diff --git a/src/lambdas/agent-runner/handler.py b/src/lambdas/agent-runner/handler.py
index cd35982..a58c69e 100644
--- a/src/lambdas/agent-runner/handler.py
+++ b/src/lambdas/agent-runner/handler.py
@@ -67,7 +67,17 @@ def update_user_status(actor_id: str, name: str, status: str) -> None:
     )
 
 
+# Per-invocation dedup: track sent message hashes to prevent AgentCore retry duplicates
+_sent_hashes: set = set()
+
+
 def send_telegram_direct(chat_id: str, token: str, text: str) -> None:
+    import hashlib
+    h = hashlib.md5(f'{chat_id}:{text}'.encode()).hexdigest()[:12]
+    if h in _sent_hashes:
+        print(f'[agent-runner] dedup: skipping duplicate message (hash={h})')
+        return
+    _sent_hashes.add(h)
     url = f'https://api.telegram.org/bot{token}/sendMessage'
     data = json.dumps({'chat_id': chat_id, 'text': text}).encode()
     req = urllib.request.Request(url, data=data, headers={'Content-Type': 'application/json'})