It is possible to create and store a signed transaction and broadcast it later (maximum allowed delay is one hour or 3600 seconds).
At the beginning, the current block number and prefix has to be fetched from the api node.
Then the transaction can be created, signed and stored in a text file.
This allows using beem with other libraries for broadcasting.
import time
from beembase import operations
from beem.transactionbuilder import TransactionBuilder
from beem.steem import Steem
from beem.nodelist import NodeList
from beembase.transactions import getBlockParams
import json
wif = "5xxx"
if __name__ == "__main__":
stm_online = Steem()
ref_block_num, ref_block_prefix = getBlockParams(stm_online)
print("ref_block_num %d - ref_block_prefix %d" % (ref_block_num, ref_block_prefix))
stm = Steem(offline=True)
op = operations.Transfer({'from': 'beembot',
'to': 'holger80',
'amount': "0.001 SBD",
'memo': ""})
tb = TransactionBuilder(steem_instance=stm, expiration=3600)
tb.appendOps([op])
tb.appendWif(wif)
tb.constructTx(ref_block_num=ref_block_num, ref_block_prefix=ref_block_prefix)
tx = tb.sign(reconstruct_tx=False)
params = (tx.json())
broadcast_json = {"jsonrpc":"2.0", "method":"condenser_api.broadcast_transaction", "params":[params], "id":1}
with open("broadcast_transfer.json", "w") as f:
f.write(json.dumps(broadcast_json))
This script fetches the ref_block_num and ref_block_prefix and builds a json dictionary which contains the signed transaction. The json is written into a text file broadcast_transfer.json.
It is only possible to send a transaction once. Resending will lead to Duplicate transaction check failed. The @ sign means that the following is not a text for sending but a file name.
curl -s --data "@broadcast_transfer.json" https://api.steemit.com
The content of this file is read and then broadcasted to the node.
It worked.
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Can you do incremental signing with this too?
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Great work. May I suggest using this in a proof of concept for this task request. The 34 STEEM bounty is supposed to end in 26 hours and a bit, but if before the deadline anyone tells me they are working on it and need a few more days, I'll be happy to extend the deadline a bit.