If a reorg occurs, what happens to the operations that get reorged out and are not already included in the new chain? Would they need to be broadcasted again or would they automatically be re-entered into the mempool?

1 Answer 1


If it is reorged out it will need to be broadcast again, but you cannot just re-broadcast the same operation. You'll have to give it an updated valid branch field in the operation, since the original branch no longer exists.

Also, by default it seems items time out of the mempool after 60 blocks. I believe that 60 blocks start from the branch you specify, but not 100% sure, would like a dev to comment.

Also, I think that the figure 60 was supposed to be a constant, but don't see it in the context/contents RPC.

  • Thanks. I have the same impression as you, apart from I think if the operation is referencing a block header from the past that is also present on the new branch, then the identical operation could just be re-broadcast. And if this is the case, it may make sense for bakers to re-insert it into their mempool automatically, since they are still incentivized to receive fees from it.
    – Darius
    Jul 13, 2021 at 19:32
  • In that case though its not reorged out at all and would still be in the mempool.
    – Bo Byrd
    Jul 14, 2021 at 3:39
  • when I say 'reorged out', I mean it was in the blockchain and had say 2 confirmations, but then it's not included in the new branch. So in that sense, it was moved 'out of the blockchain and either into the mempool or just evicted altogether.
    – Darius
    Jul 14, 2021 at 5:28
  • 1
    If one specifies the branch field to be for instance head~10 (one can do that using the tezos-client's -b argument) and the reorg is only 2 blocks long, then exactly the same operation would be valid on the new branch. However, I think it still needs to be broadcasted again, as nodes would have removed it from their mempool after it was first included in a block.
    – Eugen
    Jul 15, 2021 at 10:53
  • Thanks, that makes sense. I know in bitcoin such a transaction would get automatically re-inserted to the mempool, but I wasn't sure if it's the same with Tezos.
    – Darius
    Jul 16, 2021 at 8:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.