diff --git a/AGENTS.md b/AGENTS.md
index f3c4dc8..bf08955 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -42,6 +42,7 @@ to the custom scripts instead of system-installed packages.
 - **4-space indentation**
 - **No semicolons after closing braces** for namespaces/classes
 - `auto` for obvious types (e.g. `auto main(...) -> int`)
+- **East const** (e.g. `char const*` not `const char*`)
 - `<>` includes only for system headers (std, OS, etc.)
 - `""` includes for third-party dependencies (e.g. `fmt`, `nlohmann/json`)
 - **Naming:** `snake_case` for variables, functions, and classes
diff --git a/cbt/opengl/buffer.cpp b/cbt/opengl/buffer.cpp
index 38d527c..1cd9766 100644
--- a/cbt/opengl/buffer.cpp
+++ b/cbt/opengl/buffer.cpp
@@ -45,7 +45,7 @@ auto buffer::unbind() const -> void {
     glBindBuffer(static_cast<GLenum>(m_type), 0);
 }
 
-auto buffer::upload(const void* data, size_t size) -> void {
+auto buffer::upload(void const* data, size_t size) -> void {
     bind();
     glBufferData(static_cast<GLenum>(m_type), size, data, GL_STATIC_DRAW);
     unbind();
@@ -55,7 +55,7 @@ auto buffer::upload(std::vector<uint8_t> data) -> void {
     upload(data.data(), data.size());
 }
 
-auto buffer::upload_dynamic(const void* data, size_t size) -> void {
+auto buffer::upload_dynamic(void const* data, size_t size) -> void {
     bind();
     glBufferData(static_cast<GLenum>(m_type), size, data, GL_DYNAMIC_DRAW);
     unbind();
diff --git a/cbt/opengl/buffer.hpp b/cbt/opengl/buffer.hpp
index e959c9c..5dbd631 100644
--- a/cbt/opengl/buffer.hpp
+++ b/cbt/opengl/buffer.hpp
@@ -23,17 +23,17 @@ public:
     explicit buffer(buffer_type type);
     ~buffer();
 
-    buffer(const buffer&) = delete;
-    buffer& operator=(const buffer&) = delete;
+    buffer(buffer const&) = delete;
+    buffer& operator=(buffer const&) = delete;
 
     buffer(buffer&& other) noexcept;
     buffer& operator=(buffer&& other) noexcept;
 
     auto bind() const -> void;
     auto unbind() const -> void;
-    auto upload(const void* data, size_t size) -> void;
+    auto upload(void const* data, size_t size) -> void;
     auto upload(std::vector<uint8_t> data) -> void;
-    auto upload_dynamic(const void* data, size_t size) -> void;
+    auto upload_dynamic(void const* data, size_t size) -> void;
     auto id() const -> GLuint;
     auto valid() const -> bool;
 };
diff --git a/cbt/opengl/context.cpp b/cbt/opengl/context.cpp
index a550d98..04adf10 100644
--- a/cbt/opengl/context.cpp
+++ b/cbt/opengl/context.cpp
@@ -33,10 +33,10 @@ auto context::setup_gl() -> bool {
 
 auto context::print_info() -> void {
     fmt::print("OpenGL Info:\n");
-    fmt::print("  vendor  | {}\n", std::string_view(reinterpret_cast<const char*>(glGetString(GL_VENDOR))));
-    fmt::print("  renderer| {}\n", std::string_view(reinterpret_cast<const char*>(glGetString(GL_RENDERER))));
-    fmt::print("  version | {}\n", std::string_view(reinterpret_cast<const char*>(glGetString(GL_VERSION))));
-    fmt::print("  glsl    | {}\n", std::string_view(reinterpret_cast<const char*>(glGetString(GL_SHADING_LANGUAGE_VERSION))));
+    fmt::print("  vendor  | {}\n", std::string_view(reinterpret_cast<char const*>(glGetString(GL_VENDOR))));
+    fmt::print("  renderer| {}\n", std::string_view(reinterpret_cast<char const*>(glGetString(GL_RENDERER))));
+    fmt::print("  version | {}\n", std::string_view(reinterpret_cast<char const*>(glGetString(GL_VERSION))));
+    fmt::print("  glsl    | {}\n", std::string_view(reinterpret_cast<char const*>(glGetString(GL_SHADING_LANGUAGE_VERSION))));
     fmt::print("\n");
 }
 
diff --git a/cbt/opengl/shader.cpp b/cbt/opengl/shader.cpp
index 0c31153..b730d43 100644
--- a/cbt/opengl/shader.cpp
+++ b/cbt/opengl/shader.cpp
@@ -31,7 +31,7 @@ shader& shader::operator=(shader&& other) noexcept {
     return *this;
 }
 
-auto shader::compile_vertex(const char* source) -> bool {
+auto shader::compile_vertex(char const* source) -> bool {
     auto vert = glCreateShader(GL_VERTEX_SHADER);
     glShaderSource(vert, 1, &source, nullptr);
     glCompileShader(vert);
@@ -55,7 +55,7 @@ auto shader::compile_vertex(const char* source) -> bool {
     return true;
 }
 
-auto shader::compile_fragment(const char* source) -> bool {
+auto shader::compile_fragment(char const* source) -> bool {
     auto frag = glCreateShader(GL_FRAGMENT_SHADER);
     glShaderSource(frag, 1, &source, nullptr);
     glCompileShader(frag);
diff --git a/cbt/opengl/shader.hpp b/cbt/opengl/shader.hpp
index 0494296..5864a5a 100644
--- a/cbt/opengl/shader.hpp
+++ b/cbt/opengl/shader.hpp
@@ -13,14 +13,14 @@ public:
     shader();
     ~shader();
 
-    shader(const shader&) = delete;
-    shader& operator=(const shader&) = delete;
+    shader(shader const&) = delete;
+    shader& operator=(shader const&) = delete;
 
     shader(shader&& other) noexcept;
     shader& operator=(shader&& other) noexcept;
 
-    auto compile_vertex(const char* source) -> bool;
-    auto compile_fragment(const char* source) -> bool;
+    auto compile_vertex(char const* source) -> bool;
+    auto compile_fragment(char const* source) -> bool;
     auto link() -> bool;
     auto use() const -> void;
     auto unuse() const -> void;
diff --git a/cbt/opengl/texture.cpp b/cbt/opengl/texture.cpp
index 9e9b815..4702a64 100644
--- a/cbt/opengl/texture.cpp
+++ b/cbt/opengl/texture.cpp
@@ -46,7 +46,7 @@ auto texture::unbind() -> void {
     glBindTexture(static_cast<GLenum>(m_target), 0);
 }
 
-auto texture::upload(const void* data, int width, int height, texture_format format, texture_type type) -> void {
+auto texture::upload(void const* data, int width, int height, texture_format format, texture_type type) -> void {
     bind();
     glTexImage2D(static_cast<GLenum>(m_target), 0,
                  static_cast<GLenum>(format), width, height, 0,
diff --git a/cbt/opengl/texture.hpp b/cbt/opengl/texture.hpp
index d77f856..6329074 100644
--- a/cbt/opengl/texture.hpp
+++ b/cbt/opengl/texture.hpp
@@ -38,15 +38,15 @@ public:
     explicit texture(texture_target target);
     ~texture();
 
-    texture(const texture&) = delete;
-    texture& operator=(const texture&) = delete;
+    texture(texture const&) = delete;
+    texture& operator=(texture const&) = delete;
 
     texture(texture&& other) noexcept;
     texture& operator=(texture&& other) noexcept;
 
     auto bind(GLuint unit = 0) -> void;
     auto unbind() -> void;
-    auto upload(const void* data, int width, int height, texture_format format, texture_type type) -> void;
+    auto upload(void const* data, int width, int height, texture_format format, texture_type type) -> void;
     auto set_filter(GLenum min_filter, GLenum mag_filter) -> void;
     auto set_wrap(GLenum wrap_s, GLenum wrap_t) -> void;
     auto generate_mipmaps() -> void;
diff --git a/cbt/opengl/vao.hpp b/cbt/opengl/vao.hpp
index 41603e5..ca07609 100644
--- a/cbt/opengl/vao.hpp
+++ b/cbt/opengl/vao.hpp
@@ -11,8 +11,8 @@ public:
     vao();
     ~vao();
 
-    vao(const vao&) = delete;
-    vao& operator=(const vao&) = delete;
+    vao(vao const&) = delete;
+    vao& operator=(vao const&) = delete;
 
     vao(vao&& other) noexcept;
     vao& operator=(vao&& other) noexcept;
diff --git a/cuber.cpp b/cuber.cpp
index 8ae2f44..5ec52b7 100644
--- a/cuber.cpp
+++ b/cuber.cpp
@@ -19,7 +19,7 @@ auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
     // compile shader
     auto prog = cbt::opengl::shader();
 
-    const char* vert_src = R"glsl(
+    char const* vert_src = R"glsl(
         #version 410 core
         layout(location = 0) in vec3 a_pos;
         layout(location = 1) in vec3 a_color;
@@ -30,7 +30,7 @@ auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
         }
     )glsl";
 
-    const char* frag_src = R"glsl(
+    char const* frag_src = R"glsl(
         #version 410 core
         in vec3 v_color;
         out vec4 frag_color;