So 3 days ago i was sending XTZ from one cex to another and it looks like the transaction is still stuck in the mempool

hash id
onk4Rda4WacNreRM4yqHg6G89JkfChauLSynWUtoWtAt2USRTwh fee paid 0.2xtz

whats the reason for that? thanks

  • How does the CEX report the transaction as being stuckl in the mempool? Did it provide some explorer link? Jul 24, 2023 at 21:20
  • Is it possible to manually revoke that pending transaction in your CEX interface? Did you retry the transaction? Jul 24, 2023 at 21:40

1 Answer 1


TL;DR This doesn't make much sense for the most common failures of regular tez transfers, and without further detail (e.g. like the gas limit used in the operation, the version of the Octez node used by the originating CEX, or the actual reported error), it is hard to provide more concrete answers. Best course of action is to try to re-issue the transaction or contact the CEX in question.

Long Version:

The maximal "time to live" of an operation in the mempool is adjusted to 1 human hour, currently set to 240 blocks in the Nairobi protocol.

Normally, operations whose branch (i.e the block they point to) is older than 1 hour are discarded when the mempool recycles itself, for example when the node changes heads (a new block is added to the blockchain). Except if the operation is permanently REFUSED by the Tezos protocol, in which case it's kept around longer because it is considered as spam. How longer depends on traffic and uptime as the Octez node keeps a fixed number of recently Refused operations -- 1000 by default.

Now, it is uncommon that a simple transfer operations yields such an error. Plausible causes to that would point to some internal issue with your CEX (e.g. they are not correctly crafting the transactions / signing issues). Or, maybe, it was just that the operation was briefly stuck in the mempool (e.g. for low fees) and it just continues to appear as "stuck in the mempool" in their front-end when in fact it is gone. All of these are mere speculations, which only your CEX can provide answers to.

  • Thanks for the response, CEX says its in the mempool also i cant revoke it manually on its interface unfortunately, it looks like that can be some cex internal issue indeed then
    – user10629
    Jul 24, 2023 at 21:59
  • Well. I don't want to be snarky, but I suspect that the CEX in question's support did not understand the question. To be fair, user-facing first-level support cannot know all the details of all blockchains. Jul 25, 2023 at 13:45
  • Which CEX is this? If you doint want to share this information here, reach out to me on Tezos Slacks or Discord. Jul 25, 2023 at 13:45

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