diff --git a/src/entrypoints/run.ts b/src/entrypoints/run.ts
index b79d7bb..ca24252 100644
--- a/src/entrypoints/run.ts
+++ b/src/entrypoints/run.ts
@@ -142,6 +142,19 @@ async function run() {
     // Phase 1: Prepare
     const actionInputsPresent = collectActionInputsPresence();
     context = parseGitHubContext();
+    // Debug: dump event details for issues events (M4 debugging)
+    if (context.eventName === "issues") {
+      console.log(
+        `[debug] issues event — eventAction: ${(context as any).eventAction}`,
+      );
+      console.log(
+        `[debug] payload.action: ${(context as any).payload?.action}`,
+      );
+      console.log(
+        `[debug] payload.label: ${JSON.stringify((context as any).payload?.label)}`,
+      );
+      console.log(`[debug] LABEL_TRIGGER env: ${process.env.LABEL_TRIGGER}`);
+    }
     const modeName = detectMode(context);
     console.log(
       `Auto-detected mode: ${modeName} for event: ${context.eventName}`,