I want to send a Transaction to follow a specific Transaction in the same block.

Now I can guaranty my Transaction exactly been placed in the same Block. But there are a lots of other TXs between my Tx and my target Tx.

All of those Txs include mine, my target are using the same gasPrice.

I learned a lot finally found the basic strategy for ordering is GasPrice+FirstSeenTime. (Let's ignore the Nonce that only considered for duplicate Txs from same account).

I wonder how the miner's full node/validator decide FirstSeenTime. Is FirstSeenTime propaganda from peer by peer? Or it is generated when Tx is reached miner's node?

If the answer is the first one. I think I can build a full node that can modify my Tx's firstSeenTime, then propaganda it to other peers.

Is this possible?


1 Answer 1


There is a better way to ensure specific transaction order inside the block - use flashbots. It allows you to send a bundle of transactions guaranteeing that they will be mined in a block in this exact order next to each other. Futhermore, if one of the bundled transactions reverts the entire bundle will not be included in a block so you don't have to pay gas fees for reverts.

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