diff --git a/docs/modernization/build-inventory.md b/docs/modernization/build-inventory.md
index a8b4cd2..807fae4 100644
--- a/docs/modernization/build-inventory.md
+++ b/docs/modernization/build-inventory.md
@@ -167,6 +167,8 @@ Known local toolchain state:
   texture unit selection also consume the backend mapping. Canvas undo/redo
   dirty-region texture updates and readbacks also consume the backend-owned 2D
   texture target, RGBA pixel format, and unsigned-byte component mapping.
+  `NodeViewport` preview rendering also consumes backend-owned viewport query,
+  clear-color query, color-buffer clear mask, and blend-state tokens.
 - `windows-msvc-vcpkg-headless` validates manifest install/configure/build/test
   for the current headless component matrix; see DEBT-0007 for remaining app
   and platform triplet migration.
diff --git a/docs/modernization/roadmap.md b/docs/modernization/roadmap.md
index 4a2baa1..f649c72 100644
--- a/docs/modernization/roadmap.md
+++ b/docs/modernization/roadmap.md
@@ -433,6 +433,9 @@ delegate to `pp_renderer_gl`; `Font` no longer spells GL enum names directly.
 Canvas undo/redo dirty-region texture updates and readbacks now also delegate
 their 2D texture target, RGBA pixel format, and unsigned-byte component type
 mapping to `pp_renderer_gl`.
+`NodeViewport` preview rendering now also delegates viewport query,
+clear-color query, color-buffer clear mask, and blend-state tokens to
+`pp_renderer_gl`.
 The existing renderer classes are not yet fully
 behind the renderer interfaces.
 
diff --git a/src/node_viewport.cpp b/src/node_viewport.cpp
index dab2aad..3c8f43d 100644
--- a/src/node_viewport.cpp
+++ b/src/node_viewport.cpp
@@ -1,6 +1,7 @@
 #include "pch.h"
 #include "log.h"
 #include "node_viewport.h"
+#include "renderer_gl/opengl_capabilities.h"
 #include "shader.h"
 #include "app.h"
 
@@ -11,24 +12,24 @@ void NodeViewport::draw()
 
     GLint vp[4];
     GLfloat cc[4];
-    glGetIntegerv(GL_VIEWPORT, vp);
-    glGetFloatv(GL_COLOR_CLEAR_VALUE, cc);
+    glGetIntegerv(pp::renderer::gl::viewport_query(), vp);
+    glGetFloatv(pp::renderer::gl::color_clear_value_query(), cc);
 
     glClearColor(1, 0, 0, 1);
-    glClear(GL_COLOR_BUFFER_BIT);
+    glClear(pp::renderer::gl::framebuffer_color_buffer_mask());
     auto box = m_clip * root()->m_zoom;
     glm::ivec4 c = (glm::ivec4)glm::vec4(box.x, (int)(vp[3] - box.y - box.w), box.z, box.w);
     glViewport(c.x + App::I->off_x, c.y + App::I->off_y, c.z, c.w);
     TextureManager::get(m_tex_id).bind();
     m_sampler->bind(0);
-    glEnable(GL_BLEND);
+    glEnable(pp::renderer::gl::blend_state());
     ShaderManager::use(kShader::Texture);
     ShaderManager::u_int(kShaderUniform::Tex, 0);
     ShaderManager::u_mat4(kShaderUniform::MVP, proj * cam);
     m_faces->draw_fill();
     m_sampler->unbind();
     TextureManager::get(m_tex_id).unbind();
-    glDisable(GL_BLEND);
+    glDisable(pp::renderer::gl::blend_state());
 
     glViewport(vp[0], vp[1], vp[2], vp[3]);
     glClearColor(cc[0], cc[1], cc[2], cc[3]);
diff --git a/src/renderer_gl/opengl_capabilities.cpp b/src/renderer_gl/opengl_capabilities.cpp
index 93fcd6a..8409639 100644
--- a/src/renderer_gl/opengl_capabilities.cpp
+++ b/src/renderer_gl/opengl_capabilities.cpp
@@ -35,6 +35,9 @@ constexpr std::uint32_t gl_debug_severity_notification = 0x826BU;
 constexpr std::uint32_t gl_src_alpha = 0x0302U;
 constexpr std::uint32_t gl_one_minus_src_alpha = 0x0303U;
 constexpr std::uint32_t gl_line_smooth = 0x0B20U;
+constexpr std::uint32_t gl_viewport = 0x0BA2U;
+constexpr std::uint32_t gl_blend = 0x0BE2U;
+constexpr std::uint32_t gl_color_clear_value = 0x0C22U;
 constexpr std::uint32_t gl_scissor_test = 0x0C11U;
 constexpr std::uint32_t gl_depth_test = 0x0B71U;
 constexpr std::uint32_t gl_func_add = 0x8006U;
@@ -480,6 +483,21 @@ std::uint32_t shading_language_version_string_name() noexcept
     return gl_shading_language_version;
 }
 
+std::uint32_t viewport_query() noexcept
+{
+    return gl_viewport;
+}
+
+std::uint32_t color_clear_value_query() noexcept
+{
+    return gl_color_clear_value;
+}
+
+std::uint32_t blend_state() noexcept
+{
+    return gl_blend;
+}
+
 std::uint32_t depth_test_state() noexcept
 {
     return gl_depth_test;
diff --git a/src/renderer_gl/opengl_capabilities.h b/src/renderer_gl/opengl_capabilities.h
index 3e304bb..0ecd9d0 100644
--- a/src/renderer_gl/opengl_capabilities.h
+++ b/src/renderer_gl/opengl_capabilities.h
@@ -99,6 +99,9 @@ struct OpenGlReadbackFormat {
 [[nodiscard]] std::uint32_t vendor_string_name() noexcept;
 [[nodiscard]] std::uint32_t renderer_string_name() noexcept;
 [[nodiscard]] std::uint32_t shading_language_version_string_name() noexcept;
+[[nodiscard]] std::uint32_t viewport_query() noexcept;
+[[nodiscard]] std::uint32_t color_clear_value_query() noexcept;
+[[nodiscard]] std::uint32_t blend_state() noexcept;
 [[nodiscard]] std::uint32_t depth_test_state() noexcept;
 [[nodiscard]] std::uint32_t scissor_test_state() noexcept;
 [[nodiscard]] std::uint32_t program_point_size_state() noexcept;
diff --git a/tests/renderer_gl/capabilities_tests.cpp b/tests/renderer_gl/capabilities_tests.cpp
index dfd24ab..471ae43 100644
--- a/tests/renderer_gl/capabilities_tests.cpp
+++ b/tests/renderer_gl/capabilities_tests.cpp
@@ -324,6 +324,9 @@ void maps_app_initialization_parameters(pp::tests::Harness& h)
     PP_EXPECT(h, pp::renderer::gl::renderer_string_name() == 0x1F01U);
     PP_EXPECT(h, pp::renderer::gl::shading_language_version_string_name() == 0x8B8CU);
 
+    PP_EXPECT(h, pp::renderer::gl::viewport_query() == 0x0BA2U);
+    PP_EXPECT(h, pp::renderer::gl::color_clear_value_query() == 0x0C22U);
+    PP_EXPECT(h, pp::renderer::gl::blend_state() == 0x0BE2U);
     PP_EXPECT(h, pp::renderer::gl::depth_test_state() == 0x0B71U);
     PP_EXPECT(h, pp::renderer::gl::scissor_test_state() == 0x0C11U);
     PP_EXPECT(h, pp::renderer::gl::program_point_size_state() == 0x8642U);