diff --git a/api/transaction_payment_call/module.go b/api/transaction_payment_call/module.go
index fa98519b..90d543ba 100644
--- a/api/transaction_payment_call/module.go
+++ b/api/transaction_payment_call/module.go
@@ -23,7 +23,7 @@ type Module struct {
 	memUtils   utils.WasmMemoryTranslator
 }
 
-func NewCallApi(decoder types.RuntimeDecoder, txPayments transaction_payment.Module) Module {
+func New(decoder types.RuntimeDecoder, txPayments transaction_payment.Module) Module {
 	return Module{
 		decoder:    decoder,
 		txPayments: txPayments,
diff --git a/api/transaction_payment_call/module_test.go b/api/transaction_payment_call/module_test.go
new file mode 100644
index 00000000..ea46efbe
--- /dev/null
+++ b/api/transaction_payment_call/module_test.go
@@ -0,0 +1,139 @@
+package transaction_payment_call
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/ChainSafe/gossamer/lib/common"
+	sc "github.com/LimeChain/goscale"
+	"github.com/LimeChain/gosemble/constants"
+	"github.com/LimeChain/gosemble/mocks"
+	primitives "github.com/LimeChain/gosemble/primitives/types"
+	"github.com/stretchr/testify/assert"
+)
+
+var (
+	dataPtr    = int32(0)
+	dataLen    = int32(1)
+	ptrAndSize = int64(2)
+
+	length = sc.U32(5)
+
+	baseWeight         = primitives.WeightFromParts(1, 2)
+	dispatchInfoWeight = primitives.WeightFromParts(2, 3)
+	dispatchInfoClass  = primitives.NewDispatchClassNormal()
+	dispatchInfoPays   = primitives.NewPaysYes()
+
+	dispatchInfo = primitives.DispatchInfo{
+		Weight:  dispatchInfoWeight,
+		Class:   dispatchInfoClass,
+		PaysFee: dispatchInfoPays,
+	}
+)
+
+var (
+	mockTransactionPayment *mocks.TransactionPaymentModule
+	mockRuntimeDecoder     *mocks.RuntimeDecoder
+	mockMemoryUtils        *mocks.MemoryTranslator
+	mockCall               *mocks.Call
+)
+
+func Test_Module_Name(t *testing.T) {
+	target := setup()
+
+	result := target.Name()
+
+	assert.Equal(t, ApiModuleName, result)
+}
+
+func Test_Module_Item(t *testing.T) {
+	target := setup()
+
+	hexName := common.MustBlake2b8([]byte(ApiModuleName))
+	expect := primitives.NewApiItem(hexName[:], apiVersion)
+
+	result := target.Item()
+
+	assert.Equal(t, expect, result)
+}
+
+func Test_Module_QueryCallInfo(t *testing.T) {
+	target := setup()
+
+	partialFee := sc.NewU128(10)
+	runtimeDispatchInfo := primitives.RuntimeDispatchInfo{
+		Weight:     dispatchInfoWeight,
+		Class:      dispatchInfoClass,
+		PartialFee: partialFee,
+	}
+	bufferCall := bytes.NewBuffer(length.Bytes())
+
+	mockMemoryUtils.On("GetWasmMemorySlice", dataPtr, dataLen).Return(length.Bytes())
+	mockRuntimeDecoder.On("DecodeCall", bufferCall).Return(mockCall)
+	mockCall.On("BaseWeight").Return(baseWeight)
+	mockCall.On("WeighData", baseWeight).Return(dispatchInfoWeight)
+	mockCall.On("ClassifyDispatch", baseWeight).Return(dispatchInfoClass)
+	mockCall.On("PaysFee", baseWeight).Return(dispatchInfoPays)
+	mockTransactionPayment.On("ComputeFee", length, dispatchInfo, constants.DefaultTip).Return(partialFee)
+	mockMemoryUtils.On("BytesToOffsetAndSize", runtimeDispatchInfo.Bytes()).Return(ptrAndSize)
+
+	result := target.QueryCallInfo(dataPtr, dataLen)
+
+	assert.Equal(t, ptrAndSize, result)
+	mockMemoryUtils.AssertCalled(t, "GetWasmMemorySlice", dataPtr, dataLen)
+	mockRuntimeDecoder.AssertExpectations(t)
+	mockCall.AssertCalled(t, "BaseWeight")
+	mockCall.AssertCalled(t, "WeighData", baseWeight)
+	mockCall.AssertCalled(t, "ClassifyDispatch", baseWeight)
+	mockCall.AssertCalled(t, "PaysFee", baseWeight)
+	mockTransactionPayment.AssertCalled(t, "ComputeFee", length, dispatchInfo, constants.DefaultTip)
+	mockMemoryUtils.AssertCalled(t, "BytesToOffsetAndSize", runtimeDispatchInfo.Bytes())
+}
+
+func Test_Module_QueryCallFeeDetails(t *testing.T) {
+	target := setup()
+
+	feeDetails := primitives.FeeDetails{
+		InclusionFee: sc.NewOption[primitives.InclusionFee](
+			primitives.NewInclusionFee(
+				sc.NewU128(9),
+				sc.NewU128(8),
+				sc.NewU128(7),
+			)),
+		Tip: constants.DefaultTip,
+	}
+	bufferCall := bytes.NewBuffer(length.Bytes())
+
+	mockMemoryUtils.On("GetWasmMemorySlice", dataPtr, dataLen).Return(length.Bytes())
+	mockRuntimeDecoder.On("DecodeCall", bufferCall).Return(mockCall)
+	mockCall.On("BaseWeight").Return(baseWeight)
+	mockCall.On("WeighData", baseWeight).Return(dispatchInfoWeight)
+	mockCall.On("ClassifyDispatch", baseWeight).Return(dispatchInfoClass)
+	mockCall.On("PaysFee", baseWeight).Return(dispatchInfoPays)
+	mockTransactionPayment.On("ComputeFeeDetails", length, dispatchInfo, constants.DefaultTip).Return(feeDetails)
+	mockMemoryUtils.On("BytesToOffsetAndSize", feeDetails.Bytes()).Return(ptrAndSize)
+
+	result := target.QueryCallFeeDetails(dataPtr, dataLen)
+
+	assert.Equal(t, ptrAndSize, result)
+	mockMemoryUtils.AssertCalled(t, "GetWasmMemorySlice", dataPtr, dataLen)
+	mockRuntimeDecoder.AssertExpectations(t)
+	mockCall.AssertCalled(t, "BaseWeight")
+	mockCall.AssertCalled(t, "WeighData", baseWeight)
+	mockCall.AssertCalled(t, "ClassifyDispatch", baseWeight)
+	mockCall.AssertCalled(t, "PaysFee", baseWeight)
+	mockTransactionPayment.AssertCalled(t, "ComputeFeeDetails", length, dispatchInfo, constants.DefaultTip)
+	mockMemoryUtils.AssertCalled(t, "BytesToOffsetAndSize", feeDetails.Bytes())
+}
+
+func setup() Module {
+	mockTransactionPayment = new(mocks.TransactionPaymentModule)
+	mockRuntimeDecoder = new(mocks.RuntimeDecoder)
+	mockMemoryUtils = new(mocks.MemoryTranslator)
+	mockCall = new(mocks.Call)
+
+	target := New(mockRuntimeDecoder, mockTransactionPayment)
+	target.memUtils = mockMemoryUtils
+
+	return target
+}
diff --git a/runtime/runtime.go b/runtime/runtime.go
index b8bf13d7..8b526eef 100644
--- a/runtime/runtime.go
+++ b/runtime/runtime.go
@@ -185,7 +185,7 @@ func runtimeApi() types.RuntimeApi {
 		apiGrandpa.New(grandpaModule),
 		account_nonce.New(modules[SystemIndex].(system.Module)),
 		apiTxPayments.New(decoder, txPaymentsModule),
-		apiTxPaymentsCall.NewCallApi(decoder, txPaymentsModule),
+		apiTxPaymentsCall.New(decoder, txPaymentsModule),
 		session_keys.New(sessions),
 		offchain_worker.New(executiveModule),
 	}