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The image below shows a decoded finalized transaction that deploys a flipper contract on my local substrate network. I am not sure what the data field represents here.

Contract deployment transaction

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It is the data passed to the constructor of the contract.

Pallet contracts docs

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    To expand, data is an encoded message or constructor selector (because you can have multiple constructors) with input for it (if needed).
    – Daan - R0GUE
    Commented Feb 15, 2023 at 9:32
  • Well in my case the function signature looks like this: pub fn new(init_value: bool) -> Self I believe I initialized it with false. Can you elaborate what encoding or other mechanism led it to be 0x9bae9d5e00?
    – Non-named
    Commented Feb 15, 2023 at 9:37
  • first 4 bytes is the selector (9bae9d5e) then you have the args (00 = false in your case)
    – kriko.eth
    Commented Feb 16, 2023 at 9:17
  • I need to pass the data field through my code using polkadot-js/api library. So can you tell me how I can get the first 4 bytes i.e. the selector, given the function signature and the params passed during the contract instantiation?
    – Non-named
    Commented Feb 20, 2023 at 8:13

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