in a single transaction:

viem

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',
  ],
});

Operator Approval

viem

// 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'],
});

Watching Transfer Events

viem

// Watch single transfers
const unwatch = client.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 = client.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);
    });
  },
});