[General] How do I get L1 finalize block count

[blueberry6401]

Discussion Topic

Hello,
What I want to do is quite like this: Binance will acknowledge the deposit when there is 64 block confirmations on L1.

So how do I check how many block is finalized on L1 from a L2 transaction?
Thank.

[imtipi]

i never can't get the mean of bundle1/2..

So how do I check how many block is finalized on L1 from a L2 transaction?

first get blocknumber from hash(etherscan/eth_getTransactionReceipt)
then compare the blocknumber between eth_getBlockByNumber with the parameter finalized as the block number.

resource:https://docs.optimism.io/builders/app-developers/transactions/statuses#finalized

Finalized
Typically within 15-20 minutes, up to 24 hours

A transaction is considered "finalized" when it has been included in a block by the Sequencer, that block has been published to Ethereum, and that block has been finalized. Once a block has been finalized it is guaranteed to be included in the OP Mainnet blockchain. Applications that require the highest level of certainty that a transaction will be included in the blockchain should wait until the transaction is "finalized" before considering the transaction to be successful.

The latest "finalized" block can be retrieved by calling the standard JSON-RPC method eth_getBlockByNumber with the parameter finalized as the block number.

[IvanKodak]

@imtipi your answer is correct, but it does not cover the case when you want to count L1 confirmations of L2 transaction.
For example, how can I get the L1 block number in which included my L2 transaction?

[joohhnnn]

@imtipi your answer is correct, but it does not cover the case when you want to count L1 confirmations of L2 transaction. For example, how can I get the L1 block number in which included my L2 transaction?

You can filter out the L1 blocks that contain batch transactions from the batcher, and then use optimism_safeHeadAtL1Block to determine which L1 block corresponds to the L2 block. cc @imtipi @blueberry6401