This is mainly a note to myself as every time I want to do this I end up searching through my history doing something like this.
history | grep hexyl
So here’s the code to extract the OP_RETURN message from the bitcoin blockchain. This needs to be run on the machine running your full node.
bitcoin-cli getblockhash 0|xargs -I '{}' bitcoin-cli getblock '{}' 0| xxd -r -p | hexyl -n 256
The output looks like this for the Genesis block.
