kernel: Add API function for getting a tx input's nSequence

src/kernel/bitcoinkernel.cpp

@@ -697,6 +697,11 @@ const btck_TransactionOutPoint* btck_transaction_input_get_out_point(const btck_
     return btck_TransactionOutPoint::ref(&btck_TransactionInput::get(input).prevout);
 }
 
+uint32_t btck_transaction_input_get_sequence(const btck_TransactionInput* input)
+{
+    return btck_TransactionInput::get(input).nSequence;
+}
+
 void btck_transaction_input_destroy(btck_TransactionInput* input)
 {
     delete input;

src/kernel/bitcoinkernel.h

@@ -1514,6 +1514,15 @@ BITCOINKERNEL_API btck_TransactionInput* BITCOINKERNEL_WARN_UNUSED_RESULT btck_t
 BITCOINKERNEL_API const btck_TransactionOutPoint* BITCOINKERNEL_WARN_UNUSED_RESULT btck_transaction_input_get_out_point(
     const btck_TransactionInput* transaction_input) BITCOINKERNEL_ARG_NONNULL(1);
 
+/**
+ * @brief Get a transaction input's nSequence value.
+ *
+ * @param[in] transaction_input Non-null.
+ * @return                      The nSequence value.
+ */
+BITCOINKERNEL_API uint32_t BITCOINKERNEL_WARN_UNUSED_RESULT btck_transaction_input_get_sequence(
+    const btck_TransactionInput* transaction_input) BITCOINKERNEL_ARG_NONNULL(1);
+
 /**
  * Destroy the transaction input.
  */

src/kernel/bitcoinkernel_wrapper.h

@@ -551,6 +551,11 @@ public:
     {
         return OutPointView{btck_transaction_input_get_out_point(impl())};
     }
+
+    uint32_t GetSequence() const
+    {
+        return btck_transaction_input_get_sequence(impl());
+    }
 };
 
 class TransactionInputView : public View<btck_TransactionInput>, public TransactionInputApi<TransactionInputView>

src/test/kernel/test_kernel.cpp

@@ -404,6 +404,8 @@ BOOST_AUTO_TEST_CASE(btck_transaction_tests)
     BOOST_CHECK_EQUAL(tx.GetLocktime(), 510826);
     auto broken_tx_data{std::span<std::byte>{tx_data.begin(), tx_data.begin() + 10}};
     BOOST_CHECK_THROW(Transaction{broken_tx_data}, std::runtime_error);
+    auto input{tx.GetInput(0)};
+    BOOST_CHECK_EQUAL(input.GetSequence(), 0xfffffffe);
     auto output{tx.GetOutput(tx.CountOutputs() - 1)};
     BOOST_CHECK_EQUAL(output.Amount(), 42130042);
     auto script_pubkey{output.GetScriptPubkey()};