From 91b7552f09a69cfc672480b1df3701c0b3c9a8da Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=8E=98=E6=9D=83=20=E9=A9=AC?= <mashenquan@fuzhi.ai>
Date: Tue, 29 Aug 2023 11:33:50 +0800
Subject: [PATCH] fixbug: fix get_by_tags

---
 metagpt/roles/role.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/metagpt/roles/role.py b/metagpt/roles/role.py
index 5d2cce802..aba7d4574 100644
--- a/metagpt/roles/role.py
+++ b/metagpt/roles/role.py
@@ -95,7 +95,9 @@ class RoleContext(BaseModel):
     @property
     def prerequisite(self):
         """Retrieve information with `prerequisite` tag"""
-        return self.memory.get_by_tags([MessageTag.Prerequisite.value])
+        if self.memory and hasattr(self.memory, 'get_by_tags'):
+            return self.memory.get_by_tags([MessageTag.Prerequisite.value])
+        return ""
 
 
 class Role: