rfc core: basemessage.text

libs/core/langchain_core/messages/base.py

@@ -92,6 +92,27 @@ def get_lc_namespace(cls) -> list[str]:
         """
         return ["langchain", "schema", "messages"]
 
+    def text(self) -> str:
+        """Get the text content of the message.
+
+        Returns:
+            The text content of the message.
+        """
+        if isinstance(self.content, str):
+            return self.content
+
+        # must be a list
+        blocks = [
+            block
+            for block in self.content
+            if isinstance(block, str)
+            or block.get("type") == "text"
+            and isinstance(block.get("text"), str)
+        ]
+        return "".join(
+            block if isinstance(block, str) else block["text"] for block in blocks
+        )
+
     def __add__(self, other: Any) -> ChatPromptTemplate:
         """Concatenate this message with another message."""
         from langchain_core.prompts.chat import ChatPromptTemplate