diff --git a/src/router.ts b/src/router.ts
index edecea8..5d374a7 100644
--- a/src/router.ts
+++ b/src/router.ts
@@ -130,6 +130,16 @@ export class EventRouter {
       return;
     }
 
+    // Ignore messages from other agents (unless explicitly @mentioned)
+    // Prevents infinite reply loops between agents
+    if (authorType === 'agent') {
+      if (!content.includes(`@${this.config.slug}`)) {
+        this.log.info('│  Skipping agent message (not mentioned): @%s "%s"', resolvedAuthorSlug, content.slice(0, 80));
+        return;
+      }
+      this.log.info('│  Processing agent message (mentioned): @%s', resolvedAuthorSlug);
+    }
+
     // System messages: only process if agent is explicitly mentioned (@slug)
     // This lets assignment/mention notifications through, but ignores generic lifecycle events
     if (authorType === 'system') {