diff --git a/libs/core/langchain_core/messages/utils.py b/libs/core/langchain_core/messages/utils.py
index 9e9c5228cb2..f78d877e595 100644
--- a/libs/core/langchain_core/messages/utils.py
+++ b/libs/core/langchain_core/messages/utils.py
@@ -29,6 +29,9 @@ from typing import (
     overload,
 )
 
+from pydantic import Discriminator, Field
+from typing_extensions import Annotated
+
 from langchain_core.messages.ai import AIMessage, AIMessageChunk
 from langchain_core.messages.base import BaseMessage, BaseMessageChunk
 from langchain_core.messages.chat import ChatMessage, ChatMessageChunk
@@ -45,19 +48,23 @@ if TYPE_CHECKING:
     from langchain_core.prompt_values import PromptValue
     from langchain_core.runnables.base import Runnable
 
-AnyMessage = Union[
-    AIMessage,
-    HumanMessage,
-    ChatMessage,
-    SystemMessage,
-    FunctionMessage,
-    ToolMessage,
-    AIMessageChunk,
-    HumanMessageChunk,
-    ChatMessageChunk,
-    SystemMessageChunk,
-    FunctionMessageChunk,
-    ToolMessageChunk,
+
+AnyMessage = Annotated[
+    Union[
+        AIMessage,
+        HumanMessage,
+        ChatMessage,
+        SystemMessage,
+        FunctionMessage,
+        ToolMessage,
+        AIMessageChunk,
+        HumanMessageChunk,
+        ChatMessageChunk,
+        SystemMessageChunk,
+        FunctionMessageChunk,
+        ToolMessageChunk,
+    ],
+    Field(discriminator=Discriminator("type")),
 ]
 
 
diff --git a/libs/core/tests/unit_tests/prompts/__snapshots__/test_chat.ambr b/libs/core/tests/unit_tests/prompts/__snapshots__/test_chat.ambr
index 29ab354d126..7c3c2ffb456 100644
--- a/libs/core/tests/unit_tests/prompts/__snapshots__/test_chat.ambr
+++ b/libs/core/tests/unit_tests/prompts/__snapshots__/test_chat.ambr
@@ -1349,7 +1349,24 @@
       'history': dict({
         'default': None,
         'items': dict({
-          'anyOf': list([
+          'discriminator': dict({
+            'mapping': dict({
+              'AIMessageChunk': '#/$defs/AIMessageChunk',
+              'ChatMessageChunk': '#/$defs/ChatMessageChunk',
+              'FunctionMessageChunk': '#/$defs/FunctionMessageChunk',
+              'HumanMessageChunk': '#/$defs/HumanMessageChunk',
+              'SystemMessageChunk': '#/$defs/SystemMessageChunk',
+              'ToolMessageChunk': '#/$defs/ToolMessageChunk',
+              'ai': '#/$defs/AIMessage',
+              'chat': '#/$defs/ChatMessage',
+              'function': '#/$defs/FunctionMessage',
+              'human': '#/$defs/HumanMessage',
+              'system': '#/$defs/SystemMessage',
+              'tool': '#/$defs/ToolMessage',
+            }),
+            'propertyName': 'type',
+          }),
+          'oneOf': list([
             dict({
               '$ref': '#/$defs/AIMessage',
             }),
@@ -2752,7 +2769,24 @@
     'properties': dict({
       'history': dict({
         'items': dict({
-          'anyOf': list([
+          'discriminator': dict({
+            'mapping': dict({
+              'AIMessageChunk': '#/$defs/AIMessageChunk',
+              'ChatMessageChunk': '#/$defs/ChatMessageChunk',
+              'FunctionMessageChunk': '#/$defs/FunctionMessageChunk',
+              'HumanMessageChunk': '#/$defs/HumanMessageChunk',
+              'SystemMessageChunk': '#/$defs/SystemMessageChunk',
+              'ToolMessageChunk': '#/$defs/ToolMessageChunk',
+              'ai': '#/$defs/AIMessage',
+              'chat': '#/$defs/ChatMessage',
+              'function': '#/$defs/FunctionMessage',
+              'human': '#/$defs/HumanMessage',
+              'system': '#/$defs/SystemMessage',
+              'tool': '#/$defs/ToolMessage',
+            }),
+            'propertyName': 'type',
+          }),
+          'oneOf': list([
             dict({
               '$ref': '#/$defs/AIMessage',
             }),
diff --git a/libs/core/tests/unit_tests/runnables/__snapshots__/test_graph.ambr b/libs/core/tests/unit_tests/runnables/__snapshots__/test_graph.ambr
index 2a6ff6ad79c..34929ad3abd 100644
--- a/libs/core/tests/unit_tests/runnables/__snapshots__/test_graph.ambr
+++ b/libs/core/tests/unit_tests/runnables/__snapshots__/test_graph.ambr
@@ -1710,40 +1710,61 @@
               'type': 'string',
             }),
             dict({
-              '$ref': '#/$defs/AIMessage',
-            }),
-            dict({
-              '$ref': '#/$defs/HumanMessage',
-            }),
-            dict({
-              '$ref': '#/$defs/ChatMessage',
-            }),
-            dict({
-              '$ref': '#/$defs/SystemMessage',
-            }),
-            dict({
-              '$ref': '#/$defs/FunctionMessage',
-            }),
-            dict({
-              '$ref': '#/$defs/ToolMessage',
-            }),
-            dict({
-              '$ref': '#/$defs/AIMessageChunk',
-            }),
-            dict({
-              '$ref': '#/$defs/HumanMessageChunk',
-            }),
-            dict({
-              '$ref': '#/$defs/ChatMessageChunk',
-            }),
-            dict({
-              '$ref': '#/$defs/SystemMessageChunk',
-            }),
-            dict({
-              '$ref': '#/$defs/FunctionMessageChunk',
-            }),
-            dict({
-              '$ref': '#/$defs/ToolMessageChunk',
+              'discriminator': dict({
+                'mapping': dict({
+                  'AIMessageChunk': '#/$defs/AIMessageChunk',
+                  'ChatMessageChunk': '#/$defs/ChatMessageChunk',
+                  'FunctionMessageChunk': '#/$defs/FunctionMessageChunk',
+                  'HumanMessageChunk': '#/$defs/HumanMessageChunk',
+                  'SystemMessageChunk': '#/$defs/SystemMessageChunk',
+                  'ToolMessageChunk': '#/$defs/ToolMessageChunk',
+                  'ai': '#/$defs/AIMessage',
+                  'chat': '#/$defs/ChatMessage',
+                  'function': '#/$defs/FunctionMessage',
+                  'human': '#/$defs/HumanMessage',
+                  'system': '#/$defs/SystemMessage',
+                  'tool': '#/$defs/ToolMessage',
+                }),
+                'propertyName': 'type',
+              }),
+              'oneOf': list([
+                dict({
+                  '$ref': '#/$defs/AIMessage',
+                }),
+                dict({
+                  '$ref': '#/$defs/HumanMessage',
+                }),
+                dict({
+                  '$ref': '#/$defs/ChatMessage',
+                }),
+                dict({
+                  '$ref': '#/$defs/SystemMessage',
+                }),
+                dict({
+                  '$ref': '#/$defs/FunctionMessage',
+                }),
+                dict({
+                  '$ref': '#/$defs/ToolMessage',
+                }),
+                dict({
+                  '$ref': '#/$defs/AIMessageChunk',
+                }),
+                dict({
+                  '$ref': '#/$defs/HumanMessageChunk',
+                }),
+                dict({
+                  '$ref': '#/$defs/ChatMessageChunk',
+                }),
+                dict({
+                  '$ref': '#/$defs/SystemMessageChunk',
+                }),
+                dict({
+                  '$ref': '#/$defs/FunctionMessageChunk',
+                }),
+                dict({
+                  '$ref': '#/$defs/ToolMessageChunk',
+                }),
+              ]),
             }),
           ]),
           'title': 'RunnableParallel<as_list,as_str>Input',
diff --git a/libs/core/tests/unit_tests/runnables/__snapshots__/test_runnable.ambr b/libs/core/tests/unit_tests/runnables/__snapshots__/test_runnable.ambr
index b9d75f3c74d..07be8ecbd5d 100644
--- a/libs/core/tests/unit_tests/runnables/__snapshots__/test_runnable.ambr
+++ b/libs/core/tests/unit_tests/runnables/__snapshots__/test_runnable.ambr
@@ -6525,7 +6525,24 @@
     'properties': dict({
       'history': dict({
         'items': dict({
-          'anyOf': list([
+          'discriminator': dict({
+            'mapping': dict({
+              'AIMessageChunk': '#/$defs/AIMessageChunk',
+              'ChatMessageChunk': '#/$defs/ChatMessageChunk',
+              'FunctionMessageChunk': '#/$defs/FunctionMessageChunk',
+              'HumanMessageChunk': '#/$defs/HumanMessageChunk',
+              'SystemMessageChunk': '#/$defs/SystemMessageChunk',
+              'ToolMessageChunk': '#/$defs/ToolMessageChunk',
+              'ai': '#/$defs/AIMessage',
+              'chat': '#/$defs/ChatMessage',
+              'function': '#/$defs/FunctionMessage',
+              'human': '#/$defs/HumanMessage',
+              'system': '#/$defs/SystemMessage',
+              'tool': '#/$defs/ToolMessage',
+            }),
+            'propertyName': 'type',
+          }),
+          'oneOf': list([
             dict({
               '$ref': '#/$defs/AIMessage',
             }),
@@ -6973,7 +6990,24 @@
         'properties': dict({
           'messages': dict({
             'items': dict({
-              'anyOf': list([
+              'discriminator': dict({
+                'mapping': dict({
+                  'AIMessageChunk': '#/$defs/AIMessageChunk',
+                  'ChatMessageChunk': '#/$defs/ChatMessageChunk',
+                  'FunctionMessageChunk': '#/$defs/FunctionMessageChunk',
+                  'HumanMessageChunk': '#/$defs/HumanMessageChunk',
+                  'SystemMessageChunk': '#/$defs/SystemMessageChunk',
+                  'ToolMessageChunk': '#/$defs/ToolMessageChunk',
+                  'ai': '#/$defs/AIMessage',
+                  'chat': '#/$defs/ChatMessage',
+                  'function': '#/$defs/FunctionMessage',
+                  'human': '#/$defs/HumanMessage',
+                  'system': '#/$defs/SystemMessage',
+                  'tool': '#/$defs/ToolMessage',
+                }),
+                'propertyName': 'type',
+              }),
+              'oneOf': list([
                 dict({
                   '$ref': '#/$defs/AIMessage',
                 }),
@@ -8035,7 +8069,24 @@
       }),
       dict({
         'items': dict({
-          'anyOf': list([
+          'discriminator': dict({
+            'mapping': dict({
+              'AIMessageChunk': '#/definitions/AIMessageChunk',
+              'ChatMessageChunk': '#/definitions/ChatMessageChunk',
+              'FunctionMessageChunk': '#/definitions/FunctionMessageChunk',
+              'HumanMessageChunk': '#/definitions/HumanMessageChunk',
+              'SystemMessageChunk': '#/definitions/SystemMessageChunk',
+              'ToolMessageChunk': '#/definitions/ToolMessageChunk',
+              'ai': '#/definitions/AIMessage',
+              'chat': '#/definitions/ChatMessage',
+              'function': '#/definitions/FunctionMessage',
+              'human': '#/definitions/HumanMessage',
+              'system': '#/definitions/SystemMessage',
+              'tool': '#/definitions/ToolMessage',
+            }),
+            'propertyName': 'type',
+          }),
+          'oneOf': list([
             dict({
               '$ref': '#/definitions/AIMessage',
             }),
@@ -8473,7 +8524,24 @@
         'properties': dict({
           'messages': dict({
             'items': dict({
-              'anyOf': list([
+              'discriminator': dict({
+                'mapping': dict({
+                  'AIMessageChunk': '#/definitions/AIMessageChunk',
+                  'ChatMessageChunk': '#/definitions/ChatMessageChunk',
+                  'FunctionMessageChunk': '#/definitions/FunctionMessageChunk',
+                  'HumanMessageChunk': '#/definitions/HumanMessageChunk',
+                  'SystemMessageChunk': '#/definitions/SystemMessageChunk',
+                  'ToolMessageChunk': '#/definitions/ToolMessageChunk',
+                  'ai': '#/definitions/AIMessage',
+                  'chat': '#/definitions/ChatMessage',
+                  'function': '#/definitions/FunctionMessage',
+                  'human': '#/definitions/HumanMessage',
+                  'system': '#/definitions/SystemMessage',
+                  'tool': '#/definitions/ToolMessage',
+                }),
+                'propertyName': 'type',
+              }),
+              'oneOf': list([
                 dict({
                   '$ref': '#/definitions/AIMessage',
                 }),
@@ -9513,44 +9581,6 @@
 # ---
 # name: test_schemas[fake_chat_output_schema]
   dict({
-    'anyOf': list([
-      dict({
-        '$ref': '#/definitions/AIMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/HumanMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/ChatMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/SystemMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/FunctionMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/ToolMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/AIMessageChunk',
-      }),
-      dict({
-        '$ref': '#/definitions/HumanMessageChunk',
-      }),
-      dict({
-        '$ref': '#/definitions/ChatMessageChunk',
-      }),
-      dict({
-        '$ref': '#/definitions/SystemMessageChunk',
-      }),
-      dict({
-        '$ref': '#/definitions/FunctionMessageChunk',
-      }),
-      dict({
-        '$ref': '#/definitions/ToolMessageChunk',
-      }),
-    ]),
     'definitions': dict({
       'AIMessage': dict({
         'additionalProperties': True,
@@ -10893,6 +10923,61 @@
         'type': 'object',
       }),
     }),
+    'discriminator': dict({
+      'mapping': dict({
+        'AIMessageChunk': '#/definitions/AIMessageChunk',
+        'ChatMessageChunk': '#/definitions/ChatMessageChunk',
+        'FunctionMessageChunk': '#/definitions/FunctionMessageChunk',
+        'HumanMessageChunk': '#/definitions/HumanMessageChunk',
+        'SystemMessageChunk': '#/definitions/SystemMessageChunk',
+        'ToolMessageChunk': '#/definitions/ToolMessageChunk',
+        'ai': '#/definitions/AIMessage',
+        'chat': '#/definitions/ChatMessage',
+        'function': '#/definitions/FunctionMessage',
+        'human': '#/definitions/HumanMessage',
+        'system': '#/definitions/SystemMessage',
+        'tool': '#/definitions/ToolMessage',
+      }),
+      'propertyName': 'type',
+    }),
+    'oneOf': list([
+      dict({
+        '$ref': '#/definitions/AIMessage',
+      }),
+      dict({
+        '$ref': '#/definitions/HumanMessage',
+      }),
+      dict({
+        '$ref': '#/definitions/ChatMessage',
+      }),
+      dict({
+        '$ref': '#/definitions/SystemMessage',
+      }),
+      dict({
+        '$ref': '#/definitions/FunctionMessage',
+      }),
+      dict({
+        '$ref': '#/definitions/ToolMessage',
+      }),
+      dict({
+        '$ref': '#/definitions/AIMessageChunk',
+      }),
+      dict({
+        '$ref': '#/definitions/HumanMessageChunk',
+      }),
+      dict({
+        '$ref': '#/definitions/ChatMessageChunk',
+      }),
+      dict({
+        '$ref': '#/definitions/SystemMessageChunk',
+      }),
+      dict({
+        '$ref': '#/definitions/FunctionMessageChunk',
+      }),
+      dict({
+        '$ref': '#/definitions/ToolMessageChunk',
+      }),
+    ]),
     'title': 'FakeListChatModelOutput',
   })
 # ---
@@ -10910,7 +10995,24 @@
       }),
       dict({
         'items': dict({
-          'anyOf': list([
+          'discriminator': dict({
+            'mapping': dict({
+              'AIMessageChunk': '#/definitions/AIMessageChunk',
+              'ChatMessageChunk': '#/definitions/ChatMessageChunk',
+              'FunctionMessageChunk': '#/definitions/FunctionMessageChunk',
+              'HumanMessageChunk': '#/definitions/HumanMessageChunk',
+              'SystemMessageChunk': '#/definitions/SystemMessageChunk',
+              'ToolMessageChunk': '#/definitions/ToolMessageChunk',
+              'ai': '#/definitions/AIMessage',
+              'chat': '#/definitions/ChatMessage',
+              'function': '#/definitions/FunctionMessage',
+              'human': '#/definitions/HumanMessage',
+              'system': '#/definitions/SystemMessage',
+              'tool': '#/definitions/ToolMessage',
+            }),
+            'propertyName': 'type',
+          }),
+          'oneOf': list([
             dict({
               '$ref': '#/definitions/AIMessage',
             }),
@@ -11348,7 +11450,24 @@
         'properties': dict({
           'messages': dict({
             'items': dict({
-              'anyOf': list([
+              'discriminator': dict({
+                'mapping': dict({
+                  'AIMessageChunk': '#/definitions/AIMessageChunk',
+                  'ChatMessageChunk': '#/definitions/ChatMessageChunk',
+                  'FunctionMessageChunk': '#/definitions/FunctionMessageChunk',
+                  'HumanMessageChunk': '#/definitions/HumanMessageChunk',
+                  'SystemMessageChunk': '#/definitions/SystemMessageChunk',
+                  'ToolMessageChunk': '#/definitions/ToolMessageChunk',
+                  'ai': '#/definitions/AIMessage',
+                  'chat': '#/definitions/ChatMessage',
+                  'function': '#/definitions/FunctionMessage',
+                  'human': '#/definitions/HumanMessage',
+                  'system': '#/definitions/SystemMessage',
+                  'tool': '#/definitions/ToolMessage',
+                }),
+                'propertyName': 'type',
+              }),
+              'oneOf': list([
                 dict({
                   '$ref': '#/definitions/AIMessage',
                 }),
@@ -12393,40 +12512,61 @@
         'type': 'string',
       }),
       dict({
-        '$ref': '#/definitions/AIMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/HumanMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/ChatMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/SystemMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/FunctionMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/ToolMessage',
-      }),
-      dict({
-        '$ref': '#/definitions/AIMessageChunk',
-      }),
-      dict({
-        '$ref': '#/definitions/HumanMessageChunk',
-      }),
-      dict({
-        '$ref': '#/definitions/ChatMessageChunk',
-      }),
-      dict({
-        '$ref': '#/definitions/SystemMessageChunk',
-      }),
-      dict({
-        '$ref': '#/definitions/FunctionMessageChunk',
-      }),
-      dict({
-        '$ref': '#/definitions/ToolMessageChunk',
+        'discriminator': dict({
+          'mapping': dict({
+            'AIMessageChunk': '#/definitions/AIMessageChunk',
+            'ChatMessageChunk': '#/definitions/ChatMessageChunk',
+            'FunctionMessageChunk': '#/definitions/FunctionMessageChunk',
+            'HumanMessageChunk': '#/definitions/HumanMessageChunk',
+            'SystemMessageChunk': '#/definitions/SystemMessageChunk',
+            'ToolMessageChunk': '#/definitions/ToolMessageChunk',
+            'ai': '#/definitions/AIMessage',
+            'chat': '#/definitions/ChatMessage',
+            'function': '#/definitions/FunctionMessage',
+            'human': '#/definitions/HumanMessage',
+            'system': '#/definitions/SystemMessage',
+            'tool': '#/definitions/ToolMessage',
+          }),
+          'propertyName': 'type',
+        }),
+        'oneOf': list([
+          dict({
+            '$ref': '#/definitions/AIMessage',
+          }),
+          dict({
+            '$ref': '#/definitions/HumanMessage',
+          }),
+          dict({
+            '$ref': '#/definitions/ChatMessage',
+          }),
+          dict({
+            '$ref': '#/definitions/SystemMessage',
+          }),
+          dict({
+            '$ref': '#/definitions/FunctionMessage',
+          }),
+          dict({
+            '$ref': '#/definitions/ToolMessage',
+          }),
+          dict({
+            '$ref': '#/definitions/AIMessageChunk',
+          }),
+          dict({
+            '$ref': '#/definitions/HumanMessageChunk',
+          }),
+          dict({
+            '$ref': '#/definitions/ChatMessageChunk',
+          }),
+          dict({
+            '$ref': '#/definitions/SystemMessageChunk',
+          }),
+          dict({
+            '$ref': '#/definitions/FunctionMessageChunk',
+          }),
+          dict({
+            '$ref': '#/definitions/ToolMessageChunk',
+          }),
+        ]),
       }),
     ]),
     'definitions': dict({
@@ -14172,7 +14312,24 @@
         'properties': dict({
           'messages': dict({
             'items': dict({
-              'anyOf': list([
+              'discriminator': dict({
+                'mapping': dict({
+                  'AIMessageChunk': '#/definitions/AIMessageChunk',
+                  'ChatMessageChunk': '#/definitions/ChatMessageChunk',
+                  'FunctionMessageChunk': '#/definitions/FunctionMessageChunk',
+                  'HumanMessageChunk': '#/definitions/HumanMessageChunk',
+                  'SystemMessageChunk': '#/definitions/SystemMessageChunk',
+                  'ToolMessageChunk': '#/definitions/ToolMessageChunk',
+                  'ai': '#/definitions/AIMessage',
+                  'chat': '#/definitions/ChatMessage',
+                  'function': '#/definitions/FunctionMessage',
+                  'human': '#/definitions/HumanMessage',
+                  'system': '#/definitions/SystemMessage',
+                  'tool': '#/definitions/ToolMessage',
+                }),
+                'propertyName': 'type',
+              }),
+              'oneOf': list([
                 dict({
                   '$ref': '#/definitions/AIMessage',
                 }),
@@ -15631,7 +15788,24 @@
         'properties': dict({
           'messages': dict({
             'items': dict({
-              'anyOf': list([
+              'discriminator': dict({
+                'mapping': dict({
+                  'AIMessageChunk': '#/definitions/AIMessageChunk',
+                  'ChatMessageChunk': '#/definitions/ChatMessageChunk',
+                  'FunctionMessageChunk': '#/definitions/FunctionMessageChunk',
+                  'HumanMessageChunk': '#/definitions/HumanMessageChunk',
+                  'SystemMessageChunk': '#/definitions/SystemMessageChunk',
+                  'ToolMessageChunk': '#/definitions/ToolMessageChunk',
+                  'ai': '#/definitions/AIMessage',
+                  'chat': '#/definitions/ChatMessage',
+                  'function': '#/definitions/FunctionMessage',
+                  'human': '#/definitions/HumanMessage',
+                  'system': '#/definitions/SystemMessage',
+                  'tool': '#/definitions/ToolMessage',
+                }),
+                'propertyName': 'type',
+              }),
+              'oneOf': list([
                 dict({
                   '$ref': '#/definitions/AIMessage',
                 }),
diff --git a/libs/core/tests/unit_tests/test_prompt_values.py b/libs/core/tests/unit_tests/test_prompt_values.py
index 625cd51202b..6a08a4270ac 100644
--- a/libs/core/tests/unit_tests/test_prompt_values.py
+++ b/libs/core/tests/unit_tests/test_prompt_values.py
@@ -1,5 +1,3 @@
-import pytest
-
 from langchain_core.messages import (
     AIMessage,
     AIMessageChunk,
@@ -13,7 +11,6 @@ from langchain_core.messages import (
 from langchain_core.prompt_values import ChatPromptValueConcrete
 
 
-@pytest.mark.xfail(reason="Broken union type.")
 def test_chat_prompt_value_concrete() -> None:
     messages: list = [
         AIMessage("foo"),
diff --git a/libs/langchain/tests/unit_tests/test_schema.py b/libs/langchain/tests/unit_tests/test_schema.py
index 1c4136a60e9..aa0cc26dd9a 100644
--- a/libs/langchain/tests/unit_tests/test_schema.py
+++ b/libs/langchain/tests/unit_tests/test_schema.py
@@ -16,6 +16,7 @@ from langchain_core.messages import (
     HumanMessageChunk,
     SystemMessage,
     SystemMessageChunk,
+    ToolMessage,
 )
 from langchain_core.outputs import ChatGeneration, ChatGenerationChunk, Generation
 from langchain_core.prompt_values import ChatPromptValueConcrete, StringPromptValue
@@ -73,7 +74,12 @@ def test_serialization_of_wellknown_objects() -> None:
             content="human",
         ),
         StringPromptValue(text="hello"),
+        ChatPromptValueConcrete(messages=[AIMessage(content="foo")]),
         ChatPromptValueConcrete(messages=[HumanMessage(content="human")]),
+        ChatPromptValueConcrete(
+            messages=[ToolMessage(content="foo", tool_call_id="bar")]
+        ),
+        ChatPromptValueConcrete(messages=[SystemMessage(content="foo")]),
         Document(page_content="hello"),
         AgentFinish(return_values={}, log=""),
         AgentAction(tool="tool", tool_input="input", log=""),