diff --git a/libs/core/langchain_core/messages/ai.py b/libs/core/langchain_core/messages/ai.py
index a829641cce8..2f800319335 100644
--- a/libs/core/langchain_core/messages/ai.py
+++ b/libs/core/langchain_core/messages/ai.py
@@ -213,7 +213,11 @@ class AIMessage(BaseMessage):
         otherwise, does best-effort parsing to standard types.
         """
         blocks: list[types.ContentBlock] = []
-        content = [self.content] if isinstance(self.content, str) else self.content
+        content = (
+            [self.content]
+            if isinstance(self.content, str) and self.content
+            else self.content
+        )
         for item in content:
             if isinstance(item, str):
                 blocks.append({"type": "text", "text": item})
@@ -227,6 +231,7 @@ class AIMessage(BaseMessage):
                         "that this attribute is set on initialization."
                     )
                     raise ValueError(msg)
+                blocks.append(cast("types.ContentBlock", item))
             else:
                 pass
 
diff --git a/libs/core/tests/unit_tests/messages/test_ai.py b/libs/core/tests/unit_tests/messages/test_ai.py
index d36d0347128..ef6a38750b8 100644
--- a/libs/core/tests/unit_tests/messages/test_ai.py
+++ b/libs/core/tests/unit_tests/messages/test_ai.py
@@ -1,5 +1,8 @@
+from typing import Union, cast
+
 from langchain_core.load import dumpd, load
 from langchain_core.messages import AIMessage, AIMessageChunk
+from langchain_core.messages import content_blocks as types
 from langchain_core.messages.ai import (
     InputTokenDetails,
     OutputTokenDetails,
@@ -196,3 +199,71 @@ def test_add_ai_message_chunks_usage() -> None:
             output_token_details=OutputTokenDetails(audio=1, reasoning=2),
         ),
     )
+
+
+class ReasoningContentBlockWithID(types.ReasoningContentBlock):
+    id: str
+
+
+def test_beta_content() -> None:
+    # Simple case
+    message = AIMessage("Hello")
+    assert len(message.beta_content) == 1
+    assert message.beta_content[0]["type"] == "text"
+    for block in message.beta_content:
+        if block["type"] == "text":
+            text_block: types.TextContentBlock = block
+            assert text_block == {"type": "text", "text": "Hello"}
+
+    # With tool calls
+    message = AIMessage(
+        "",
+        tool_calls=[
+            {"type": "tool_call", "name": "foo", "args": {"a": "b"}, "id": "abc_123"}
+        ],
+    )
+    assert len(message.beta_content) == 1
+    assert message.beta_content[0]["type"] == "tool_call"
+    for block in message.beta_content:
+        if block["type"] == "tool_call":
+            tool_call_block: types.ToolCallContentBlock = block
+            assert tool_call_block == {"type": "tool_call", "id": "abc_123"}
+
+    # With standard blocks
+    reasoning_with_id: ReasoningContentBlockWithID = {
+        "type": "reasoning",
+        "reasoning": "foo",
+        "id": "rs_abc123",
+    }
+    standard_content: list[types.ContentBlock] = [
+        {"type": "reasoning", "reasoning": "foo"},
+        reasoning_with_id,
+        {"type": "text", "text": "bar"},
+        {
+            "type": "text",
+            "text": "baz",
+            "annotations": [{"type": "url_citation", "url": "http://example.com"}],
+        },
+        {
+            "type": "image",
+            "source_type": "url",
+            "url": "http://example.com/image.png",
+        },
+        {
+            "type": "non_standard",
+            "value": {"custom_key": "custom_value", "another_key": 123},
+        },
+        {
+            "type": "tool_call",
+            "id": "abc_123",
+        },
+    ]
+    message = AIMessage(
+        cast("list[Union[str, dict]]", standard_content),
+        tool_calls=[
+            {"type": "tool_call", "name": "foo", "args": {"a": "b"}, "id": "abc_123"},
+            {"type": "tool_call", "name": "bar", "args": {"c": "d"}, "id": "abc_234"},
+        ],
+    )
+    missing_tool_call = {"type": "tool_call", "id": "abc_234"}
+    assert message.beta_content == [*standard_content, missing_tool_call]