core: populate tool_calls when initializing AIMessage via content_blocks

libs/core/langchain_core/messages/ai.py

@@ -203,6 +203,13 @@ class AIMessage(BaseMessage):
     ) -> None:
         """Specify content as a positional arg or content_blocks for typing support."""
         if content_blocks is not None:
+            # If there are tool calls in content_blocks, but not in tool_calls, add them
+            content_tool_calls = [
+                block for block in content_blocks if block.get("type") == "tool_call"
+            ]
+            if content_tool_calls and "tool_calls" not in kwargs:
+                kwargs["tool_calls"] = content_tool_calls
+
             super().__init__(
                 content=cast("Union[str, list[Union[str, dict]]]", content_blocks),
                 **kwargs,
@@ -273,7 +280,9 @@ class AIMessage(BaseMessage):
         # Ensure "type" is properly set on all tool call-like dicts.
         if tool_calls := values.get("tool_calls"):
             values["tool_calls"] = [
-                create_tool_call(**{k: v for k, v in tc.items() if k != "type"})
+                create_tool_call(
+                    **{k: v for k, v in tc.items() if k not in ("type", "extras")}
+                )
                 for tc in tool_calls
             ]
         if invalid_tool_calls := values.get("invalid_tool_calls"):

libs/core/tests/unit_tests/messages/test_ai.py

@@ -253,7 +253,7 @@ def test_content_blocks() -> None:
             "id": "abc_123",
         },
     ]
-    missing_tool_call = {
+    missing_tool_call: types.ToolCall = {
         "type": "tool_call",
         "name": "bar",
         "args": {"c": "d"},
@@ -267,3 +267,20 @@ def test_content_blocks() -> None:
         ],
     )
     assert message.content_blocks == [*standard_content, missing_tool_call]
+
+    # Check we auto-populate tool_calls
+    standard_content = [
+        {"type": "text", "text": "foo"},
+        {
+            "type": "tool_call",
+            "name": "foo",
+            "args": {"a": "b"},
+            "id": "abc_123",
+        },
+        missing_tool_call,
+    ]
+    message = AIMessage(content_blocks=standard_content)
+    assert message.tool_calls == [
+        {"type": "tool_call", "name": "foo", "args": {"a": "b"}, "id": "abc_123"},
+        missing_tool_call,
+    ]