Use Txid in COutpoint

48 files changed, 124 insertions, 114 deletions

diff --git a/src/bench/disconnected_transactions.cpp b/src/bench/disconnected_transactions.cpp
index 91ce904dd9..f48175d472 100644
--- a/src/bench/disconnected_transactions.cpp
+++ b/src/bench/disconnected_transactions.cpp
@@ -28,7 +28,7 @@ struct ReorgTxns {
 static BlockTxns CreateRandomTransactions(size_t num_txns)
 {
     // Ensure every transaction has a different txid by having each one spend the previous one.
-    static uint256 prevout_hash{uint256::ZERO};
+    static Txid prevout_hash{};
 
     BlockTxns txns;
     txns.reserve(num_txns);
diff --git a/src/bench/duplicate_inputs.cpp b/src/bench/duplicate_inputs.cpp
index a1c8d4d942..b56054ae89 100644
--- a/src/bench/duplicate_inputs.cpp
+++ b/src/bench/duplicate_inputs.cpp
@@ -47,7 +47,7 @@ static void DuplicateInputs(benchmark::Bench& bench)
 
     uint64_t n_inputs = (((MAX_BLOCK_SERIALIZED_SIZE / WITNESS_SCALE_FACTOR) - (CTransaction(coinbaseTx).GetTotalSize() + CTransaction(naughtyTx).GetTotalSize())) / 41) - 100;
     for (uint64_t x = 0; x < (n_inputs - 1); ++x) {
-        naughtyTx.vin.emplace_back(GetRandHash(), 0, CScript(), 0);
+        naughtyTx.vin.emplace_back(Txid::FromUint256(GetRandHash()), 0, CScript(), 0);
     }
     naughtyTx.vin.emplace_back(naughtyTx.vin.back());
 
diff --git a/src/bench/mempool_stress.cpp b/src/bench/mempool_stress.cpp
index 993db66653..fe3e204fb3 100644
--- a/src/bench/mempool_stress.cpp
+++ b/src/bench/mempool_stress.cpp
@@ -56,7 +56,7 @@ static std::vector<CTransactionRef> CreateOrderedCoins(FastRandomContext& det_ra
         for (size_t ancestor = 0; ancestor < n_ancestors && !available_coins.empty(); ++ancestor){
             size_t idx = det_rand.randrange(available_coins.size());
             Available coin = available_coins[idx];
-            uint256 hash = coin.ref->GetHash();
+            Txid hash = coin.ref->GetHash();
             // biased towards taking min_ancestors parents, but maybe more
             size_t n_to_take = det_rand.randrange(2) == 0 ?
                                min_ancestors :
diff --git a/src/bitcoin-tx.cpp b/src/bitcoin-tx.cpp
index 103d8885db..8fe2881f6f 100644
--- a/src/bitcoin-tx.cpp
+++ b/src/bitcoin-tx.cpp
@@ -280,7 +280,7 @@ static void MutateTxAddInput(CMutableTransaction& tx, const std::string& strInpu
     }
 
     // append to transaction input list
-    CTxIn txin(txid, vout, CScript(), nSequenceIn);
+    CTxIn txin(Txid::FromUint256(txid), vout, CScript(), nSequenceIn);
     tx.vin.push_back(txin);
 }
 
@@ -629,7 +629,7 @@ static void MutateTxSign(CMutableTransaction& tx, const std::string& flagStr)
             if (nOut < 0)
                 throw std::runtime_error("vout cannot be negative");
 
-            COutPoint out(txid, nOut);
+            COutPoint out(Txid::FromUint256(txid), nOut);
             std::vector<unsigned char> pkData(ParseHexUV(prevOut["scriptPubKey"], "scriptPubKey"));
             CScript scriptPubKey(pkData.begin(), pkData.end());
 
diff --git a/src/coins.cpp b/src/coins.cpp
index f576fae748..b62653e0de 100644
--- a/src/coins.cpp
+++ b/src/coins.cpp
@@ -116,7 +116,7 @@ void CCoinsViewCache::EmplaceCoinInternalDANGER(COutPoint&& outpoint, Coin&& coi
 
 void AddCoins(CCoinsViewCache& cache, const CTransaction &tx, int nHeight, bool check_for_overwrite) {
     bool fCoinbase = tx.IsCoinBase();
-    const uint256& txid = tx.GetHash();
+    const Txid& txid = tx.GetHash();
     for (size_t i = 0; i < tx.vout.size(); ++i) {
         bool overwrite = check_for_overwrite ? cache.HaveCoin(COutPoint(txid, i)) : fCoinbase;
         // Coinbase transactions can always be overwritten, in order to correctly
@@ -341,7 +341,7 @@ void CCoinsViewCache::SanityCheck() const
 static const size_t MIN_TRANSACTION_OUTPUT_WEIGHT = WITNESS_SCALE_FACTOR * ::GetSerializeSize(CTxOut());
 static const size_t MAX_OUTPUTS_PER_BLOCK = MAX_BLOCK_WEIGHT / MIN_TRANSACTION_OUTPUT_WEIGHT;
 
-const Coin& AccessByTxid(const CCoinsViewCache& view, const uint256& txid)
+const Coin& AccessByTxid(const CCoinsViewCache& view, const Txid& txid)
 {
     COutPoint iter(txid, 0);
     while (iter.n < MAX_OUTPUTS_PER_BLOCK) {
diff --git a/src/coins.h b/src/coins.h
index a6cbb03133..63a27fe012 100644
--- a/src/coins.h
+++ b/src/coins.h
@@ -364,7 +364,7 @@ void AddCoins(CCoinsViewCache& cache, const CTransaction& tx, int nHeight, bool
 //! This function can be quite expensive because in the event of a transaction
 //! which is not found in the cache, it can cause up to MAX_OUTPUTS_PER_BLOCK
 //! lookups to database, so it should be used with care.
-const Coin& AccessByTxid(const CCoinsViewCache& cache, const uint256& txid);
+const Coin& AccessByTxid(const CCoinsViewCache& cache, const Txid& txid);
 
 /**
  * This is a minimally invasive approach to shutdown on LevelDB read errors from the
diff --git a/src/common/bloom.cpp b/src/common/bloom.cpp
index 5c3ad882a1..ca6af90b76 100644
--- a/src/common/bloom.cpp
+++ b/src/common/bloom.cpp
@@ -98,8 +98,8 @@ bool CBloomFilter::IsRelevantAndUpdate(const CTransaction& tx)
     //  for finding tx when they appear in a block
     if (vData.empty()) // zero-size = "match-all" filter
         return true;
-    const uint256& hash = tx.GetHash();
-    if (contains(hash))
+    const Txid& hash = tx.GetHash();
+    if (contains(hash.ToUint256()))
         fFound = true;
 
     for (unsigned int i = 0; i < tx.vout.size(); i++)
diff --git a/src/kernel/coinstats.cpp b/src/kernel/coinstats.cpp
index 302638cdbe..ff8a33e804 100644
--- a/src/kernel/coinstats.cpp
+++ b/src/kernel/coinstats.cpp
@@ -89,7 +89,7 @@ static void ApplyCoinHash(std::nullptr_t, const COutPoint& outpoint, const Coin&
 //! construction could cause a previously invalid (and potentially malicious)
 //! UTXO snapshot to be considered valid.
 template <typename T>
-static void ApplyHash(T& hash_obj, const uint256& hash, const std::map<uint32_t, Coin>& outputs)
+static void ApplyHash(T& hash_obj, const Txid& hash, const std::map<uint32_t, Coin>& outputs)
 {
     for (auto it = outputs.begin(); it != outputs.end(); ++it) {
         COutPoint outpoint = COutPoint(hash, it->first);
@@ -118,7 +118,7 @@ static bool ComputeUTXOStats(CCoinsView* view, CCoinsStats& stats, T hash_obj, c
     std::unique_ptr<CCoinsViewCursor> pcursor(view->Cursor());
     assert(pcursor);
 
-    uint256 prevkey;
+    Txid prevkey;
     std::map<uint32_t, Coin> outputs;
     while (pcursor->Valid()) {
         if (interruption_point) interruption_point();
diff --git a/src/node/transaction.cpp b/src/node/transaction.cpp
index 026c8084dd..e8ab2326c1 100644
--- a/src/node/transaction.cpp
+++ b/src/node/transaction.cpp
@@ -40,7 +40,7 @@ TransactionError BroadcastTransaction(NodeContext& node, const CTransactionRef t
     assert(node.peerman);
 
     std::promise<void> promise;
-    uint256 txid = tx->GetHash();
+    Txid txid = tx->GetHash();
     uint256 wtxid = tx->GetWitnessHash();
     bool callback_set = false;
 
diff --git a/src/primitives/transaction.cpp b/src/primitives/transaction.cpp
index 82fb59d349..002c922c0d 100644
--- a/src/primitives/transaction.cpp
+++ b/src/primitives/transaction.cpp
@@ -29,7 +29,7 @@ CTxIn::CTxIn(COutPoint prevoutIn, CScript scriptSigIn, uint32_t nSequenceIn)
     nSequence = nSequenceIn;
 }
 
-CTxIn::CTxIn(uint256 hashPrevTx, uint32_t nOut, CScript scriptSigIn, uint32_t nSequenceIn)
+CTxIn::CTxIn(Txid hashPrevTx, uint32_t nOut, CScript scriptSigIn, uint32_t nSequenceIn)
 {
     prevout = COutPoint(hashPrevTx, nOut);
     scriptSig = scriptSigIn;
diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
index ad190f7d7f..e0c0c860c6 100644
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -28,13 +28,13 @@
 class COutPoint
 {
 public:
-    uint256 hash;
+    Txid hash;
     uint32_t n;
 
     static constexpr uint32_t NULL_INDEX = std::numeric_limits<uint32_t>::max();
 
     COutPoint(): n(NULL_INDEX) { }
-    COutPoint(const uint256& hashIn, uint32_t nIn): hash(hashIn), n(nIn) { }
+    COutPoint(const Txid& hashIn, uint32_t nIn): hash(hashIn), n(nIn) { }
 
     SERIALIZE_METHODS(COutPoint, obj) { READWRITE(obj.hash, obj.n); }
 
@@ -43,8 +43,7 @@ public:
 
     friend bool operator<(const COutPoint& a, const COutPoint& b)
     {
-        int cmp = a.hash.Compare(b.hash);
-        return cmp < 0 || (cmp == 0 && a.n < b.n);
+        return std::tie(a.hash, a.n) < std::tie(b.hash, b.n);
     }
 
     friend bool operator==(const COutPoint& a, const COutPoint& b)
@@ -125,7 +124,7 @@ public:
     }
 
     explicit CTxIn(COutPoint prevoutIn, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
-    CTxIn(uint256 hashPrevTx, uint32_t nOut, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
+    CTxIn(Txid hashPrevTx, uint32_t nOut, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
 
     SERIALIZE_METHODS(CTxIn, obj) { READWRITE(obj.prevout, obj.scriptSig, obj.nSequence); }
 
diff --git a/src/qt/coincontroldialog.cpp b/src/qt/coincontroldialog.cpp
index 70aa9bc8da..9e49fd87fb 100644
--- a/src/qt/coincontroldialog.cpp
+++ b/src/qt/coincontroldialog.cpp
@@ -181,7 +181,7 @@ void CoinControlDialog::showMenu(const QPoint &point)
         if (item->data(COLUMN_ADDRESS, TxHashRole).toString().length() == 64) // transaction hash is 64 characters (this means it is a child node, so it is not a parent node in tree mode)
         {
             m_copy_transaction_outpoint_action->setEnabled(true);
-            if (model->wallet().isLockedCoin(COutPoint(uint256S(item->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), item->data(COLUMN_ADDRESS, VOutRole).toUInt())))
+            if (model->wallet().isLockedCoin(COutPoint(TxidFromString(item->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), item->data(COLUMN_ADDRESS, VOutRole).toUInt())))
             {
                 lockAction->setEnabled(false);
                 unlockAction->setEnabled(true);
@@ -244,7 +244,7 @@ void CoinControlDialog::lockCoin()
     if (contextMenuItem->checkState(COLUMN_CHECKBOX) == Qt::Checked)
         contextMenuItem->setCheckState(COLUMN_CHECKBOX, Qt::Unchecked);
 
-    COutPoint outpt(uint256S(contextMenuItem->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), contextMenuItem->data(COLUMN_ADDRESS, VOutRole).toUInt());
+    COutPoint outpt(TxidFromString(contextMenuItem->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), contextMenuItem->data(COLUMN_ADDRESS, VOutRole).toUInt());
     model->wallet().lockCoin(outpt, /* write_to_db = */ true);
     contextMenuItem->setDisabled(true);
     contextMenuItem->setIcon(COLUMN_CHECKBOX, platformStyle->SingleColorIcon(":/icons/lock_closed"));
@@ -254,7 +254,7 @@ void CoinControlDialog::lockCoin()
 // context menu action: unlock coin
 void CoinControlDialog::unlockCoin()
 {
-    COutPoint outpt(uint256S(contextMenuItem->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), contextMenuItem->data(COLUMN_ADDRESS, VOutRole).toUInt());
+    COutPoint outpt(TxidFromString(contextMenuItem->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), contextMenuItem->data(COLUMN_ADDRESS, VOutRole).toUInt());
     model->wallet().unlockCoin(outpt);
     contextMenuItem->setDisabled(false);
     contextMenuItem->setIcon(COLUMN_CHECKBOX, QIcon());
@@ -346,7 +346,7 @@ void CoinControlDialog::viewItemChanged(QTreeWidgetItem* item, int column)
 {
     if (column == COLUMN_CHECKBOX && item->data(COLUMN_ADDRESS, TxHashRole).toString().length() == 64) // transaction hash is 64 characters (this means it is a child node, so it is not a parent node in tree mode)
     {
-        COutPoint outpt(uint256S(item->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), item->data(COLUMN_ADDRESS, VOutRole).toUInt());
+        COutPoint outpt(TxidFromString(item->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), item->data(COLUMN_ADDRESS, VOutRole).toUInt());
 
         if (item->checkState(COLUMN_CHECKBOX) == Qt::Unchecked)
             m_coin_control.UnSelect(outpt);
diff --git a/src/rest.cpp b/src/rest.cpp
index 3894b5141d..bb54e780b2 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -789,7 +789,6 @@ static bool rest_getutxos(const std::any& context, HTTPRequest* req, const std::
 
         for (size_t i = (fCheckMemPool) ? 1 : 0; i < uriParts.size(); i++)
         {
-            uint256 txid;
             int32_t nOutput;
             std::string strTxid = uriParts[i].substr(0, uriParts[i].find('-'));
             std::string strOutput = uriParts[i].substr(uriParts[i].find('-')+1);
@@ -797,8 +796,7 @@ static bool rest_getutxos(const std::any& context, HTTPRequest* req, const std::
             if (!ParseInt32(strOutput, &nOutput) || !IsHex(strTxid))
                 return RESTERR(req, HTTP_BAD_REQUEST, "Parse error");
 
-            txid.SetHex(strTxid);
-            vOutPoints.emplace_back(txid, (uint32_t)nOutput);
+            vOutPoints.emplace_back(TxidFromString(strTxid), (uint32_t)nOutput);
         }
 
         if (vOutPoints.size() > 0)
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 6a3aa397d9..be6a8c47fd 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1057,7 +1057,7 @@ static RPCHelpMan gettxout()
 
     UniValue ret(UniValue::VOBJ);
 
-    uint256 hash(ParseHashV(request.params[0], "txid"));
+    auto hash{Txid::FromUint256(ParseHashV(request.params[0], "txid"))};
     COutPoint out{hash, request.params[1].getInt<uint32_t>()};
     bool fMempool = true;
     if (!request.params[2].isNull())
@@ -2014,7 +2014,7 @@ bool FindScriptPubKey(std::atomic<int>& scan_progress, const std::atomic<bool>&
         }
         if (count % 256 == 0) {
             // update progress reference every 256 item
-            uint32_t high = 0x100 * *key.hash.begin() + *(key.hash.begin() + 1);
+            uint32_t high = 0x100 * *UCharCast(key.hash.begin()) + *(UCharCast(key.hash.begin()) + 1);
             scan_progress = (int)(high * 100.0 / 65536.0 + 0.5);
         }
         if (needles.count(coin.out.scriptPubKey)) {
diff --git a/src/rpc/mempool.cpp b/src/rpc/mempool.cpp
index bf60eae433..6cbc96c5ec 100644
--- a/src/rpc/mempool.cpp
+++ b/src/rpc/mempool.cpp
@@ -633,7 +633,7 @@ static RPCHelpMan gettxspendingprevout()
                                     {"vout", UniValueType(UniValue::VNUM)},
                                 }, /*fAllowNull=*/false, /*fStrict=*/true);
 
-                const uint256 txid(ParseHashO(o, "txid"));
+                const Txid txid = Txid::FromUint256(ParseHashO(o, "txid"));
                 const int nOutput{o.find_value("vout").getInt<int>()};
                 if (nOutput < 0) {
                     throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, vout cannot be negative");
diff --git a/src/rpc/rawtransaction_util.cpp b/src/rpc/rawtransaction_util.cpp
index 3a6fa39e4d..c471986a44 100644
--- a/src/rpc/rawtransaction_util.cpp
+++ b/src/rpc/rawtransaction_util.cpp
@@ -34,7 +34,7 @@ void AddInputs(CMutableTransaction& rawTx, const UniValue& inputs_in, std::optio
         const UniValue& input = inputs[idx];
         const UniValue& o = input.get_obj();
 
-        uint256 txid = ParseHashO(o, "txid");
+        Txid txid = Txid::FromUint256(ParseHashO(o, "txid"));
 
         const UniValue& vout_v = o.find_value("vout");
         if (!vout_v.isNum())
@@ -185,7 +185,7 @@ void ParsePrevouts(const UniValue& prevTxsUnival, FillableSigningProvider* keyst
                     {"scriptPubKey", UniValueType(UniValue::VSTR)},
                 });
 
-            uint256 txid = ParseHashO(prevOut, "txid");
+            Txid txid = Txid::FromUint256(ParseHashO(prevOut, "txid"));
 
             int nOut = prevOut.find_value("vout").getInt<int>();
             if (nOut < 0) {
diff --git a/src/rpc/txoutproof.cpp b/src/rpc/txoutproof.cpp
index d74959cecc..46a22e9338 100644
--- a/src/rpc/txoutproof.cpp
+++ b/src/rpc/txoutproof.cpp
@@ -69,7 +69,7 @@ static RPCHelpMan gettxoutproof()
 
                 // Loop through txids and try to find which block they're in. Exit loop once a block is found.
                 for (const auto& tx : setTxids) {
-                    const Coin& coin = AccessByTxid(active_chainstate.CoinsTip(), tx);
+                    const Coin& coin = AccessByTxid(active_chainstate.CoinsTip(), Txid::FromUint256(tx));
                     if (!coin.IsSpent()) {
                         pblockindex = active_chainstate.m_chain[coin.nHeight];
                         break;
diff --git a/src/test/blockencodings_tests.cpp b/src/test/blockencodings_tests.cpp
index e4ef019daf..7968966303 100644
--- a/src/test/blockencodings_tests.cpp
+++ b/src/test/blockencodings_tests.cpp
@@ -32,13 +32,13 @@ static CBlock BuildBlockTestCase() {
     block.hashPrevBlock = InsecureRand256();
     block.nBits = 0x207fffff;
 
-    tx.vin[0].prevout.hash = InsecureRand256();
+    tx.vin[0].prevout.hash = Txid::FromUint256(InsecureRand256());
     tx.vin[0].prevout.n = 0;
     block.vtx[1] = MakeTransactionRef(tx);
 
     tx.vin.resize(10);
     for (size_t i = 0; i < tx.vin.size(); i++) {
-        tx.vin[i].prevout.hash = InsecureRand256();
+        tx.vin[i].prevout.hash = Txid::FromUint256(InsecureRand256());
         tx.vin[i].prevout.n = 0;
     }
     block.vtx[2] = MakeTransactionRef(tx);
diff --git a/src/test/bloom_tests.cpp b/src/test/bloom_tests.cpp
index 23cbe921ba..daa5a56a14 100644
--- a/src/test/bloom_tests.cpp
+++ b/src/test/bloom_tests.cpp
@@ -136,11 +136,11 @@ BOOST_AUTO_TEST_CASE(bloom_match)
     BOOST_CHECK_MESSAGE(filter.IsRelevantAndUpdate(tx), "Simple Bloom filter didn't match output address");
 
     filter = CBloomFilter(10, 0.000001, 0, BLOOM_UPDATE_ALL);
-    filter.insert(COutPoint(uint256S("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0));
+    filter.insert(COutPoint(TxidFromString("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0));
     BOOST_CHECK_MESSAGE(filter.IsRelevantAndUpdate(tx), "Simple Bloom filter didn't match COutPoint");
 
     filter = CBloomFilter(10, 0.000001, 0, BLOOM_UPDATE_ALL);
-    COutPoint prevOutPoint(uint256S("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0);
+    COutPoint prevOutPoint(TxidFromString("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0);
     {
         std::vector<unsigned char> data(32 + sizeof(unsigned int));
         memcpy(data.data(), prevOutPoint.hash.begin(), 32);
@@ -158,11 +158,11 @@ BOOST_AUTO_TEST_CASE(bloom_match)
     BOOST_CHECK_MESSAGE(!filter.IsRelevantAndUpdate(tx), "Simple Bloom filter matched random address");
 
     filter = CBloomFilter(10, 0.000001, 0, BLOOM_UPDATE_ALL);
-    filter.insert(COutPoint(uint256S("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 1));
+    filter.insert(COutPoint(TxidFromString("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 1));
     BOOST_CHECK_MESSAGE(!filter.IsRelevantAndUpdate(tx), "Simple Bloom filter matched COutPoint for an output we didn't care about");
 
     filter = CBloomFilter(10, 0.000001, 0, BLOOM_UPDATE_ALL);
-    filter.insert(COutPoint(uint256S("0x000000d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0));
+    filter.insert(COutPoint(TxidFromString("0x000000d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0));
     BOOST_CHECK_MESSAGE(!filter.IsRelevantAndUpdate(tx), "Simple Bloom filter matched COutPoint for an output we didn't care about");
 }
 
@@ -414,9 +414,9 @@ BOOST_AUTO_TEST_CASE(merkle_block_4_test_p2pubkey_only)
     BOOST_CHECK(merkleBlock.header.GetHash() == block.GetHash());
 
     // We should match the generation outpoint
-    BOOST_CHECK(filter.contains(COutPoint(uint256S("0x147caa76786596590baa4e98f5d9f48b86c7765e489f7a6ff3360fe5c674360b"), 0)));
+    BOOST_CHECK(filter.contains(COutPoint(TxidFromString("0x147caa76786596590baa4e98f5d9f48b86c7765e489f7a6ff3360fe5c674360b"), 0)));
     // ... but not the 4th transaction's output (its not pay-2-pubkey)
-    BOOST_CHECK(!filter.contains(COutPoint(uint256S("0x02981fa052f0481dbc5868f4fc2166035a10f27a03cfd2de67326471df5bc041"), 0)));
+    BOOST_CHECK(!filter.contains(COutPoint(TxidFromString("0x02981fa052f0481dbc5868f4fc2166035a10f27a03cfd2de67326471df5bc041"), 0)));
 }
 
 BOOST_AUTO_TEST_CASE(merkle_block_4_test_update_none)
@@ -437,8 +437,8 @@ BOOST_AUTO_TEST_CASE(merkle_block_4_test_update_none)
     BOOST_CHECK(merkleBlock.header.GetHash() == block.GetHash());
 
     // We shouldn't match any outpoints (UPDATE_NONE)
-    BOOST_CHECK(!filter.contains(COutPoint(uint256S("0x147caa76786596590baa4e98f5d9f48b86c7765e489f7a6ff3360fe5c674360b"), 0)));
-    BOOST_CHECK(!filter.contains(COutPoint(uint256S("0x02981fa052f0481dbc5868f4fc2166035a10f27a03cfd2de67326471df5bc041"), 0)));
+    BOOST_CHECK(!filter.contains(COutPoint(TxidFromString("0x147caa76786596590baa4e98f5d9f48b86c7765e489f7a6ff3360fe5c674360b"), 0)));
+    BOOST_CHECK(!filter.contains(COutPoint(TxidFromString("0x02981fa052f0481dbc5868f4fc2166035a10f27a03cfd2de67326471df5bc041"), 0)));
 }
 
 static std::vector<unsigned char> RandomData()
diff --git a/src/test/coins_tests.cpp b/src/test/coins_tests.cpp
index 12dc4d1ccc..b6d3e7d567 100644
--- a/src/test/coins_tests.cpp
+++ b/src/test/coins_tests.cpp
@@ -137,16 +137,16 @@ void SimulationTest(CCoinsView* base, bool fake_best_block)
     stack.push_back(std::make_unique<CCoinsViewCacheTest>(base)); // Start with one cache.
 
     // Use a limited set of random transaction ids, so we do test overwriting entries.
-    std::vector<uint256> txids;
+    std::vector<Txid> txids;
     txids.resize(NUM_SIMULATION_ITERATIONS / 8);
     for (unsigned int i = 0; i < txids.size(); i++) {
-        txids[i] = InsecureRand256();
+        txids[i] = Txid::FromUint256(InsecureRand256());
     }
 
     for (unsigned int i = 0; i < NUM_SIMULATION_ITERATIONS; i++) {
         // Do a random modification.
         {
-            uint256 txid = txids[InsecureRandRange(txids.size())]; // txid we're going to modify in this iteration.
+            auto txid = txids[InsecureRandRange(txids.size())]; // txid we're going to modify in this iteration.
             Coin& coin = result[COutPoint(txid, 0)];
 
             // Determine whether to test HaveCoin before or after Access* (or both). As these functions
@@ -290,7 +290,7 @@ UtxoData utxoData;
 
 UtxoData::iterator FindRandomFrom(const std::set<COutPoint> &utxoSet) {
     assert(utxoSet.size());
-    auto utxoSetIt = utxoSet.lower_bound(COutPoint(InsecureRand256(), 0));
+    auto utxoSetIt = utxoSet.lower_bound(COutPoint(Txid::FromUint256(InsecureRand256()), 0));
     if (utxoSetIt == utxoSet.end()) {
         utxoSetIt = utxoSet.begin();
     }
@@ -926,7 +926,7 @@ void TestFlushBehavior(
         }
     };
 
-    uint256 txid = InsecureRand256();
+    Txid txid = Txid::FromUint256(InsecureRand256());
     COutPoint outp = COutPoint(txid, 0);
     Coin coin = MakeCoin();
     // Ensure the coins views haven't seen this coin before.
@@ -1017,7 +1017,7 @@ void TestFlushBehavior(
     // --- Bonus check: ensure that a coin added to the base view via one cache
     //     can be spent by another cache which has never seen it.
     //
-    txid = InsecureRand256();
+    txid = Txid::FromUint256(InsecureRand256());
     outp = COutPoint(txid, 0);
     coin = MakeCoin();
     BOOST_CHECK(!base.HaveCoin(outp));
@@ -1040,7 +1040,7 @@ void TestFlushBehavior(
 
     // --- Bonus check 2: ensure that a FRESH, spent coin is deleted by Sync()
     //
-    txid = InsecureRand256();
+    txid = Txid::FromUint256(InsecureRand256());
     outp = COutPoint(txid, 0);
     coin = MakeCoin();
     CAmount coin_val = coin.out.nValue;
diff --git a/src/test/fuzz/coinscache_sim.cpp b/src/test/fuzz/coinscache_sim.cpp
index f350c9d032..648e96b4a0 100644
--- a/src/test/fuzz/coinscache_sim.cpp
+++ b/src/test/fuzz/coinscache_sim.cpp
@@ -43,7 +43,9 @@ struct PrecomputedData
         for (uint32_t i = 0; i < NUM_OUTPOINTS; ++i) {
             uint32_t idx = (i * 1200U) >> 12; /* Map 3 or 4 entries to same txid. */
             const uint8_t ser[4] = {uint8_t(idx), uint8_t(idx >> 8), uint8_t(idx >> 16), uint8_t(idx >> 24)};
-            CSHA256().Write(PREFIX_O, 1).Write(ser, sizeof(ser)).Finalize(outpoints[i].hash.begin());
+            uint256 txid;
+            CSHA256().Write(PREFIX_O, 1).Write(ser, sizeof(ser)).Finalize(txid.begin());
+            outpoints[i].hash = Txid::FromUint256(txid);
             outpoints[i].n = i;
         }
 
diff --git a/src/test/fuzz/mini_miner.cpp b/src/test/fuzz/mini_miner.cpp
index 2f53943c31..84f9bb4ad0 100644
--- a/src/test/fuzz/mini_miner.cpp
+++ b/src/test/fuzz/mini_miner.cpp
@@ -25,7 +25,7 @@ void initialize_miner()
     static const auto testing_setup = MakeNoLogFileContext<const TestingSetup>();
     g_setup = testing_setup.get();
     for (uint32_t i = 0; i < uint32_t{100}; ++i) {
-        g_available_coins.emplace_back(uint256::ZERO, i);
+        g_available_coins.emplace_back(Txid::FromUint256(uint256::ZERO), i);
     }
 }
 
diff --git a/src/test/fuzz/package_eval.cpp b/src/test/fuzz/package_eval.cpp
index 8658c0b45a..064930c5aa 100644
--- a/src/test/fuzz/package_eval.cpp
+++ b/src/test/fuzz/package_eval.cpp
@@ -252,10 +252,10 @@ FUZZ_TARGET(tx_package_eval, .init = initialize_tx_pool)
         }
         if (fuzzed_data_provider.ConsumeBool()) {
             const auto& txid = fuzzed_data_provider.ConsumeBool() ?
-                                   txs.back()->GetHash().ToUint256() :
+                                   txs.back()->GetHash() :
                                    PickValue(fuzzed_data_provider, mempool_outpoints).hash;
             const auto delta = fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(-50 * COIN, +50 * COIN);
-            tx_pool.PrioritiseTransaction(txid, delta);
+            tx_pool.PrioritiseTransaction(txid.ToUint256(), delta);
         }
 
         // Remember all added transactions
diff --git a/src/test/fuzz/tx_pool.cpp b/src/test/fuzz/tx_pool.cpp
index 96095539ec..ffa0c1216e 100644
--- a/src/test/fuzz/tx_pool.cpp
+++ b/src/test/fuzz/tx_pool.cpp
@@ -277,10 +277,10 @@ FUZZ_TARGET(tx_pool_standard, .init = initialize_tx_pool)
         }
         if (fuzzed_data_provider.ConsumeBool()) {
             const auto& txid = fuzzed_data_provider.ConsumeBool() ?
-                                   tx->GetHash().ToUint256() :
+                                   tx->GetHash() :
                                    PickValue(fuzzed_data_provider, outpoints_rbf).hash;
             const auto delta = fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(-50 * COIN, +50 * COIN);
-            tx_pool.PrioritiseTransaction(txid, delta);
+            tx_pool.PrioritiseTransaction(txid.ToUint256(), delta);
         }
 
         // Remember all removed and added transactions
@@ -367,7 +367,7 @@ FUZZ_TARGET(tx_pool, .init = initialize_tx_pool)
 
     MockTime(fuzzed_data_provider, chainstate);
 
-    std::vector<uint256> txids;
+    std::vector<Txid> txids;
     txids.reserve(g_outpoints_coinbase_init_mature.size());
     for (const auto& outpoint : g_outpoints_coinbase_init_mature) {
         txids.push_back(outpoint.hash);
@@ -375,7 +375,7 @@ FUZZ_TARGET(tx_pool, .init = initialize_tx_pool)
     for (int i{0}; i <= 3; ++i) {
         // Add some immature and non-existent outpoints
         txids.push_back(g_outpoints_coinbase_init_immature.at(i).hash);
-        txids.push_back(ConsumeUInt256(fuzzed_data_provider));
+        txids.push_back(Txid::FromUint256(ConsumeUInt256(fuzzed_data_provider)));
     }
 
     SetMempoolConstraints(*node.args, fuzzed_data_provider);
@@ -396,10 +396,10 @@ FUZZ_TARGET(tx_pool, .init = initialize_tx_pool)
         }
         if (fuzzed_data_provider.ConsumeBool()) {
             const auto txid = fuzzed_data_provider.ConsumeBool() ?
-                                   mut_tx.GetHash().ToUint256() :
+                                   mut_tx.GetHash() :
                                    PickValue(fuzzed_data_provider, txids);
             const auto delta = fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(-50 * COIN, +50 * COIN);
-            tx_pool.PrioritiseTransaction(txid, delta);
+            tx_pool.PrioritiseTransaction(txid.ToUint256(), delta);
         }
 
         const auto tx = MakeTransactionRef(mut_tx);
diff --git a/src/test/fuzz/txorphan.cpp b/src/test/fuzz/txorphan.cpp
index a84dc951fc..e9ceb299fe 100644
--- a/src/test/fuzz/txorphan.cpp
+++ b/src/test/fuzz/txorphan.cpp
@@ -39,7 +39,7 @@ FUZZ_TARGET(txorphan, .init = initialize_orphanage)
     std::vector<COutPoint> outpoints;
     // initial outpoints used to construct transactions later
     for (uint8_t i = 0; i < 4; i++) {
-        outpoints.emplace_back(uint256{i}, 0);
+        outpoints.emplace_back(Txid::FromUint256(uint256{i}), 0);
     }
     // if true, allow duplicate input when constructing tx
     const bool duplicate_input = fuzzed_data_provider.ConsumeBool();
diff --git a/src/test/fuzz/util.cpp b/src/test/fuzz/util.cpp
index 87ca2f6aed..79bffa8369 100644
--- a/src/test/fuzz/util.cpp
+++ b/src/test/fuzz/util.cpp
@@ -40,7 +40,7 @@ int64_t ConsumeTime(FuzzedDataProvider& fuzzed_data_provider, const std::optiona
     return fuzzed_data_provider.ConsumeIntegralInRange<int64_t>(min.value_or(time_min), max.value_or(time_max));
 }
 
-CMutableTransaction ConsumeTransaction(FuzzedDataProvider& fuzzed_data_provider, const std::optional<std::vector<uint256>>& prevout_txids, const int max_num_in, const int max_num_out) noexcept
+CMutableTransaction ConsumeTransaction(FuzzedDataProvider& fuzzed_data_provider, const std::optional<std::vector<Txid>>& prevout_txids, const int max_num_in, const int max_num_out) noexcept
 {
     CMutableTransaction tx_mut;
     const auto p2wsh_op_true = fuzzed_data_provider.ConsumeBool();
@@ -53,7 +53,7 @@ CMutableTransaction ConsumeTransaction(FuzzedDataProvider& fuzzed_data_provider,
     for (int i = 0; i < num_in; ++i) {
         const auto& txid_prev = prevout_txids ?
                                     PickValue(fuzzed_data_provider, *prevout_txids) :
-                                    ConsumeUInt256(fuzzed_data_provider);
+                                    Txid::FromUint256(ConsumeUInt256(fuzzed_data_provider));
         const auto index_out = fuzzed_data_provider.ConsumeIntegralInRange<uint32_t>(0, max_num_out);
         const auto sequence = ConsumeSequence(fuzzed_data_provider);
         const auto script_sig = p2wsh_op_true ? CScript{} : ConsumeScript(fuzzed_data_provider);
diff --git a/src/test/fuzz/util.h b/src/test/fuzz/util.h
index 0ad2ed6128..fb566fcf22 100644
--- a/src/test/fuzz/util.h
+++ b/src/test/fuzz/util.h
@@ -145,7 +145,7 @@ template <typename WeakEnumType, size_t size>
 
 [[nodiscard]] int64_t ConsumeTime(FuzzedDataProvider& fuzzed_data_provider, const std::optional<int64_t>& min = std::nullopt, const std::optional<int64_t>& max = std::nullopt) noexcept;
 
-[[nodiscard]] CMutableTransaction ConsumeTransaction(FuzzedDataProvider& fuzzed_data_provider, const std::optional<std::vector<uint256>>& prevout_txids, const int max_num_in = 10, const int max_num_out = 10) noexcept;
+[[nodiscard]] CMutableTransaction ConsumeTransaction(FuzzedDataProvider& fuzzed_data_provider, const std::optional<std::vector<Txid>>& prevout_txids, const int max_num_in = 10, const int max_num_out = 10) noexcept;
 
 [[nodiscard]] CScriptWitness ConsumeScriptWitness(FuzzedDataProvider& fuzzed_data_provider, const size_t max_stack_elem_size = 32) noexcept;
 
diff --git a/src/test/miner_tests.cpp b/src/test/miner_tests.cpp
index 96acbea317..342d2514ed 100644
--- a/src/test/miner_tests.cpp
+++ b/src/test/miner_tests.cpp
@@ -118,19 +118,19 @@ void MinerTestingSetup::TestPackageSelection(const CScript& scriptPubKey, const
     tx.vout.resize(1);
     tx.vout[0].nValue = 5000000000LL - 1000;
     // This tx has a low fee: 1000 satoshis
-    uint256 hashParentTx = tx.GetHash(); // save this txid for later use
+    Txid hashParentTx = tx.GetHash(); // save this txid for later use
     tx_mempool.addUnchecked(entry.Fee(1000).Time(Now<NodeSeconds>()).SpendsCoinbase(true).FromTx(tx));
 
     // This tx has a medium fee: 10000 satoshis
     tx.vin[0].prevout.hash = txFirst[1]->GetHash();
     tx.vout[0].nValue = 5000000000LL - 10000;
-    uint256 hashMediumFeeTx = tx.GetHash();
+    Txid hashMediumFeeTx = tx.GetHash();
     tx_mempool.addUnchecked(entry.Fee(10000).Time(Now<NodeSeconds>()).SpendsCoinbase(true).FromTx(tx));
 
     // This tx has a high fee, but depends on the first transaction
     tx.vin[0].prevout.hash = hashParentTx;
     tx.vout[0].nValue = 5000000000LL - 1000 - 50000; // 50k satoshi fee
-    uint256 hashHighFeeTx = tx.GetHash();
+    Txid hashHighFeeTx = tx.GetHash();
     tx_mempool.addUnchecked(entry.Fee(50000).Time(Now<NodeSeconds>()).SpendsCoinbase(false).FromTx(tx));
 
     std::unique_ptr<CBlockTemplate> pblocktemplate = AssemblerForTest(tx_mempool).CreateNewBlock(scriptPubKey);
@@ -142,7 +142,7 @@ void MinerTestingSetup::TestPackageSelection(const CScript& scriptPubKey, const
     // Test that a package below the block min tx fee doesn't get included
     tx.vin[0].prevout.hash = hashHighFeeTx;
     tx.vout[0].nValue = 5000000000LL - 1000 - 50000; // 0 fee
-    uint256 hashFreeTx = tx.GetHash();
+    Txid hashFreeTx = tx.GetHash();
     tx_mempool.addUnchecked(entry.Fee(0).FromTx(tx));
     size_t freeTxSize = ::GetSerializeSize(TX_WITH_WITNESS(tx));
 
@@ -152,7 +152,7 @@ void MinerTestingSetup::TestPackageSelection(const CScript& scriptPubKey, const
 
     tx.vin[0].prevout.hash = hashFreeTx;
     tx.vout[0].nValue = 5000000000LL - 1000 - 50000 - feeToUse;
-    uint256 hashLowFeeTx = tx.GetHash();
+    Txid hashLowFeeTx = tx.GetHash();
     tx_mempool.addUnchecked(entry.Fee(feeToUse).FromTx(tx));
     pblocktemplate = AssemblerForTest(tx_mempool).CreateNewBlock(scriptPubKey);
     // Verify that the free tx and the low fee tx didn't get selected
@@ -180,7 +180,7 @@ void MinerTestingSetup::TestPackageSelection(const CScript& scriptPubKey, const
     tx.vout.resize(2);
     tx.vout[0].nValue = 5000000000LL - 100000000;
     tx.vout[1].nValue = 100000000; // 1BTC output
-    uint256 hashFreeTx2 = tx.GetHash();
+    Txid hashFreeTx2 = tx.GetHash();
     tx_mempool.addUnchecked(entry.Fee(0).SpendsCoinbase(true).FromTx(tx));
 
     // This tx can't be mined by itself
@@ -188,7 +188,7 @@ void MinerTestingSetup::TestPackageSelection(const CScript& scriptPubKey, const
     tx.vout.resize(1);
     feeToUse = blockMinFeeRate.GetFee(freeTxSize);
     tx.vout[0].nValue = 5000000000LL - 100000000 - feeToUse;
-    uint256 hashLowFeeTx2 = tx.GetHash();
+    Txid hashLowFeeTx2 = tx.GetHash();
     tx_mempool.addUnchecked(entry.Fee(feeToUse).SpendsCoinbase(false).FromTx(tx));
     pblocktemplate = AssemblerForTest(tx_mempool).CreateNewBlock(scriptPubKey);
 
@@ -210,7 +210,7 @@ void MinerTestingSetup::TestPackageSelection(const CScript& scriptPubKey, const
 
 void MinerTestingSetup::TestBasicMining(const CScript& scriptPubKey, const std::vector<CTransactionRef>& txFirst, int baseheight)
 {
-    uint256 hash;
+    Txid hash;
     CMutableTransaction tx;
     TestMemPoolEntryHelper entry;
     entry.nFee = 11;
@@ -545,20 +545,20 @@ void MinerTestingSetup::TestPrioritisedMining(const CScript& scriptPubKey, const
     tx.vin[0].prevout.n = 0;
     tx.vout[0].nValue = 5000000000LL - 1000;
     // This tx has a low fee: 1000 satoshis
-    uint256 hashParentTx = tx.GetHash(); // save this txid for later use
+    Txid hashParentTx = tx.GetHash(); // save this txid for later use
     tx_mempool.addUnchecked(entry.Fee(1000).Time(Now<NodeSeconds>()).SpendsCoinbase(true).FromTx(tx));
 
     // This tx has a medium fee: 10000 satoshis
     tx.vin[0].prevout.hash = txFirst[2]->GetHash();
     tx.vout[0].nValue = 5000000000LL - 10000;
-    uint256 hashMediumFeeTx = tx.GetHash();
+    Txid hashMediumFeeTx = tx.GetHash();
     tx_mempool.addUnchecked(entry.Fee(10000).Time(Now<NodeSeconds>()).SpendsCoinbase(true).FromTx(tx));
     tx_mempool.PrioritiseTransaction(hashMediumFeeTx, -5 * COIN);
 
     // This tx also has a low fee, but is prioritised
     tx.vin[0].prevout.hash = hashParentTx;
     tx.vout[0].nValue = 5000000000LL - 1000 - 1000; // 1000 satoshi fee
-    uint256 hashPrioritsedChild = tx.GetHash();
+    Txid hashPrioritsedChild = tx.GetHash();
     tx_mempool.addUnchecked(entry.Fee(1000).Time(Now<NodeSeconds>()).SpendsCoinbase(false).FromTx(tx));
     tx_mempool.PrioritiseTransaction(hashPrioritsedChild, 2 * COIN);
 
@@ -570,19 +570,19 @@ void MinerTestingSetup::TestPrioritisedMining(const CScript& scriptPubKey, const
     // When FreeChild is included, FreeChild's prioritisation should also not be included.
     tx.vin[0].prevout.hash = txFirst[3]->GetHash();
     tx.vout[0].nValue = 5000000000LL; // 0 fee
-    uint256 hashFreeParent = tx.GetHash();
+    Txid hashFreeParent = tx.GetHash();
     tx_mempool.addUnchecked(entry.Fee(0).SpendsCoinbase(true).FromTx(tx));
     tx_mempool.PrioritiseTransaction(hashFreeParent, 10 * COIN);
 
     tx.vin[0].prevout.hash = hashFreeParent;
     tx.vout[0].nValue = 5000000000LL; // 0 fee
-    uint256 hashFreeChild = tx.GetHash();
+    Txid hashFreeChild = tx.GetHash();
     tx_mempool.addUnchecked(entry.Fee(0).SpendsCoinbase(false).FromTx(tx));
     tx_mempool.PrioritiseTransaction(hashFreeChild, 1 * COIN);
 
     tx.vin[0].prevout.hash = hashFreeChild;
     tx.vout[0].nValue = 5000000000LL; // 0 fee
-    uint256 hashFreeGrandchild = tx.GetHash();
+    Txid hashFreeGrandchild = tx.GetHash();
     tx_mempool.addUnchecked(entry.Fee(0).SpendsCoinbase(false).FromTx(tx));
 
     auto pblocktemplate = AssemblerForTest(tx_mempool).CreateNewBlock(scriptPubKey);
diff --git a/src/test/miniminer_tests.cpp b/src/test/miniminer_tests.cpp
index 311e402e3e..5b007997b9 100644
--- a/src/test/miniminer_tests.cpp
+++ b/src/test/miniminer_tests.cpp
@@ -190,7 +190,7 @@ BOOST_FIXTURE_TEST_CASE(miniminer_1p1c, TestChain100Setup)
                                                          CFeeRate(23330), CFeeRate(50000), CFeeRate(5*CENT)});
 
     // All nonexistent entries have a bumpfee of zero, regardless of feerate
-    std::vector<COutPoint> nonexistent_outpoints({ COutPoint{GetRandHash(), 0}, COutPoint{GetRandHash(), 3} });
+    std::vector<COutPoint> nonexistent_outpoints({ COutPoint{Txid::FromUint256(GetRandHash()), 0}, COutPoint{Txid::FromUint256(GetRandHash()), 3} });
     for (const auto& outpoint : nonexistent_outpoints) BOOST_CHECK(!pool.isSpent(outpoint));
     for (const auto& feerate : various_normal_feerates) {
         node::MiniMiner mini_miner(pool, nonexistent_outpoints);
@@ -590,9 +590,17 @@ BOOST_FIXTURE_TEST_CASE(calculate_cluster, TestChain100Setup)
     CTxMemPool& pool = *Assert(m_node.mempool);
     LOCK2(cs_main, pool.cs);
 
+    // TODO this can be removed once the mempool interface uses Txid, Wtxid
+    auto convert_to_uint256_vec = [](const std::vector<Txid>& vec) -> std::vector<uint256> {
+        std::vector<uint256> out;
+        std::transform(vec.begin(), vec.end(), std::back_inserter(out),
+                       [](const Txid& txid) { return txid.ToUint256(); });
+        return out;
+    };
+
     // Add chain of size 500
     TestMemPoolEntryHelper entry;
-    std::vector<uint256> chain_txids;
+    std::vector<Txid> chain_txids;
     auto& lasttx = m_coinbase_txns[0];
     for (auto i{0}; i < 500; ++i) {
         const auto tx = make_tx({COutPoint{lasttx->GetHash(), 0}}, /*num_outputs=*/1);
@@ -603,7 +611,7 @@ BOOST_FIXTURE_TEST_CASE(calculate_cluster, TestChain100Setup)
     const auto cluster_500tx = pool.GatherClusters({lasttx->GetHash()});
     CTxMemPool::setEntries cluster_500tx_set{cluster_500tx.begin(), cluster_500tx.end()};
     BOOST_CHECK_EQUAL(cluster_500tx.size(), cluster_500tx_set.size());
-    const auto vec_iters_500 = pool.GetIterVec(chain_txids);
+    const auto vec_iters_500 = pool.GetIterVec(convert_to_uint256_vec(chain_txids));
     for (const auto& iter : vec_iters_500) BOOST_CHECK(cluster_500tx_set.count(iter));
 
     // GatherClusters stops at 500 transactions.
@@ -618,9 +626,9 @@ BOOST_FIXTURE_TEST_CASE(calculate_cluster, TestChain100Setup)
      *     txc0     txc1    txc2  ...    txc48
      * Note that each transaction's ancestor size is 1 or 3, and each descendant size is 1, 2 or 3.
      * However, all of these transactions are in the same cluster. */
-    std::vector<uint256> zigzag_txids;
+    std::vector<Txid> zigzag_txids;
     for (auto p{0}; p < 50; ++p) {
-        const auto txp = make_tx({COutPoint{GetRandHash(), 0}}, /*num_outputs=*/2);
+        const auto txp = make_tx({COutPoint{Txid::FromUint256(GetRandHash()), 0}}, /*num_outputs=*/2);
         pool.addUnchecked(entry.Fee(CENT).FromTx(txp));
         zigzag_txids.push_back(txp->GetHash());
     }
@@ -629,7 +637,7 @@ BOOST_FIXTURE_TEST_CASE(calculate_cluster, TestChain100Setup)
         pool.addUnchecked(entry.Fee(CENT).FromTx(txc));
         zigzag_txids.push_back(txc->GetHash());
     }
-    const auto vec_iters_zigzag = pool.GetIterVec(zigzag_txids);
+    const auto vec_iters_zigzag = pool.GetIterVec(convert_to_uint256_vec(zigzag_txids));
     // It doesn't matter which tx we calculate cluster for, everybody is in it.
     const std::vector<size_t> indices{0, 22, 72, zigzag_txids.size() - 1};
     for (const auto index : indices) {
diff --git a/src/test/orphanage_tests.cpp b/src/test/orphanage_tests.cpp
index b51de30cb2..bf465c0c64 100644
--- a/src/test/orphanage_tests.cpp
+++ b/src/test/orphanage_tests.cpp
@@ -68,7 +68,7 @@ BOOST_AUTO_TEST_CASE(DoS_mapOrphans)
         CMutableTransaction tx;
         tx.vin.resize(1);
         tx.vin[0].prevout.n = 0;
-        tx.vin[0].prevout.hash = InsecureRand256();
+        tx.vin[0].prevout.hash = Txid::FromUint256(InsecureRand256());
         tx.vin[0].scriptSig << OP_1;
         tx.vout.resize(1);
         tx.vout[0].nValue = 1*CENT;
diff --git a/src/test/sighash_tests.cpp b/src/test/sighash_tests.cpp
index bc2e3ca45e..0da9283fa8 100644
--- a/src/test/sighash_tests.cpp
+++ b/src/test/sighash_tests.cpp
@@ -102,7 +102,7 @@ void static RandomTransaction(CMutableTransaction& tx, bool fSingle)
     for (int in = 0; in < ins; in++) {
         tx.vin.emplace_back();
         CTxIn &txin = tx.vin.back();
-        txin.prevout.hash = InsecureRand256();
+        txin.prevout.hash = Txid::FromUint256(InsecureRand256());
         txin.prevout.n = InsecureRandBits(2);
         RandomScript(txin.scriptSig);
         txin.nSequence = (InsecureRandBool()) ? InsecureRand32() : std::numeric_limits<uint32_t>::max();
diff --git a/src/test/transaction_tests.cpp b/src/test/transaction_tests.cpp
index 220b61f7e7..0a7ef3f780 100644
--- a/src/test/transaction_tests.cpp
+++ b/src/test/transaction_tests.cpp
@@ -27,6 +27,7 @@
 #include <test/util/transaction_utils.h>
 #include <util/strencodings.h>
 #include <util/string.h>
+#include <util/transaction_identifier.h>
 #include <validation.h>
 
 #include <functional>
@@ -219,7 +220,7 @@ BOOST_AUTO_TEST_CASE(tx_valid)
                     fValid = false;
                     break;
                 }
-                COutPoint outpoint{uint256S(vinput[0].get_str()), uint32_t(vinput[1].getInt<int>())};
+                COutPoint outpoint{TxidFromString(vinput[0].get_str()), uint32_t(vinput[1].getInt<int>())};
                 mapprevOutScriptPubKeys[outpoint] = ParseScript(vinput[2].get_str());
                 if (vinput.size() >= 4)
                 {
@@ -307,7 +308,7 @@ BOOST_AUTO_TEST_CASE(tx_invalid)
                     fValid = false;
                     break;
                 }
-                COutPoint outpoint{uint256S(vinput[0].get_str()), uint32_t(vinput[1].getInt<int>())};
+                COutPoint outpoint{TxidFromString(vinput[0].get_str()), uint32_t(vinput[1].getInt<int>())};
                 mapprevOutScriptPubKeys[outpoint] = ParseScript(vinput[2].get_str());
                 if (vinput.size() >= 4)
                 {
@@ -504,9 +505,7 @@ BOOST_AUTO_TEST_CASE(test_big_witness_transaction)
     // create a big transaction of 4500 inputs signed by the same key
     for(uint32_t ij = 0; ij < 4500; ij++) {
         uint32_t i = mtx.vin.size();
-        uint256 prevId;
-        prevId.SetHex("0000000000000000000000000000000000000000000000000000000000000100");
-        COutPoint outpoint(prevId, i);
+        COutPoint outpoint(TxidFromString("0000000000000000000000000000000000000000000000000000000000000100"), i);
 
         mtx.vin.resize(mtx.vin.size() + 1);
         mtx.vin[i].prevout = outpoint;
diff --git a/src/test/txpackage_tests.cpp b/src/test/txpackage_tests.cpp
index 84c9ecc3d1..637f92bd0f 100644
--- a/src/test/txpackage_tests.cpp
+++ b/src/test/txpackage_tests.cpp
@@ -29,7 +29,7 @@ inline CTransactionRef create_placeholder_tx(size_t num_inputs, size_t num_outpu
     mtx.vout.resize(num_outputs);
     auto random_script = CScript() << ToByteVector(InsecureRand256()) << ToByteVector(InsecureRand256());
     for (size_t i{0}; i < num_inputs; ++i) {
-        mtx.vin[i].prevout.hash = InsecureRand256();
+        mtx.vin[i].prevout.hash = Txid::FromUint256(InsecureRand256());
         mtx.vin[i].prevout.n = 0;
         mtx.vin[i].scriptSig = random_script;
     }
@@ -83,7 +83,7 @@ BOOST_FIXTURE_TEST_CASE(package_sanitization_tests, TestChain100Setup)
     // Packages can't have transactions spending the same prevout
     CMutableTransaction tx_zero_1;
     CMutableTransaction tx_zero_2;
-    COutPoint same_prevout{InsecureRand256(), 0};
+    COutPoint same_prevout{Txid::FromUint256(InsecureRand256()), 0};
     tx_zero_1.vin.emplace_back(same_prevout);
     tx_zero_2.vin.emplace_back(same_prevout);
     // Different vouts (not the same tx)
@@ -101,7 +101,7 @@ BOOST_FIXTURE_TEST_CASE(package_sanitization_tests, TestChain100Setup)
     // IsConsistentPackage only cares about conflicts between transactions, not about a transaction
     // conflicting with itself (i.e. duplicate prevouts in vin).
     CMutableTransaction dup_tx;
-    const COutPoint rand_prevout{InsecureRand256(), 0};
+    const COutPoint rand_prevout{Txid::FromUint256(InsecureRand256()), 0};
     dup_tx.vin.emplace_back(rand_prevout);
     dup_tx.vin.emplace_back(rand_prevout);
     Package package_with_dup_tx{MakeTransactionRef(dup_tx)};
diff --git a/src/test/util/coins.cpp b/src/test/util/coins.cpp
index 9b6c5535c5..742dbc04d1 100644
--- a/src/test/util/coins.cpp
+++ b/src/test/util/coins.cpp
@@ -16,8 +16,7 @@
 COutPoint AddTestCoin(CCoinsViewCache& coins_view)
 {
     Coin new_coin;
-    const uint256 txid{InsecureRand256()};
-    COutPoint outpoint{txid, /*nIn=*/0};
+    COutPoint outpoint{Txid::FromUint256(InsecureRand256()), /*nIn=*/0};
     new_coin.nHeight = 1;
     new_coin.out.nValue = InsecureRandMoneyAmount();
     new_coin.out.scriptPubKey.assign(uint32_t{56}, 1);
diff --git a/src/test/util/setup_common.cpp b/src/test/util/setup_common.cpp
index 9979b75444..22fdf132c7 100644
--- a/src/test/util/setup_common.cpp
+++ b/src/test/util/setup_common.cpp
@@ -501,7 +501,7 @@ void TestChain100Setup::MockMempoolMinFee(const CFeeRate& target_feerate)
     // Manually create an invalid transaction. Manually set the fee in the CTxMemPoolEntry to
     // achieve the exact target feerate.
     CMutableTransaction mtx = CMutableTransaction();
-    mtx.vin.emplace_back(COutPoint{g_insecure_rand_ctx.rand256(), 0});
+    mtx.vin.emplace_back(COutPoint{Txid::FromUint256(g_insecure_rand_ctx.rand256()), 0});
     mtx.vout.emplace_back(1 * COIN, GetScriptForDestination(WitnessV0ScriptHash(CScript() << OP_TRUE)));
     const auto tx{MakeTransactionRef(mtx)};
     LockPoints lp;
diff --git a/src/test/validation_chainstatemanager_tests.cpp b/src/test/validation_chainstatemanager_tests.cpp
index e2541a74fd..6969822ad7 100644
--- a/src/test/validation_chainstatemanager_tests.cpp
+++ b/src/test/validation_chainstatemanager_tests.cpp
@@ -724,7 +724,7 @@ BOOST_FIXTURE_TEST_CASE(chainstatemanager_snapshot_completion_hash_mismatch, Sna
     badcoin.out.nValue = InsecureRand32();
     badcoin.nHeight = 1;
     badcoin.out.scriptPubKey.assign(InsecureRandBits(6), 0);
-    uint256 txid = InsecureRand256();
+    Txid txid = Txid::FromUint256(InsecureRand256());
     ibd_coins.AddCoin(COutPoint(txid, 0), std::move(badcoin), false);
 
     fs::path snapshot_chainstate_dir = gArgs.GetDataDirNet() / "chainstate_snapshot";
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index e057d7ece1..b6be395d74 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -124,7 +124,7 @@ void CTxMemPool::UpdateTransactionsFromBlock(const std::vector<uint256>& vHashes
         if (it == mapTx.end()) {
             continue;
         }
-        auto iter = mapNextTx.lower_bound(COutPoint(hash, 0));
+        auto iter = mapNextTx.lower_bound(COutPoint(Txid::FromUint256(hash), 0));
         // First calculate the children, and update CTxMemPoolEntry::m_children to
         // include them, and update their CTxMemPoolEntry::m_parents to include this tx.
         // we cache the in-mempool children to avoid duplicate updates
diff --git a/src/util/transaction_identifier.h b/src/util/transaction_identifier.h
index 4fb9b49966..89e10dee01 100644
--- a/src/util/transaction_identifier.h
+++ b/src/util/transaction_identifier.h
@@ -65,4 +65,9 @@ using Txid = transaction_identifier<false>;
 /** Wtxid commits to all transaction fields including the witness. */
 using Wtxid = transaction_identifier<true>;
 
+inline Txid TxidFromString(std::string_view str)
+{
+    return Txid::FromUint256(uint256S(str.data()));
+}
+
 #endif // BITCOIN_UTIL_TRANSACTION_IDENTIFIER_H
diff --git a/src/validation.cpp b/src/validation.cpp
index ed72a7c97a..56ea9363b2 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -696,7 +696,7 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
     AssertLockHeld(m_pool.cs);
     const CTransactionRef& ptx = ws.m_ptx;
     const CTransaction& tx = *ws.m_ptx;
-    const uint256& hash = ws.m_hash;
+    const Txid& hash = ws.m_hash;
 
     // Copy/alias what we need out of args
     const int64_t nAcceptTime = args.m_accept_time;
@@ -2036,7 +2036,7 @@ DisconnectResult Chainstate::DisconnectBlock(const CBlock& block, const CBlockIn
     // undo transactions in reverse order
     for (int i = block.vtx.size() - 1; i >= 0; i--) {
         const CTransaction &tx = *(block.vtx[i]);
-        uint256 hash = tx.GetHash();
+        Txid hash = tx.GetHash();
         bool is_coinbase = tx.IsCoinBase();
         bool is_bip30_exception = (is_coinbase && !fEnforceBIP30);
 
diff --git a/src/wallet/receive.cpp b/src/wallet/receive.cpp
index 0a75bb6d92..b9d8d9abc9 100644
--- a/src/wallet/receive.cpp
+++ b/src/wallet/receive.cpp
@@ -173,7 +173,7 @@ CAmount CachedTxGetAvailableCredit(const CWallet& wallet, const CWalletTx& wtx,
 
     bool allow_used_addresses = (filter & ISMINE_USED) || !wallet.IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);
     CAmount nCredit = 0;
-    uint256 hashTx = wtx.GetHash();
+    Txid hashTx = wtx.GetHash();
     for (unsigned int i = 0; i < wtx.tx->vout.size(); i++) {
         const CTxOut& txout = wtx.tx->vout[i];
         if (!wallet.IsSpent(COutPoint(hashTx, i)) && (allow_used_addresses || !wallet.IsSpentKey(txout.scriptPubKey))) {
@@ -348,7 +348,7 @@ std::map<CTxDestination, CAmount> GetAddressBalances(const CWallet& wallet)
                 if(!ExtractDestination(output.scriptPubKey, addr))
                     continue;
 
-                CAmount n = wallet.IsSpent(COutPoint(walletEntry.first, i)) ? 0 : output.nValue;
+                CAmount n = wallet.IsSpent(COutPoint(Txid::FromUint256(walletEntry.first), i)) ? 0 : output.nValue;
                 balances[addr] += n;
             }
         }
diff --git a/src/wallet/rpc/coins.cpp b/src/wallet/rpc/coins.cpp
index fdc6ee055d..0cb0891141 100644
--- a/src/wallet/rpc/coins.cpp
+++ b/src/wallet/rpc/coins.cpp
@@ -320,7 +320,7 @@ RPCHelpMan lockunspent()
                 {"vout", UniValueType(UniValue::VNUM)},
             });
 
-        const uint256 txid(ParseHashO(o, "txid"));
+        const Txid txid = Txid::FromUint256(ParseHashO(o, "txid"));
         const int nOutput = o.find_value("vout").getInt<int>();
         if (nOutput < 0) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, vout cannot be negative");
diff --git a/src/wallet/rpc/spend.cpp b/src/wallet/rpc/spend.cpp
index 6519504618..84e617c140 100644
--- a/src/wallet/rpc/spend.cpp
+++ b/src/wallet/rpc/spend.cpp
@@ -672,7 +672,7 @@ void FundTransaction(CWallet& wallet, CMutableTransaction& tx, CAmount& fee_out,
 
     if (options.exists("input_weights")) {
         for (const UniValue& input : options["input_weights"].get_array().getValues()) {
-            uint256 txid = ParseHashO(input, "txid");
+            Txid txid = Txid::FromUint256(ParseHashO(input, "txid"));
 
             const UniValue& vout_v = input.find_value("vout");
             if (!vout_v.isNum()) {
diff --git a/src/wallet/spend.cpp b/src/wallet/spend.cpp
index d586f6d4aa..35583642a5 100644
--- a/src/wallet/spend.cpp
+++ b/src/wallet/spend.cpp
@@ -321,7 +321,7 @@ CoinsResult AvailableCoins(const CWallet& wallet,
     std::set<uint256> trusted_parents;
     for (const auto& entry : wallet.mapWallet)
     {
-        const uint256& wtxid = entry.first;
+        const uint256& txid = entry.first;
         const CWalletTx& wtx = entry.second;
 
         if (wallet.IsTxImmatureCoinBase(wtx) && !params.include_immature_coinbase)
@@ -381,7 +381,7 @@ CoinsResult AvailableCoins(const CWallet& wallet,
 
         for (unsigned int i = 0; i < wtx.tx->vout.size(); i++) {
             const CTxOut& output = wtx.tx->vout[i];
-            const COutPoint outpoint(wtxid, i);
+            const COutPoint outpoint(Txid::FromUint256(txid), i);
 
             if (output.nValue < params.min_amount || output.nValue > params.max_amount)
                 continue;
diff --git a/src/wallet/test/feebumper_tests.cpp b/src/wallet/test/feebumper_tests.cpp
index 2480a9b4e1..80fd778419 100644
--- a/src/wallet/test/feebumper_tests.cpp
+++ b/src/wallet/test/feebumper_tests.cpp
@@ -21,7 +21,7 @@ static void CheckMaxWeightComputation(const std::string& script_str, const std::
 {
     std::vector script_data(ParseHex(script_str));
     CScript script(script_data.begin(), script_data.end());
-    CTxIn input(uint256(), 0, script);
+    CTxIn input(Txid{}, 0, script);
 
     for (const auto& s : witness_str_stack) {
         input.scriptWitness.stack.push_back(ParseHex(s));
diff --git a/src/wallet/test/fuzz/notifications.cpp b/src/wallet/test/fuzz/notifications.cpp
index abd788f96f..b243d5f471 100644
--- a/src/wallet/test/fuzz/notifications.cpp
+++ b/src/wallet/test/fuzz/notifications.cpp
@@ -100,7 +100,7 @@ FUZZ_TARGET(wallet_notifications, .init = initialize_setup)
         // Add the initial entry
         chain.emplace_back();
         auto& [coins, block]{chain.back()};
-        coins.emplace(total_amount, COutPoint{uint256::ONE, 1});
+        coins.emplace(total_amount, COutPoint{Txid::FromUint256(uint256::ONE), 1});
     }
     LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 200)
     {
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index bcbc31ed3e..63932c6430 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -946,7 +946,7 @@ BOOST_FIXTURE_TEST_CASE(wallet_sync_tx_invalid_state_test, TestingSetup)
 
     CMutableTransaction mtx;
     mtx.vout.emplace_back(COIN, GetScriptForDestination(op_dest));
-    mtx.vin.emplace_back(g_insecure_rand_ctx.rand256(), 0);
+    mtx.vin.emplace_back(Txid::FromUint256(g_insecure_rand_ctx.rand256()), 0);
     const auto& tx_id_to_spend = wallet.AddToWallet(MakeTransactionRef(mtx), TxStateInMempool{})->GetHash();
 
     {
@@ -963,12 +963,12 @@ BOOST_FIXTURE_TEST_CASE(wallet_sync_tx_invalid_state_test, TestingSetup)
     mtx.vin.clear();
     mtx.vin.emplace_back(tx_id_to_spend, 0);
     wallet.transactionAddedToMempool(MakeTransactionRef(mtx));
-    const auto good_tx_id{mtx.GetHash().ToUint256()};
+    const auto good_tx_id{mtx.GetHash()};
 
     {
         // Verify balance update for the new tx and the old one
         LOCK(wallet.cs_wallet);
-        const CWalletTx* new_wtx = wallet.GetWalletTx(good_tx_id);
+        const CWalletTx* new_wtx = wallet.GetWalletTx(good_tx_id.ToUint256());
         BOOST_CHECK_EQUAL(CachedTxGetAvailableCredit(wallet, *new_wtx), 1 * COIN);
 
         // Now the old wtx
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index ecf18fbe78..c34bf96b5e 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -681,7 +681,7 @@ std::set<uint256> CWallet::GetConflicts(const uint256& txid) const
 bool CWallet::HasWalletSpend(const CTransactionRef& tx) const
 {
     AssertLockHeld(cs_wallet);
-    const uint256& txid = tx->GetHash();
+    const Txid& txid = tx->GetHash();
     for (unsigned int i = 0; i < tx->vout.size(); ++i) {
         if (IsSpent(COutPoint(txid, i))) {
             return true;
@@ -1373,7 +1373,7 @@ void CWallet::RecursiveUpdateTxState(const uint256& tx_hash, const TryUpdatingSt
             batch.WriteTx(wtx);
             // Iterate over all its outputs, and update those tx states as well (if applicable)
             for (unsigned int i = 0; i < wtx.tx->vout.size(); ++i) {
-                std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range = mapTxSpends.equal_range(COutPoint(now, i));
+                std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range = mapTxSpends.equal_range(COutPoint(Txid::FromUint256(now), i));
                 for (TxSpends::const_iterator iter = range.first; iter != range.second; ++iter) {
                     if (!done.count(iter->second)) {
                         todo.insert(iter->second);
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index 92eca46f05..66da5c1dc4 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -1073,7 +1073,7 @@ static DBErrors LoadTxRecords(CWallet* pwallet, DatabaseBatch& batch, std::vecto
     // Load locked utxo record
     LoadResult locked_utxo_res = LoadRecords(pwallet, batch, DBKeys::LOCKED_UTXO,
         [] (CWallet* pwallet, DataStream& key, CDataStream& value, std::string& err) EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet) {
-        uint256 hash;
+        Txid hash;
         uint32_t n;
         key >> hash;
         key >> n;