diff --git a/app/services/guidance_functions.py b/app/services/guidance_functions.py
new file mode 100644
index 00000000..18e6f9dc
--- /dev/null
+++ b/app/services/guidance_functions.py
@@ -0,0 +1,3 @@
+def truncate(history: list[any], max_length: int):
+    return history[-max_length:]
+
diff --git a/app/services/guidance_wrapper.py b/app/services/guidance_wrapper.py
index 43f94177..6c7243bb 100644
--- a/app/services/guidance_wrapper.py
+++ b/app/services/guidance_wrapper.py
@@ -2,6 +2,7 @@
 
 from app.config import LLMModelConfig
 from app.models.dtos import Content, ContentType
+from app.services.guidance_functions import truncate
 
 
 class GuidanceWrapper:
@@ -30,6 +31,7 @@ def query(self) -> Content:
         template = guidance(self.handlebars)
         result = template(
             llm=self._get_llm(),
+            truncate=truncate,
             **self.parameters,
         )