How to find contract creation block time with web3?

Question

Is it possible to find out in which block a contract was created using web3?

score 4 · Answer 1 · answered Aug 14 '17 at 06:06

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If you have the transaction hash that created the contract, do a web3.eth.getTransactionReceipt(*hash*). The resulting object will contain a blockNumber.

You can make sure that this is the creation hash by checking whether contractAddress in the object is populated with your contract's address (to should be empty).

answered Aug 14 '17 at 06:06

Joël

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What if you don't have the txhash? – 0xcaff Aug 14 '17 at 06:07
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is this on the public chain? – Joël Aug 14 '17 at 06:07
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Yes. I know I can look on a site etherscan to find this information, but I want to do it programatically. – 0xcaff Aug 14 '17 at 06:09
So ofc normally you'd store the txnHash, but if you anticipate more missing txnHashes you could call etherscan's API - see "get list of transactions" at https://etherscan.io/apis#accounts – Joël Aug 14 '17 at 06:12
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What if I'm analyzing contracts I didn't deploy? How does etherscan do it? – 0xcaff Aug 14 '17 at 06:13
Not sure about the question - if you didn't deploy you won't have a blockNumber or any hash at all. – Joël Aug 14 '17 at 06:13
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I meant contracts which were deployed by other parties. – 0xcaff Aug 14 '17 at 06:14
Let us continue this discussion in chat. – Joël Aug 14 '17 at 06:14

score 1 · Answer 2 · answered Jan 12 '22 at 18:41

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This is not using web3, but I found it pretty easy to find the block id in a bigquery Public dataset by running this:

SELECT block_number FROM `bigquery-public-data.ethereum_blockchain.contracts` WHERE address = CONTRACT_ADDRESS

answered Jan 12 '22 at 18:41

skud

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score 0 · Answer 3 · answered Sep 21 '22 at 12:13

You can binary search on all blocks for existence of w3.eth.get_code. Given that at the time of this answer the ethereum chain is on block 15581647, it'll take about log2(15581647) = 24 calls to chain node to get to the creation transaction for that contract. The blockNumber field of that transaction will give you the block in which that contract was created.

How to find contract creation block time with web3?

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