`combinepsbt` RPC does not work with P2TR inputs

ghost commented at 11:14 am on March 7, 2023: none

combinepsbt allows to distribute identical PSBTs to peers for signature and consolidate the resulting PSBT. However, this does not work with taproot UTXOs for me.

Expected behavior

Combined PSBT should return 'complete': True if all inputs are signed in different PSBTs and finalized with finalizepsbt

Actual behavior

Unable to finalize the transaction that was combined from multiple signed PSBTs.

To reproduce

PSBT 1

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

PSBT 2

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

PSBT 3

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

PSBT 4

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

PSBT 5

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

Combined PSBT:

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

System information

Bitcoin Core v24.0.1 and all the above PSBTs are for Signet

unknown added the label Bug on Mar 7, 2023

achow101 commented at 3:59 pm on March 7, 2023: member

The combined PSBT is correctly combined, there are just no signatures in any of the PSBTs. There’s nothing to finalize, so it cannot be finalized.

ghost commented at 4:20 pm on March 7, 2023: none

The combined PSBT is correctly combined, there are just no signatures in any of the PSBTs. There’s nothing to finalize, so it cannot be finalized.

This wasn’t don’t manually, all PSBTs passed through walletprocesspsbt, I used the same code for segwit inputs and it worked. I will re-test everything although fractalenrypt told me this can be fixed with an open PR: https://twitter.com/FractalEncrypt/status/1633073353580859396

achow101 commented at 4:22 pm on March 7, 2023: member

Yes, it is a bug in signing, not in combining.

fanquake commented at 8:50 am on March 8, 2023: member

Ok. So this is fixed/closed by #23502 (assume the same for one of the alternate PRs).

maflcko added the label PSBT on Mar 8, 2023

b-l-u-e commented at 6:44 pm on July 24, 2025: none

I’ve tested this issue with the current Bitcoin Core version 29 and can confirm that the combinepsbt RPC now works correctly with P2TR inputs.

Test Results:

I created a test scenario with:

A Taproot address (bcrt1ph7wt8kmwvp87hp0re43vvme8c3y8tyg49ghstkaufxs8qjf6j4hskqejs7)
A PSBT spending a Taproot UTXO
Signed the PSBT using walletprocesspsbt
Combined the signed PSBT using combinepsbt
Finalized the combined PSBT using finalizepsbt

Key Findings:

✅ PSBT signing works: walletprocesspsbt returns "complete": true and properly converts Taproot signatures to final_scriptwitness

✅ PSBT combining works: combinepsbt successfully combines PSBTs with Taproot inputs

✅ PSBT finalization works: finalizepsbt returns "complete": true and generates valid hex transactions

Analysis:

The issue appears to be resolved because the signing process now properly converts Taproot signatures to the final_scriptwitness format, which the PSBTInputSigned function can detect. The decoded PSBT shows:

0"final_scriptwitness": [
1  "261ec36113f5c3217aaa174d30b84ba6d56bbb9df025831ad8394bfe28a38c06552ec883cb9f0a85d923c512659aaf5252472ab30882c5708a59b715551eaee0"
2]

Conclusion:

Ithink this issue can be closed - the combinepsbt RPC functionality with P2TR inputs is working correctly in the current version. The fix appears to have been implemented as part of the Taproot signing improvements.

combinepsbt RPC does not work with P2TR inputs #27219

Test Results:

Key Findings:

Analysis:

Conclusion:

`combinepsbt` RPC does not work with P2TR inputs #27219