Generate sha3-256 of file:

cat <FILENAME> | openssl dgst -sha3-256

Get transaction details:

bitcoin-cli -regtest getrawtransaction <TRANSACTION_ID> true

Convert Hex to Text / op_return data:

echo <HEX_VALUE> | xxd -r -p

btc-transaction: https://www.blockchain.com/explorer/assets/btc/decode-transaction

op_return data: https://www.hextotext.com/en/convert-hex-to-text

This docker image runs a Bitcoin node with --regtest flag (regression tests), and a rest server able to get coins from faucet or mine n blocks instantly.

docker run --name bitcoin-regtest -p 8080:8080 junderw/bitcoinjs-regtest-server

https://github.com/bitcoinjs/bitcoinjs-lib

pnpm init
pnpm start