Can we really put a transaction to buy in the same block of when the token gets added liquidity?

[rafaelfaria]

I have been reading a lot about bots lately, which motivated me to start playing with it and see how the blockchain works and maybe even build something that I can use to make a buck.

This one, for example, claims to put the transaction in the same block as when a token adds liquidity.

"The fact that our buy transaction is in the same block, but only slightly behind the developer transaction means that we can buy almost instantaneously."

How is this even possible?

2 questions:

1. Is there a way to subscribe to the token, and listen to see when the first transaction is made, then we push a transaction?
2. How do we specify what block we want the transaction to be pushed, and how do we make sure it is in that particular block?

Thanks.

[rafaelfaria]

So, I'm making a bit of progress.

I am subscribing to listen for pending transactions. From what I understand when the liquidity gets added, it goes to the pending pool. So subscribing to the "pending" event, should help me find if the liquidity is on its way or not.

I am not sure about a few things thou:

1. Not really a problem, but more curiosity. I saw a few examples where pending would return the hash (as string) and then you need to get the object through getTransaction. In my case, the txHash is actually the object (is this because of the latest versions?) which is a good thing, but wanted to make sure I am in the right track.
2. How do I actually know any of these pending hashes is the liquidity of the contract I am listening? What is the right way to decode the object to find out it is in the event of adding liquidity and from the contract I want?
3. Ok, let's say I found the pending transaction, it is not confirmed yet. How do i know when its confirmed? Should i listen for the .on('block') at the same time?
   Thanks

provider.on("pending", async (txHash: any) => {
    console.log({ txHash });
});

The console log above gives me this as an example (completely random from one of the outputs):

{
    "hash": "0x0cd4c902fc5cebd7b031e4e10dca7f991a5f66f0e172f9af0e486273d3459b3d",
    "type": 0,
    "accessList": null,
    "blockHash": null,
    "blockNumber": null,
    "transactionIndex": null,
    "confirmations": 0,
    "from": "0x958e483D63d04Cad80C1bC8Bd633a5bF0f888C02",
    "gasPrice": {
        "type": "BigNumber",
        "hex": "0x012a05f200"
    },
    "gasLimit": {
        "type": "BigNumber",
        "hex": "0x0263f4"
    },
    "to": "0x10ED43C718714eb63d5aA57B78B54704E256024E",
    "value": {
        "type": "BigNumber",
        "hex": "0x00"
    },
    "nonce": 38,
    "data": "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",
    "r": "0xc194e37da84d4f0ef1fe729607c579eb90f8817e626f255e9186d51002cf2c6d",
    "s": "0x5f8042e306c233c277251356ba02f30ab922e924e91c702754ae78ccda1ccf37",
    "v": 148,
    "creates": null,
    "chainId": 56
}

[rafaelfaria]

Have anyone solved this before?

[ritz0801]

Have you solved this so far? I'm also looking into this problem, let me know the solution if you got it. Thanks!