From a6a66bc3677bb2405005cabff52a6d637104017c Mon Sep 17 00:00:00 2001
From: russeree <git@qrsnap.io>
Date: Mon, 29 Dec 2025 14:34:04 -0800
Subject: [PATCH] [Policy] Support raw transaction versions == 3

Co-authored-by: scgbckbone <scgbckbone@proton.me>
---
 releases/Next-ChangeLog.md |  1 +
 shared/psbt.py             |  2 +-
 testing/conftest.py        |  2 +-
 testing/psbt.py            |  2 +-
 testing/test_sign.py       | 83 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 87 insertions(+), 3 deletions(-)

diff --git a/releases/Next-ChangeLog.md b/releases/Next-ChangeLog.md
index 5bcf6d92..d8b3dc82 100644
--- a/releases/Next-ChangeLog.md
+++ b/releases/Next-ChangeLog.md
@@ -6,6 +6,7 @@ This lists the new changes that have not yet been published in a normal release.
 
 - New Feature: Export [BIP-380](https://github.com/bitcoin/bips/blob/master/bip-0380.mediawiki) extended key expression.
   Navigate to `Advanced/Tools -> Export Wallet -> Key Expression`
+- New Feature: Support for v3 transactions
 
 # Mk4 Specific Changes
 
diff --git a/shared/psbt.py b/shared/psbt.py
index 76c5acc3..1ffe9a69 100644
--- a/shared/psbt.py
+++ b/shared/psbt.py
@@ -1138,7 +1138,7 @@ class psbtObject(psbtProxy):
         self.txn_version, marker, flags = unpack("<iBB", fd.read(6))
         self.had_witness = (marker == 0 and flags != 0x0)
 
-        assert self.txn_version in {1,2}, "bad txn version"
+        assert self.txn_version in {1,2,3}, "bad txn version"
 
         if not self.had_witness:
             # rewind back over marker+flags
diff --git a/testing/conftest.py b/testing/conftest.py
index 1bd5d76c..651b0626 100644
--- a/testing/conftest.py
+++ b/testing/conftest.py
@@ -1477,7 +1477,7 @@ def end_sign(dev, need_keypress, press_cancel):
             assert res[0:4] != b'psbt', 'still a PSBT, but asked for finalize'
             t = CTransaction()
             t.deserialize(io.BytesIO(res))
-            assert t.nVersion in [1, 2]
+            assert t.nVersion in [1, 2, 3]
 
             # TODO: pull out signatures from signed txn
                     
diff --git a/testing/psbt.py b/testing/psbt.py
index ca556d7d..dbcf509d 100644
--- a/testing/psbt.py
+++ b/testing/psbt.py
@@ -432,7 +432,7 @@ class BasicPSBT:
                 assert self.txn, 'v0: missing reqd section - PSBT_GLOBAL_UNSIGNED_TX'
             elif self.version == 2:
                 # tx version needs to be at least 2 because locktimes
-                assert self.txn_version == 2, 'v2: missing reqd section - PSBT_GLOBAL_TX_VERSION'
+                assert self.txn_version in {2, 3}, 'v2: missing reqd section - PSBT_GLOBAL_TX_VERSION'
                 assert self.input_count is not None, 'v2: missing reqd section - PSBT_GLOBAL_INPUT_COUNT'
                 assert self.output_count is not None, 'v2: missing reqd section - PSBT_GLOBAL_OUTPUT_COUNT'
 
diff --git a/testing/test_sign.py b/testing/test_sign.py
index 0e581a2a..e337cec7 100644
--- a/testing/test_sign.py
+++ b/testing/test_sign.py
@@ -3411,4 +3411,87 @@ def test_finalize_with_foreign_inputs(bitcoind, bitcoind_d_sim_watch, start_sign
     assert title == "PSBT Signed"
     assert "Finalized transaction (ready for broadcast)" in story
 
+
+@pytest.mark.parametrize("psbt_v2", [False, True])
+def test_txn_v3(psbt_v2, fake_txn, start_sign, end_sign, cap_story):
+
+    psbt = fake_txn(2, 2, segwit_in=True, change_outputs=[0],
+                    outstyles=ADDR_STYLES_SINGLE, psbt_v2=psbt_v2)
+
+    po = BasicPSBT().parse(psbt)
+    if psbt_v2:
+        po.txn_version = 3
+    else:
+        txo = CTransaction()
+        txo.deserialize(BytesIO(po.txn))
+        txo.nVersion = 3
+        po.txn = txo.serialize()
+
+    start_sign(po.as_bytes())
+    title, story = cap_story()
+    assert title == "OK TO SEND?"
+    assert "Consolidating" not in story
+    assert "Change back" in story
+    assert "to script" not in story
+
+    signed = end_sign(accept=True, finalize=False)
+    assert signed
+
+    po_signed = BasicPSBT().parse(signed)
+    if psbt_v2:
+        assert po_signed.version == 2
+        assert po_signed.txn is None
+        assert po_signed.txn_version == 3
+    else:
+        assert po_signed.txn
+        assert po_signed.version == 0
+        assert po_signed.txn_version is None
+        txo0 = CTransaction()
+        txo0.deserialize(BytesIO(po_signed.txn))
+        assert txo0.nVersion == 3
+
+
+@pytest.mark.parametrize("finalize", [False, True])
+def test_txn_v3_eph_anchor(finalize, set_seed_words, start_sign, end_sign, cap_story):
+    # https://github.com/portlandhodl/jade-docker-web-server/blob/main/example_tools/test_vectors.py
+    TEST_PSBT_V3 = "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"
+    TEST_PSBT_V3_EPHEMERAL_ANCHOR = "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"
+    TEST_MNEMONIC = "tobacco tobacco tobacco tobacco tobacco tobacco tobacco tobacco tobacco tobacco tobacco tobacco"
+    set_seed_words(TEST_MNEMONIC)
+
+    v3 = base64.b64decode(TEST_PSBT_V3)
+    po = BasicPSBT().parse(v3)
+    assert po.version == 0
+    start_sign(v3, finalize=finalize)
+    title, story = cap_story()
+    assert title == "OK TO SEND?"
+    assert "warning" not in story
+    res = end_sign(finalize=finalize)
+    if not finalize:
+        po_signed = BasicPSBT().parse(res)
+        assert po_signed.txn_version is None
+        res = po_signed.txn
+
+    txo = CTransaction()
+    txo.deserialize(BytesIO(res))
+    assert txo.nVersion == 3
+
+    v3_eph_anchor = base64.b64decode(TEST_PSBT_V3_EPHEMERAL_ANCHOR)
+    po = BasicPSBT().parse(v3)
+    assert po.version == 0
+    start_sign(v3_eph_anchor, finalize=finalize)
+    title, story = cap_story()
+    assert title == "OK TO SEND?"
+    assert "1 warning below" in story
+    assert "Non-standard zero value output(s)" in story
+    res = end_sign(finalize=finalize)
+    if not finalize:
+        po_signed = BasicPSBT().parse(res)
+        assert po_signed.txn_version is None
+        res = po_signed.txn
+
+    txo = CTransaction()
+    txo.deserialize(BytesIO(res))
+    assert txo.nVersion == 3
+
 # EOF