diff --git a/src/uipath_langchain/agent/react/types.py b/src/uipath_langchain/agent/react/types.py
index 68d794b11..028a16a03 100644
--- a/src/uipath_langchain/agent/react/types.py
+++ b/src/uipath_langchain/agent/react/types.py
@@ -81,19 +81,15 @@ class MemoryConfig(BaseModel):
     # Defaults match FE episodic memory settings (agentEditor.ts:324-328)
     result_count: int = Field(default=3, ge=1, le=10)
     threshold: float = Field(default=0.0, ge=0.0, le=1.0)
-    field_weights: dict[str, float] = Field(
+    field_weights: dict[str, float] | None = Field(
+        default=None,
         description=(
             "Per-field search weights. Keys are input field names, values are "
-            "weights between 0.0 and 1.0. At least one field must be specified."
+            "weights between 0.0 and 1.0. When None, all input fields are "
+            "searched with default weights."
         ),
     )
 
-    @model_validator(mode="after")
-    def _validate_field_weights(self) -> "MemoryConfig":
-        if not self.field_weights:
-            raise ValueError("field_weights must contain at least one field")
-        return self
-
 
 class AgentGraphConfig(BaseModel):
     llm_messages_limit: int = Field(