diff --git a/src/core_ffi/python_ffi/CMakeLists.txt b/src/core_ffi/python_ffi/CMakeLists.txt
index 5df5d96..18ebc0e 100644
--- a/src/core_ffi/python_ffi/CMakeLists.txt
+++ b/src/core_ffi/python_ffi/CMakeLists.txt
@@ -13,7 +13,7 @@ set(KLSK_PYTHON_FFI_SRC
     binder/fast_cal.cc
 
     wrapper/short_code.cc
-    wrapper/common_codec.cc
+    wrapper/layout.cc
     wrapper/cases.cc
     wrapper/group_union.cc
     wrapper/group.cc
diff --git a/src/core_ffi/python_ffi/binder/fast_cal.cc b/src/core_ffi/python_ffi/binder/fast_cal.cc
index e37ac7d..3afe1dd 100644
--- a/src/core_ffi/python_ffi/binder/fast_cal.cc
+++ b/src/core_ffi/python_ffi/binder/fast_cal.cc
@@ -5,20 +5,20 @@
 #include "py_ffi/cases.h"
 #include "py_ffi/group.h"
 #include "py_ffi/short_code.h"
-#include "py_ffi/common_code.h"
+#include "py_ffi/layout.h"
 #include "py_ffi/fast_cal.h"
 
 using klotski::ffi::PyCases;
 using klotski::ffi::PyCasesIter;
 using klotski::ffi::PyShortCode;
-using klotski::ffi::PyCommonCode;
+using klotski::ffi::PyLayout;
 using klotski::ffi::PyGroupUnion;
 using klotski::ffi::PyGroup;
 using klotski::ffi::PyFastCal;
 
 void bind_fast_cal(const py::module_ &m) {
     py::class_<PyFastCal>(m, "FastCal")
-        .def(py::init<PyCommonCode>())
+        .def(py::init<PyLayout>())
         .def("solve", &PyFastCal::solve)
         .def("exports", &PyFastCal::exports)
         .def("build_all", &PyFastCal::build_all)
diff --git a/src/core_ffi/python_ffi/binder/group.cc b/src/core_ffi/python_ffi/binder/group.cc
index 373a210..3874b1b 100644
--- a/src/core_ffi/python_ffi/binder/group.cc
+++ b/src/core_ffi/python_ffi/binder/group.cc
@@ -3,13 +3,13 @@
 #include "py_ffi/cases.h"
 #include "py_ffi/group.h"
 #include "py_ffi/short_code.h"
-#include "py_ffi/common_code.h"
+#include "py_ffi/layout.h"
 #include "py_ffi/fast_cal.h"
 
 using klotski::ffi::PyCases;
 using klotski::ffi::PyCasesIter;
 using klotski::ffi::PyShortCode;
-using klotski::ffi::PyCommonCode;
+using klotski::ffi::PyLayout;
 using klotski::ffi::PyGroupUnion;
 using klotski::ffi::PyGroup;
 using klotski::ffi::PyFastCal;
diff --git a/src/core_ffi/python_ffi/binder/group_union.cc b/src/core_ffi/python_ffi/binder/group_union.cc
index 54aa5be..5e739c2 100644
--- a/src/core_ffi/python_ffi/binder/group_union.cc
+++ b/src/core_ffi/python_ffi/binder/group_union.cc
@@ -3,13 +3,13 @@
 #include "py_ffi/cases.h"
 #include "py_ffi/group.h"
 #include "py_ffi/short_code.h"
-#include "py_ffi/common_code.h"
+#include "py_ffi/layout.h"
 #include "py_ffi/fast_cal.h"
 
 using klotski::ffi::PyCases;
 using klotski::ffi::PyCasesIter;
 using klotski::ffi::PyShortCode;
-using klotski::ffi::PyCommonCode;
+using klotski::ffi::PyLayout;
 using klotski::ffi::PyGroupUnion;
 using klotski::ffi::PyGroup;
 using klotski::ffi::PyFastCal;
@@ -20,7 +20,7 @@ void bind_group_union(const py::module_ &m) {
     py::class_<PyGroupUnion>(m, "GroupUnion")
         .def(py::init<uint8_t>())
         .def(py::init<PyShortCode>())
-        .def(py::init<PyCommonCode>())
+        .def(py::init<PyLayout>())
 
 //        .def(py::hash(py::self))
 //        .def(py::self == py::self)
diff --git a/src/core_ffi/python_ffi/binder/klsk_code.cc b/src/core_ffi/python_ffi/binder/klsk_code.cc
index 7d39846..6ed4dea 100644
--- a/src/core_ffi/python_ffi/binder/klsk_code.cc
+++ b/src/core_ffi/python_ffi/binder/klsk_code.cc
@@ -1,14 +1,15 @@
+#include <pybind11/stl.h>
 #include <pybind11/operators.h>
 
 #include "binder.h"
+#include "py_ffi/layout.h"
 #include "py_ffi/short_code.h"
-#include "py_ffi/common_code.h"
 
+using klotski::ffi::PyLayout;
 using klotski::ffi::PyShortCode;
-using klotski::ffi::PyCommonCode;
 
-static void bind_common_code(const py::module_ &mod) {
-    py::class_<PyCommonCode>(mod, "Code")
+static void bind_layout(const py::module_ &mod) {
+    py::class_<PyLayout>(mod, "Layout")
         .def(py::init<uint64_t>())
         .def(py::init<PyShortCode>())
         .def(py::init<std::string_view>())
@@ -21,27 +22,27 @@ static void bind_common_code(const py::module_ &mod) {
         .def(py::self > uint64_t()).def(py::self >= uint64_t())
 
         .def(py::hash(py::self))
-        .def("__str__", &PyCommonCode::str)
-        .def("__int__", &PyCommonCode::value)
-        .def("__repr__", &PyCommonCode::repr)
+        .def("__str__", &PyLayout::str)
+        .def("__int__", &PyLayout::value)
+        .def("__repr__", &PyLayout::repr)
 
-        .def("next_cases", &PyCommonCode::next_cases)
+        .def("next_cases", &PyLayout::next_cases)
         // TODO: add fast_cal / fast_cal_multi / ...
 
-        .def("to_short_code", &PyCommonCode::short_code)
-        .def("to_string", &PyCommonCode::string, py::arg("shorten") = false)
+        .def("to_short_code", &PyLayout::short_code)
+        .def("to_string", &PyLayout::string, py::arg("shorten") = false)
 
-        .def_property_readonly("value", &PyCommonCode::value)
+        .def_property_readonly("value", &PyLayout::value)
         // TODO: add n_1x1 / n_1x2 / n_2x1 / ...
 
-        .def_static("check", py::overload_cast<uint64_t>(&PyCommonCode::check))
-        .def_static("check", py::overload_cast<std::string_view>(&PyCommonCode::check));
+        .def_static("check", py::overload_cast<uint64_t>(&PyLayout::check))
+        .def_static("check", py::overload_cast<std::string_view>(&PyLayout::check));
 }
 
 static void bind_short_code(const py::module_ &mod) {
     py::class_<PyShortCode>(mod, "ShortCode")
         .def(py::init<uint32_t>())
-        .def(py::init<PyCommonCode>())
+        .def(py::init<PyLayout>())
         .def(py::init<std::string_view>())
 
         .def(py::self == py::self)
@@ -58,7 +59,7 @@ static void bind_short_code(const py::module_ &mod) {
 
         .def_property_readonly("value", &PyShortCode::value)
 
-        .def("to_common_code", &PyShortCode::common_code)
+        .def("to_layout", &PyShortCode::layout)
 
         .def_static("check", py::overload_cast<uint32_t>(&PyShortCode::check))
         .def_static("check", py::overload_cast<std::string_view>(&PyShortCode::check))
@@ -67,6 +68,6 @@ static void bind_short_code(const py::module_ &mod) {
 }
 
 void bind_klsk_code(const py::module_ &mod) {
+    bind_layout(mod);
     bind_short_code(mod);
-    bind_common_code(mod);
 }
diff --git a/src/core_ffi/python_ffi/include/py_ffi/cases.h b/src/core_ffi/python_ffi/include/py_ffi/cases.h
index ca44870..63dbae0 100644
--- a/src/core_ffi/python_ffi/include/py_ffi/cases.h
+++ b/src/core_ffi/python_ffi/include/py_ffi/cases.h
@@ -5,7 +5,7 @@
 #include <variant>
 #include <ranges/ranges.h>
 
-#include "py_ffi/common_code.h"
+#include "py_ffi/layout.h"
 
 namespace klotski::ffi {
 
@@ -17,7 +17,7 @@ public:
     explicit PyCasesIter(const RangesUnion &data) noexcept;
 
     /// Get the next CommonCode or throw `stop_iteration` exception.
-    PyCommonCode next();
+    PyLayout next();
 
 private:
     size_t index_ {0};
@@ -25,12 +25,12 @@ private:
     const RangesUnion &data_;
 };
 
+// TODO: add `copy` and `pickle` support
+
 class PyCases {
 public:
     PyCases() = delete;
 
-    // TODO: add pickle support
-
     // ------------------------------------------------------------------------------------- //
 
     /// Constructing from r-value.
@@ -48,7 +48,9 @@ public:
     [[nodiscard]] PyCasesIter iter() const noexcept;
 
     /// Get the CommonCode of the specified index.
-    [[nodiscard]] PyCommonCode at(int32_t index) const;
+    [[nodiscard]] PyLayout at(int32_t index) const;
+
+    // TODO: add `contain` interface
 
     // ------------------------------------------------------------------------------------- //
 
diff --git a/src/core_ffi/python_ffi/include/py_ffi/fast_cal.h b/src/core_ffi/python_ffi/include/py_ffi/fast_cal.h
index 746caf6..a42c671 100644
--- a/src/core_ffi/python_ffi/include/py_ffi/fast_cal.h
+++ b/src/core_ffi/python_ffi/include/py_ffi/fast_cal.h
@@ -4,7 +4,7 @@
 
 #include <fast_cal/fast_cal.h>
 
-#include "py_ffi/common_code.h"
+#include "py_ffi/layout.h"
 
 namespace klotski::ffi {
 
@@ -12,14 +12,14 @@ using fast_cal::FastCal;
 
 class PyFastCal {
 public:
-    explicit PyFastCal(PyCommonCode code)
+    explicit PyFastCal(PyLayout code)
         : fast_cal_(FastCal(std::bit_cast<codec::CommonCode>(code).to_raw_code())) {}
 
     // TODO: export solution path directly
-    std::optional<PyCommonCode> solve() {
+    std::optional<PyLayout> solve() {
         auto tmp = fast_cal_.solve();
         if (tmp.has_value()) {
-            return std::bit_cast<PyCommonCode>(tmp.value().to_common_code());
+            return std::bit_cast<PyLayout>(tmp.value().to_common_code());
         }
         return std::nullopt;
     }
@@ -30,24 +30,24 @@ public:
         fast_cal_.build_all();
     }
 
-    [[nodiscard]] std::vector<PyCommonCode> backtrack(PyCommonCode code) const {
-        std::vector<PyCommonCode> path;
+    [[nodiscard]] std::vector<PyLayout> backtrack(PyLayout code) const {
+        std::vector<PyLayout> path;
         for (auto x : fast_cal_.backtrack(std::bit_cast<codec::CommonCode>(code).to_raw_code())) {
-            path.emplace_back(std::bit_cast<PyCommonCode>(x.to_common_code()));
+            path.emplace_back(std::bit_cast<PyLayout>(x.to_common_code()));
         }
         return path;
     }
 
-    [[nodiscard]] std::vector<std::vector<PyCommonCode>> exports() const {
-        std::vector<std::vector<PyCommonCode>> result;
+    [[nodiscard]] std::vector<std::vector<PyLayout>> exports() const {
+        std::vector<std::vector<PyLayout>> result;
 
         const auto data = fast_cal_.exports();
         result.reserve(data.size());
         for (const auto &layer_raw : data) {
-            std::vector<PyCommonCode> layer;
+            std::vector<PyLayout> layer;
             layer.reserve(layer_raw.size());
             for (auto x : layer_raw) {
-                layer.emplace_back(std::bit_cast<PyCommonCode>(x.to_common_code()));
+                layer.emplace_back(std::bit_cast<PyLayout>(x.to_common_code()));
             }
             result.emplace_back(layer);
         }
diff --git a/src/core_ffi/python_ffi/include/py_ffi/group.h b/src/core_ffi/python_ffi/include/py_ffi/group.h
index 300a223..d96dd86 100644
--- a/src/core_ffi/python_ffi/include/py_ffi/group.h
+++ b/src/core_ffi/python_ffi/include/py_ffi/group.h
@@ -7,7 +7,8 @@
 #include <group/group.h>
 
 #include "py_ffi/cases.h"
-#include "py_ffi/common_code.h"
+#include "py_ffi/layout.h"
+#include "py_ffi/short_code.h"
 
 namespace klotski::ffi {
 
@@ -44,9 +45,9 @@ private:
 
 class PyGroupUnion {
 public:
-    PyGroupUnion(uint8_t type_id);
-    PyGroupUnion(PyShortCode short_code);
-    PyGroupUnion(PyCommonCode common_code);
+    explicit PyGroupUnion(uint8_t type_id);
+    explicit PyGroupUnion(PyLayout layout);
+    explicit PyGroupUnion(PyShortCode short_code);
 
     [[nodiscard]] uint32_t value() const;
 
diff --git a/src/core_ffi/python_ffi/include/py_ffi/common_code.h b/src/core_ffi/python_ffi/include/py_ffi/layout.h
similarity index 61%
rename from src/core_ffi/python_ffi/include/py_ffi/common_code.h
rename to src/core_ffi/python_ffi/include/py_ffi/layout.h
index 2a230ea..2bec073 100644
--- a/src/core_ffi/python_ffi/include/py_ffi/common_code.h
+++ b/src/core_ffi/python_ffi/include/py_ffi/layout.h
@@ -7,24 +7,24 @@
 
 #include "py_ffi/short_code.h"
 
-// TODO: maybe using `PyLayout` instead of `PyCommonCode`
+// TODO: add `copy` and `pickle` support
 
 namespace klotski::ffi {
 
-class PyCommonCode {
+class PyLayout {
 public:
-    PyCommonCode() = delete;
+    PyLayout() = delete;
 
     // ------------------------------------------------------------------------------------- //
 
     /// Construct from origin u64 value.
-    explicit PyCommonCode(uint64_t code);
+    explicit PyLayout(uint64_t code);
 
     /// Construct from origin string form.
-    explicit PyCommonCode(std::string_view code);
+    explicit PyLayout(std::string_view code);
 
     /// Construct from PyShortCode object.
-    explicit PyCommonCode(PyShortCode code) noexcept;
+    explicit PyLayout(PyShortCode code) noexcept;
 
     // ------------------------------------------------------------------------------------- //
 
@@ -39,23 +39,23 @@ public:
     /// Get original value.
     [[nodiscard]] uint64_t value() const noexcept;
 
-    /// Convert CommonCode as ShortCode.
+    /// Convert Layout as ShortCode.
     [[nodiscard]] PyShortCode short_code() const noexcept;
 
-    /// Convert CommonCode as string form.
+    /// Convert Layout as string form.
     [[nodiscard]] std::string string(bool shorten) const noexcept;
 
     // ------------------------------------------------------------------------------------- //
 
     /// Wrapper of `__str__` method in Python.
-    static std::string str(PyCommonCode code) noexcept;
+    static std::string str(PyLayout code) noexcept;
 
     /// Wrapper of `__repr__` method in Python.
-    static std::string repr(PyCommonCode code) noexcept;
+    static std::string repr(PyLayout code) noexcept;
 
     // ------------------------------------------------------------------------------------- //
 
-    [[nodiscard]] std::vector<PyCommonCode> next_cases() const noexcept;
+    [[nodiscard]] std::vector<PyLayout> next_cases() const noexcept;
 
     // ------------------------------------------------------------------------------------- //
 
@@ -63,24 +63,24 @@ private:
     codec::CommonCode code_;
 };
 
-static_assert(std::is_trivially_copyable_v<PyCommonCode>);
-static_assert(sizeof(PyCommonCode) == sizeof(codec::CommonCode));
+static_assert(std::is_trivially_copyable_v<PyLayout>);
+static_assert(sizeof(PyLayout) == sizeof(codec::CommonCode));
 
 // ----------------------------------------------------------------------------------------- //
 
-constexpr auto operator==(const PyCommonCode &lhs, const uint64_t rhs) {
+constexpr auto operator==(const PyLayout &lhs, const uint64_t rhs) {
     return lhs.value() == rhs;
 }
 
-constexpr auto operator<=>(const PyCommonCode &lhs, const uint64_t rhs) {
+constexpr auto operator<=>(const PyLayout &lhs, const uint64_t rhs) {
     return lhs.value() <=> rhs;
 }
 
-constexpr auto operator==(const PyCommonCode &lhs, const PyCommonCode &rhs) {
+constexpr auto operator==(const PyLayout &lhs, const PyLayout &rhs) {
     return lhs.value() == rhs.value();
 }
 
-constexpr auto operator<=>(const PyCommonCode &lhs, const PyCommonCode &rhs) {
+constexpr auto operator<=>(const PyLayout &lhs, const PyLayout &rhs) {
     return lhs.value() <=> rhs.value();
 }
 
@@ -89,8 +89,8 @@ constexpr auto operator<=>(const PyCommonCode &lhs, const PyCommonCode &rhs) {
 } // namespace klotski::ffi
 
 template <>
-struct std::hash<klotski::ffi::PyCommonCode> {
-    size_t operator()(const klotski::ffi::PyCommonCode &code) const noexcept {
-        return std::hash<uint64_t>{}(code.value());
+struct std::hash<klotski::ffi::PyLayout> {
+    size_t operator()(const klotski::ffi::PyLayout &layout) const noexcept {
+        return std::hash<uint64_t>{}(layout.value());
     }
 };
diff --git a/src/core_ffi/python_ffi/include/py_ffi/short_code.h b/src/core_ffi/python_ffi/include/py_ffi/short_code.h
index 5a330fa..d33217e 100644
--- a/src/core_ffi/python_ffi/include/py_ffi/short_code.h
+++ b/src/core_ffi/python_ffi/include/py_ffi/short_code.h
@@ -6,7 +6,7 @@
 
 namespace klotski::ffi {
 
-class PyCommonCode;
+class PyLayout;
 
 class PyShortCode {
 public:
@@ -20,8 +20,8 @@ public:
     /// Construct from origin string form.
     explicit PyShortCode(std::string_view code);
 
-    /// Construct from PyCommonCode object.
-    explicit PyShortCode(PyCommonCode code) noexcept;
+    /// Construct from PyLayout object.
+    explicit PyShortCode(PyLayout code) noexcept;
 
     // ------------------------------------------------------------------------------------- //
 
@@ -36,8 +36,8 @@ public:
     /// Get original value.
     [[nodiscard]] uint32_t value() const noexcept;
 
-    /// Convert ShortCode as CommonCode.
-    [[nodiscard]] PyCommonCode common_code() const noexcept;
+    /// Convert ShortCode as Layout.
+    [[nodiscard]] PyLayout layout() const noexcept;
 
     // ------------------------------------------------------------------------------------- //
 
diff --git a/src/core_ffi/python_ffi/wrapper/cases.cc b/src/core_ffi/python_ffi/wrapper/cases.cc
index 8fae0c3..f75b37f 100644
--- a/src/core_ffi/python_ffi/wrapper/cases.cc
+++ b/src/core_ffi/python_ffi/wrapper/cases.cc
@@ -12,10 +12,10 @@ using klotski::cases::AllCases;
 
 PyCasesIter::PyCasesIter(const RangesUnion &data) noexcept : data_(data) {}
 
-PyCommonCode PyCasesIter::next() {
+PyLayout PyCasesIter::next() {
     while (head_ < 16) {
         if (const auto &ranges = data_.ranges(head_); index_ < ranges.size()) {
-            return std::bit_cast<PyCommonCode>((head_ << 32) | ranges[index_++]);
+            return std::bit_cast<PyLayout>((head_ << 32) | ranges[index_++]);
         }
         index_ = 0, ++head_;
     }
@@ -32,13 +32,13 @@ PyCasesIter PyCases::iter() const noexcept {
     return PyCasesIter(data_ref());
 }
 
-PyCommonCode PyCases::at(const int32_t index) const {
+PyLayout PyCases::at(const int32_t index) const {
     const auto size_ = static_cast<int32_t>(size());
     if (index >= size_ || index < -size_) {
         throw py::index_error("cases index out of range");
     }
     const auto code = data_ref()[index < 0 ? index + size_ : index];
-    return std::bit_cast<PyCommonCode>(code);
+    return std::bit_cast<PyLayout>(code);
 }
 
 // ----------------------------------------------------------------------------------------- //
diff --git a/src/core_ffi/python_ffi/wrapper/group_union.cc b/src/core_ffi/python_ffi/wrapper/group_union.cc
index 4838516..eac93ba 100644
--- a/src/core_ffi/python_ffi/wrapper/group_union.cc
+++ b/src/core_ffi/python_ffi/wrapper/group_union.cc
@@ -11,7 +11,7 @@ using klotski::ffi::PyGroupUnion;
 static klotski::group::GroupUnion convert(uint8_t type_id) {
     auto group_union = klotski::group::GroupUnion::create(type_id);
     if (!group_union.has_value()) {
-        throw PyExc_GroupError(std::format("invalid type id -> {}", type_id));
+        throw PyExc_GroupError(std::format("invalid type id: {}", type_id));
     }
     return group_union.value();
 }
@@ -22,8 +22,8 @@ PyGroupUnion::PyGroupUnion(const uint8_t type_id) :
 PyGroupUnion::PyGroupUnion(const PyShortCode short_code) :
     group_union_(GroupUnion::from_short_code(std::bit_cast<ShortCode>(short_code))) {}
 
-PyGroupUnion::PyGroupUnion(const PyCommonCode common_code) :
-    group_union_(GroupUnion::from_common_code(std::bit_cast<CommonCode>(common_code))) {}
+PyGroupUnion::PyGroupUnion(const PyLayout layout) :
+    group_union_(GroupUnion::from_common_code(std::bit_cast<CommonCode>(layout))) {}
 
 uint32_t PyGroupUnion::value() const {
     return group_union_.unwrap();
diff --git a/src/core_ffi/python_ffi/wrapper/common_codec.cc b/src/core_ffi/python_ffi/wrapper/layout.cc
similarity index 64%
rename from src/core_ffi/python_ffi/wrapper/common_codec.cc
rename to src/core_ffi/python_ffi/wrapper/layout.cc
index a24ecab..22e7d26 100644
--- a/src/core_ffi/python_ffi/wrapper/common_codec.cc
+++ b/src/core_ffi/python_ffi/wrapper/layout.cc
@@ -1,7 +1,7 @@
 #include <format>
 
 #include "exception.h"
-#include "py_ffi/common_code.h"
+#include "py_ffi/layout.h"
 
 using namespace klotski::ffi;
 using klotski::codec::ShortCode;
@@ -9,34 +9,34 @@ using klotski::codec::CommonCode;
 
 // ----------------------------------------------------------------------------------------- //
 
-uint64_t PyCommonCode::value() const noexcept {
+uint64_t PyLayout::value() const noexcept {
     return code_.unwrap();
 }
 
-std::string PyCommonCode::string(const bool shorten) const noexcept {
+std::string PyLayout::string(const bool shorten) const noexcept {
     return code_.to_string(shorten);
 }
 
-PyShortCode PyCommonCode::short_code() const noexcept {
+PyShortCode PyLayout::short_code() const noexcept {
     return std::bit_cast<PyShortCode>(code_.to_short_code());
 }
 
 // ----------------------------------------------------------------------------------------- //
 
-bool PyCommonCode::check(const uint64_t code) noexcept {
+bool PyLayout::check(const uint64_t code) noexcept {
     return CommonCode::check(code);
 }
 
-bool PyCommonCode::check(const std::string_view code) noexcept {
+bool PyLayout::check(const std::string_view code) noexcept {
     return CommonCode::from_string(code).has_value();
 }
 
 // ----------------------------------------------------------------------------------------- //
 
-[[nodiscard]] std::vector<PyCommonCode> PyCommonCode::next_cases() const noexcept {
-    std::vector<PyCommonCode> cases;
+[[nodiscard]] std::vector<PyLayout> PyLayout::next_cases() const noexcept {
+    std::vector<PyLayout> cases;
     auto mover = mover::MaskMover([&cases](const codec::RawCode code, uint64_t) {
-        cases.emplace_back(std::bit_cast<PyCommonCode>(code.to_common_code()));
+        cases.emplace_back(std::bit_cast<PyLayout>(code.to_common_code()));
     });
     mover.next_cases(code_.to_raw_code(), 0);
     return cases;
@@ -44,12 +44,12 @@ bool PyCommonCode::check(const std::string_view code) noexcept {
 
 // ----------------------------------------------------------------------------------------- //
 
-std::string PyCommonCode::str(const PyCommonCode code) noexcept {
+std::string PyLayout::str(const PyLayout code) noexcept {
     return code.code_.to_string();
 }
 
-std::string PyCommonCode::repr(const PyCommonCode code) noexcept {
-    return std::format("<klotski.Code 0x{}>", str(code));
+std::string PyLayout::repr(const PyLayout code) noexcept {
+    return std::format("<klotski.Layout 0x{}>", str(code));
 }
 
 // ----------------------------------------------------------------------------------------- //
@@ -72,8 +72,8 @@ static CommonCode convert(const std::string_view code) {
     throw PyExc_CodecError(std::format("invalid code: `{}`", code));
 }
 
-PyCommonCode::PyCommonCode(const uint64_t code) : code_(convert(code)) {}
-PyCommonCode::PyCommonCode(const std::string_view code) : code_(convert(code)) {}
-PyCommonCode::PyCommonCode(const PyShortCode code) noexcept : code_(convert(code)) {}
+PyLayout::PyLayout(const uint64_t code) : code_(convert(code)) {}
+PyLayout::PyLayout(const std::string_view code) : code_(convert(code)) {}
+PyLayout::PyLayout(const PyShortCode code) noexcept : code_(convert(code)) {}
 
 // ----------------------------------------------------------------------------------------- //
diff --git a/src/core_ffi/python_ffi/wrapper/short_code.cc b/src/core_ffi/python_ffi/wrapper/short_code.cc
index bfba390..a1aeca4 100644
--- a/src/core_ffi/python_ffi/wrapper/short_code.cc
+++ b/src/core_ffi/python_ffi/wrapper/short_code.cc
@@ -1,8 +1,8 @@
 #include <format>
 
 #include "exception.h"
+#include "py_ffi/layout.h"
 #include "py_ffi/short_code.h"
-#include "py_ffi/common_code.h"
 
 using namespace klotski::ffi;
 using klotski::codec::ShortCode;
@@ -14,8 +14,8 @@ uint32_t PyShortCode::value() const noexcept {
     return code_.unwrap();
 }
 
-PyCommonCode PyShortCode::common_code() const noexcept {
-    return std::bit_cast<PyCommonCode>(code_.to_common_code());
+PyLayout PyShortCode::layout() const noexcept {
+    return std::bit_cast<PyLayout>(code_.to_common_code());
 }
 
 // ----------------------------------------------------------------------------------------- //
@@ -40,8 +40,8 @@ std::string PyShortCode::repr(const PyShortCode code) noexcept {
 
 // ----------------------------------------------------------------------------------------- //
 
-static ShortCode convert(const PyCommonCode code) noexcept {
-    return std::bit_cast<CommonCode>(code).to_short_code();
+static ShortCode convert(const PyLayout layout) noexcept {
+    return std::bit_cast<CommonCode>(layout).to_short_code();
 }
 
 static ShortCode convert(const uint32_t code) {
@@ -60,6 +60,6 @@ static ShortCode convert(const std::string_view code) {
 
 PyShortCode::PyShortCode(const uint32_t code) : code_(convert(code)) {}
 PyShortCode::PyShortCode(const std::string_view code) : code_(convert(code)) {}
-PyShortCode::PyShortCode(const PyCommonCode code) noexcept : code_(convert(code)) {}
+PyShortCode::PyShortCode(const PyLayout code) noexcept : code_(convert(code)) {}
 
 // ----------------------------------------------------------------------------------------- //