segregated witness – Error Validating Segwit Transactions utilizing Python Blockcypher API: Error Working Enter Script

Because the title states, I am making an attempt to ship a Litecoin transaction utilizing the Blockcypher API Python SDK, and utilizing Bitcoinlib for key administration. I’ve extensively reviewed the documentation and supply code for the instruments I am working with, and I’ve tried researching this particular error however nonetheless have but to get previous this roadblock.

I’ve gotten to some extent the place the transaction is constructed and and signatures are created, however once I attempt broadcasting it, the API returns this error to my console:

{'errors': [{'error': 'Error validating generated transaction: 
Error running script for input 0 referencing 79d841bf41ead0e4ecbb58197c289ec9cc087e85cf1a98196e2e415b8990357a at 0:
Script was NOT verified successfully.'}], 

'tx': {'block_height': -1, 'block_index': -1, 
'hash': 'f2ae95498b3b209ee077ad8a32292a0461ab2d37b807a647520aee31e9c62d29', 
'addresses': ['ltc1q7nyvlc6jkznpemw3g0n8f3z5z4eatfhevy07au', 'ltc1qxdvtqt9tm7rwplk8upezujtjsh6k3l85tw39ue'], 
'complete': 98100, 
'charges': 1900, 
'measurement': 221, 
'vsize': 140, 
'desire': 'low', 
'relayed_by': '35.226.89.167', 
'obtained': '2023-07-05T08:53:48.287727164Z', 
'ver': 1, 
'double_spend': False,
'vin_sz': 1, 
'vout_sz': 2, 
'confirmations': 0, 
'inputs': [
    {'prev_hash': '79d841bf41ead0e4ecbb58197c289ec9cc087e85cf1a98196e2e415b8990357a',
     'output_index': 0, 
     'output_value': 100000,
     'sequence': 4294967295,
     'addresses': ['ltc1q7nyvlc6jkznpemw3g0n8f3z5z4eatfhevy07au'], 
     'script_type': 'pay-to-witness-pubkey-hash', 
     'age': 2502561,
     'witness': 
['3044022077515b45f26a56b0dfff42eb94b69d98dbf8fb896fda079ea7e99a17a768fd6f022008b3c435ee0816801e1eea22871cb935a7eaaa8df6ad472eab19b096fb62cd82'
, '034b3110d0be2b52a14c4bbccef285396c67c29586463f278a8d1efacb3c33f439']}], 
'outputs': [{
     'value': 10000, 
     'script': '00143358b02cabdf86e0fec7e0722e497285f568fcf4',
     'addresses': ['ltc1qxdvtqt9tm7rwplk8upezujtjsh6k3l85tw39ue'], 
     'script_type': 'pay-to-witness-pubkey-hash'}, 
     {'worth': 88100, 
     'script': '0014f4c8cfe352b0a61cedd143e674c4541573d5a6f9', 
     'addresses': ['ltc1q7nyvlc6jkznpemw3g0n8f3z5z4eatfhevy07au'], 
     'script_type': 'pay-to-witness-pubkey-hash'}]},
'tosign': ['']}

First, I attempted utilizing the simple_spend technique as proven under…

from blockcypher import simple_spend
simple_tx = simple_spend(api_key = API_KEY, from_privkey=priv_key_hex,
to_address="ltc1qxdvtqt9tm7rwplk8upezujtjsh6k3l85tw39ue", to_satoshis=10000, coin_symbol="ltc")
print('tx:', simple_tx)

… and this error was produced:

TX Error(s): Tx NOT Signed or Broadcast
Unable to discover a transaction to spend for handle LhYFhgm6iai5da8ADeoUjs2BnAPoPm74cm.
Not sufficient funds in 0 inputs to pay for 1 outputs, lacking -10000.
Not sufficient funds after charges in 0 inputs to pay for 1 outputs, lacking -11400.
Error validating generated transaction: Transaction lacking enter or output.
Traceback (most up-to-date name final):
  File "foremost.py", line 33, in 
    simple_tx = simple_spend(api_key = API_KEY, from_privkey=priv_key_hex, to_address="ltc1qxdvtqt9tm7rwplk8upezujtjsh6k3l85tw39ue", to_satoshis=10000, coin_symbol="ltc")
  File "/residence/runner/sendltc/venv/lib/python3.10/site-packages/blockcypher/api.py", line 1684, in simple_spend
    elevate Exception('Construct Unsigned TX Error')
Exception: Construct Unsigned TX Error

This means that the personal key I offered is routinely being formatted as a legacy handle, the place no funds for the enter transaction exist as a result of I funded the segwit by-product of the personal key. I’ve since verified that this code will correctly execute transactions once I fund the legacy by-product of the personal key. But it surely doesn’t work once I try to contain a segwit addresses because the sender or receiver.

Since I’m not sure of how to make sure that the simple_spend technique makes an attempt a segwit transaction, I attempted setting up it piece-by-piece.

This is the code for that:

from bitcoinlib.keys import Key
from blockcypher import create_unsigned_tx, make_tx_signatures, broadcast_signed_transaction

API_KEY = ''

wif=""


priv_key_hex = Key(wif, community = 'litecoin').private_hex
pub_key_hex = Key(wif, community = 'litecoin').public_hex

sender = Key(priv_key_hex, community = 'litecoin').handle(prefix='ltc', script_type="p2wpkh", encoding='bech32')
inputs = [{'address': f"{sender}"}]
outputs = [{'address': 'ltc1qxdvtqt9tm7rwplk8upezujtjsh6k3l85tw39ue', 'value': 10000}]

unsigned_tx = create_unsigned_tx(inputs=inputs, outputs=outputs, include_tosigntx=True, coin_symbol="ltc", api_key = API_KEY)
print(unsigned_tx)

privkey_list = [str(priv_key_hex)]
pubkey_list = [str(pub_key_hex)]

tx_signatures = make_tx_signatures(txs_to_sign=unsigned_tx['tosign'], privkey_list=privkey_list, pubkey_list=pubkey_list)
print('')
print(tx_signatures)

tx = broadcast_signed_transaction(unsigned_tx=unsigned_tx, signatures=tx_signatures, pubkeys=pubkey_list, coin_symbol="ltc", api_key = API_KEY)
print('')
print(tx)

So when I attempt to run this, the aforementioned error is returned, stating that the script couldn’t be verified. My hunch is that it has one thing to do with trying to broadcast a legacy transaction whereas I offered a segwit handle. Upon viewing related threads on right here, it could appear that the signature is being malformed both as a result of there’s a drawback with how I am deriving my keys, or by some means I have to set a flag indicating a segwit transaction. This might result in the basis of the issue, however I is also overlooking different points.

Any recommendation, pointers, or solutions can be enormously appreciated. Thanks on your time.