README.rst

btctxstore

A library to read/write data to bitcoin transactions as nulldata outputs.

Installation

Install btctxstore lib

pip install btctxstore

Use fast native functions

There is experimental code that will call into OpenSSL for slow functions. To enable this, set (and export) environment variable PYCOIN_NATIVE=openssl.

$ export PYCOIN_NATIVE=openssl

storing data in nulldata outputs

Store data in blockchain in new transaction with nulldata output.

# from examples/store_nulldata.py
import binascii
from btctxstore import BtcTxStore

# Wallet used to pay for fee. Please do not spend the testnet coins is
# this wallet or the example will fail due to lack of funds.
wifs = ["cUZfG8KJ3BrXneg2LjUX4VoMg76Fcgx6QDiAZj2oGbuw6da8Lzv1"]

# use testnet and dont post tx to blockchain for example
api = BtcTxStore(testnet=True, dryrun=True)

# store data in blockchain as nulldata output (max 40bytes)
data = binascii.hexlify(b"github.com/F483/btctxstore")
txid = api.store_nulldata(data, wifs)
print(txid)

retrieving data from nulldata outputs

Retrieve transaction from blockchain and read data stored as nulldata output.

# from examples/retrieve_nulldata.py
from btctxstore import BtcTxStore

api = BtcTxStore(testnet=True, dryrun=True)  # use testing setup for example
txid = "987451c344c504d07c1fa12cfbf84b5346535da5154006f6dc8399a8fae127eb"
hexnulldata = api.retrieve_nulldata(txid)
print(hexnulldata)

sign/verify data (bitcoind compatible)

# from examples/signverify.py
import binascii
from btctxstore import BtcTxStore

api = BtcTxStore(testnet=True, dryrun=True)  # use testing setup for example
wif = api.create_key()  # create new private key
address = api.get_address(wif)  # get private key address
data = binascii.hexlify(b"messagetext")  # hexlify messagetext

# sign data with private key
signature = api.sign_data(wif, data)
print("signature:", signature)

# verify signature (no public or private key needed)
isvalid = api.verify_signature(address, signature, data)
print("valid signature" if isvalid else "invalid signature")

Split utxos

Split utxos of wallet unitil limit or max_outputs reached.

# from examples/split_utxos.py
from btctxstore import BtcTxStore

# Please do not spend the testnet coins is this wallet
# or the example will fail due to lack of funds.
wif = "cUZfG8KJ3BrXneg2LjUX4VoMg76Fcgx6QDiAZj2oGbuw6da8Lzv1"

# use testnet and dont post tx to blockchain for example
api = BtcTxStore(testnet=True, dryrun=True)

limit = 10000000  # 0.1BTC
txids = api.split_utxos(wif, limit)
print(txids)