ERCs

ERC-721 — Non-Fungible Token Standard

eips.ethereum.org/EIPS/eip-721

import {
  balanceOf,
  ownerOf,
  transferFrom,
  safeTransferFrom_42842e0e,
  safeTransferFrom_b88d4fde,
  approve,
  getApproved,
  setApprovalForAll,
  isApprovedForAll,
} from "@ethernauta/erc/721";

void balanceOf;
void ownerOf;
void transferFrom;
void safeTransferFrom_42842e0e;
void safeTransferFrom_b88d4fde;
void approve;
void getApproved;
void setApprovalForAll;
void isApprovedForAll;

Core methods

Method	Shape	Purpose
`balanceOf({ owner })`	`Callable<Uint256>`	NFT count owned.
`ownerOf({ token_id })`	`Callable<Address>`	Current owner.
`transferFrom({ from, to, token_id })`	`Signable<Hash32>`	Unsafe transfer.
`safeTransferFrom({ from, to, token_id, data? })`	`Signable<Hash32>`	Safe transfer (checks receiver).
`approve({ to, token_id })`	`Signable<Hash32>`	Per-token approval.
`getApproved({ token_id })`	`Callable<Address>`	Read approval.
`setApprovalForAll({ operator, approved })`	`Signable<Hash32>`	All-token approval.
`isApprovedForAll({ owner, operator })`	`Callable<boolean>`	Read operator approval.

Extensions

Subpath	Methods
`@ethernauta/erc/721/burnable`	`burn`
`@ethernauta/erc/721/enumerable`	`totalSupply`, `token_of_owner_by_index`, `token_by_index`
`@ethernauta/erc/721/metadata`	`name`, `symbol`, `tokenURI`
`@ethernauta/erc/721/pausable`	`pause`, `unpause`, `paused`

Reading owner + metadata

import { parse } from "valibot";
import type { Bytes } from "@ethernauta/core";
import { AddressSchema, Uint256Schema } from "@ethernauta/core";
import { ownerOf } from "@ethernauta/erc/721";
import { tokenURI } from "@ethernauta/erc/721/extensions/metadata";
import { eth_call } from "@ethernauta/eth";
import { contract, create_reader, encode_chain_id, http } from "@ethernauta/transport";
import { eip155_1 } from "@ethernauta/chain/eip155-1";

const CHAIN_ID = encode_chain_id({ namespace: "eip155", reference: eip155_1.chainId });
const reader = create_reader([
  { chainId: CHAIN_ID, transports: [http("https://ethereum-rpc.publicnode.com")] },
]);

const collection = parse(AddressSchema, "0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D");
const tokenId = parse(Uint256Schema, "0x1");
const ctx = contract({ chain_id: CHAIN_ID, to: collection });

const owner_callable = ownerOf({ tokenId })(ctx);
const owner_bytes: Bytes = await eth_call([{ to: owner_callable.to, input: owner_callable.data }])(
  reader({ chain_id: CHAIN_ID }),
);
const owner = owner_callable.decode(owner_bytes);
void owner;

const uri_callable = tokenURI({ tokenId })(ctx);
const uri_bytes: Bytes = await eth_call([{ to: uri_callable.to, input: uri_callable.data }])(
  reader({ chain_id: CHAIN_ID }),
);
const uri = uri_callable.decode(uri_bytes);
void uri;

ERC-721 — Non-Fungible Token Standard

Core methods

Extensions

Reading owner + metadata

See also