diff --git a/src/main/java/com/tiedup/remake/client/gltf/GltfClientSetup.java b/src/main/java/com/tiedup/remake/client/gltf/GltfClientSetup.java
index 8868887..4fa21f6 100644
--- a/src/main/java/com/tiedup/remake/client/gltf/GltfClientSetup.java
+++ b/src/main/java/com/tiedup/remake/client/gltf/GltfClientSetup.java
@@ -118,6 +118,10 @@ public final class GltfClientSetup {
             LOGGER.info(
                 "[GltfPipeline] Data-driven item reload listener registered"
             );
+
+            // GLB structural validation (runs after item definitions are loaded)
+            event.registerReloadListener(new com.tiedup.remake.client.gltf.diagnostic.GlbValidationReloadListener());
+            LOGGER.info("[GltfPipeline] GLB validation reload listener registered");
         }
     }
 
diff --git a/src/main/java/com/tiedup/remake/client/gltf/diagnostic/GlbValidationReloadListener.java b/src/main/java/com/tiedup/remake/client/gltf/diagnostic/GlbValidationReloadListener.java
new file mode 100644
index 0000000..bf724b4
--- /dev/null
+++ b/src/main/java/com/tiedup/remake/client/gltf/diagnostic/GlbValidationReloadListener.java
@@ -0,0 +1,138 @@
+package com.tiedup.remake.client.gltf.diagnostic;
+
+import com.tiedup.remake.v2.bondage.datadriven.DataDrivenItemDefinition;
+import com.tiedup.remake.v2.bondage.datadriven.DataDrivenItemRegistry;
+import java.io.InputStream;
+import java.util.Collection;
+import java.util.List;
+import java.util.Optional;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.packs.resources.Resource;
+import net.minecraft.server.packs.resources.ResourceManager;
+import net.minecraft.server.packs.resources.SimplePreparableReloadListener;
+import net.minecraft.util.profiling.ProfilerFiller;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.api.distmarker.OnlyIn;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+/**
+ * Reload listener that validates all data-driven item GLB models on resource
+ * reload (F3+T or startup).
+ *
+ * <p>Must be registered AFTER {@link com.tiedup.remake.v2.bondage.datadriven.DataDrivenItemReloadListener}
+ * so that the item registry is populated before validation runs.</p>
+ *
+ * <p>On each reload:
+ * <ol>
+ *   <li>Clears the {@link GlbDiagnosticRegistry}</li>
+ *   <li>Iterates all {@link DataDrivenItemDefinition}s</li>
+ *   <li>For each definition with a model location, attempts to open the GLB
+ *       resource and runs {@link GlbValidator#validate} on it</li>
+ *   <li>Records results into the diagnostic registry and logs a summary</li>
+ * </ol>
+ */
+@OnlyIn(Dist.CLIENT)
+public class GlbValidationReloadListener
+    extends SimplePreparableReloadListener<Void>
+{
+
+    private static final Logger LOGGER = LogManager.getLogger("GltfValidation");
+
+    @Override
+    protected Void prepare(
+        ResourceManager resourceManager,
+        ProfilerFiller profiler
+    ) {
+        return null;
+    }
+
+    @Override
+    protected void apply(
+        Void nothing,
+        ResourceManager resourceManager,
+        ProfilerFiller profiler
+    ) {
+        GlbDiagnosticRegistry.clear();
+
+        Collection<DataDrivenItemDefinition> definitions =
+            DataDrivenItemRegistry.getAll();
+
+        if (definitions.isEmpty()) {
+            LOGGER.warn(
+                "[GltfValidation] No data-driven item definitions found — skipping GLB validation"
+            );
+            return;
+        }
+
+        int passed = 0;
+        int withWarnings = 0;
+        int withErrors = 0;
+
+        for (DataDrivenItemDefinition def : definitions) {
+            ResourceLocation modelLoc = def.modelLocation();
+            if (modelLoc == null) {
+                continue;
+            }
+
+            Optional<Resource> resourceOpt =
+                resourceManager.getResource(modelLoc);
+
+            if (resourceOpt.isEmpty()) {
+                // GLB file not found in any resource pack
+                GlbValidationResult missingResult = GlbValidationResult.of(
+                    modelLoc,
+                    List.of(new GlbDiagnostic(
+                        modelLoc,
+                        def.id(),
+                        GlbDiagnostic.Severity.ERROR,
+                        "MISSING_GLB",
+                        "GLB file not found: " + modelLoc
+                            + " (referenced by item " + def.id() + ")"
+                    ))
+                );
+                GlbDiagnosticRegistry.addResult(missingResult);
+                withErrors++;
+                continue;
+            }
+
+            try (InputStream stream = resourceOpt.get().open()) {
+                GlbValidationResult result =
+                    GlbValidator.validate(stream, modelLoc);
+                GlbDiagnosticRegistry.addResult(result);
+
+                if (!result.passed()) {
+                    withErrors++;
+                } else if (hasWarnings(result)) {
+                    withWarnings++;
+                } else {
+                    passed++;
+                }
+            } catch (Exception e) {
+                GlbValidationResult errorResult = GlbValidationResult.of(
+                    modelLoc,
+                    List.of(new GlbDiagnostic(
+                        modelLoc,
+                        def.id(),
+                        GlbDiagnostic.Severity.ERROR,
+                        "GLB_READ_ERROR",
+                        "Failed to read GLB file: " + e.getMessage()
+                    ))
+                );
+                GlbDiagnosticRegistry.addResult(errorResult);
+                withErrors++;
+            }
+        }
+
+        int total = passed + withWarnings + withErrors;
+        LOGGER.info(
+            "[GltfValidation] Validated {} GLBs: {} passed, {} with warnings, {} with errors",
+            total, passed, withWarnings, withErrors
+        );
+    }
+
+    private static boolean hasWarnings(GlbValidationResult result) {
+        return result.diagnostics().stream()
+            .anyMatch(d -> d.severity() == GlbDiagnostic.Severity.WARNING);
+    }
+}