Have you seen #7753?

For now, a workaround I found is to patch CZMQNotificationInterface::BlockDisconnected before building Bitcoin Core and comment out the loop that fires NotifyTransaction() like so:

void CZMQNotificationInterface::BlockDisconnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexDisconnected)
{
/* ----- this part is deleted - causes Core to *not* publish confirmed transactions
    for (const CTransactionRef& ptx : pblock->vtx) {
        const CTransaction& tx = *ptx;
        TryForEachAndRemoveFailed(notifiers, [&tx](CZMQAbstractNotifier* notifier) {
            return notifier->NotifyTransaction(tx);
        });
    }
--------- */
    // Next we notify BlockDisconnect listeners for *all* blocks
    TryForEachAndRemoveFailed(notifiers, [pindexDisconnected](CZMQAbstractNotifier* notifier) {
        return notifier->NotifyBlockDisconnect(pindexDisconnected);
    });
}

For reading only confirmed transactions (and throwing away the unconfirmed ones from the mempool), I believe a similar patch can be made to CZMQNotificationInterface::BlockDisconnected or CZMQNotificationInterface::TransactionAddedToMempool, but I have not tested this. But the procedure is similar.

Of course, I know that such a modification cannot be merged, I'm just leaving this here for anyone else who finds themselves in a similar situation in the future.

Concept ACK, I think having notifications to monitor the mempool makes sense, there has been interest in this in the past, I tried to do this at some point but lost interest.

The mempool only contains unconfirmed transactions and I don't see that changing, therefore is the addition of the word "raw" to the flag/topic necessary?

Have you seen #7753?

According to the description of this PR:

Add notifications when transactions enter or leave the mempool.
It also makes it possible to keep statistics on why transactions disappear from the mempool.

Isn't this already possible with #19572 ?

The mempool only contains unconfirmed transactions and I don't see that changing, therefore is the addition of the word "raw" to the flag/topic necessary?

I think so, it tells you that it will send the raw bytes of the tx rather than the txid

Concept ACK

The mempool only contains unconfirmed transactions and I don't see that changing, therefore is the addition of the word "raw" to the flag/topic necessary?

I think so, it tells you that it will send the raw bytes of the tx rather than the txid

Good point. Though I think the use of "tx" and "txid" already provide context.

This topic needs documentation and a rebase with #23471 merged.

Concept ACK

The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

Conflicts

Reviewers, this pull request conflicts with the following ones:

• #17783 (util: Fix -norpcwhitelist, -norpcallowip, and similar corner case behavior by ryanofsky)
• #17581 (refactor: Remove settings merge reverse precedence code by ryanofsky)
• #17580 (refactor: Add ALLOW_LIST flags and enforce usage in CheckArgFlags by ryanofsky)
• #17493 (util: Forbid ambiguous multiple assignments in config file by ryanofsky)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

I haven't gotten around to pick this up again and will close it for now. It has a few Concept ACKs so might be worth adding an up-for-grabs label.