I need to see bitcoin transactions before they were included in the block. Interested in transactions to specific addresses.
After some research, it became clear that the mempool is synchronized heterogeneous. And it is not necessary that the transaction I am interested in, in principle, will be on my node..
While it is not 100% sure that your node will get every transaction, the probability is very high.
Nodes do relay received transactions to every other node (exceptions do exist: non-standard tx, maliciously edited software, ...) .
Each node receives the transactions in a different order (and at a different time +/- a few seconds usually).
Moreover, from second to second, the pool of transactions contains a completely different number of transactions, so even to have time to read them all and filter it is not possible. Or could someone have done it?
Are there people who have faced such a challenge? Fetch transactions in mempool
Well, if you try it to do
by hand you just have to open any block explorer (e.g.
blockchain.info), enter the address and refresh every second to see any incoming transactions to this particular address (in blockchain.info's mempool).
The
smoother alternative would be to write a small script (e.g. bash / python / .. ) and query your own node (or an online service API) each x seconds and perfom an action to inform you (e.g. console log, window popup, email, etc..).