ERC-721: How to get all token ids?

Question

I want to iterate over all token ids of a ethereum ERC-721 contract. Some contracts have counting ids (0, 1, 2, 3, ...) which is easy, but some have random ids, e.g. https://etherscan.io/token/0xf87e31492faf9a91b02ee0deaad50d51d56d5d4d#inventory

Sadly etherscan only shows the last 10000 token ids used, but I want to iterate over all 79490. Is there a way to accomplish this? For me, everything is fine. Setup my own ethereum node, using some API.

Answer 1

You can loop through all Transfer() events emitted by the collection contract.

You're looking for transfers from address 0x0 (minted tokens). And excluding from the list transfers to address 0x0 (destroyed tokens).

One way to achieve this is by using the Web3 Contract getPastEvents() function (docs).

const myContract = new web3.eth.Contract(abiJson, contractAddress);
myContract.getPastEvents('Transfer', {
    filter: {
        _from: '0x0000000000000000000000000000000000000000'
    },
    fromBlock: 0
}).then((events) => {
    for (let event of events) {
        console.log(event.returnValues._tokenId);
    }
});