diff --git a/libs/core/langchain_core/_api/deprecation.py b/libs/core/langchain_core/_api/deprecation.py
index 45930c3e6c..1492e21780 100644
--- a/libs/core/langchain_core/_api/deprecation.py
+++ b/libs/core/langchain_core/_api/deprecation.py
@@ -331,7 +331,7 @@ def deprecated(
             if not _obj_type:
                 _obj_type = "attribute"
             wrapped = None
-            _name = _name or cast("type | Callable", obj.fget).__qualname__
+            _name = _name or cast("type", obj.fget).__qualname__
             old_doc = obj.__doc__
 
             class _DeprecatedProperty(property):
@@ -386,7 +386,7 @@ def deprecated(
                 return cast("T", prop)
 
         else:
-            _name = _name or cast("type | Callable", obj).__qualname__
+            _name = _name or cast("type", obj).__qualname__
             if not _obj_type:
                 # edge case: when a function is within another function
                 # within a test, this will call it a "method" not a "function"
diff --git a/libs/core/langchain_core/agents.py b/libs/core/langchain_core/agents.py
index 76f818b06a..1ccc1c1585 100644
--- a/libs/core/langchain_core/agents.py
+++ b/libs/core/langchain_core/agents.py
@@ -51,7 +51,7 @@ class AgentAction(Serializable):
     tool: str
     """The name of the `Tool` to execute."""
 
-    tool_input: str | dict
+    tool_input: str | dict[Any, Any]
     """The input to pass in to the `Tool`."""
 
     log: str
@@ -68,7 +68,9 @@ class AgentAction(Serializable):
     type: Literal["AgentAction"] = "AgentAction"
 
     # Override init to support instantiation by position for backward compat.
-    def __init__(self, tool: str, tool_input: str | dict, log: str, **kwargs: Any):
+    def __init__(
+        self, tool: str, tool_input: str | dict[Any, Any], log: str, **kwargs: Any
+    ):
         """Create an `AgentAction`.
 
         Args:
@@ -149,7 +151,7 @@ class AgentFinish(Serializable):
     Agents return an `AgentFinish` when they have reached a stopping condition.
     """
 
-    return_values: dict
+    return_values: dict[Any, Any]
     """Dictionary of return values."""
 
     log: str
@@ -164,7 +166,7 @@ class AgentFinish(Serializable):
     """
     type: Literal["AgentFinish"] = "AgentFinish"
 
-    def __init__(self, return_values: dict, log: str, **kwargs: Any):
+    def __init__(self, return_values: dict[Any, Any], log: str, **kwargs: Any):
         """Override init to support instantiation by position for backward compat."""
         super().__init__(return_values=return_values, log=log, **kwargs)
 
diff --git a/libs/core/langchain_core/callbacks/manager.py b/libs/core/langchain_core/callbacks/manager.py
index c1ba9b76c0..40fd907272 100644
--- a/libs/core/langchain_core/callbacks/manager.py
+++ b/libs/core/langchain_core/callbacks/manager.py
@@ -214,7 +214,7 @@ async def atrace_as_chain_group(
             await run_manager.on_chain_end({})
 
 
-Func = TypeVar("Func", bound=Callable)
+Func = TypeVar("Func", bound=Callable[..., Any])
 
 
 def shielded(func: Func) -> Func:
@@ -327,9 +327,7 @@ def handle_event(
                 # running coroutine, which we cannot interrupt to run this one.
                 # The solution is to run the synchronous function on the globally shared
                 # thread pool executor to avoid blocking the main event loop.
-                _executor().submit(
-                    cast("Callable", copy_context().run), _run_coros, coros
-                ).result()
+                _executor().submit(copy_context().run, _run_coros, coros).result()
             else:
                 # If there's no running loop, we can run the coroutines directly.
                 _run_coros(coros)
@@ -381,10 +379,7 @@ async def _ahandle_event_for_handler(
             else:
                 await asyncio.get_event_loop().run_in_executor(
                     None,
-                    cast(
-                        "Callable",
-                        functools.partial(copy_context().run, event, *args, **kwargs),
-                    ),
+                    functools.partial(copy_context().run, event, *args, **kwargs),
                 )
     except NotImplementedError as e:
         if event_name == "on_chat_model_start":
diff --git a/libs/core/langchain_core/chat_sessions.py b/libs/core/langchain_core/chat_sessions.py
index ed8c6343c5..c4219217ea 100644
--- a/libs/core/langchain_core/chat_sessions.py
+++ b/libs/core/langchain_core/chat_sessions.py
@@ -1,7 +1,7 @@
 """**Chat Sessions** are a collection of messages and function calls."""
 
 from collections.abc import Sequence
-from typing import TypedDict
+from typing import Any, TypedDict
 
 from langchain_core.messages import BaseMessage
 
@@ -15,5 +15,5 @@ class ChatSession(TypedDict, total=False):
     messages: Sequence[BaseMessage]
     """A sequence of the LangChain chat messages loaded from the source."""
 
-    functions: Sequence[dict]
+    functions: Sequence[dict[str, Any]]
     """A sequence of the function calling specs for the messages."""
diff --git a/libs/core/langchain_core/document_loaders/langsmith.py b/libs/core/langchain_core/document_loaders/langsmith.py
index 23a44e05d4..3c6a04b886 100644
--- a/libs/core/langchain_core/document_loaders/langsmith.py
+++ b/libs/core/langchain_core/document_loaders/langsmith.py
@@ -48,7 +48,7 @@ class LangSmithLoader(BaseLoader):
         inline_s3_urls: bool = True,
         offset: int = 0,
         limit: int | None = None,
-        metadata: dict | None = None,
+        metadata: dict[str, Any] | None = None,
         filter: str | None = None,  # noqa: A002
         content_key: str = "",
         format_content: Callable[..., str] | None = None,
diff --git a/libs/core/langchain_core/documents/base.py b/libs/core/langchain_core/documents/base.py
index 969ee49a17..efb2e23e90 100644
--- a/libs/core/langchain_core/documents/base.py
+++ b/libs/core/langchain_core/documents/base.py
@@ -52,7 +52,7 @@ class BaseMedia(Serializable):
     as a UUID, but this will not be enforced.
     """
 
-    metadata: dict = Field(default_factory=dict)
+    metadata: dict[Any, Any] = Field(default_factory=dict)
     """Arbitrary metadata associated with the content."""
 
 
@@ -218,7 +218,7 @@ class Blob(BaseMedia):
         encoding: str = "utf-8",
         mime_type: str | None = None,
         guess_type: bool = True,
-        metadata: dict | None = None,
+        metadata: dict[Any, Any] | None = None,
     ) -> Blob:
         """Load the blob from a path like object.
 
@@ -255,7 +255,7 @@ class Blob(BaseMedia):
         encoding: str = "utf-8",
         mime_type: str | None = None,
         path: str | None = None,
-        metadata: dict | None = None,
+        metadata: dict[Any, Any] | None = None,
     ) -> Blob:
         """Initialize the `Blob` from in-memory data.
 
diff --git a/libs/core/langchain_core/env.py b/libs/core/langchain_core/env.py
index 240e62a8e6..20d384ee75 100644
--- a/libs/core/langchain_core/env.py
+++ b/libs/core/langchain_core/env.py
@@ -7,7 +7,7 @@ from langchain_core import __version__
 
 
 @lru_cache(maxsize=1)
-def get_runtime_environment() -> dict:
+def get_runtime_environment() -> dict[str, str]:
     """Get information about the LangChain runtime environment.
 
     Returns:
diff --git a/libs/core/langchain_core/example_selectors/base.py b/libs/core/langchain_core/example_selectors/base.py
index ec845cfc2e..7297c75468 100644
--- a/libs/core/langchain_core/example_selectors/base.py
+++ b/libs/core/langchain_core/example_selectors/base.py
@@ -34,7 +34,7 @@ class BaseExampleSelector(ABC):
         return await run_in_executor(None, self.add_example, example)
 
     @abstractmethod
-    def select_examples(self, input_variables: dict[str, str]) -> list[dict]:
+    def select_examples(self, input_variables: dict[str, str]) -> list[dict[str, Any]]:
         """Select which examples to use based on the inputs.
 
         Args:
@@ -45,7 +45,9 @@ class BaseExampleSelector(ABC):
             A list of examples.
         """
 
-    async def aselect_examples(self, input_variables: dict[str, str]) -> list[dict]:
+    async def aselect_examples(
+        self, input_variables: dict[str, str]
+    ) -> list[dict[str, Any]]:
         """Async select which examples to use based on the inputs.
 
         Args:
diff --git a/libs/core/langchain_core/example_selectors/length_based.py b/libs/core/langchain_core/example_selectors/length_based.py
index e60e47e891..7205635f42 100644
--- a/libs/core/langchain_core/example_selectors/length_based.py
+++ b/libs/core/langchain_core/example_selectors/length_based.py
@@ -2,6 +2,7 @@
 
 import re
 from collections.abc import Callable
+from typing import Any
 
 from pydantic import BaseModel, Field, model_validator
 from typing_extensions import Self
@@ -48,7 +49,7 @@ class LengthBasedExampleSelector(BaseExampleSelector, BaseModel):
         ```
     """
 
-    examples: list[dict]
+    examples: list[dict[str, Any]]
     """A list of the examples that the prompt template expects."""
 
     example_prompt: PromptTemplate
@@ -92,12 +93,12 @@ class LengthBasedExampleSelector(BaseExampleSelector, BaseModel):
         self.example_text_lengths = [self.get_text_length(eg) for eg in string_examples]
         return self
 
-    def select_examples(self, input_variables: dict[str, str]) -> list[dict]:
+    def select_examples(self, input_variables: dict[str, str]) -> list[dict[str, Any]]:
         """Select which examples to use based on the input lengths.
 
         Args:
             input_variables: A dictionary with keys as input variables
-               and values as their values.
+                and values as their values.
 
         Returns:
             A list of examples to include in the prompt.
@@ -115,12 +116,14 @@ class LengthBasedExampleSelector(BaseExampleSelector, BaseModel):
             i += 1
         return examples
 
-    async def aselect_examples(self, input_variables: dict[str, str]) -> list[dict]:
+    async def aselect_examples(
+        self, input_variables: dict[str, str]
+    ) -> list[dict[str, Any]]:
         """Async select which examples to use based on the input lengths.
 
         Args:
             input_variables: A dictionary with keys as input variables
-               and values as their values.
+                and values as their values.
 
         Returns:
             A list of examples to include in the prompt.
diff --git a/libs/core/langchain_core/example_selectors/semantic_similarity.py b/libs/core/langchain_core/example_selectors/semantic_similarity.py
index 1e7491a2eb..42e711a8be 100644
--- a/libs/core/langchain_core/example_selectors/semantic_similarity.py
+++ b/libs/core/langchain_core/example_selectors/semantic_similarity.py
@@ -15,7 +15,7 @@ if TYPE_CHECKING:
     from langchain_core.embeddings import Embeddings
 
 
-def sorted_values(values: dict[str, str]) -> list[Any]:
+def sorted_values(values: dict[str, str]) -> list[str]:
     """Return a list of values in dict sorted by key.
 
     Args:
@@ -33,13 +33,17 @@ class _VectorStoreExampleSelector(BaseExampleSelector, BaseModel, ABC):
 
     vectorstore: VectorStore
     """VectorStore that contains information about examples."""
+
     k: int = 4
     """Number of examples to select."""
+
     example_keys: list[str] | None = None
     """Optional keys to filter examples to."""
+
     input_keys: list[str] | None = None
     """Optional keys to filter input to. If provided, the search is based on
     the input variables instead of all variables."""
+
     vectorstore_kwargs: dict[str, Any] | None = None
     """Extra arguments passed to similarity_search function of the `VectorStore`."""
 
@@ -54,7 +58,7 @@ class _VectorStoreExampleSelector(BaseExampleSelector, BaseModel, ABC):
             return " ".join(sorted_values({key: example[key] for key in input_keys}))
         return " ".join(sorted_values(example))
 
-    def _documents_to_examples(self, documents: list[Document]) -> list[dict]:
+    def _documents_to_examples(self, documents: list[Document]) -> list[dict[str, Any]]:
         # Get the examples from the metadata.
         # This assumes that examples are stored in metadata.
         examples = [dict(e.metadata) for e in documents]
@@ -97,7 +101,7 @@ class _VectorStoreExampleSelector(BaseExampleSelector, BaseModel, ABC):
 class SemanticSimilarityExampleSelector(_VectorStoreExampleSelector):
     """Select examples based on semantic similarity."""
 
-    def select_examples(self, input_variables: dict[str, str]) -> list[dict]:
+    def select_examples(self, input_variables: dict[str, str]) -> list[dict[str, Any]]:
         """Select examples based on semantic similarity.
 
         Args:
@@ -115,7 +119,9 @@ class SemanticSimilarityExampleSelector(_VectorStoreExampleSelector):
         )
         return self._documents_to_examples(example_docs)
 
-    async def aselect_examples(self, input_variables: dict[str, str]) -> list[dict]:
+    async def aselect_examples(
+        self, input_variables: dict[str, str]
+    ) -> list[dict[str, Any]]:
         """Asynchronously select examples based on semantic similarity.
 
         Args:
@@ -136,14 +142,14 @@ class SemanticSimilarityExampleSelector(_VectorStoreExampleSelector):
     @classmethod
     def from_examples(
         cls,
-        examples: list[dict],
+        examples: list[dict[str, str]],
         embeddings: Embeddings,
         vectorstore_cls: type[VectorStore],
         k: int = 4,
         input_keys: list[str] | None = None,
         *,
         example_keys: list[str] | None = None,
-        vectorstore_kwargs: dict | None = None,
+        vectorstore_kwargs: dict[str, Any] | None = None,
         **vectorstore_cls_kwargs: Any,
     ) -> SemanticSimilarityExampleSelector:
         """Create k-shot example selector using example list and embeddings.
@@ -180,14 +186,14 @@ class SemanticSimilarityExampleSelector(_VectorStoreExampleSelector):
     @classmethod
     async def afrom_examples(
         cls,
-        examples: list[dict],
+        examples: list[dict[str, str]],
         embeddings: Embeddings,
         vectorstore_cls: type[VectorStore],
         k: int = 4,
         input_keys: list[str] | None = None,
         *,
         example_keys: list[str] | None = None,
-        vectorstore_kwargs: dict | None = None,
+        vectorstore_kwargs: dict[str, Any] | None = None,
         **vectorstore_cls_kwargs: Any,
     ) -> SemanticSimilarityExampleSelector:
         """Async create k-shot example selector using example list and embeddings.
@@ -232,7 +238,7 @@ class MaxMarginalRelevanceExampleSelector(_VectorStoreExampleSelector):
     fetch_k: int = 20
     """Number of examples to fetch to rerank."""
 
-    def select_examples(self, input_variables: dict[str, str]) -> list[dict]:
+    def select_examples(self, input_variables: dict[str, str]) -> list[dict[str, Any]]:
         """Select examples based on Max Marginal Relevance.
 
         Args:
@@ -248,7 +254,9 @@ class MaxMarginalRelevanceExampleSelector(_VectorStoreExampleSelector):
         )
         return self._documents_to_examples(example_docs)
 
-    async def aselect_examples(self, input_variables: dict[str, str]) -> list[dict]:
+    async def aselect_examples(
+        self, input_variables: dict[str, str]
+    ) -> list[dict[str, Any]]:
         """Asynchronously select examples based on Max Marginal Relevance.
 
         Args:
@@ -267,14 +275,14 @@ class MaxMarginalRelevanceExampleSelector(_VectorStoreExampleSelector):
     @classmethod
     def from_examples(
         cls,
-        examples: list[dict],
+        examples: list[dict[str, str]],
         embeddings: Embeddings,
         vectorstore_cls: type[VectorStore],
         k: int = 4,
         input_keys: list[str] | None = None,
         fetch_k: int = 20,
         example_keys: list[str] | None = None,
-        vectorstore_kwargs: dict | None = None,
+        vectorstore_kwargs: dict[str, Any] | None = None,
         **vectorstore_cls_kwargs: Any,
     ) -> MaxMarginalRelevanceExampleSelector:
         """Create k-shot example selector using example list and embeddings.
@@ -313,7 +321,7 @@ class MaxMarginalRelevanceExampleSelector(_VectorStoreExampleSelector):
     @classmethod
     async def afrom_examples(
         cls,
-        examples: list[dict],
+        examples: list[dict[str, str]],
         embeddings: Embeddings,
         vectorstore_cls: type[VectorStore],
         *,
@@ -321,7 +329,7 @@ class MaxMarginalRelevanceExampleSelector(_VectorStoreExampleSelector):
         input_keys: list[str] | None = None,
         fetch_k: int = 20,
         example_keys: list[str] | None = None,
-        vectorstore_kwargs: dict | None = None,
+        vectorstore_kwargs: dict[str, Any] | None = None,
         **vectorstore_cls_kwargs: Any,
     ) -> MaxMarginalRelevanceExampleSelector:
         """Create k-shot example selector using example list and embeddings.
diff --git a/libs/core/langchain_core/language_models/_utils.py b/libs/core/langchain_core/language_models/_utils.py
index 289b675307..c463db9c7b 100644
--- a/libs/core/langchain_core/language_models/_utils.py
+++ b/libs/core/langchain_core/language_models/_utils.py
@@ -31,7 +31,7 @@ def _filter_invocation_params_for_tracing(params: dict[str, Any]) -> dict[str, A
 
 
 def is_openai_data_block(
-    block: dict, filter_: Literal["image", "audio", "file"] | None = None
+    block: dict[str, Any], filter_: Literal["image", "audio", "file"] | None = None
 ) -> bool:
     """Check whether a block contains multimodal data in OpenAI Chat Completions format.
 
@@ -318,7 +318,7 @@ def _ensure_message_copy(message: T, formatted_message: T) -> T:
 
 
 def _update_content_block(
-    formatted_message: "BaseMessage", idx: int, new_block: ContentBlock | dict
+    formatted_message: "BaseMessage", idx: int, new_block: ContentBlock | dict[str, Any]
 ) -> None:
     """Update a content block at the given index, handling type issues."""
     # Type ignore needed because:
diff --git a/libs/core/langchain_core/language_models/base.py b/libs/core/langchain_core/language_models/base.py
index 570076290e..fb416887e7 100644
--- a/libs/core/langchain_core/language_models/base.py
+++ b/libs/core/langchain_core/language_models/base.py
@@ -294,8 +294,8 @@ class BaseLanguageModel(
         """
 
     def with_structured_output(
-        self, schema: dict | type, **kwargs: Any
-    ) -> Runnable[LanguageModelInput, dict | BaseModel]:
+        self, schema: dict[str, Any] | type, **kwargs: Any
+    ) -> Runnable[LanguageModelInput, dict[str, Any] | BaseModel]:
         """Not implemented on this class."""
         # Implement this on child class if there is a way of steering the model to
         # generate responses that match a given schema.
@@ -356,7 +356,7 @@ class BaseLanguageModel(
     def get_num_tokens_from_messages(
         self,
         messages: list[BaseMessage],
-        tools: Sequence | None = None,
+        tools: Sequence[Any] | None = None,
     ) -> int:
         """Get the number of tokens in the messages.
 
diff --git a/libs/core/langchain_core/language_models/chat_models.py b/libs/core/langchain_core/language_models/chat_models.py
index 76c8728c1b..cc946a919b 100644
--- a/libs/core/langchain_core/language_models/chat_models.py
+++ b/libs/core/langchain_core/language_models/chat_models.py
@@ -67,6 +67,7 @@ from langchain_core.messages.block_translators.openai import (
 )
 from langchain_core.output_parsers.openai_tools import (
     JsonOutputKeyToolsParser,
+    JsonOutputToolsParser,
     PydanticToolsParser,
 )
 from langchain_core.outputs import (
@@ -99,7 +100,6 @@ if TYPE_CHECKING:
 
     from langchain_protocol.protocol import MessagesData
 
-    from langchain_core.output_parsers.base import OutputParserLike
     from langchain_core.runnables import Runnable, RunnableConfig
     from langchain_core.runnables.schema import StreamEvent
     from langchain_core.tools import BaseTool
@@ -108,7 +108,7 @@ if TYPE_CHECKING:
 def _generate_response_from_error(error: BaseException) -> list[ChatGeneration]:
     if hasattr(error, "response"):
         response = error.response
-        metadata: dict = {}
+        metadata: dict[str, Any] = {}
         if hasattr(response, "json"):
             try:
                 metadata["body"] = response.json()
@@ -248,7 +248,9 @@ async def agenerate_from_stream(
     return await run_in_executor(None, generate_from_stream, iter(chunks))
 
 
-def _format_ls_structured_output(ls_structured_output_format: dict | None) -> dict:
+def _format_ls_structured_output(
+    ls_structured_output_format: dict[str, Any] | None,
+) -> dict[str, Any]:
     if ls_structured_output_format:
         try:
             ls_structured_output_format_dict = {
@@ -804,7 +806,7 @@ class BaseChatModel(BaseLanguageModel[AIMessage], ABC):
                     and isinstance(chunk.message, AIMessageChunk)
                     and not chunk.message.chunk_position
                 ):
-                    empty_content: str | list = (
+                    empty_content: str | list[str | dict[str, Any]] = (
                         "" if isinstance(chunk.message.content, str) else []
                     )
                     msg_chunk = AIMessageChunk(
@@ -938,7 +940,7 @@ class BaseChatModel(BaseLanguageModel[AIMessage], ABC):
                 and isinstance(chunk.message, AIMessageChunk)
                 and not chunk.message.chunk_position
             ):
-                empty_content: str | list = (
+                empty_content: str | list[str | dict[str, Any]] = (
                     "" if isinstance(chunk.message.content, str) else []
                 )
                 msg_chunk = AIMessageChunk(
@@ -1372,11 +1374,13 @@ class BaseChatModel(BaseLanguageModel[AIMessage], ABC):
     # --- Custom methods ---
 
     def _combine_llm_outputs(
-        self, _llm_outputs: list[builtins.dict | None], /
-    ) -> builtins.dict:
+        self, _llm_outputs: list[builtins.dict[str, Any] | None], /
+    ) -> builtins.dict[str, Any]:
         return {}
 
-    def _convert_cached_generations(self, cache_val: list) -> list[ChatGeneration]:
+    def _convert_cached_generations(
+        self, cache_val: list[Generation]
+    ) -> list[ChatGeneration]:
         """Convert cached Generation objects to ChatGeneration objects.
 
         Handle case where cache contains Generation objects instead of
@@ -1466,7 +1470,7 @@ class BaseChatModel(BaseLanguageModel[AIMessage], ABC):
         self,
         stop: list[str] | None = None,
         **kwargs: Any,
-    ) -> builtins.dict:
+    ) -> builtins.dict[str, Any]:
         params = self._dict_for_compat()
         params["stop"] = stop
         return {**params, **kwargs}
@@ -1980,7 +1984,7 @@ class BaseChatModel(BaseLanguageModel[AIMessage], ABC):
                 and isinstance(chunk.message, AIMessageChunk)
                 and not chunk.message.chunk_position
             ):
-                empty_content: str | list = (
+                empty_content: str | list[str | dict[str, Any]] = (
                     "" if isinstance(chunk.message.content, str) else []
                 )
                 chunk = ChatGenerationChunk(
@@ -2137,7 +2141,7 @@ class BaseChatModel(BaseLanguageModel[AIMessage], ABC):
                 and isinstance(chunk.message, AIMessageChunk)
                 and not chunk.message.chunk_position
             ):
-                empty_content: str | list = (
+                empty_content: str | list[str | dict[str, Any]] = (
                     "" if isinstance(chunk.message.content, str) else []
                 )
                 chunk = ChatGenerationChunk(
@@ -2339,7 +2343,7 @@ class BaseChatModel(BaseLanguageModel[AIMessage], ABC):
 
     def bind_tools(
         self,
-        tools: Sequence[builtins.dict[str, Any] | type | Callable | BaseTool],
+        tools: Sequence[builtins.dict[str, Any] | type | Callable[..., Any] | BaseTool],
         *,
         tool_choice: str | None = None,
         **kwargs: Any,
@@ -2519,8 +2523,9 @@ class BaseChatModel(BaseLanguageModel[AIMessage], ABC):
                 "schema": schema,
             },
         )
+        output_parser: JsonOutputToolsParser
         if isinstance(schema, type) and is_basemodel_subclass(schema):
-            output_parser: OutputParserLike = PydanticToolsParser(
+            output_parser = PydanticToolsParser(
                 tools=[cast("TypeBaseModel", schema)], first_tool_only=True
             )
         else:
@@ -2679,7 +2684,7 @@ class SimpleChatModel(BaseChatModel):
 
 def _gen_info_and_msg_metadata(
     generation: ChatGeneration | ChatGenerationChunk,
-) -> dict:
+) -> dict[str, Any]:
     return {
         **(generation.generation_info or {}),
         **generation.message.response_metadata,
diff --git a/libs/core/langchain_core/language_models/llms.py b/libs/core/langchain_core/language_models/llms.py
index 614e12ec16..79736b86e5 100644
--- a/libs/core/langchain_core/language_models/llms.py
+++ b/libs/core/langchain_core/language_models/llms.py
@@ -6,7 +6,7 @@ These are traditionally older models (newer models generally are chat models).
 from __future__ import annotations
 
 import asyncio
-import builtins  # noqa: TC003
+import builtins
 import functools
 import inspect
 import json
@@ -60,11 +60,12 @@ from langchain_core.runnables import RunnableConfig, ensure_config, get_config_l
 from langchain_core.runnables.config import run_in_executor
 
 if TYPE_CHECKING:
+    import builtins
     import uuid
 
 logger = logging.getLogger(__name__)
 
-_background_tasks: set[asyncio.Task] = set()
+_background_tasks: set[asyncio.Task[None]] = set()
 
 
 @functools.lru_cache
@@ -159,7 +160,7 @@ def get_prompts(
     params: dict[str, Any],
     prompts: list[str],
     cache: BaseCache | bool | None = None,  # noqa: FBT001
-) -> tuple[dict[int, list], str, list[int], list[str]]:
+) -> tuple[dict[int, list[Generation]], str, list[int], list[str]]:
     """Get prompts that are already cached.
 
     Args:
@@ -195,7 +196,7 @@ async def aget_prompts(
     params: dict[str, Any],
     prompts: list[str],
     cache: BaseCache | bool | None = None,  # noqa: FBT001
-) -> tuple[dict[int, list], str, list[int], list[str]]:
+) -> tuple[dict[int, list[Generation]], str, list[int], list[str]]:
     """Get prompts that are already cached. Async version.
 
     Args:
@@ -228,12 +229,12 @@ async def aget_prompts(
 
 def update_cache(
     cache: BaseCache | bool | None,  # noqa: FBT001
-    existing_prompts: dict[int, list],
+    existing_prompts: dict[int, list[Generation]],
     llm_string: str,
     missing_prompt_idxs: list[int],
     new_results: LLMResult,
     prompts: list[str],
-) -> dict | None:
+) -> dict[str, Any] | None:
     """Update the cache and get the LLM output.
 
     Args:
@@ -261,12 +262,12 @@ def update_cache(
 
 async def aupdate_cache(
     cache: BaseCache | bool | None,  # noqa: FBT001
-    existing_prompts: dict[int, list],
+    existing_prompts: dict[int, list[Generation]],
     llm_string: str,
     missing_prompt_idxs: list[int],
     new_results: LLMResult,
     prompts: list[str],
-) -> dict | None:
+) -> dict[str, Any] | None:
     """Update the cache and get the LLM output. Async version.
 
     Args:
@@ -954,7 +955,8 @@ class BaseLLM(BaseLanguageModel[str], ABC):
             callbacks = cast("list[Callbacks]", callbacks)
             tags_list = cast("list[list[str] | None]", tags or ([None] * len(prompts)))
             metadata_list = cast(
-                "list[dict[str, Any] | None]", metadata or ([{}] * len(prompts))
+                "list[builtins.dict[str, Any] | None]",
+                metadata or ([{}] * len(prompts)),
             )
             run_name_list = run_name or cast(
                 "list[str | None]", ([None] * len(prompts))
@@ -989,7 +991,7 @@ class BaseLLM(BaseLanguageModel[str], ABC):
                     self.verbose,
                     cast("list[str]", tags),
                     self.tags,
-                    cast("dict[str, Any]", metadata),
+                    cast("builtins.dict[str, Any]", metadata),
                     self.metadata,
                     langsmith_inheritable_metadata=_filter_invocation_params_for_tracing(
                         params
@@ -1074,8 +1076,8 @@ class BaseLLM(BaseLanguageModel[str], ABC):
 
     @staticmethod
     def _get_run_ids_list(
-        run_id: uuid.UUID | list[uuid.UUID | None] | None, prompts: list
-    ) -> list:
+        run_id: uuid.UUID | list[uuid.UUID | None] | None, prompts: list[str]
+    ) -> list[uuid.UUID | None]:
         if run_id is None:
             return [None] * len(prompts)
         if isinstance(run_id, list):
@@ -1226,7 +1228,8 @@ class BaseLLM(BaseLanguageModel[str], ABC):
             callbacks = cast("list[Callbacks]", callbacks)
             tags_list = cast("list[list[str] | None]", tags or ([None] * len(prompts)))
             metadata_list = cast(
-                "list[dict[str, Any] | None]", metadata or ([{}] * len(prompts))
+                "list[builtins.dict[str, Any] | None]",
+                metadata or ([{}] * len(prompts)),
             )
             run_name_list = run_name or cast(
                 "list[str | None]", ([None] * len(prompts))
@@ -1261,7 +1264,7 @@ class BaseLLM(BaseLanguageModel[str], ABC):
                     self.verbose,
                     cast("list[str]", tags),
                     self.tags,
-                    cast("dict[str, Any]", metadata),
+                    cast("builtins.dict[str, Any]", metadata),
                     self.metadata,
                     langsmith_inheritable_metadata=_filter_invocation_params_for_tracing(
                         params
diff --git a/libs/core/langchain_core/load/serializable.py b/libs/core/langchain_core/load/serializable.py
index 429a5e8f88..4764282655 100644
--- a/libs/core/langchain_core/load/serializable.py
+++ b/libs/core/langchain_core/load/serializable.py
@@ -165,7 +165,7 @@ class Serializable(BaseModel, ABC):
         return {}
 
     @property
-    def lc_attributes(self) -> dict:
+    def lc_attributes(self) -> dict[str, Any]:
         """List of attribute names that should be included in the serialized kwargs.
 
         These attributes must be accepted by the constructor.
diff --git a/libs/core/langchain_core/messages/ai.py b/libs/core/langchain_core/messages/ai.py
index 92bac634d6..b6ed773872 100644
--- a/libs/core/langchain_core/messages/ai.py
+++ b/libs/core/langchain_core/messages/ai.py
@@ -185,21 +185,21 @@ class AIMessage(BaseMessage):
     @overload
     def __init__(
         self,
-        content: str | list[str | dict],
+        content: str | list[str | dict[Any, Any]],
         **kwargs: Any,
     ) -> None: ...
 
     @overload
     def __init__(
         self,
-        content: str | list[str | dict] | None = None,
+        content: str | list[str | dict[Any, Any]] | None = None,
         content_blocks: list[types.ContentBlock] | None = None,
         **kwargs: Any,
     ) -> None: ...
 
     def __init__(
         self,
-        content: str | list[str | dict] | None = None,
+        content: str | list[str | dict[Any, Any]] | None = None,
         content_blocks: list[types.ContentBlock] | None = None,
         **kwargs: Any,
     ) -> None:
@@ -221,14 +221,14 @@ class AIMessage(BaseMessage):
                 kwargs["tool_calls"] = content_tool_calls
 
             super().__init__(
-                content=cast("str | list[str | dict]", content_blocks),
+                content=cast("list[str | dict[Any, Any]]", content_blocks),
                 **kwargs,
             )
         else:
             super().__init__(content=content, **kwargs)
 
     @property
-    def lc_attributes(self) -> dict:
+    def lc_attributes(self) -> dict[str, Any]:
         """Attributes to be serialized.
 
         Includes all attributes, even if they are derived from other initialization
@@ -301,7 +301,7 @@ class AIMessage(BaseMessage):
     # TODO: remove this logic if possible, reducing breaking nature of changes
     @model_validator(mode="before")
     @classmethod
-    def _backwards_compat_tool_calls(cls, values: dict) -> Any:
+    def _backwards_compat_tool_calls(cls, values: dict[str, Any]) -> Any:
         check_additional_kwargs = not any(
             values.get(k)
             for k in ("tool_calls", "invalid_tool_calls", "tool_call_chunks")
@@ -431,7 +431,7 @@ class AIMessageChunk(AIMessage, BaseMessageChunk):
 
     @property
     @override
-    def lc_attributes(self) -> dict:
+    def lc_attributes(self) -> dict[str, Any]:
         return {
             "tool_calls": self.tool_calls,
             "invalid_tool_calls": self.invalid_tool_calls,
@@ -769,8 +769,8 @@ def add_usage(left: UsageMetadata | None, right: UsageMetadata | None) -> UsageM
         **cast(
             "UsageMetadata",
             _dict_int_op(
-                cast("dict", left),
-                cast("dict", right),
+                cast("dict[str, Any]", left),
+                cast("dict[str, Any]", right),
                 operator.add,
             ),
         )
@@ -832,8 +832,8 @@ def subtract_usage(
         **cast(
             "UsageMetadata",
             _dict_int_op(
-                cast("dict", left),
-                cast("dict", right),
+                cast("dict[str, Any]", left),
+                cast("dict[str, Any]", right),
                 (lambda le, ri: max(le - ri, 0)),
             ),
         )
diff --git a/libs/core/langchain_core/messages/base.py b/libs/core/langchain_core/messages/base.py
index 2b0e998c70..21760e2100 100644
--- a/libs/core/langchain_core/messages/base.py
+++ b/libs/core/langchain_core/messages/base.py
@@ -100,10 +100,10 @@ class BaseMessage(Serializable):
     [`SystemMessage`][langchain.messages.SystemMessage].
     """
 
-    content: str | list[str | dict]
+    content: str | list[str | dict[Any, Any]]
     """The contents of the message."""
 
-    additional_kwargs: dict = Field(default_factory=dict)
+    additional_kwargs: dict[Any, Any] = Field(default_factory=dict)
     """Reserved for additional payload data associated with the message.
 
     For example, for a message from an AI, this could include tool calls as
@@ -111,7 +111,7 @@ class BaseMessage(Serializable):
 
     """
 
-    response_metadata: dict = Field(default_factory=dict)
+    response_metadata: dict[Any, Any] = Field(default_factory=dict)
     """Examples: response headers, logprobs, token counts, model name."""
 
     type: str
@@ -146,21 +146,21 @@ class BaseMessage(Serializable):
     @overload
     def __init__(
         self,
-        content: str | list[str | dict],
+        content: str | list[str | dict[Any, Any]],
         **kwargs: Any,
     ) -> None: ...
 
     @overload
     def __init__(
         self,
-        content: str | list[str | dict] | None = None,
+        content: str | list[str | dict[Any, Any]] | None = None,
         content_blocks: list[types.ContentBlock] | None = None,
         **kwargs: Any,
     ) -> None: ...
 
     def __init__(
         self,
-        content: str | list[str | dict] | None = None,
+        content: str | list[str | dict[Any, Any]] | None = None,
         content_blocks: list[types.ContentBlock] | None = None,
         **kwargs: Any,
     ) -> None:
@@ -364,9 +364,9 @@ class BaseMessage(Serializable):
 
 
 def merge_content(
-    first_content: str | list[str | dict],
-    *contents: str | list[str | dict],
-) -> str | list[str | dict]:
+    first_content: str | list[str | dict[Any, Any]],
+    *contents: str | list[str | dict[Any, Any]],
+) -> str | list[str | dict[Any, Any]]:
     """Merge multiple message contents.
 
     Args:
@@ -377,7 +377,7 @@ def merge_content(
         The merged content.
 
     """
-    merged: str | list[str | dict]
+    merged: str | list[str | dict[Any, Any]]
     merged = "" if first_content is None else first_content
 
     for content in contents:
@@ -391,7 +391,7 @@ def merge_content(
                 merged = [merged, *content]
         elif isinstance(content, list):
             # If both are lists
-            merged = merge_lists(cast("list", merged), content)  # type: ignore[assignment]
+            merged = merge_lists(merged, content)  # type: ignore[assignment]
         # If the first content is a list, and the second content is a string
         # If the last element of the first content is a string
         # Add the second content to the last element
@@ -471,7 +471,7 @@ class BaseMessageChunk(BaseMessage):
         raise TypeError(msg)
 
 
-def message_to_dict(message: BaseMessage) -> dict:
+def message_to_dict(message: BaseMessage) -> dict[str, Any]:
     """Convert a Message to a dictionary.
 
     Args:
@@ -485,7 +485,7 @@ def message_to_dict(message: BaseMessage) -> dict:
     return {"type": message.type, "data": message.model_dump()}
 
 
-def messages_to_dict(messages: Sequence[BaseMessage]) -> list[dict]:
+def messages_to_dict(messages: Sequence[BaseMessage]) -> list[dict[str, Any]]:
     """Convert a sequence of Messages to a list of dictionaries.
 
     Args:
diff --git a/libs/core/langchain_core/messages/block_translators/anthropic.py b/libs/core/langchain_core/messages/block_translators/anthropic.py
index eab2163f07..fb70388d60 100644
--- a/libs/core/langchain_core/messages/block_translators/anthropic.py
+++ b/libs/core/langchain_core/messages/block_translators/anthropic.py
@@ -197,8 +197,9 @@ def _convert_citation_to_v1(citation: dict[str, Any]) -> types.Annotation:
 
 def _convert_to_v1_from_anthropic(message: AIMessage) -> list[types.ContentBlock]:
     """Convert Anthropic message content to v1 format."""
+    content: list[str | dict[str, Any]]
     if isinstance(message.content, str):
-        content: list[str | dict] = [{"type": "text", "text": message.content}]
+        content = [{"type": "text", "text": message.content}]
     else:
         content = message.content
 
diff --git a/libs/core/langchain_core/messages/block_translators/groq.py b/libs/core/langchain_core/messages/block_translators/groq.py
index bcaa1a15b7..773f3fd7fb 100644
--- a/libs/core/langchain_core/messages/block_translators/groq.py
+++ b/libs/core/langchain_core/messages/block_translators/groq.py
@@ -27,7 +27,7 @@ def _populate_extras(
     return standard_block
 
 
-def _parse_code_json(s: str) -> dict:
+def _parse_code_json(s: str) -> dict[str, Any]:
     """Extract Python code from Groq built-in tool content.
 
     Extracts the value of the 'code' field from a string of the form:
diff --git a/libs/core/langchain_core/messages/block_translators/langchain_v0.py b/libs/core/langchain_core/messages/block_translators/langchain_v0.py
index f7cb03839e..3d25e19f17 100644
--- a/libs/core/langchain_core/messages/block_translators/langchain_v0.py
+++ b/libs/core/langchain_core/messages/block_translators/langchain_v0.py
@@ -44,8 +44,8 @@ def _convert_v0_multimodal_input_to_v1(
 
 
 def _convert_legacy_v0_content_block_to_v1(
-    block: dict,
-) -> types.ContentBlock | dict:
+    block: dict[str, Any],
+) -> types.ContentBlock | dict[str, Any]:
     """Convert a LangChain v0 content block to v1 format.
 
     Preserves unknown keys as extras to avoid data loss.
@@ -53,7 +53,9 @@ def _convert_legacy_v0_content_block_to_v1(
     Returns the original block unchanged if it's not in v0 format.
     """
 
-    def _extract_v0_extras(block_dict: dict, known_keys: set[str]) -> dict[str, Any]:
+    def _extract_v0_extras(
+        block_dict: dict[str, Any], known_keys: set[str]
+    ) -> dict[str, Any]:
         """Extract unknown keys from v0 block to preserve as extras.
 
         Args:
diff --git a/libs/core/langchain_core/messages/block_translators/openai.py b/libs/core/langchain_core/messages/block_translators/openai.py
index 627459254c..86c201dcc4 100644
--- a/libs/core/langchain_core/messages/block_translators/openai.py
+++ b/libs/core/langchain_core/messages/block_translators/openai.py
@@ -19,7 +19,7 @@ if TYPE_CHECKING:
     from langchain_core.messages import AIMessage
 
 
-def convert_to_openai_image_block(block: dict[str, Any]) -> dict:
+def convert_to_openai_image_block(block: dict[str, Any]) -> dict[str, Any]:
     """Convert `ImageContentBlock` to format expected by OpenAI Chat Completions.
 
     Args:
@@ -56,8 +56,9 @@ def convert_to_openai_image_block(block: dict[str, Any]) -> dict:
 
 
 def convert_to_openai_data_block(
-    block: dict, api: Literal["chat/completions", "responses"] = "chat/completions"
-) -> dict:
+    block: dict[str, Any],
+    api: Literal["chat/completions", "responses"] = "chat/completions",
+) -> dict[str, Any]:
     """Format standard data content block to format expected by OpenAI.
 
     "Standard data content block" can include old-style LangChain v0 blocks
@@ -265,7 +266,7 @@ def _convert_to_v1_from_chat_completions_chunk(
 def _convert_from_v1_to_chat_completions(message: AIMessage) -> AIMessage:
     """Convert a v1 message to the Chat Completions format."""
     if isinstance(message.content, list):
-        new_content: list = []
+        new_content: list[Any] = []
         for block in message.content:
             if isinstance(block, dict):
                 block_type = block.get("type")
@@ -330,7 +331,7 @@ def _convert_from_v03_ai_message(message: AIMessage) -> AIMessage:
     ]
 
     # Build a bucket for every known block type
-    buckets: dict[str, list] = {key: [] for key in content_order}
+    buckets: dict[str, list[Any]] = {key: [] for key in content_order}
     unknown_blocks = []
 
     # Reasoning
@@ -422,8 +423,8 @@ def _convert_from_v03_ai_message(message: AIMessage) -> AIMessage:
 
 
 def _convert_openai_format_to_data_block(
-    block: dict,
-) -> types.ContentBlock | dict[Any, Any]:
+    block: dict[str, Any],
+) -> types.ContentBlock | dict[str, Any]:
     """Convert OpenAI image/audio/file content block to respective v1 multimodal block.
 
     We expect that the incoming block is verified to be in OpenAI Chat Completions
@@ -439,7 +440,9 @@ def _convert_openai_format_to_data_block(
     """
 
     # Extract extra keys to put them in `extras`
-    def _extract_extras(block_dict: dict, known_keys: set[str]) -> dict[str, Any]:
+    def _extract_extras(
+        block_dict: dict[str, Any], known_keys: set[str]
+    ) -> dict[str, Any]:
         """Extract unknown keys from block to preserve as extras."""
         return {k: v for k, v in block_dict.items() if k not in known_keys}
 
diff --git a/libs/core/langchain_core/messages/content.py b/libs/core/langchain_core/messages/content.py
index 3a02139d5b..58084e3f08 100644
--- a/libs/core/langchain_core/messages/content.py
+++ b/libs/core/langchain_core/messages/content.py
@@ -905,7 +905,7 @@ def _get_data_content_block_types() -> tuple[str, ...]:
     return tuple(data_block_types)
 
 
-def is_data_content_block(block: dict) -> bool:
+def is_data_content_block(block: dict[str, Any]) -> bool:
     """Check if the provided content block is a data content block.
 
     Returns True for both v0 (old-style) and v1 (new-style) multimodal data blocks.
diff --git a/libs/core/langchain_core/messages/human.py b/libs/core/langchain_core/messages/human.py
index 338e221370..c9a1d2756f 100644
--- a/libs/core/langchain_core/messages/human.py
+++ b/libs/core/langchain_core/messages/human.py
@@ -32,28 +32,28 @@ class HumanMessage(BaseMessage):
     @overload
     def __init__(
         self,
-        content: str | list[str | dict],
+        content: str | list[str | dict[Any, Any]],
         **kwargs: Any,
     ) -> None: ...
 
     @overload
     def __init__(
         self,
-        content: str | list[str | dict] | None = None,
+        content: str | list[str | dict[Any, Any]] | None = None,
         content_blocks: list[types.ContentBlock] | None = None,
         **kwargs: Any,
     ) -> None: ...
 
     def __init__(
         self,
-        content: str | list[str | dict] | None = None,
+        content: str | list[str | dict[Any, Any]] | None = None,
         content_blocks: list[types.ContentBlock] | None = None,
         **kwargs: Any,
     ) -> None:
         """Specify `content` as positional arg or `content_blocks` for typing."""
         if content_blocks is not None:
             super().__init__(
-                content=cast("str | list[str | dict]", content_blocks),
+                content=cast("list[str | dict[Any, Any]]", content_blocks),
                 **kwargs,
             )
         else:
diff --git a/libs/core/langchain_core/messages/system.py b/libs/core/langchain_core/messages/system.py
index 4a60811dff..3ace120f39 100644
--- a/libs/core/langchain_core/messages/system.py
+++ b/libs/core/langchain_core/messages/system.py
@@ -32,28 +32,28 @@ class SystemMessage(BaseMessage):
     @overload
     def __init__(
         self,
-        content: str | list[str | dict],
+        content: str | list[str | dict[Any, Any]],
         **kwargs: Any,
     ) -> None: ...
 
     @overload
     def __init__(
         self,
-        content: str | list[str | dict] | None = None,
+        content: str | list[str | dict[Any, Any]] | None = None,
         content_blocks: list[types.ContentBlock] | None = None,
         **kwargs: Any,
     ) -> None: ...
 
     def __init__(
         self,
-        content: str | list[str | dict] | None = None,
+        content: str | list[str | dict[Any, Any]] | None = None,
         content_blocks: list[types.ContentBlock] | None = None,
         **kwargs: Any,
     ) -> None:
         """Specify `content` as positional arg or `content_blocks` for typing."""
         if content_blocks is not None:
             super().__init__(
-                content=cast("str | list[str | dict]", content_blocks),
+                content=cast("list[str | dict[Any, Any]]", content_blocks),
                 **kwargs,
             )
         else:
diff --git a/libs/core/langchain_core/messages/tool.py b/libs/core/langchain_core/messages/tool.py
index a83d4e6eb9..7219942f02 100644
--- a/libs/core/langchain_core/messages/tool.py
+++ b/libs/core/langchain_core/messages/tool.py
@@ -76,20 +76,20 @@ class ToolMessage(BaseMessage, ToolOutputMixin):
     Should only be specified if it is different from the message content, e.g. if only
     a subset of the full tool output is being passed as message content but the full
     output is needed in other parts of the code.
-
     """
 
     status: Literal["success", "error"] = "success"
     """Status of the tool invocation."""
 
-    additional_kwargs: dict = Field(default_factory=dict, repr=False)
+    additional_kwargs: dict[Any, Any] = Field(default_factory=dict, repr=False)
     """Currently inherited from `BaseMessage`, but not used."""
-    response_metadata: dict = Field(default_factory=dict, repr=False)
+
+    response_metadata: dict[Any, Any] = Field(default_factory=dict, repr=False)
     """Currently inherited from `BaseMessage`, but not used."""
 
     @model_validator(mode="before")
     @classmethod
-    def coerce_args(cls, values: dict) -> dict:
+    def coerce_args(cls, values: dict[str, Any]) -> dict[str, Any]:
         """Coerce the model arguments to the correct types.
 
         Args:
@@ -135,21 +135,21 @@ class ToolMessage(BaseMessage, ToolOutputMixin):
     @overload
     def __init__(
         self,
-        content: str | list[str | dict],
+        content: str | list[str | dict[Any, Any]],
         **kwargs: Any,
     ) -> None: ...
 
     @overload
     def __init__(
         self,
-        content: str | list[str | dict] | None = None,
+        content: str | list[str | dict[Any, Any]] | None = None,
         content_blocks: list[types.ContentBlock] | None = None,
         **kwargs: Any,
     ) -> None: ...
 
     def __init__(
         self,
-        content: str | list[str | dict] | None = None,
+        content: str | list[str | dict[Any, Any]] | None = None,
         content_blocks: list[types.ContentBlock] | None = None,
         **kwargs: Any,
     ) -> None:
@@ -164,7 +164,7 @@ class ToolMessage(BaseMessage, ToolOutputMixin):
         """
         if content_blocks is not None:
             super().__init__(
-                content=cast("str | list[str | dict]", content_blocks),
+                content=cast("list[str | dict[Any, Any]]", content_blocks),
                 **kwargs,
             )
         else:
@@ -347,7 +347,7 @@ def invalid_tool_call(
 
 
 def default_tool_parser(
-    raw_tool_calls: list[dict],
+    raw_tool_calls: list[dict[str, Any]],
 ) -> tuple[list[ToolCall], list[InvalidToolCall]]:
     """Best-effort parsing of tools.
 
@@ -383,7 +383,9 @@ def default_tool_parser(
     return tool_calls, invalid_tool_calls
 
 
-def default_tool_chunk_parser(raw_tool_calls: list[dict]) -> list[ToolCallChunk]:
+def default_tool_chunk_parser(
+    raw_tool_calls: list[dict[str, Any]],
+) -> list[ToolCallChunk]:
     """Best-effort parsing of tool chunks.
 
     Args:
diff --git a/libs/core/langchain_core/messages/utils.py b/libs/core/langchain_core/messages/utils.py
index 095ae805b2..c1657145cc 100644
--- a/libs/core/langchain_core/messages/utils.py
+++ b/libs/core/langchain_core/messages/utils.py
@@ -512,7 +512,7 @@ def get_buffer_string(
     return message_separator.join(string_messages)
 
 
-def _message_from_dict(message: dict) -> BaseMessage:
+def _message_from_dict(message: dict[str, Any]) -> BaseMessage:
     type_ = message["type"]
     if type_ == "human":
         return HumanMessage(**message["data"])
@@ -544,7 +544,7 @@ def _message_from_dict(message: dict) -> BaseMessage:
     raise ValueError(msg)
 
 
-def messages_from_dict(messages: Sequence[dict]) -> list[BaseMessage]:
+def messages_from_dict(messages: Sequence[dict[str, Any]]) -> list[BaseMessage]:
     """Convert a sequence of messages from dicts to `Message` objects.
 
     Args:
@@ -709,9 +709,9 @@ def _convert_to_message(message: MessageLikeRepresentation) -> BaseMessage:
     - 2-tuple of (role string, template); e.g., (`'human'`, `'{user_input}'`)
     - dict: a message dict with role and content keys
     - dict: the `Serializable` constructor-envelope wire shape
-      `{"lc": 1, "type": "constructor", "id": [..., "<ClassName>"],
-      "kwargs": {...}}` — unpacked structurally and routed through the
-      standard dict-with-type dispatch.
+        `{"lc": 1, "type": "constructor", "id": [..., "<ClassName>"],
+        "kwargs": {...}}` — unpacked structurally and routed through the
+        standard dict-with-type dispatch.
     - string: shorthand for (`'human'`, template); e.g., `'{user_input}'`
 
     Args:
@@ -1132,7 +1132,7 @@ def trim_messages(
     max_tokens: int,
     token_counter: Callable[[list[BaseMessage]], int]
     | Callable[[BaseMessage], int]
-    | BaseLanguageModel
+    | BaseLanguageModel[Any]
     | Literal["approximate"],
     strategy: Literal["first", "last"] = "last",
     allow_partial: bool = False,
@@ -1484,10 +1484,11 @@ def trim_messages(
         )
         raise ValueError(msg)
 
+    text_splitter_fn: Callable[[str], list[str]]
     if _HAS_LANGCHAIN_TEXT_SPLITTERS and isinstance(text_splitter, TextSplitter):
         text_splitter_fn = text_splitter.split_text
     elif text_splitter:
-        text_splitter_fn = cast("Callable", text_splitter)
+        text_splitter_fn = cast("Callable[[str], list[str]]", text_splitter)
     else:
         text_splitter_fn = _default_text_splitter
 
@@ -1528,7 +1529,7 @@ def convert_to_openai_messages(
     text_format: Literal["string", "block"] = "string",
     include_id: bool = False,
     pass_through_unknown_blocks: bool = True,
-) -> dict: ...
+) -> dict[str, Any]: ...
 
 
 @overload
@@ -1538,7 +1539,7 @@ def convert_to_openai_messages(
     text_format: Literal["string", "block"] = "string",
     include_id: bool = False,
     pass_through_unknown_blocks: bool = True,
-) -> list[dict]: ...
+) -> list[dict[str, Any]]: ...
 
 
 def convert_to_openai_messages(
@@ -1547,7 +1548,7 @@ def convert_to_openai_messages(
     text_format: Literal["string", "block"] = "string",
     include_id: bool = False,
     pass_through_unknown_blocks: bool = True,
-) -> dict | list[dict]:
+) -> dict[str, Any] | list[dict[str, Any]]:
     """Convert LangChain messages into OpenAI message dicts.
 
     Args:
@@ -1636,7 +1637,7 @@ def convert_to_openai_messages(
         err = f"Unrecognized {text_format=}, expected one of 'string' or 'block'."
         raise ValueError(err)
 
-    oai_messages: list[dict] = []
+    oai_messages: list[dict[str, Any]] = []
 
     if is_single := isinstance(messages, (BaseMessage, dict, str)):
         messages = [messages]
@@ -1644,9 +1645,9 @@ def convert_to_openai_messages(
     messages = convert_to_messages(messages)
 
     for i, message in enumerate(messages):
-        oai_msg: dict = {"role": _get_message_openai_role(message)}
-        tool_messages: list = []
-        content: str | list[dict]
+        oai_msg: dict[str, Any] = {"role": _get_message_openai_role(message)}
+        tool_messages: list[dict[str, Any]] = []
+        content: str | list[dict[str, Any]]
 
         if message.name:
             oai_msg["name"] = message.name
@@ -2216,7 +2217,7 @@ def _get_message_openai_role(message: BaseMessage) -> str:
     raise ValueError(msg)
 
 
-def _convert_to_openai_tool_calls(tool_calls: list[ToolCall]) -> list[dict]:
+def _convert_to_openai_tool_calls(tool_calls: list[ToolCall]) -> list[dict[str, Any]]:
     return [
         {
             "type": "function",
@@ -2247,7 +2248,7 @@ def count_tokens_approximately(
     - For AI messages, the token count also includes stringified tool calls.
     - For tool messages, the token count also includes the tool call ID.
     - For multimodal messages with images, applies a fixed token penalty per image
-      instead of counting base64-encoded characters.
+        instead of counting base64-encoded characters.
     - If tools are provided, the token count also includes stringified tool schemas.
 
     Args:
diff --git a/libs/core/langchain_core/output_parsers/base.py b/libs/core/langchain_core/output_parsers/base.py
index b316abad92..9f9548edbf 100644
--- a/libs/core/langchain_core/output_parsers/base.py
+++ b/libs/core/langchain_core/output_parsers/base.py
@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-import builtins  # noqa: TC003
+import builtins
 import contextlib
 from abc import ABC, abstractmethod
 from typing import (
@@ -23,6 +23,8 @@ from langchain_core.runnables import Runnable, RunnableConfig, RunnableSerializa
 from langchain_core.runnables.config import run_in_executor
 
 if TYPE_CHECKING:
+    import builtins
+
     from langchain_core.prompt_values import PromptValue
 
 T = TypeVar("T")
@@ -70,7 +72,7 @@ class BaseLLMOutputParser(ABC, Generic[T]):
 
 
 class BaseGenerationOutputParser(
-    BaseLLMOutputParser, RunnableSerializable[LanguageModelOutput, T]
+    BaseLLMOutputParser[T], RunnableSerializable[LanguageModelOutput, T]
 ):
     """Base class to parse the output of an LLM call."""
 
@@ -136,7 +138,7 @@ class BaseGenerationOutputParser(
 
 
 class BaseOutputParser(
-    BaseLLMOutputParser, RunnableSerializable[LanguageModelOutput, T]
+    BaseLLMOutputParser[T], RunnableSerializable[LanguageModelOutput, T]
 ):
     """Base class to parse the output of an LLM call.
 
diff --git a/libs/core/langchain_core/output_parsers/list.py b/libs/core/langchain_core/output_parsers/list.py
index 834c9ec153..f2c9cb5d45 100644
--- a/libs/core/langchain_core/output_parsers/list.py
+++ b/libs/core/langchain_core/output_parsers/list.py
@@ -58,7 +58,7 @@ class ListOutputParser(BaseTransformOutputParser[list[str]]):
             A list of strings.
         """
 
-    def parse_iter(self, text: str) -> Iterator[re.Match]:
+    def parse_iter(self, text: str) -> Iterator[re.Match[str]]:
         """Parse the output of an LLM call.
 
         Args:
@@ -210,7 +210,7 @@ class NumberedListOutputParser(ListOutputParser):
         return re.findall(self.pattern, text)
 
     @override
-    def parse_iter(self, text: str) -> Iterator[re.Match]:
+    def parse_iter(self, text: str) -> Iterator[re.Match[str]]:
         return re.finditer(self.pattern, text)
 
     @property
@@ -241,7 +241,7 @@ class MarkdownListOutputParser(ListOutputParser):
         return re.findall(self.pattern, text, re.MULTILINE)
 
     @override
-    def parse_iter(self, text: str) -> Iterator[re.Match]:
+    def parse_iter(self, text: str) -> Iterator[re.Match[str]]:
         return re.finditer(self.pattern, text, re.MULTILINE)
 
     @property
diff --git a/libs/core/langchain_core/output_parsers/openai_tools.py b/libs/core/langchain_core/output_parsers/openai_tools.py
index c42e094665..78be65ecef 100644
--- a/libs/core/langchain_core/output_parsers/openai_tools.py
+++ b/libs/core/langchain_core/output_parsers/openai_tools.py
@@ -100,7 +100,7 @@ def make_invalid_tool_call(
 
 
 def parse_tool_calls(
-    raw_tool_calls: list[dict],
+    raw_tool_calls: list[dict[str, Any]],
     *,
     partial: bool = False,
     strict: bool = False,
diff --git a/libs/core/langchain_core/output_parsers/pydantic.py b/libs/core/langchain_core/output_parsers/pydantic.py
index 7a7eee972d..ab89c91754 100644
--- a/libs/core/langchain_core/output_parsers/pydantic.py
+++ b/libs/core/langchain_core/output_parsers/pydantic.py
@@ -1,7 +1,7 @@
 """Output parsers using Pydantic."""
 
 import json
-from typing import Annotated, Generic, Literal, overload
+from typing import Annotated, Any, Generic, Literal, overload
 
 import pydantic
 from pydantic import SkipValidation
@@ -22,7 +22,7 @@ class PydanticOutputParser(JsonOutputParser, Generic[TBaseModel]):
     pydantic_object: Annotated[type[TBaseModel], SkipValidation()]
     """The Pydantic model to parse."""
 
-    def _parse_obj(self, obj: dict) -> TBaseModel:
+    def _parse_obj(self, obj: Any) -> TBaseModel:
         try:
             if issubclass(self.pydantic_object, pydantic.BaseModel):
                 return self.pydantic_object.model_validate(obj)
@@ -35,7 +35,7 @@ class PydanticOutputParser(JsonOutputParser, Generic[TBaseModel]):
             raise self._parser_exception(e, obj) from e
 
     def _parser_exception(
-        self, e: Exception, json_object: dict
+        self, e: Exception, json_object: Any
     ) -> OutputParserException:
         json_string = json.dumps(json_object, ensure_ascii=False)
         name = self.pydantic_object.__name__
diff --git a/libs/core/langchain_core/output_parsers/xml.py b/libs/core/langchain_core/output_parsers/xml.py
index c65a1db329..a26a37ffcf 100644
--- a/libs/core/langchain_core/output_parsers/xml.py
+++ b/libs/core/langchain_core/output_parsers/xml.py
@@ -148,7 +148,7 @@ class _StreamingParser:
             self.pull_parser.close()
 
 
-class XMLOutputParser(BaseTransformOutputParser):
+class XMLOutputParser(BaseTransformOutputParser[dict[str, Any]]):
     """Parse an output using xml format.
 
     Returns a dictionary of tags.
@@ -170,7 +170,7 @@ class XMLOutputParser(BaseTransformOutputParser):
     3. A badly-formatted XML instance (unexpected 'tag' element):
         `'<foo>\n   <tag>\n   </tag>\n</foo>'`
     """
-    encoding_matcher: re.Pattern = re.compile(
+    encoding_matcher: re.Pattern[str] = re.compile(
         r"<([^>]*encoding[^>]*)>\n(.*)", re.MULTILINE | re.DOTALL
     )
 
@@ -272,13 +272,13 @@ class XMLOutputParser(BaseTransformOutputParser):
             # If root text contains any non-whitespace character it
             # returns {root.tag: root.text}
             return {root.tag: root.text}
-        result: dict = {root.tag: []}
+        root_tag: list[Any] = []
         for child in root:
             if len(child) == 0:
-                result[root.tag].append({child.tag: child.text})
+                root_tag.append({child.tag: child.text})
             else:
-                result[root.tag].append(self._root_to_dict(child))
-        return result
+                root_tag.append(self._root_to_dict(child))
+        return {root.tag: root_tag}
 
     @property
     def _type(self) -> str:
diff --git a/libs/core/langchain_core/outputs/chat_result.py b/libs/core/langchain_core/outputs/chat_result.py
index 1cc814310e..2b7bc91fe5 100644
--- a/libs/core/langchain_core/outputs/chat_result.py
+++ b/libs/core/langchain_core/outputs/chat_result.py
@@ -1,5 +1,7 @@
 """Chat result schema."""
 
+from typing import Any
+
 from pydantic import BaseModel
 
 from langchain_core.outputs.chat_generation import ChatGeneration
@@ -25,7 +27,7 @@ class ChatResult(BaseModel):
     input prompt.
     """
 
-    llm_output: dict | None = None
+    llm_output: dict[str, Any] | None = None
     """For arbitrary model provider-specific output.
 
     This dictionary is a free-form dictionary that can contain any information that the
diff --git a/libs/core/langchain_core/outputs/llm_result.py b/libs/core/langchain_core/outputs/llm_result.py
index df40c41975..5e0fa42968 100644
--- a/libs/core/langchain_core/outputs/llm_result.py
+++ b/libs/core/langchain_core/outputs/llm_result.py
@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 from copy import deepcopy
-from typing import Literal
+from typing import Any, Literal
 
 from pydantic import BaseModel
 
@@ -37,7 +37,7 @@ class LLMResult(BaseModel):
     chat message.
     """
 
-    llm_output: dict | None = None
+    llm_output: dict[str, Any] | None = None
     """For arbitrary model provider-specific output.
 
     This dictionary is a free-form dictionary that can contain any information that the
diff --git a/libs/core/langchain_core/prompt_values.py b/libs/core/langchain_core/prompt_values.py
index e85fe1efb4..668871e221 100644
--- a/libs/core/langchain_core/prompt_values.py
+++ b/libs/core/langchain_core/prompt_values.py
@@ -8,7 +8,7 @@ from __future__ import annotations
 
 from abc import ABC, abstractmethod
 from collections.abc import Sequence
-from typing import Literal, cast
+from typing import Any, Literal, cast
 
 from typing_extensions import TypedDict
 
@@ -146,7 +146,7 @@ class ImagePromptValue(PromptValue):
 
     def to_messages(self) -> list[BaseMessage]:
         """Return prompt (image URL) as messages."""
-        return [HumanMessage(content=[cast("dict", self.image_url)])]
+        return [HumanMessage(content=[cast("dict[str, Any]", self.image_url)])]
 
 
 class ChatPromptValueConcrete(ChatPromptValue):
diff --git a/libs/core/langchain_core/prompts/base.py b/libs/core/langchain_core/prompts/base.py
index 9a9cc30242..e90220b796 100644
--- a/libs/core/langchain_core/prompts/base.py
+++ b/libs/core/langchain_core/prompts/base.py
@@ -36,7 +36,7 @@ FormatOutputType = TypeVar("FormatOutputType")
 
 
 class BasePromptTemplate(
-    RunnableSerializable[dict, PromptValue], ABC, Generic[FormatOutputType]
+    RunnableSerializable[dict[str, Any], PromptValue], ABC, Generic[FormatOutputType]
 ):
     """Base class for all prompt templates, returning a prompt."""
 
@@ -155,7 +155,7 @@ class BasePromptTemplate(
             field_definitions={**required_input_variables, **optional_input_variables},
         )
 
-    def _validate_input(self, inner_input: Any) -> builtins.dict:
+    def _validate_input(self, inner_input: Any) -> builtins.dict[str, Any]:
         if not isinstance(inner_input, dict):
             if len(self.input_variables) == 1:
                 var_name = self.input_variables[0]
@@ -192,22 +192,23 @@ class BasePromptTemplate(
         return inner_input_
 
     def _format_prompt_with_error_handling(
-        self,
-        inner_input: builtins.dict,
+        self, inner_input: builtins.dict[str, Any]
     ) -> PromptValue:
         inner_input_ = self._validate_input(inner_input)
         return self.format_prompt(**inner_input_)
 
     async def _aformat_prompt_with_error_handling(
-        self,
-        inner_input: builtins.dict,
+        self, inner_input: builtins.dict[str, Any]
     ) -> PromptValue:
         inner_input_ = self._validate_input(inner_input)
         return await self.aformat_prompt(**inner_input_)
 
     @override
     def invoke(
-        self, input: builtins.dict, config: RunnableConfig | None = None, **kwargs: Any
+        self,
+        input: builtins.dict[str, Any],
+        config: RunnableConfig | None = None,
+        **kwargs: Any,
     ) -> PromptValue:
         """Invoke the prompt.
 
@@ -233,7 +234,10 @@ class BasePromptTemplate(
 
     @override
     async def ainvoke(
-        self, input: builtins.dict, config: RunnableConfig | None = None, **kwargs: Any
+        self,
+        input: builtins.dict[str, Any],
+        config: RunnableConfig | None = None,
+        **kwargs: Any,
     ) -> PromptValue:
         """Async invoke the prompt.
 
@@ -279,7 +283,9 @@ class BasePromptTemplate(
         """
         return self.format_prompt(**kwargs)
 
-    def partial(self, **kwargs: str | Callable[[], str]) -> BasePromptTemplate:
+    def partial(
+        self, **kwargs: str | Callable[[], str]
+    ) -> BasePromptTemplate[FormatOutputType]:
         """Return a partial of the prompt template.
 
         Args:
@@ -420,7 +426,9 @@ class BasePromptTemplate(
             raise ValueError(msg)
 
 
-def _get_document_info(doc: Document, prompt: BasePromptTemplate[str]) -> dict:
+def _get_document_info(
+    doc: Document, prompt: BasePromptTemplate[str]
+) -> dict[str, Any]:
     base_info = {"page_content": doc.page_content, **doc.metadata}
     missing_metadata = set(prompt.input_variables).difference(base_info)
     if len(missing_metadata) > 0:
diff --git a/libs/core/langchain_core/prompts/chat.py b/libs/core/langchain_core/prompts/chat.py
index ebd58c8031..4a912f64b6 100644
--- a/libs/core/langchain_core/prompts/chat.py
+++ b/libs/core/langchain_core/prompts/chat.py
@@ -33,7 +33,7 @@ from langchain_core.messages import (
     convert_to_messages,
 )
 from langchain_core.messages.base import get_msg_title_repr
-from langchain_core.prompt_values import ChatPromptValue, ImageURL
+from langchain_core.prompt_values import ChatPromptValue
 from langchain_core.prompts.base import BasePromptTemplate
 from langchain_core.prompts.dict import DictPromptTemplate
 from langchain_core.prompts.image import ImagePromptTemplate
@@ -229,7 +229,7 @@ class BaseStringMessagePromptTemplate(BaseMessagePromptTemplate, ABC):
     prompt: StringPromptTemplate
     """String prompt template."""
 
-    additional_kwargs: dict = Field(default_factory=dict)
+    additional_kwargs: dict[str, Any] = Field(default_factory=dict)
     """Additional keyword arguments to pass to the prompt template."""
 
     @classmethod
@@ -387,11 +387,11 @@ class ChatMessagePromptTemplate(BaseStringMessagePromptTemplate):
 
 
 class _TextTemplateParam(TypedDict, total=False):
-    text: str | dict
+    text: str | dict[str, Any]
 
 
 class _ImageTemplateParam(TypedDict, total=False):
-    image_url: str | dict
+    image_url: str | dict[str, Any]
 
 
 class _StringImageMessagePromptTemplate(BaseMessagePromptTemplate):
@@ -402,7 +402,7 @@ class _StringImageMessagePromptTemplate(BaseMessagePromptTemplate):
         | list[StringPromptTemplate | ImagePromptTemplate | DictPromptTemplate]
     )
     """Prompt template."""
-    additional_kwargs: dict = Field(default_factory=dict)
+    additional_kwargs: dict[str, Any] = Field(default_factory=dict)
     """Additional keyword arguments to pass to the prompt template."""
 
     _msg_class: type[BaseMessage]
@@ -411,7 +411,7 @@ class _StringImageMessagePromptTemplate(BaseMessagePromptTemplate):
     def from_template(
         cls: type[Self],
         template: str
-        | list[str | _TextTemplateParam | _ImageTemplateParam | dict[str, Any]],
+        | Sequence[str | _TextTemplateParam | _ImageTemplateParam | dict[str, Any]],
         template_format: PromptTemplateFormat = "f-string",
         *,
         partial_variables: dict[str, Any] | None = None,
@@ -434,14 +434,18 @@ class _StringImageMessagePromptTemplate(BaseMessagePromptTemplate):
         Raises:
             ValueError: If the template is not a string or list of strings.
         """
+        prompt: (
+            StringPromptTemplate
+            | list[StringPromptTemplate | ImagePromptTemplate | DictPromptTemplate]
+        )
         if isinstance(template, str):
-            prompt: StringPromptTemplate | list = PromptTemplate.from_template(
+            prompt = PromptTemplate.from_template(
                 template,
                 template_format=template_format,
                 partial_variables=partial_variables,
             )
             return cls(prompt=prompt, **kwargs)
-        if isinstance(template, list):
+        if isinstance(template, Sequence):
             if (partial_variables is not None) and len(partial_variables) > 0:
                 msg = "Partial variables are not supported for list of templates."
                 raise ValueError(msg)
@@ -595,18 +599,18 @@ class _StringImageMessagePromptTemplate(BaseMessagePromptTemplate):
             return self._msg_class(
                 content=text, additional_kwargs=self.additional_kwargs
             )
-        content: list = []
+        content: list[str | dict[str, Any]] = []
         for prompt in self.prompt:
             inputs = {var: kwargs[var] for var in prompt.input_variables}
             if isinstance(prompt, StringPromptTemplate):
-                formatted_text: str = prompt.format(**inputs)
+                formatted_text = prompt.format(**inputs)
                 if formatted_text != "":
                     content.append({"type": "text", "text": formatted_text})
             elif isinstance(prompt, ImagePromptTemplate):
-                formatted_image: ImageURL = prompt.format(**inputs)
+                formatted_image = prompt.format(**inputs)
                 content.append({"type": "image_url", "image_url": formatted_image})
             elif isinstance(prompt, DictPromptTemplate):
-                formatted_dict: dict[str, Any] = prompt.format(**inputs)
+                formatted_dict = prompt.format(**inputs)
                 content.append(formatted_dict)
         return self._msg_class(
             content=content, additional_kwargs=self.additional_kwargs
@@ -626,18 +630,18 @@ class _StringImageMessagePromptTemplate(BaseMessagePromptTemplate):
             return self._msg_class(
                 content=text, additional_kwargs=self.additional_kwargs
             )
-        content: list = []
+        content: list[str | dict[str, Any]] = []
         for prompt in self.prompt:
             inputs = {var: kwargs[var] for var in prompt.input_variables}
             if isinstance(prompt, StringPromptTemplate):
-                formatted_text: str = await prompt.aformat(**inputs)
+                formatted_text = await prompt.aformat(**inputs)
                 if formatted_text != "":
                     content.append({"type": "text", "text": formatted_text})
             elif isinstance(prompt, ImagePromptTemplate):
-                formatted_image: ImageURL = await prompt.aformat(**inputs)
+                formatted_image = await prompt.aformat(**inputs)
                 content.append({"type": "image_url", "image_url": formatted_image})
             elif isinstance(prompt, DictPromptTemplate):
-                formatted_dict: dict[str, Any] = prompt.format(**inputs)
+                formatted_dict = prompt.format(**inputs)
                 content.append(formatted_dict)
         return self._msg_class(
             content=content, additional_kwargs=self.additional_kwargs
@@ -688,12 +692,12 @@ class SystemMessagePromptTemplate(_StringImageMessagePromptTemplate):
     _msg_class: type[BaseMessage] = SystemMessage
 
 
-class BaseChatPromptTemplate(BasePromptTemplate, ABC):
+class BaseChatPromptTemplate(BasePromptTemplate[str], ABC):
     """Base class for chat prompt templates."""
 
     @property
     @override
-    def lc_attributes(self) -> dict:
+    def lc_attributes(self) -> dict[str, Any]:
         return {"input_variables": self.input_variables}
 
     def format(self, **kwargs: Any) -> str:
@@ -781,7 +785,7 @@ MessageLike = BaseMessagePromptTemplate | BaseMessage | BaseChatPromptTemplate
 
 MessageLikeRepresentation = (
     MessageLike
-    | tuple[str | type, str | Sequence[dict] | Sequence[object]]
+    | tuple[str | type, str | Sequence[dict[str, Any]] | Sequence[object]]
     | str
     | dict[str, Any]
 )
@@ -1046,7 +1050,7 @@ class ChatPromptTemplate(BaseChatPromptTemplate):
 
     @model_validator(mode="before")
     @classmethod
-    def validate_input_variables(cls, values: dict) -> Any:
+    def validate_input_variables(cls, values: dict[str, Any]) -> Any:
         """Validate input variables.
 
         If `input_variables` is not set, it will be set to the union of all input
@@ -1062,7 +1066,7 @@ class ChatPromptTemplate(BaseChatPromptTemplate):
             ValueError: If input variables do not match.
         """
         messages = values["messages"]
-        input_vars: set = set()
+        input_vars: set[str] = set()
         optional_variables = set()
         input_types: dict[str, Any] = values.get("input_types", {})
         for message in messages:
@@ -1336,7 +1340,7 @@ class ChatPromptTemplate(BaseChatPromptTemplate):
 
 def _create_template_from_message_type(
     message_type: str,
-    template: str | list,
+    template: str | list[str | dict[str, Any]],
     template_format: PromptTemplateFormat = "f-string",
 ) -> BaseMessagePromptTemplate:
     """Create a message prompt template from a message type and template string.
diff --git a/libs/core/langchain_core/prompts/dict.py b/libs/core/langchain_core/prompts/dict.py
index 5a665bfbb8..bb68d4f28d 100644
--- a/libs/core/langchain_core/prompts/dict.py
+++ b/libs/core/langchain_core/prompts/dict.py
@@ -16,7 +16,7 @@ from langchain_core.runnables import RunnableConfig, RunnableSerializable
 from langchain_core.runnables.config import ensure_config
 
 
-class DictPromptTemplate(RunnableSerializable[dict, dict]):
+class DictPromptTemplate(RunnableSerializable[dict[str, Any], dict[str, Any]]):
     """Template represented by a dictionary.
 
     Recognizes variables in f-string or mustache formatted string dict values.
@@ -74,8 +74,8 @@ class DictPromptTemplate(RunnableSerializable[dict, dict]):
 
     @override
     def invoke(
-        self, input: dict, config: RunnableConfig | None = None, **kwargs: Any
-    ) -> dict:
+        self, input: dict[str, Any], config: RunnableConfig | None = None, **kwargs: Any
+    ) -> dict[str, Any]:
         return self._call_with_config(
             lambda x: self.format(**x),
             input,
@@ -123,7 +123,7 @@ class DictPromptTemplate(RunnableSerializable[dict, dict]):
 
 
 def _get_input_variables(
-    template: dict, template_format: Literal["f-string", "mustache"]
+    template: dict[str, Any], template_format: Literal["f-string", "mustache"]
 ) -> list[str]:
     input_variables = []
     for v in template.values():
diff --git a/libs/core/langchain_core/prompts/few_shot.py b/libs/core/langchain_core/prompts/few_shot.py
index 8e8e9aa315..cfe46d84d2 100644
--- a/libs/core/langchain_core/prompts/few_shot.py
+++ b/libs/core/langchain_core/prompts/few_shot.py
@@ -34,7 +34,7 @@ if TYPE_CHECKING:
 class _FewShotPromptTemplateMixin(BaseModel):
     """Prompt template that contains few shot examples."""
 
-    examples: list[dict] | None = None
+    examples: list[dict[str, Any]] | None = None
     """Examples to format into the prompt.
 
     Either this or `example_selector` should be provided.
@@ -53,7 +53,7 @@ class _FewShotPromptTemplateMixin(BaseModel):
 
     @model_validator(mode="before")
     @classmethod
-    def check_examples_and_selector(cls, values: dict) -> Any:
+    def check_examples_and_selector(cls, values: dict[str, Any]) -> Any:
         """Check that one and only one of `examples`/`example_selector` are provided.
 
         Args:
@@ -79,7 +79,7 @@ class _FewShotPromptTemplateMixin(BaseModel):
 
         return values
 
-    def _get_examples(self, **kwargs: Any) -> list[dict]:
+    def _get_examples(self, **kwargs: Any) -> list[dict[str, Any]]:
         """Get the examples to use for formatting the prompt.
 
         Args:
@@ -98,7 +98,7 @@ class _FewShotPromptTemplateMixin(BaseModel):
         msg = "One of 'examples' and 'example_selector' should be provided"
         raise ValueError(msg)
 
-    async def _aget_examples(self, **kwargs: Any) -> list[dict]:
+    async def _aget_examples(self, **kwargs: Any) -> list[dict[str, Any]]:
         """Async get the examples to use for formatting the prompt.
 
         Args:
diff --git a/libs/core/langchain_core/prompts/few_shot_with_templates.py b/libs/core/langchain_core/prompts/few_shot_with_templates.py
index ca664cabee..f70cdc6e66 100644
--- a/libs/core/langchain_core/prompts/few_shot_with_templates.py
+++ b/libs/core/langchain_core/prompts/few_shot_with_templates.py
@@ -19,7 +19,7 @@ from langchain_core.prompts.string import (
 class FewShotPromptWithTemplates(StringPromptTemplate):
     """Prompt template that contains few shot examples."""
 
-    examples: list[dict] | None = None
+    examples: list[dict[str, Any]] | None = None
     """Examples to format into the prompt.
 
     Either this or `example_selector` should be provided.
@@ -63,7 +63,7 @@ class FewShotPromptWithTemplates(StringPromptTemplate):
 
     @model_validator(mode="before")
     @classmethod
-    def check_examples_and_selector(cls, values: dict) -> Any:
+    def check_examples_and_selector(cls, values: dict[str, Any]) -> Any:
         """Check that one and only one of examples/example_selector are provided."""
         examples = values.get("examples")
         example_selector = values.get("example_selector")
@@ -106,14 +106,14 @@ class FewShotPromptWithTemplates(StringPromptTemplate):
         extra="forbid",
     )
 
-    def _get_examples(self, **kwargs: Any) -> list[dict]:
+    def _get_examples(self, **kwargs: Any) -> list[dict[str, Any]]:
         if self.examples is not None:
             return self.examples
         if self.example_selector is not None:
             return self.example_selector.select_examples(kwargs)
         raise ValueError
 
-    async def _aget_examples(self, **kwargs: Any) -> list[dict]:
+    async def _aget_examples(self, **kwargs: Any) -> list[dict[str, Any]]:
         if self.examples is not None:
             return self.examples
         if self.example_selector is not None:
diff --git a/libs/core/langchain_core/prompts/image.py b/libs/core/langchain_core/prompts/image.py
index ee8c9421f2..ce8054bf59 100644
--- a/libs/core/langchain_core/prompts/image.py
+++ b/libs/core/langchain_core/prompts/image.py
@@ -29,7 +29,7 @@ class ImagePromptTemplate(BasePromptTemplate[ImageURL]):
         ```
     """
 
-    template: dict = Field(default_factory=dict)
+    template: dict[str, Any] = Field(default_factory=dict)
     """Template for the prompt."""
 
     template_format: PromptTemplateFormat = "f-string"
diff --git a/libs/core/langchain_core/prompts/loading.py b/libs/core/langchain_core/prompts/loading.py
index d130f9d871..bfd2f23856 100644
--- a/libs/core/langchain_core/prompts/loading.py
+++ b/libs/core/langchain_core/prompts/loading.py
@@ -4,6 +4,7 @@ import json
 import logging
 from collections.abc import Callable
 from pathlib import Path
+from typing import Any
 
 import yaml
 
@@ -52,8 +53,8 @@ def _validate_path(path: Path) -> None:
     "prompts and `load`/`loads` to deserialize them.",
 )
 def load_prompt_from_config(
-    config: dict, *, allow_dangerous_paths: bool = False
-) -> BasePromptTemplate:
+    config: dict[str, Any], *, allow_dangerous_paths: bool = False
+) -> BasePromptTemplate[str]:
     """Load prompt from config dict.
 
     Args:
@@ -83,8 +84,8 @@ def load_prompt_from_config(
 
 
 def _load_template(
-    var_name: str, config: dict, *, allow_dangerous_paths: bool = False
-) -> dict:
+    var_name: str, config: dict[str, Any], *, allow_dangerous_paths: bool = False
+) -> dict[str, Any]:
     """Load template from the path if applicable."""
     # Check if template_path exists in config.
     if f"{var_name}_path" in config:
@@ -109,7 +110,9 @@ def _load_template(
     return config
 
 
-def _load_examples(config: dict, *, allow_dangerous_paths: bool = False) -> dict:
+def _load_examples(
+    config: dict[str, Any], *, allow_dangerous_paths: bool = False
+) -> dict[str, Any]:
     """Load examples if necessary."""
     if isinstance(config["examples"], list):
         pass
@@ -132,7 +135,7 @@ def _load_examples(config: dict, *, allow_dangerous_paths: bool = False) -> dict
     return config
 
 
-def _load_output_parser(config: dict) -> dict:
+def _load_output_parser(config: dict[str, Any]) -> dict[str, Any]:
     """Load output parser."""
     if config_ := config.get("output_parser"):
         if output_parser_type := config_.get("_type") != "default":
@@ -143,7 +146,7 @@ def _load_output_parser(config: dict) -> dict:
 
 
 def _load_few_shot_prompt(
-    config: dict, *, allow_dangerous_paths: bool = False
+    config: dict[str, Any], *, allow_dangerous_paths: bool = False
 ) -> FewShotPromptTemplate:
     """Load the "few shot" prompt from the config."""
     # Load the suffix and prefix templates.
@@ -178,7 +181,7 @@ def _load_few_shot_prompt(
 
 
 def _load_prompt(
-    config: dict, *, allow_dangerous_paths: bool = False
+    config: dict[str, Any], *, allow_dangerous_paths: bool = False
 ) -> PromptTemplate:
     """Load the prompt template from config."""
     # Load the template from disk if necessary.
@@ -212,7 +215,7 @@ def load_prompt(
     encoding: str | None = None,
     *,
     allow_dangerous_paths: bool = False,
-) -> BasePromptTemplate:
+) -> BasePromptTemplate[str]:
     """Unified method for loading a prompt from LangChainHub or local filesystem.
 
     Args:
@@ -247,7 +250,7 @@ def _load_prompt_from_file(
     encoding: str | None = None,
     *,
     allow_dangerous_paths: bool = False,
-) -> BasePromptTemplate:
+) -> BasePromptTemplate[str]:
     """Load prompt from file."""
     # Convert file to a Path object.
     file_path = Path(file)
@@ -266,7 +269,7 @@ def _load_prompt_from_file(
 
 
 def _load_chat_prompt(
-    config: dict,
+    config: dict[str, Any],
     *,
     allow_dangerous_paths: bool = False,  # noqa: ARG001
 ) -> ChatPromptTemplate:
@@ -282,7 +285,7 @@ def _load_chat_prompt(
     return ChatPromptTemplate.from_template(template=template, **config)
 
 
-type_to_loader_dict: dict[str, Callable[..., BasePromptTemplate]] = {
+type_to_loader_dict: dict[str, Callable[..., BasePromptTemplate[str]]] = {
     "prompt": _load_prompt,
     "few_shot": _load_few_shot_prompt,
     "chat": _load_chat_prompt,
diff --git a/libs/core/langchain_core/prompts/prompt.py b/libs/core/langchain_core/prompts/prompt.py
index cef55a5c2f..bbf72ebc00 100644
--- a/libs/core/langchain_core/prompts/prompt.py
+++ b/libs/core/langchain_core/prompts/prompt.py
@@ -88,7 +88,7 @@ class PromptTemplate(StringPromptTemplate):
 
     @model_validator(mode="before")
     @classmethod
-    def pre_init_validation(cls, values: dict) -> Any:
+    def pre_init_validation(cls, values: dict[str, Any]) -> Any:
         """Check that template and input variables are consistent."""
         if values.get("template") is None:
             # Will let pydantic fail with a ValidationError if template
diff --git a/libs/core/langchain_core/prompts/string.py b/libs/core/langchain_core/prompts/string.py
index f37bdba221..f96d83e492 100644
--- a/libs/core/langchain_core/prompts/string.py
+++ b/libs/core/langchain_core/prompts/string.py
@@ -213,7 +213,7 @@ DEFAULT_FORMATTER_MAPPING: dict[str, Callable[..., str]] = {
     "jinja2": jinja2_formatter,
 }
 
-DEFAULT_VALIDATOR_MAPPING: dict[str, Callable] = {
+DEFAULT_VALIDATOR_MAPPING: dict[str, Callable[[str, list[str]], None]] = {
     "f-string": formatter.validate_input_variables,
     "jinja2": validate_jinja2,
 }
@@ -325,7 +325,7 @@ def get_template_variables(template: str, template_format: str) -> list[str]:
     return sorted(input_variables)
 
 
-class StringPromptTemplate(BasePromptTemplate, ABC):
+class StringPromptTemplate(BasePromptTemplate[str], ABC):
     """String prompt that exposes the format method, returning a prompt."""
 
     @classmethod
@@ -390,7 +390,7 @@ class StringPromptTemplate(BasePromptTemplate, ABC):
         print(self.pretty_repr(html=is_interactive_env()))  # noqa: T201
 
 
-def is_subsequence(child: Sequence, parent: Sequence) -> bool:
+def is_subsequence(child: Sequence[Any], parent: Sequence[Any]) -> bool:
     """Return `True` if child is subsequence of parent."""
     if len(child) == 0 or len(parent) == 0:
         return False
diff --git a/libs/core/langchain_core/prompts/structured.py b/libs/core/langchain_core/prompts/structured.py
index 00ac407fb7..0150007984 100644
--- a/libs/core/langchain_core/prompts/structured.py
+++ b/libs/core/langchain_core/prompts/structured.py
@@ -28,7 +28,7 @@ from langchain_core.utils import get_pydantic_field_names
 class StructuredPrompt(ChatPromptTemplate):
     """Structured prompt template for a language model."""
 
-    schema_: dict | type
+    schema_: dict[str, Any] | type
     """Schema for the structured prompt."""
 
     structured_output_kwargs: dict[str, Any] = Field(default_factory=dict)
@@ -36,7 +36,7 @@ class StructuredPrompt(ChatPromptTemplate):
     def __init__(
         self,
         messages: Sequence[MessageLikeRepresentation],
-        schema_: dict | type[BaseModel] | None = None,
+        schema_: dict[str, Any] | type[BaseModel] | None = None,
         *,
         structured_output_kwargs: dict[str, Any] | None = None,
         template_format: PromptTemplateFormat = "f-string",
@@ -87,7 +87,7 @@ class StructuredPrompt(ChatPromptTemplate):
     def from_messages_and_schema(
         cls,
         messages: Sequence[MessageLikeRepresentation],
-        schema: dict | type,
+        schema: dict[str, Any] | type,
         **kwargs: Any,
     ) -> ChatPromptTemplate:
         """Create a chat prompt template from a variety of message formats.
@@ -143,7 +143,7 @@ class StructuredPrompt(ChatPromptTemplate):
         | Callable[[AsyncIterator[Any]], AsyncIterator[Other]]
         | Callable[[Any], Other]
         | Mapping[str, Runnable[Any, Other] | Callable[[Any], Other] | Any],
-    ) -> RunnableSerializable[dict, Other]:
+    ) -> RunnableSerializable[dict[str, Any], Other]:
         return self.pipe(other)
 
     def pipe(
@@ -154,7 +154,7 @@ class StructuredPrompt(ChatPromptTemplate):
         | Callable[[Any], Other]
         | Mapping[str, Runnable[Any, Other] | Callable[[Any], Other] | Any],
         name: str | None = None,
-    ) -> RunnableSerializable[dict, Other]:
+    ) -> RunnableSerializable[dict[str, Any], Other]:
         """Pipe the structured prompt to a language model.
 
         Args:
diff --git a/libs/core/langchain_core/runnables/base.py b/libs/core/langchain_core/runnables/base.py
index 3a9b0cdcfc..65a53fb1d6 100644
--- a/libs/core/langchain_core/runnables/base.py
+++ b/libs/core/langchain_core/runnables/base.py
@@ -605,7 +605,7 @@ class Runnable(ABC, Generic[Input, Output]):
 
     def get_prompts(
         self, config: RunnableConfig | None = None
-    ) -> list[BasePromptTemplate]:
+    ) -> list[BasePromptTemplate[Any]]:
         """Return a list of prompts used by this `Runnable`."""
         # Import locally to prevent circular import
         from langchain_core.prompts.base import BasePromptTemplate  # noqa: PLC0415
@@ -2488,7 +2488,7 @@ class Runnable(ABC, Generic[Input, Output]):
                 iterator = context.run(transformer, input_for_transform, **kwargs)  # type: ignore[arg-type]
                 if stream_handler := next(
                     (
-                        cast("_StreamingCallbackHandler", h)
+                        h
                         for h in run_manager.handlers
                         # instance check OK here, it's a mixin
                         if isinstance(h, _StreamingCallbackHandler)
@@ -2590,7 +2590,7 @@ class Runnable(ABC, Generic[Input, Output]):
 
                 if stream_handler := next(
                     (
-                        cast("_StreamingCallbackHandler", h)
+                        h
                         for h in run_manager.handlers
                         # instance check OK here, it's a mixin
                         if isinstance(h, _StreamingCallbackHandler)
@@ -3088,7 +3088,7 @@ class RunnableSequence(RunnableSerializable[Input, Output]):
 
     def __init__(
         self,
-        *steps: RunnableLike,
+        *steps: RunnableLike[Any, Any],
         name: str | None = None,
         first: Runnable[Any, Any] | None = None,
         middle: list[Runnable[Any, Any]] | None = None,
@@ -3106,7 +3106,7 @@ class RunnableSequence(RunnableSerializable[Input, Output]):
         Raises:
             ValueError: If the sequence has less than 2 steps.
         """
-        steps_flat: list[Runnable] = []
+        steps_flat: list[Runnable[Any, Any]] = []
         if not steps and first is not None and last is not None:
             steps_flat = [first] + (middle or []) + [last]
         for step in steps:
@@ -4216,7 +4216,7 @@ class RunnableParallel(RunnableSerializable[Input, dict[str, Any]]):
         ]
 
         # Wrap in a coroutine to satisfy linter
-        async def get_next_chunk(generator: AsyncIterator) -> Output | None:
+        async def get_next_chunk(generator: AsyncIterator[Any]) -> Output | None:
             return await anext(generator)
 
         # Start the first iteration of each generator
@@ -4383,9 +4383,10 @@ class RunnableGenerator(Runnable[Input, Output]):
             TypeError: If the transform is not a generator function.
 
         """
+        func_for_name: Callable[..., Any]
         if atransform is not None:
             self._atransform = atransform
-            func_for_name: Callable = atransform
+            func_for_name = atransform
 
         if is_async_generator(transform):
             self._atransform = transform
@@ -4795,9 +4796,10 @@ class RunnableLambda(Runnable[Input, Output]):
             TypeError: If both `func` and `afunc` are provided.
 
         """
+        func_for_name: Callable[..., Any]
         if afunc is not None:
             self.afunc = afunc
-            func_for_name: Callable = afunc
+            func_for_name = afunc
 
         if is_async_callable(func) or is_async_generator(func):
             if afunc is not None:
@@ -4939,7 +4941,7 @@ class RunnableLambda(Runnable[Input, Output]):
         )
 
     @functools.cached_property
-    def deps(self) -> list[Runnable]:
+    def deps(self) -> list[Runnable[Any, Any]]:
         """The dependencies of this `Runnable`.
 
         Returns:
@@ -4954,7 +4956,7 @@ class RunnableLambda(Runnable[Input, Output]):
         else:
             objects = []
 
-        deps: list[Runnable] = []
+        deps: list[Runnable[Any, Any]] = []
         for obj in objects:
             if isinstance(obj, Runnable):
                 deps.append(obj)
@@ -5130,7 +5132,7 @@ class RunnableLambda(Runnable[Input, Output]):
                 cast(
                     "AsyncGenerator[Any, Any]",
                     acall_func_with_variable_args(
-                        cast("Callable", afunc),
+                        cast("Callable[..., Any]", afunc),
                         value,
                         config,
                         run_manager,
@@ -5151,7 +5153,7 @@ class RunnableLambda(Runnable[Input, Output]):
                             output = chunk
         else:
             output = await acall_func_with_variable_args(
-                cast("Callable", afunc), value, config, run_manager, **kwargs
+                cast("Callable[..., Any]", afunc), value, config, run_manager, **kwargs
             )
         # If the output is a Runnable, invoke it
         if isinstance(output, Runnable):
@@ -5373,7 +5375,7 @@ class RunnableLambda(Runnable[Input, Output]):
             async for chunk in cast(
                 "AsyncIterator[Output]",
                 acall_func_with_variable_args(
-                    cast("Callable", afunc),
+                    cast("Callable[..., Any]", afunc),
                     final,
                     config,
                     run_manager,
@@ -5390,7 +5392,7 @@ class RunnableLambda(Runnable[Input, Output]):
                         output = chunk
         else:
             output = await acall_func_with_variable_args(
-                cast("Callable", afunc),
+                cast("Callable[..., Any]", afunc),
                 final,
                 config,
                 run_manager,
@@ -6486,7 +6488,7 @@ RunnableLike = (
 )
 
 
-def coerce_to_runnable(thing: RunnableLike) -> Runnable[Input, Output]:
+def coerce_to_runnable(thing: RunnableLike[Input, Output]) -> Runnable[Input, Output]:
     """Coerce a `Runnable`-like object into a `Runnable`.
 
     Args:
diff --git a/libs/core/langchain_core/runnables/branch.py b/libs/core/langchain_core/runnables/branch.py
index ca3dfd99da..b8a3ffb7d1 100644
--- a/libs/core/langchain_core/runnables/branch.py
+++ b/libs/core/langchain_core/runnables/branch.py
@@ -77,9 +77,9 @@ class RunnableBranch(RunnableSerializable[Input, Output]):
             Runnable[Input, bool]
             | Callable[[Input], bool]
             | Callable[[Input], Awaitable[bool]],
-            RunnableLike,
+            RunnableLike[Input, Output],
         ]
-        | RunnableLike,
+        | RunnableLike[Input, Output],
     ) -> None:
         """A `Runnable` that runs one of two branches based on a condition.
 
@@ -106,9 +106,7 @@ class RunnableBranch(RunnableSerializable[Input, Output]):
             msg = "RunnableBranch default must be Runnable, callable or mapping."
             raise TypeError(msg)
 
-        default_ = cast(
-            "Runnable[Input, Output]", coerce_to_runnable(cast("RunnableLike", default))
-        )
+        default_ = coerce_to_runnable(cast("RunnableLike[Input, Output]", default))
 
         branches_ = []
 
diff --git a/libs/core/langchain_core/runnables/graph.py b/libs/core/langchain_core/runnables/graph.py
index cdab7d4884..4b5bfdfb83 100644
--- a/libs/core/langchain_core/runnables/graph.py
+++ b/libs/core/langchain_core/runnables/graph.py
@@ -97,7 +97,7 @@ class Node(NamedTuple):
     """The unique identifier of the node."""
     name: str
     """The name of the node."""
-    data: type[BaseModel] | RunnableType | None
+    data: type[BaseModel] | RunnableType[Any, Any] | None
     """The data of the node."""
     metadata: dict[str, Any] | None
     """Optional metadata for the node. """
@@ -177,7 +177,7 @@ class MermaidDrawMethod(Enum):
 
 def node_data_str(
     id: str,
-    data: type[BaseModel] | RunnableType | None,
+    data: type[BaseModel] | RunnableType[Any, Any] | None,
 ) -> str:
     """Convert the data of a node to a string.
 
@@ -311,7 +311,7 @@ class Graph:
 
     def add_node(
         self,
-        data: type[BaseModel] | RunnableType | None,
+        data: type[BaseModel] | RunnableType[Any, Any] | None,
         id: str | None = None,
         *,
         metadata: dict[str, Any] | None = None,
diff --git a/libs/core/langchain_core/runnables/history.py b/libs/core/langchain_core/runnables/history.py
index c85386735c..d04e3226d9 100644
--- a/libs/core/langchain_core/runnables/history.py
+++ b/libs/core/langchain_core/runnables/history.py
@@ -36,7 +36,7 @@ MessagesOrDictWithMessages = Sequence["BaseMessage"] | dict[str, Any]
 GetSessionHistoryCallable = Callable[..., BaseChatMessageHistory]
 
 
-class RunnableWithMessageHistory(RunnableBindingBase):  # type: ignore[no-redef]
+class RunnableWithMessageHistory(RunnableBindingBase[Any, Any]):  # type: ignore[no-redef]
     """`Runnable` that manages chat message history for another `Runnable`.
 
     A chat message history is a sequence of messages that represent a conversation.
@@ -391,7 +391,7 @@ class RunnableWithMessageHistory(RunnableBindingBase):  # type: ignore[no-redef]
 
     @override
     def get_input_schema(self, config: RunnableConfig | None = None) -> type[BaseModel]:
-        fields: dict = {}
+        fields: dict[str, Any] = {}
         if self.input_messages_key and self.history_messages_key:
             fields[self.input_messages_key] = (
                 str | BaseMessage | Sequence[BaseMessage],
@@ -450,7 +450,7 @@ class RunnableWithMessageHistory(RunnableBindingBase):  # type: ignore[no-redef]
         )
 
     def _get_input_messages(
-        self, input_val: str | BaseMessage | Sequence[BaseMessage] | dict
+        self, input_val: str | BaseMessage | Sequence[BaseMessage] | dict[str, Any]
     ) -> list[BaseMessage]:
         # If dictionary, try to pluck the single key representing messages
         if isinstance(input_val, dict):
@@ -488,7 +488,7 @@ class RunnableWithMessageHistory(RunnableBindingBase):  # type: ignore[no-redef]
         raise ValueError(msg)
 
     def _get_output_messages(
-        self, output_val: str | BaseMessage | Sequence[BaseMessage] | dict
+        self, output_val: str | BaseMessage | Sequence[BaseMessage] | dict[str, Any]
     ) -> list[BaseMessage]:
         # If dictionary, try to pluck the single key representing messages
         if isinstance(output_val, dict):
diff --git a/libs/core/langchain_core/runnables/passthrough.py b/libs/core/langchain_core/runnables/passthrough.py
index f5e01cfe20..0df584d252 100644
--- a/libs/core/langchain_core/runnables/passthrough.py
+++ b/libs/core/langchain_core/runnables/passthrough.py
@@ -9,7 +9,6 @@ from collections.abc import Awaitable, Callable
 from typing import (
     TYPE_CHECKING,
     Any,
-    cast,
 )
 
 from pydantic import BaseModel, RootModel
@@ -346,7 +345,7 @@ class RunnablePassthrough(RunnableSerializable[Other, Other]):
             yield chunk
 
 
-_graph_passthrough: RunnablePassthrough = RunnablePassthrough()
+_graph_passthrough = RunnablePassthrough[Any]()
 
 
 class RunnableAssign(RunnableSerializable[dict[str, Any], dict[str, Any]]):
@@ -577,9 +576,11 @@ class RunnableAssign(RunnableSerializable[dict[str, Any], dict[str, Any]]):
                 if filtered:
                     yield filtered
             # yield map output
-            yield cast("dict[str, Any]", first_map_chunk_future.result())
-            for chunk in map_output:
-                yield chunk
+            first_chunk = first_map_chunk_future.result()
+            if first_chunk is not None:
+                yield first_chunk
+                for chunk in map_output:
+                    yield chunk
 
     @override
     def transform(
@@ -613,7 +614,7 @@ class RunnableAssign(RunnableSerializable[dict[str, Any], dict[str, Any]]):
             **kwargs,
         )
         # start map output stream
-        first_map_chunk_task: asyncio.Task = asyncio.create_task(
+        first_map_chunk_task = asyncio.create_task(
             anext(map_output, None),
         )
         # consume passthrough stream
@@ -629,9 +630,11 @@ class RunnableAssign(RunnableSerializable[dict[str, Any], dict[str, Any]]):
             if filtered:
                 yield filtered
         # yield map output
-        yield await first_map_chunk_task
-        async for chunk in map_output:
-            yield chunk
+        first_chunk = await first_map_chunk_task
+        if first_chunk is not None:
+            yield first_chunk
+            async for chunk in map_output:
+                yield chunk
 
     @override
     async def atransform(
diff --git a/libs/core/langchain_core/runnables/utils.py b/libs/core/langchain_core/runnables/utils.py
index e46251a207..1cf2371e63 100644
--- a/libs/core/langchain_core/runnables/utils.py
+++ b/libs/core/langchain_core/runnables/utils.py
@@ -46,7 +46,9 @@ Input = TypeVar("Input", contravariant=True)  # noqa: PLC0105
 Output = TypeVar("Output", covariant=True)  # noqa: PLC0105
 
 
-async def gated_coro(semaphore: asyncio.Semaphore, coro: Coroutine) -> Any:
+async def gated_coro(
+    semaphore: asyncio.Semaphore, coro: Coroutine[Any, Any, Any]
+) -> Any:
     """Run a coroutine with a semaphore.
 
     Args:
@@ -60,7 +62,9 @@ async def gated_coro(semaphore: asyncio.Semaphore, coro: Coroutine) -> Any:
         return await coro
 
 
-async def gather_with_concurrency(n: int | None, *coros: Coroutine) -> list:
+async def gather_with_concurrency(
+    n: int | None, *coros: Coroutine[Any, Any, Any]
+) -> list[Any]:
     """Gather coroutines with a limit on the number of concurrent coroutines.
 
     Args:
@@ -362,7 +366,7 @@ class GetLambdaSource(ast.NodeVisitor):
             self.source = ast.unparse(node)
 
 
-def get_function_first_arg_dict_keys(func: Callable) -> list[str] | None:
+def get_function_first_arg_dict_keys(func: Callable[..., Any]) -> list[str] | None:
     """Get the keys of the first argument of a function if it is a dict.
 
     Args:
@@ -381,7 +385,7 @@ def get_function_first_arg_dict_keys(func: Callable) -> list[str] | None:
         return None
 
 
-def get_lambda_source(func: Callable) -> str | None:
+def get_lambda_source(func: Callable[..., Any]) -> str | None:
     """Get the source code of a lambda function.
 
     Args:
@@ -405,7 +409,7 @@ def get_lambda_source(func: Callable) -> str | None:
 
 
 @lru_cache(maxsize=256)
-def get_function_nonlocals(func: Callable) -> list[Any]:
+def get_function_nonlocals(func: Callable[..., Any]) -> list[Any]:
     """Get the nonlocal variables accessed by a function.
 
     Args:
@@ -747,7 +751,7 @@ class _RootEventFilter:
 
 def is_async_generator(
     func: Any,
-) -> TypeGuard[Callable[..., AsyncIterator]]:
+) -> TypeGuard[Callable[..., AsyncIterator[Any]]]:
     """Check if a function is an async generator.
 
     Args:
@@ -764,7 +768,7 @@ def is_async_generator(
 
 def is_async_callable(
     func: Any,
-) -> TypeGuard[Callable[..., Awaitable]]:
+) -> TypeGuard[Callable[..., Awaitable[Any]]]:
     """Check if a function is async.
 
     Args:
diff --git a/libs/core/langchain_core/tools/base.py b/libs/core/langchain_core/tools/base.py
index 67c64fb1f1..a04f0abef4 100644
--- a/libs/core/langchain_core/tools/base.py
+++ b/libs/core/langchain_core/tools/base.py
@@ -122,38 +122,12 @@ def _get_annotation_description(arg_type: type) -> str | None:
     return None
 
 
-def _get_filtered_args(
-    inferred_model: type[BaseModel],
-    func: Callable,
-    *,
-    filter_args: Sequence[str],
-    include_injected: bool = True,
-) -> dict:
-    """Get filtered arguments from a function's signature.
-
-    Args:
-        inferred_model: The Pydantic model inferred from the function.
-        func: The function to extract arguments from.
-        filter_args: Arguments to exclude from the result.
-        include_injected: Whether to include injected arguments.
-
-    Returns:
-        Dictionary of filtered arguments with their schema definitions.
-    """
-    schema = inferred_model.model_json_schema()["properties"]
-    valid_keys = signature(func).parameters
-    return {
-        k: schema[k]
-        for i, (k, param) in enumerate(valid_keys.items())
-        if k not in filter_args
-        and (i > 0 or param.name not in {"self", "cls"})
-        and (include_injected or not _is_injected_arg_type(param.annotation))
-    }
-
-
 def _parse_python_function_docstring(
-    function: Callable, annotations: dict, *, error_on_invalid_docstring: bool = False
-) -> tuple[str, dict]:
+    function: Callable[..., Any],
+    annotations: dict[str, Any],
+    *,
+    error_on_invalid_docstring: bool = False,
+) -> tuple[str, dict[str, str]]:
     """Parse function and argument descriptions from a docstring.
 
     Assumes the function docstring follows Google Python style guide.
@@ -175,7 +149,7 @@ def _parse_python_function_docstring(
 
 
 def _validate_docstring_args_against_annotations(
-    arg_descriptions: dict, annotations: dict
+    arg_descriptions: dict[str, str], annotations: dict[str, Any]
 ) -> None:
     """Validate that docstring arguments match function annotations.
 
@@ -193,11 +167,11 @@ def _validate_docstring_args_against_annotations(
 
 
 def _infer_arg_descriptions(
-    fn: Callable,
+    fn: Callable[..., Any],
     *,
     parse_docstring: bool = False,
     error_on_invalid_docstring: bool = False,
-) -> tuple[str, dict]:
+) -> tuple[str, dict[str, str]]:
     """Infer argument descriptions from function docstring and annotations.
 
     Args:
@@ -244,7 +218,7 @@ def _is_pydantic_annotation(annotation: Any, pydantic_version: str = "v2") -> bo
 
 
 def _function_annotations_are_pydantic_v1(
-    signature: inspect.Signature, func: Callable
+    signature: inspect.Signature, func: Callable[..., Any]
 ) -> bool:
     """Check if all Pydantic annotations in a function are from v1.
 
@@ -287,7 +261,7 @@ class _SchemaConfig:
 
 def create_schema_from_function(
     model_name: str,
-    func: Callable,
+    func: Callable[..., Any],
     *,
     filter_args: Sequence[str] | None = None,
     parse_docstring: bool = False,
@@ -415,7 +389,7 @@ content is normalized to the content of a `ToolMessage` with `status="error"`.
 _EMPTY_SET: frozenset[str] = frozenset()
 
 
-class BaseTool(RunnableSerializable[str | dict | ToolCall, Any]):
+class BaseTool(RunnableSerializable[str | dict[str, Any] | ToolCall, Any]):
     """Base class for all LangChain tools.
 
     This abstract class defines the interface that all LangChain tools must implement.
@@ -590,7 +564,7 @@ class ChildTool(BaseTool):
         return len(keys) == 1
 
     @property
-    def args(self) -> dict:
+    def args(self) -> dict[str, Any]:
         """Get the tool's input arguments schema.
 
         Returns:
@@ -606,7 +580,7 @@ class ChildTool(BaseTool):
                 json_schema = input_schema
             else:
                 json_schema = input_schema.model_json_schema()
-        return cast("dict", json_schema["properties"])
+        return cast("dict[str, Any]", json_schema["properties"])
 
     @property
     def tool_call_schema(self) -> ArgsSchema:
@@ -659,7 +633,7 @@ class ChildTool(BaseTool):
     @override
     def invoke(
         self,
-        input: str | dict | ToolCall,
+        input: str | dict[str, Any] | ToolCall,
         config: RunnableConfig | None = None,
         **kwargs: Any,
     ) -> Any:
@@ -669,7 +643,7 @@ class ChildTool(BaseTool):
     @override
     async def ainvoke(
         self,
-        input: str | dict | ToolCall,
+        input: str | dict[str, Any] | ToolCall,
         config: RunnableConfig | None = None,
         **kwargs: Any,
     ) -> Any:
@@ -679,7 +653,7 @@ class ChildTool(BaseTool):
     # --- Tool ---
 
     def _parse_input(
-        self, tool_input: str | dict, tool_call_id: str | None
+        self, tool_input: str | dict[str, Any], tool_call_id: str | None
     ) -> str | dict[str, Any]:
         """Parse and validate tool input using the args schema.
 
@@ -825,7 +799,7 @@ class ChildTool(BaseTool):
             kwargs["run_manager"] = kwargs["run_manager"].get_sync()
         return await run_in_executor(None, self._run, *args, **kwargs)
 
-    def _filter_injected_args(self, tool_input: dict) -> dict:
+    def _filter_injected_args(self, tool_input: dict[str, Any]) -> dict[str, Any]:
         """Filter out injected tool arguments from the input dictionary.
 
         Injected arguments are those annotated with `InjectedToolArg` or its
@@ -862,8 +836,8 @@ class ChildTool(BaseTool):
         return {k: v for k, v in tool_input.items() if k not in filtered_keys}
 
     def _to_args_and_kwargs(
-        self, tool_input: str | dict, tool_call_id: str | None
-    ) -> tuple[tuple, dict]:
+        self, tool_input: str | dict[str, Any], tool_call_id: str | None
+    ) -> tuple[tuple[str, ...], dict[str, Any]]:
         """Convert tool input to positional and keyword arguments.
 
         Args:
@@ -1030,7 +1004,7 @@ class ChildTool(BaseTool):
 
     async def arun(
         self,
-        tool_input: str | dict,
+        tool_input: str | dict[str, Any],
         verbose: bool | None = None,  # noqa: FBT001
         start_color: str | None = "green",
         color: str | None = "green",
@@ -1244,10 +1218,10 @@ def _handle_tool_error(
 
 
 def _prep_run_args(
-    value: str | dict | ToolCall,
+    value: str | dict[str, Any] | ToolCall,
     config: RunnableConfig | None,
     **kwargs: Any,
-) -> tuple[str | dict, dict]:
+) -> tuple[str | dict[str, Any], dict[str, Any]]:
     """Prepare arguments for tool execution.
 
     Args:
@@ -1259,12 +1233,13 @@ def _prep_run_args(
         A tuple of `(tool_input, run_kwargs)`.
     """
     config = ensure_config(config)
+    tool_input: str | dict[str, Any]
     if _is_tool_call(value):
         tool_call_id: str | None = cast("ToolCall", value)["id"]
-        tool_input: str | dict = cast("ToolCall", value)["args"].copy()
+        tool_input = cast("ToolCall", value)["args"].copy()
     else:
         tool_call_id = None
-        tool_input = cast("str | dict", value)
+        tool_input = cast("str | dict[str, Any]", value)
     return (
         tool_input,
         dict(
@@ -1376,7 +1351,7 @@ def _stringify(content: Any) -> str:
         return str(content)
 
 
-def _get_type_hints(func: Callable) -> dict[str, type] | None:
+def _get_type_hints(func: Callable[..., Any]) -> dict[str, type] | None:
     """Get type hints from a function, handling partial functions.
 
     Args:
@@ -1393,7 +1368,7 @@ def _get_type_hints(func: Callable) -> dict[str, type] | None:
         return None
 
 
-def _get_runnable_config_param(func: Callable) -> str | None:
+def _get_runnable_config_param(func: Callable[..., Any]) -> str | None:
     """Find the parameter name for `RunnableConfig` in a function.
 
     Args:
@@ -1527,6 +1502,7 @@ def get_all_basemodel_annotations(
     Returns:
         `dict` of field names to their type annotations.
     """
+    orig_bases: tuple[type, ...]
     # cls has no subscript: cls = FooBar
     if isinstance(cls, type):
         fields = get_fields(cls)
@@ -1540,7 +1516,7 @@ def get_all_basemodel_annotations(
                 continue
             field_name = alias_map.get(name, name)
             annotations[field_name] = param.annotation
-        orig_bases: tuple = getattr(cls, "__orig_bases__", ())
+        orig_bases = getattr(cls, "__orig_bases__", ())
     # cls has subscript: cls = FooBar[int]
     else:
         annotations = get_all_basemodel_annotations(
@@ -1572,7 +1548,9 @@ def get_all_basemodel_annotations(
             # parent_origin = class Baz,
             # generic_type_vars = (type vars in Baz)
             # generic_map = {type var in Baz: str}
-            generic_type_vars: tuple = getattr(parent_origin, "__parameters__", ())
+            generic_type_vars: tuple[TypeVar, ...] = getattr(
+                parent_origin, "__parameters__", ()
+            )
             generic_map = dict(zip(generic_type_vars, get_args(parent), strict=False))
             for field in getattr(parent_origin, "__annotations__", {}):
                 annotations[field] = _replace_type_vars(
diff --git a/libs/core/langchain_core/tools/convert.py b/libs/core/langchain_core/tools/convert.py
index 48c518a298..5781afc473 100644
--- a/libs/core/langchain_core/tools/convert.py
+++ b/libs/core/langchain_core/tools/convert.py
@@ -24,13 +24,13 @@ def tool(
     parse_docstring: bool = False,
     error_on_invalid_docstring: bool = True,
     extras: dict[str, Any] | None = None,
-) -> Callable[[Callable | Runnable], BaseTool]: ...
+) -> Callable[[Callable[..., Any] | Runnable[Any, Any]], BaseTool]: ...
 
 
 @overload
 def tool(
     name_or_callable: str,
-    runnable: Runnable,
+    runnable: Runnable[Any, Any],
     *,
     description: str | None = None,
     return_direct: bool = False,
@@ -45,7 +45,7 @@ def tool(
 
 @overload
 def tool(
-    name_or_callable: Callable,
+    name_or_callable: Callable[..., Any],
     *,
     description: str | None = None,
     return_direct: bool = False,
@@ -70,12 +70,12 @@ def tool(
     parse_docstring: bool = False,
     error_on_invalid_docstring: bool = True,
     extras: dict[str, Any] | None = None,
-) -> Callable[[Callable | Runnable], BaseTool]: ...
+) -> Callable[[Callable[..., Any] | Runnable[Any, Any]], BaseTool]: ...
 
 
 def tool(
-    name_or_callable: str | Callable | None = None,
-    runnable: Runnable | None = None,
+    name_or_callable: str | Callable[..., Any] | None = None,
+    runnable: Runnable[Any, Any] | None = None,
     *args: Any,
     description: str | None = None,
     return_direct: bool = False,
@@ -85,7 +85,7 @@ def tool(
     parse_docstring: bool = False,
     error_on_invalid_docstring: bool = True,
     extras: dict[str, Any] | None = None,
-) -> BaseTool | Callable[[Callable | Runnable], BaseTool]:
+) -> BaseTool | Callable[[Callable[..., Any] | Runnable[Any, Any]], BaseTool]:
     """Convert Python functions and `Runnables` to LangChain tools.
 
     Can be used as a decorator with or without arguments to create tools from functions.
@@ -258,7 +258,7 @@ def tool(
 
     def _create_tool_factory(
         tool_name: str,
-    ) -> Callable[[Callable | Runnable], BaseTool]:
+    ) -> Callable[[Callable[..., Any] | Runnable[Any, Any]], BaseTool]:
         """Create a decorator that takes a callable and returns a tool.
 
         Args:
@@ -268,7 +268,9 @@ def tool(
             A function that takes a callable or `Runnable` and returns a tool.
         """
 
-        def _tool_factory(dec_func: Callable | Runnable) -> BaseTool:
+        def _tool_factory(
+            dec_func: Callable[..., Any] | Runnable[Any, Any],
+        ) -> BaseTool:
             tool_description = description
             if isinstance(dec_func, Runnable):
                 runnable = dec_func
@@ -381,7 +383,7 @@ def tool(
     # @tool(parse_docstring=True)
     # def my_tool():
     #    pass
-    def _partial(func: Callable | Runnable) -> BaseTool:
+    def _partial(func: Callable[..., Any] | Runnable[Any, Any]) -> BaseTool:
         """Partial function that takes a `Callable` and returns a tool."""
         name_ = func.get_name() if isinstance(func, Runnable) else func.__name__
         tool_factory = _create_tool_factory(name_)
@@ -390,14 +392,14 @@ def tool(
     return _partial
 
 
-def _get_description_from_runnable(runnable: Runnable) -> str:
+def _get_description_from_runnable(runnable: Runnable[Any, Any]) -> str:
     """Generate a placeholder description of a `Runnable`."""
     input_schema = runnable.input_schema.model_json_schema()
     return f"Takes {input_schema}."
 
 
 def _get_schema_from_runnable_and_arg_types(
-    runnable: Runnable,
+    runnable: Runnable[Any, Any],
     name: str,
     arg_types: dict[str, type] | None = None,
 ) -> type[BaseModel]:
@@ -417,7 +419,7 @@ def _get_schema_from_runnable_and_arg_types(
 
 
 def convert_runnable_to_tool(
-    runnable: Runnable,
+    runnable: Runnable[Any, Any],
     args_schema: type[BaseModel] | None = None,
     *,
     name: str | None = None,
diff --git a/libs/core/langchain_core/tools/retriever.py b/libs/core/langchain_core/tools/retriever.py
index 9e2d84dcb0..890e4ca0ff 100644
--- a/libs/core/langchain_core/tools/retriever.py
+++ b/libs/core/langchain_core/tools/retriever.py
@@ -33,7 +33,7 @@ def create_retriever_tool(
     name: str,
     description: str,
     *,
-    document_prompt: BasePromptTemplate | None = None,
+    document_prompt: BasePromptTemplate[str] | None = None,
     document_separator: str = "\n\n",
     response_format: Literal["content", "content_and_artifact"] = "content",
 ) -> StructuredTool:
diff --git a/libs/core/langchain_core/tools/simple.py b/libs/core/langchain_core/tools/simple.py
index ca80164df8..502960ce1f 100644
--- a/libs/core/langchain_core/tools/simple.py
+++ b/libs/core/langchain_core/tools/simple.py
@@ -44,7 +44,7 @@ class Tool(BaseTool):
     @override
     async def ainvoke(
         self,
-        input: str | dict | ToolCall,
+        input: str | dict[str, Any] | ToolCall,
         config: RunnableConfig | None = None,
         **kwargs: Any,
     ) -> Any:
@@ -57,7 +57,7 @@ class Tool(BaseTool):
     # --- Tool ---
 
     @property
-    def args(self) -> dict:
+    def args(self) -> dict[str, Any]:
         """The tool's input arguments.
 
         Returns:
@@ -70,8 +70,8 @@ class Tool(BaseTool):
         return {"tool_input": {"type": "string"}}
 
     def _to_args_and_kwargs(
-        self, tool_input: str | dict, tool_call_id: str | None
-    ) -> tuple[tuple, dict]:
+        self, tool_input: str | dict[str, Any], tool_call_id: str | None
+    ) -> tuple[tuple[str, ...], dict[str, Any]]:
         """Convert tool input to Pydantic model.
 
         Args:
@@ -156,7 +156,11 @@ class Tool(BaseTool):
 
     # TODO: this is for backwards compatibility, remove in future
     def __init__(
-        self, name: str, func: Callable | None, description: str, **kwargs: Any
+        self,
+        name: str,
+        func: Callable[..., Any] | None,
+        description: str,
+        **kwargs: Any,
     ) -> None:
         """Initialize tool."""
         super().__init__(name=name, func=func, description=description, **kwargs)
@@ -164,7 +168,7 @@ class Tool(BaseTool):
     @classmethod
     def from_function(
         cls,
-        func: Callable | None,
+        func: Callable[..., Any] | None,
         name: str,  # We keep these required to support backwards compatibility
         description: str,
         return_direct: bool = False,  # noqa: FBT001,FBT002
diff --git a/libs/core/langchain_core/tools/structured.py b/libs/core/langchain_core/tools/structured.py
index 8b67e3b454..e9643a0ad8 100644
--- a/libs/core/langchain_core/tools/structured.py
+++ b/libs/core/langchain_core/tools/structured.py
@@ -59,7 +59,7 @@ class StructuredTool(BaseTool):
     @override
     async def ainvoke(
         self,
-        input: str | dict | ToolCall,
+        input: str | dict[str, Any] | ToolCall,
         config: RunnableConfig | None = None,
         **kwargs: Any,
     ) -> Any:
@@ -132,7 +132,7 @@ class StructuredTool(BaseTool):
     @classmethod
     def from_function(
         cls,
-        func: Callable | None = None,
+        func: Callable[..., Any] | None = None,
         coroutine: Callable[..., Awaitable[Any]] | None = None,
         name: str | None = None,
         description: str | None = None,
@@ -263,7 +263,7 @@ class StructuredTool(BaseTool):
         )
 
 
-def _filter_schema_args(func: Callable) -> list[str]:
+def _filter_schema_args(func: Callable[..., Any]) -> list[str]:
     filter_args = list(FILTERED_ARGS)
     if config_param := _get_runnable_config_param(func):
         filter_args.append(config_param)
diff --git a/libs/core/langchain_core/tracers/base.py b/libs/core/langchain_core/tracers/base.py
index b52420f0d8..0c49530a30 100644
--- a/libs/core/langchain_core/tracers/base.py
+++ b/libs/core/langchain_core/tracers/base.py
@@ -539,7 +539,7 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         self._on_retriever_end(retrieval_run)
         return retrieval_run
 
-    def __deepcopy__(self, memo: dict) -> BaseTracer:
+    def __deepcopy__(self, memo: dict[int, Any] | None = None) -> BaseTracer:
         """Return self."""
         return self
 
diff --git a/libs/core/langchain_core/tracers/core.py b/libs/core/langchain_core/tracers/core.py
index 75614e3c88..c6f6cca167 100644
--- a/libs/core/langchain_core/tracers/core.py
+++ b/libs/core/langchain_core/tracers/core.py
@@ -555,7 +555,7 @@ class _TracerCore(ABC):
         retrieval_run.events.append({"name": "error", "time": retrieval_run.end_time})
         return retrieval_run
 
-    def __deepcopy__(self, memo: dict) -> _TracerCore:
+    def __deepcopy__(self, memo: dict[int, Any] | None = None) -> _TracerCore:
         """Return self deepcopied."""
         return self
 
diff --git a/libs/core/langchain_core/tracers/evaluation.py b/libs/core/langchain_core/tracers/evaluation.py
index 22c6f600f5..a7062cb2a2 100644
--- a/libs/core/langchain_core/tracers/evaluation.py
+++ b/libs/core/langchain_core/tracers/evaluation.py
@@ -56,7 +56,7 @@ class EvaluatorCallbackHandler(BaseTracer):
     executor: ThreadPoolExecutor | None = None
     """The thread pool executor used for running the evaluators."""
 
-    futures: weakref.WeakSet[Future] = weakref.WeakSet()
+    futures: weakref.WeakSet[Future[None]] = weakref.WeakSet()
     """The set of futures representing the running evaluators."""
 
     skip_unfinished: bool = True
diff --git a/libs/core/langchain_core/tracers/event_stream.py b/libs/core/langchain_core/tracers/event_stream.py
index 399a7c19b6..cba55b8bb9 100644
--- a/libs/core/langchain_core/tracers/event_stream.py
+++ b/libs/core/langchain_core/tracers/event_stream.py
@@ -98,7 +98,9 @@ def _assign_name(name: str | None, serialized: dict[str, Any] | None) -> str:
 T = TypeVar("T")
 
 
-class _AstreamEventsCallbackHandler(AsyncCallbackHandler, _StreamingCallbackHandler):
+class _AstreamEventsCallbackHandler(
+    AsyncCallbackHandler, _StreamingCallbackHandler[Any]
+):
     """An implementation of an async callback handler for astream events."""
 
     def __init__(
@@ -500,7 +502,7 @@ class _AstreamEventsCallbackHandler(AsyncCallbackHandler, _StreamingCallbackHand
         inputs_ = run_info.get("inputs")
 
         generations: list[list[GenerationChunk]] | list[list[ChatGenerationChunk]]
-        output: dict | BaseMessage = {}
+        output: dict[str, Any] | BaseMessage = {}
 
         if run_info["run_type"] == "chat_model":
             generations = cast("list[list[ChatGenerationChunk]]", response.generations)
@@ -815,7 +817,9 @@ class _AstreamEventsCallbackHandler(AsyncCallbackHandler, _StreamingCallbackHand
             run_info["run_type"],
         )
 
-    def __deepcopy__(self, memo: dict) -> _AstreamEventsCallbackHandler:
+    def __deepcopy__(
+        self, memo: dict[int, Any] | None = None
+    ) -> _AstreamEventsCallbackHandler:
         """Return self."""
         return self
 
diff --git a/libs/core/langchain_core/tracers/log_stream.py b/libs/core/langchain_core/tracers/log_stream.py
index 5131815ebd..ebafc14b0e 100644
--- a/libs/core/langchain_core/tracers/log_stream.py
+++ b/libs/core/langchain_core/tracers/log_stream.py
@@ -229,7 +229,7 @@ class RunLog(RunLogPatch):
 T = TypeVar("T")
 
 
-class LogStreamCallbackHandler(BaseTracer, _StreamingCallbackHandler):
+class LogStreamCallbackHandler(BaseTracer, _StreamingCallbackHandler[Any]):
     """Tracer that streams run logs to a stream."""
 
     def __init__(
diff --git a/libs/core/langchain_core/tracers/memory_stream.py b/libs/core/langchain_core/tracers/memory_stream.py
index 42e74fb00d..9047e60105 100644
--- a/libs/core/langchain_core/tracers/memory_stream.py
+++ b/libs/core/langchain_core/tracers/memory_stream.py
@@ -11,14 +11,14 @@ code.
 import asyncio
 from asyncio import AbstractEventLoop, Queue
 from collections.abc import AsyncIterator
-from typing import Generic, TypeVar
+from typing import Any, Generic, TypeVar
 
 T = TypeVar("T")
 
 
 class _SendStream(Generic[T]):
     def __init__(
-        self, reader_loop: AbstractEventLoop, queue: Queue, done: object
+        self, reader_loop: AbstractEventLoop, queue: Queue[Any], done: object
     ) -> None:
         """Create a writer for the queue and done object.
 
@@ -84,7 +84,7 @@ class _SendStream(Generic[T]):
 
 
 class _ReceiveStream(Generic[T]):
-    def __init__(self, queue: Queue, done: object) -> None:
+    def __init__(self, queue: Queue[Any], done: object) -> None:
         """Create a reader for the queue and done object.
 
         This reader should be used in the same loop as the loop that was passed to the
@@ -126,7 +126,7 @@ class _MemoryStream(Generic[T]):
                 to this constructor. This will NOT be validated at run time.
         """
         self._loop = loop
-        self._queue: asyncio.Queue = asyncio.Queue(maxsize=0)
+        self._queue = asyncio.Queue[Any](maxsize=0)
         self._done = object()
 
     def get_send_stream(self) -> _SendStream[T]:
diff --git a/libs/core/langchain_core/utils/_merge.py b/libs/core/langchain_core/utils/_merge.py
index 6a0cb38f07..d6e0cce4db 100644
--- a/libs/core/langchain_core/utils/_merge.py
+++ b/libs/core/langchain_core/utils/_merge.py
@@ -86,7 +86,7 @@ def merge_dicts(left: dict[str, Any], *others: dict[str, Any]) -> dict[str, Any]
     return merged
 
 
-def merge_lists(left: list | None, *others: list | None) -> list | None:
+def merge_lists(left: list[Any] | None, *others: list[Any] | None) -> list[Any] | None:
     """Add many lists, handling `None`.
 
     Args:
diff --git a/libs/core/langchain_core/utils/aiter.py b/libs/core/langchain_core/utils/aiter.py
index e5dc0d1aea..912fb32e70 100644
--- a/libs/core/langchain_core/utils/aiter.py
+++ b/libs/core/langchain_core/utils/aiter.py
@@ -277,7 +277,7 @@ class Tee(Generic[T]):
 atee = Tee
 
 
-class aclosing(AbstractAsyncContextManager):  # noqa: N801
+class aclosing(AbstractAsyncContextManager[Any]):  # noqa: N801
     """Async context manager to wrap an `AsyncGenerator` that has a `aclose()` method.
 
     Code like this:
diff --git a/libs/core/langchain_core/utils/formatting.py b/libs/core/langchain_core/utils/formatting.py
index 48905a4cc0..2458fdcf4c 100644
--- a/libs/core/langchain_core/utils/formatting.py
+++ b/libs/core/langchain_core/utils/formatting.py
@@ -21,7 +21,7 @@ class StrictFormatter(Formatter):
     """
 
     def vformat(
-        self, format_string: str, args: Sequence, kwargs: Mapping[str, Any]
+        self, format_string: str, args: Sequence[Any], kwargs: Mapping[str, Any]
     ) -> str:
         """Format a string using only keyword arguments.
 
diff --git a/libs/core/langchain_core/utils/function_calling.py b/libs/core/langchain_core/utils/function_calling.py
index c66df94437..eae4a8c8a0 100644
--- a/libs/core/langchain_core/utils/function_calling.py
+++ b/libs/core/langchain_core/utils/function_calling.py
@@ -72,7 +72,7 @@ class FunctionDescription(TypedDict):
     description: str
     """A description of the function."""
 
-    parameters: dict
+    parameters: dict[str, Any]
     """The parameters of the function."""
 
 
@@ -86,7 +86,7 @@ class ToolDescription(TypedDict):
     """The function description."""
 
 
-def _rm_titles(kv: dict, prev_key: str = "") -> dict:
+def _rm_titles(kv: dict[str, Any], prev_key: str = "") -> dict[str, Any]:
     """Recursively removes `'title'` fields from a JSON schema dictionary.
 
     Remove `'title'` fields from the input JSON schema dictionary,
@@ -121,7 +121,7 @@ def _rm_titles(kv: dict, prev_key: str = "") -> dict:
 
 
 def _convert_json_schema_to_openai_function(
-    schema: dict,
+    schema: dict[str, Any],
     *,
     name: str | None = None,
     description: str | None = None,
@@ -206,13 +206,13 @@ def _convert_pydantic_to_openai_function(
     )
 
 
-def _get_python_function_name(function: Callable) -> str:
+def _get_python_function_name(function: Callable[..., Any]) -> str:
     """Get the name of a Python function."""
     return function.__name__
 
 
 def _convert_python_function_to_openai_function(
-    function: Callable,
+    function: Callable[..., Any],
 ) -> FunctionDescription:
     """Convert a Python function to an OpenAI function-calling API compatible dict.
 
@@ -243,7 +243,7 @@ def _convert_python_function_to_openai_function(
 
 
 def _convert_typed_dict_to_openai_function(typed_dict: type) -> FunctionDescription:
-    visited: dict = {}
+    visited: dict[type, type] = {}
 
     model = cast(
         "type[BaseModel]",
@@ -279,7 +279,7 @@ def _convert_any_typed_dicts_to_pydantic(
         description, arg_descriptions = _parse_google_docstring(
             docstring, list(annotations_)
         )
-        fields: dict = {}
+        fields: dict[str, Any] = {}
         for arg, arg_type in annotations_.items():
             if get_origin(arg_type) in {Annotated, typing_extensions.Annotated}:
                 annotated_args = get_args(arg_type)
@@ -373,7 +373,7 @@ def _format_tool_to_openai_function(tool: BaseTool) -> FunctionDescription:
 
 
 def convert_to_openai_function(
-    function: Mapping[str, Any] | type | Callable | BaseTool,
+    function: Mapping[str, Any] | type | Callable[..., Any] | BaseTool,
     *,
     strict: bool | None = None,
 ) -> dict[str, Any]:
@@ -437,16 +437,19 @@ def convert_to_openai_function(
         if function_copy and "properties" in function_copy:
             oai_function["parameters"] = function_copy
     elif isinstance(function, type) and is_basemodel_subclass(function):
-        oai_function = cast("dict", _convert_pydantic_to_openai_function(function))
+        oai_function = cast(
+            "dict[str, Any]", _convert_pydantic_to_openai_function(function)
+        )
     elif is_typeddict(function):
         oai_function = cast(
-            "dict", _convert_typed_dict_to_openai_function(cast("type", function))
+            "dict[str, Any]",
+            _convert_typed_dict_to_openai_function(cast("type", function)),
         )
     elif isinstance(function, langchain_core.tools.base.BaseTool):
-        oai_function = cast("dict", _format_tool_to_openai_function(function))
+        oai_function = cast("dict[str, Any]", _format_tool_to_openai_function(function))
     elif callable(function):
         oai_function = cast(
-            "dict", _convert_python_function_to_openai_function(function)
+            "dict[str, Any]", _convert_python_function_to_openai_function(function)
         )
     else:
         if isinstance(function, dict) and (
@@ -514,7 +517,7 @@ _WellKnownOpenAITools = (
 
 
 def convert_to_openai_tool(
-    tool: Mapping[str, Any] | type[BaseModel] | Callable | BaseTool,
+    tool: Mapping[str, Any] | type[BaseModel] | Callable[..., Any] | BaseTool,
     *,
     strict: bool | None = None,
 ) -> dict[str, Any]:
@@ -576,7 +579,7 @@ def convert_to_openai_tool(
 
 
 def convert_to_json_schema(
-    schema: dict[str, Any] | type[BaseModel] | Callable | BaseTool,
+    schema: dict[str, Any] | type[BaseModel] | Callable[..., Any] | BaseTool,
     *,
     strict: bool | None = None,
 ) -> dict[str, Any]:
@@ -731,7 +734,7 @@ def _parse_google_docstring(
     args: list[str],
     *,
     error_on_invalid_docstring: bool = False,
-) -> tuple[str, dict]:
+) -> tuple[str, dict[str, str]]:
     """Parse the function and argument descriptions from the docstring of a function.
 
     Assumes the function docstring follows Google Python style guide.
diff --git a/libs/core/langchain_core/utils/html.py b/libs/core/langchain_core/utils/html.py
index 4798b02ce7..a2f9424e38 100644
--- a/libs/core/langchain_core/utils/html.py
+++ b/libs/core/langchain_core/utils/html.py
@@ -44,7 +44,7 @@ DEFAULT_LINK_REGEX = (
 
 
 def find_all_links(
-    raw_html: str, *, pattern: str | re.Pattern | None = None
+    raw_html: str, *, pattern: str | re.Pattern[str] | None = None
 ) -> list[str]:
     """Extract all links from a raw HTML string.
 
@@ -64,7 +64,7 @@ def extract_sub_links(
     url: str,
     *,
     base_url: str | None = None,
-    pattern: str | re.Pattern | None = None,
+    pattern: str | re.Pattern[str] | None = None,
     prevent_outside: bool = True,
     exclude_prefixes: Sequence[str] = (),
     continue_on_failure: bool = False,
diff --git a/libs/core/langchain_core/utils/input.py b/libs/core/langchain_core/utils/input.py
index d97d4006d3..34eb2c2bb0 100644
--- a/libs/core/langchain_core/utils/input.py
+++ b/libs/core/langchain_core/utils/input.py
@@ -12,7 +12,7 @@ _TEXT_COLOR_MAPPING = {
 
 
 def get_color_mapping(
-    items: list[str], excluded_colors: list | None = None
+    items: list[str], excluded_colors: list[str] | None = None
 ) -> dict[str, str]:
     """Get mapping for items to a support color.
 
diff --git a/libs/core/langchain_core/utils/json.py b/libs/core/langchain_core/utils/json.py
index a836ffc4e6..d772a81078 100644
--- a/libs/core/langchain_core/utils/json.py
+++ b/libs/core/langchain_core/utils/json.py
@@ -191,7 +191,9 @@ def _parse_json(
     return parser(json_str)
 
 
-def parse_and_check_json_markdown(text: str, expected_keys: list[str]) -> dict:
+def parse_and_check_json_markdown(
+    text: str, expected_keys: list[str]
+) -> dict[str, Any]:
     """Parse and check a JSON string from a Markdown string.
 
     Checks that it contains the expected keys.
diff --git a/libs/core/langchain_core/utils/json_schema.py b/libs/core/langchain_core/utils/json_schema.py
index d1ff1de5fc..eface5da2e 100644
--- a/libs/core/langchain_core/utils/json_schema.py
+++ b/libs/core/langchain_core/utils/json_schema.py
@@ -9,7 +9,7 @@ if TYPE_CHECKING:
     from collections.abc import Sequence
 
 
-def _retrieve_ref(path: str, schema: dict) -> list | dict:
+def _retrieve_ref(path: str, schema: dict[str, Any]) -> list[Any] | dict[Any, Any]:
     """Retrieve a referenced object from a JSON schema using a path.
 
     Resolves JSON schema references (e.g., `'#/definitions/MyType'`) by traversing the
@@ -33,7 +33,7 @@ def _retrieve_ref(path: str, schema: dict) -> list | dict:
             "with #."
         )
         raise ValueError(msg)
-    out: list | dict = schema
+    out: list[Any] | dict[Any, Any] = schema
     for component in components[1:]:
         if component in out:
             if isinstance(out, list):
@@ -186,11 +186,11 @@ def _dereference_refs_helper(
 
 
 def dereference_refs(
-    schema_obj: dict,
+    schema_obj: dict[str, Any],
     *,
-    full_schema: dict | None = None,
+    full_schema: dict[str, Any] | None = None,
     skip_keys: Sequence[str] | None = None,
-) -> dict:
+) -> dict[str, Any]:
     """Resolve and inline JSON Schema `$ref` references in a schema object.
 
     This function processes a JSON Schema and resolves all `$ref` references by
@@ -266,7 +266,7 @@ def dereference_refs(
     keys_to_skip = list(skip_keys) if skip_keys is not None else ["$defs"]
     shallow = skip_keys is None
     return cast(
-        "dict",
+        "dict[str, Any]",
         _dereference_refs_helper(
             schema_obj, full, None, keys_to_skip, shallow_refs=shallow
         ),
diff --git a/libs/core/langchain_core/utils/pydantic.py b/libs/core/langchain_core/utils/pydantic.py
index d1c152d8d5..7fed428145 100644
--- a/libs/core/langchain_core/utils/pydantic.py
+++ b/libs/core/langchain_core/utils/pydantic.py
@@ -126,7 +126,9 @@ def is_basemodel_instance(obj: Any) -> bool:
 
 
 # How to type hint this?
-def pre_init(func: Callable) -> Any:
+def pre_init(
+    func: Callable[[Any, dict[str, Any]], Any],
+) -> Callable[[Any, dict[str, Any]], Any]:
     """Decorator to run a function before model initialization.
 
     Args:
@@ -202,9 +204,9 @@ class _IgnoreUnserializable(GenerateJsonSchema):
 def _create_subset_model_v1(
     name: str,
     model: type[BaseModelV1],
-    field_names: list,
+    field_names: list[str],
     *,
-    descriptions: dict | None = None,
+    descriptions: dict[str, str] | None = None,
     fn_description: str | None = None,
 ) -> type[BaseModelV1]:
     """Create a Pydantic model with only a subset of model's fields."""
@@ -233,7 +235,7 @@ def _create_subset_model_v2(
     model: type[BaseModel],
     field_names: list[str],
     *,
-    descriptions: dict | None = None,
+    descriptions: dict[str, str] | None = None,
     fn_description: str | None = None,
 ) -> type[BaseModel]:
     """Create a Pydantic model with a subset of the model fields."""
@@ -283,7 +285,7 @@ def _create_subset_model(
     model: TypeBaseModel,
     field_names: list[str],
     *,
-    descriptions: dict | None = None,
+    descriptions: dict[str, str] | None = None,
     fn_description: str | None = None,
 ) -> type[BaseModel]:
     """Create subset model using the same pydantic version as the input model.
diff --git a/libs/core/langchain_core/utils/strings.py b/libs/core/langchain_core/utils/strings.py
index 357b16f8e1..c9f001934f 100644
--- a/libs/core/langchain_core/utils/strings.py
+++ b/libs/core/langchain_core/utils/strings.py
@@ -22,7 +22,7 @@ def stringify_value(val: Any) -> str:
     return str(val)
 
 
-def stringify_dict(data: dict) -> str:
+def stringify_dict(data: dict[Any, Any]) -> str:
     """Stringify a dictionary.
 
     Args:
diff --git a/libs/core/langchain_core/utils/usage.py b/libs/core/langchain_core/utils/usage.py
index 47e483a555..99784f2c6c 100644
--- a/libs/core/langchain_core/utils/usage.py
+++ b/libs/core/langchain_core/utils/usage.py
@@ -1,17 +1,18 @@
 """Usage utilities."""
 
 from collections.abc import Callable
+from typing import Any
 
 
 def _dict_int_op(
-    left: dict,
-    right: dict,
+    left: dict[str, Any],
+    right: dict[str, Any],
     op: Callable[[int, int], int],
     *,
     default: int = 0,
     depth: int = 0,
     max_depth: int = 100,
-) -> dict:
+) -> dict[str, Any]:
     """Apply an integer operation to corresponding values in two dictionaries.
 
     Recursively combines two dictionaries by applying the given operation to integer
@@ -36,7 +37,7 @@ def _dict_int_op(
     if depth >= max_depth:
         msg = f"{max_depth=} exceeded, unable to combine dicts."
         raise ValueError(msg)
-    combined: dict = {}
+    combined: dict[str, Any] = {}
     for k in set(left).union(right):
         if isinstance(left.get(k, default), int) and isinstance(
             right.get(k, default), int
diff --git a/libs/core/langchain_core/utils/utils.py b/libs/core/langchain_core/utils/utils.py
index e8a5ed999a..ac9c3e0611 100644
--- a/libs/core/langchain_core/utils/utils.py
+++ b/libs/core/langchain_core/utils/utils.py
@@ -21,7 +21,7 @@ from langchain_core.utils.pydantic import (
 )
 
 
-def xor_args(*arg_groups: tuple[str, ...]) -> Callable:
+def xor_args(*arg_groups: tuple[str, ...]) -> Callable[..., Any]:
     """Validate specified keyword args are mutually exclusive.
 
     Args:
@@ -31,7 +31,7 @@ def xor_args(*arg_groups: tuple[str, ...]) -> Callable:
         Decorator that validates the specified keyword args are mutually exclusive.
     """
 
-    def decorator(func: Callable) -> Callable:
+    def decorator(func: Callable[..., Any]) -> Callable[..., Any]:
         @functools.wraps(func)
         def wrapper(*args: Any, **kwargs: Any) -> Any:
             """Validate exactly one arg in each group is not None."""
diff --git a/libs/core/langchain_core/vectorstores/base.py b/libs/core/langchain_core/vectorstores/base.py
index 827a05cc90..7d14506182 100644
--- a/libs/core/langchain_core/vectorstores/base.py
+++ b/libs/core/langchain_core/vectorstores/base.py
@@ -46,7 +46,7 @@ class VectorStore(ABC):
     def add_texts(
         self,
         texts: Iterable[str],
-        metadatas: list[dict] | None = None,
+        metadatas: list[dict[str, Any]] | None = None,
         *,
         ids: list[str] | None = None,
         **kwargs: Any,
@@ -185,7 +185,7 @@ class VectorStore(ABC):
     async def aadd_texts(
         self,
         texts: Iterable[str],
-        metadatas: list[dict] | None = None,
+        metadatas: list[dict[str, Any]] | None = None,
         *,
         ids: list[str] | None = None,
         **kwargs: Any,
@@ -849,7 +849,7 @@ class VectorStore(ABC):
         cls: type[VST],
         texts: list[str],
         embedding: Embeddings,
-        metadatas: list[dict] | None = None,
+        metadatas: list[dict[str, Any]] | None = None,
         *,
         ids: list[str] | None = None,
         **kwargs: Any,
@@ -872,7 +872,7 @@ class VectorStore(ABC):
         cls,
         texts: list[str],
         embedding: Embeddings,
-        metadatas: list[dict] | None = None,
+        metadatas: list[dict[str, Any]] | None = None,
         *,
         ids: list[str] | None = None,
         **kwargs: Any,
@@ -970,7 +970,7 @@ class VectorStoreRetriever(BaseRetriever):
     search_type: str = "similarity"
     """Type of search to perform."""
 
-    search_kwargs: dict = Field(default_factory=dict)
+    search_kwargs: dict[str, Any] = Field(default_factory=dict)
     """Keyword arguments to pass to the search function."""
 
     allowed_search_types: ClassVar[Collection[str]] = (
@@ -985,7 +985,7 @@ class VectorStoreRetriever(BaseRetriever):
 
     @model_validator(mode="before")
     @classmethod
-    def validate_search_type(cls, values: dict) -> Any:
+    def validate_search_type(cls, values: dict[str, Any]) -> Any:
         """Validate search type.
 
         Args:
diff --git a/libs/core/langchain_core/vectorstores/in_memory.py b/libs/core/langchain_core/vectorstores/in_memory.py
index ef3c78ab60..651db514d5 100644
--- a/libs/core/langchain_core/vectorstores/in_memory.py
+++ b/libs/core/langchain_core/vectorstores/in_memory.py
@@ -489,7 +489,7 @@ class InMemoryVectorStore(VectorStore):
         cls,
         texts: list[str],
         embedding: Embeddings,
-        metadatas: list[dict] | None = None,
+        metadatas: list[dict[str, Any]] | None = None,
         **kwargs: Any,
     ) -> InMemoryVectorStore:
         store = cls(
@@ -504,7 +504,7 @@ class InMemoryVectorStore(VectorStore):
         cls,
         texts: list[str],
         embedding: Embeddings,
-        metadatas: list[dict] | None = None,
+        metadatas: list[dict[str, Any]] | None = None,
         **kwargs: Any,
     ) -> InMemoryVectorStore:
         store = cls(
diff --git a/libs/core/langchain_core/vectorstores/utils.py b/libs/core/langchain_core/vectorstores/utils.py
index 551524beb3..04914e86af 100644
--- a/libs/core/langchain_core/vectorstores/utils.py
+++ b/libs/core/langchain_core/vectorstores/utils.py
@@ -10,7 +10,7 @@ from __future__ import annotations
 
 import logging
 import warnings
-from typing import TYPE_CHECKING, cast
+from typing import TYPE_CHECKING
 
 try:
     import numpy as np
@@ -27,12 +27,16 @@ except ImportError:
     _HAS_SIMSIMD = False
 
 if TYPE_CHECKING:
-    Matrix = list[list[float]] | list[np.ndarray] | np.ndarray
+    import numpy.typing as npt
+
+    Matrix = (
+        list[list[float]] | list[npt.NDArray[np.floating]] | npt.NDArray[np.floating]
+    )
 
 logger = logging.getLogger(__name__)
 
 
-def _cosine_similarity(x: Matrix, y: Matrix) -> np.ndarray:
+def _cosine_similarity(x: Matrix, y: Matrix) -> npt.NDArray[np.floating]:
     """Row-wise cosine similarity between two equal-width matrices.
 
     Args:
@@ -91,12 +95,14 @@ def _cosine_similarity(x: Matrix, y: Matrix) -> np.ndarray:
         y_norm = np.linalg.norm(y, axis=1)
         # Ignore divide by zero errors run time warnings as those are handled below.
         with np.errstate(divide="ignore", invalid="ignore"):
-            similarity = np.dot(x, y.T) / np.outer(x_norm, y_norm)
+            similarity: npt.NDArray[np.floating] = np.dot(x, y.T) / np.outer(
+                x_norm, y_norm
+            )
         if np.isnan(similarity).all():
             msg = "NaN values found, please remove the NaN values and try again"
             raise ValueError(msg) from None
         similarity[np.isnan(similarity) | np.isinf(similarity)] = 0.0
-        return cast("np.ndarray", similarity)
+        return similarity
 
     x = np.array(x, dtype=np.float32)
     y = np.array(y, dtype=np.float32)
@@ -104,8 +110,8 @@ def _cosine_similarity(x: Matrix, y: Matrix) -> np.ndarray:
 
 
 def maximal_marginal_relevance(
-    query_embedding: np.ndarray,
-    embedding_list: list,
+    query_embedding: npt.NDArray[np.floating],
+    embedding_list: list[list[float]],
     lambda_mult: float = 0.5,
     k: int = 4,
 ) -> list[int]:
diff --git a/libs/core/tests/unit_tests/documents/test_document.py b/libs/core/tests/unit_tests/documents/test_document.py
index e312121bd0..9392d746ba 100644
--- a/libs/core/tests/unit_tests/documents/test_document.py
+++ b/libs/core/tests/unit_tests/documents/test_document.py
@@ -1,4 +1,7 @@
+from pathlib import Path
+
 from langchain_core.documents import Document
+from langchain_core.documents.base import Blob
 
 
 def test_init() -> None:
@@ -10,3 +13,15 @@ def test_init() -> None:
         Document(page_content="foo", id=1),
     ]:
         assert isinstance(doc, Document)
+
+
+def test_metadata_allows_non_string_keys(tmp_path: Path) -> None:
+    metadata = {1: "one"}
+
+    doc = Document(page_content="foo", metadata=metadata)
+    blob_from_data = Blob.from_data("foo", metadata=metadata)
+    blob_from_path = Blob.from_path(tmp_path / "foo.txt", metadata=metadata)
+
+    assert doc.metadata == metadata
+    assert blob_from_data.metadata == metadata
+    assert blob_from_path.metadata == metadata
diff --git a/libs/core/tests/unit_tests/example_selectors/test_similarity.py b/libs/core/tests/unit_tests/example_selectors/test_similarity.py
index b07870121c..408c12e653 100644
--- a/libs/core/tests/unit_tests/example_selectors/test_similarity.py
+++ b/libs/core/tests/unit_tests/example_selectors/test_similarity.py
@@ -15,7 +15,7 @@ from langchain_core.vectorstores import VectorStore
 class DummyVectorStore(VectorStore):
     def __init__(self, init_arg: str | None = None):
         self.texts: list[str] = []
-        self.metadatas: list[dict] = []
+        self.metadatas: list[dict[str, Any]] = []
         self._embeddings: Embeddings | None = None
         self.init_arg = init_arg
 
@@ -27,7 +27,7 @@ class DummyVectorStore(VectorStore):
     def add_texts(
         self,
         texts: Iterable[str],
-        metadatas: list[dict] | None = None,
+        metadatas: list[dict[str, Any]] | None = None,
         **kwargs: Any,
     ) -> list[str]:
         self.texts.extend(texts)
@@ -66,7 +66,7 @@ class DummyVectorStore(VectorStore):
         cls,
         texts: list[str],
         embedding: Embeddings,
-        metadatas: list[dict] | None = None,
+        metadatas: list[dict[str, Any]] | None = None,
         **kwargs: Any,
     ) -> "DummyVectorStore":
         store = DummyVectorStore(**kwargs)
diff --git a/libs/core/tests/unit_tests/messages/test_ai.py b/libs/core/tests/unit_tests/messages/test_ai.py
index 31f8b3e1bb..a9c732c99d 100644
--- a/libs/core/tests/unit_tests/messages/test_ai.py
+++ b/libs/core/tests/unit_tests/messages/test_ai.py
@@ -1,4 +1,4 @@
-from typing import cast
+from typing import Any, cast
 
 from langchain_core.load import dumpd, load
 from langchain_core.messages import AIMessage, AIMessageChunk
@@ -355,11 +355,11 @@ def test_content_blocks() -> None:
     assert chunk.content_blocks == chunk.tool_calls
 
     # test v1 content
-    chunk_1.content = cast("str | list[str | dict]", chunk_1.content_blocks)
+    chunk_1.content = cast("list[str | dict[str, Any]]", chunk_1.content_blocks)
     assert len(chunk_1.content) == 1
     chunk_1.content[0]["extras"] = {"baz": "qux"}  # type: ignore[index]
     chunk_1.response_metadata["output_version"] = "v1"
-    chunk_2.content = cast("str | list[str | dict]", chunk_2.content_blocks)
+    chunk_2.content = cast("list[str | dict[str, Any]]", chunk_2.content_blocks)
 
     chunk = chunk_1 + chunk_2 + chunk_3
     assert chunk.content == [
@@ -379,8 +379,12 @@ def test_content_blocks() -> None:
     standard_content_2: list[types.ContentBlock] = [
         {"type": "non_standard", "index": 0, "value": {"foo": "baz"}}
     ]
-    chunk_1 = AIMessageChunk(content=cast("str | list[str | dict]", standard_content_1))
-    chunk_2 = AIMessageChunk(content=cast("str | list[str | dict]", standard_content_2))
+    chunk_1 = AIMessageChunk(
+        content=cast("list[str | dict[str, Any]]", standard_content_1)
+    )
+    chunk_2 = AIMessageChunk(
+        content=cast("list[str | dict[str, Any]]", standard_content_2)
+    )
     merged_chunk = chunk_1 + chunk_2
     assert merged_chunk.content == [
         {"type": "non_standard", "index": 0, "value": {"foo": "bar baz"}},
@@ -467,8 +471,12 @@ def test_content_blocks() -> None:
         }
     ]
     standard_content_2 = [{"type": "non_standard", "value": {"foo": "bar"}, "index": 0}]
-    chunk_1 = AIMessageChunk(content=cast("str | list[str | dict]", standard_content_1))
-    chunk_2 = AIMessageChunk(content=cast("str | list[str | dict]", standard_content_2))
+    chunk_1 = AIMessageChunk(
+        content=cast("list[str | dict[str, Any]]", standard_content_1)
+    )
+    chunk_2 = AIMessageChunk(
+        content=cast("list[str | dict[str, Any]]", standard_content_2)
+    )
     merged_chunk = chunk_1 + chunk_2
     assert merged_chunk.content == [
         {
diff --git a/libs/core/tests/unit_tests/messages/test_utils.py b/libs/core/tests/unit_tests/messages/test_utils.py
index 9b4123d859..07846eb1c2 100644
--- a/libs/core/tests/unit_tests/messages/test_utils.py
+++ b/libs/core/tests/unit_tests/messages/test_utils.py
@@ -758,7 +758,8 @@ class FakeTokenCountingModel(FakeChatModel):
     def get_num_tokens_from_messages(
         self,
         messages: list[BaseMessage],
-        tools: Sequence[dict[str, Any] | type | Callable | BaseTool] | None = None,
+        tools: Sequence[dict[str, Any] | type | Callable[..., Any] | BaseTool]
+        | None = None,
     ) -> int:
         return dummy_token_counter(messages)
 
@@ -1288,7 +1289,7 @@ def test_convert_to_openai_messages_invalid_block() -> None:
 
 
 def test_handle_openai_responses_blocks() -> None:
-    blocks: str | list[str | dict] = [
+    blocks: str | list[str | dict[str, Any]] = [
         {"type": "reasoning", "id": "1"},
         {
             "type": "function_call",
diff --git a/libs/core/tests/unit_tests/prompts/test_structured.py b/libs/core/tests/unit_tests/prompts/test_structured.py
index 77157dfae1..5cd109dcce 100644
--- a/libs/core/tests/unit_tests/prompts/test_structured.py
+++ b/libs/core/tests/unit_tests/prompts/test_structured.py
@@ -6,7 +6,7 @@ import pytest
 from pydantic import BaseModel
 from typing_extensions import override
 
-from langchain_core.language_models import FakeListChatModel
+from langchain_core.language_models import FakeListChatModel, LanguageModelInput
 from langchain_core.load.dump import dumps
 from langchain_core.load.load import loads
 from langchain_core.messages import HumanMessage
@@ -29,8 +29,8 @@ class FakeStructuredChatModel(FakeListChatModel):
 
     @override
     def with_structured_output(
-        self, schema: dict | type[BaseModel], **kwargs: Any
-    ) -> Runnable:
+        self, schema: dict[str, Any] | type[BaseModel], **kwargs: Any
+    ) -> Runnable[LanguageModelInput, dict[str, Any] | BaseModel]:
         return RunnableLambda(partial(_fake_runnable, schema=schema, **kwargs))
 
     @property
diff --git a/libs/core/tests/unit_tests/pydantic_utils.py b/libs/core/tests/unit_tests/pydantic_utils.py
index 2f01494e1d..1379c53d52 100644
--- a/libs/core/tests/unit_tests/pydantic_utils.py
+++ b/libs/core/tests/unit_tests/pydantic_utils.py
@@ -73,7 +73,7 @@ def _remove_enum(obj: Any) -> None:
             _remove_enum(item)
 
 
-def _schema(obj: Any) -> dict:
+def _schema(obj: Any) -> dict[str, Any]:
     """Return the schema of the object."""
     # Remap to old style schema
     if isclass(obj):
@@ -99,7 +99,7 @@ def _schema(obj: Any) -> dict:
     raise TypeError(msg)
 
 
-def _remove_additionalproperties(schema: dict) -> dict[str, Any]:
+def _remove_additionalproperties(schema: dict[str, Any]) -> dict[str, Any]:
     """Remove `"additionalProperties": True` from dicts in the schema.
 
     Pydantic 2.11 and later versions include `"additionalProperties": True` when
diff --git a/libs/core/tests/unit_tests/runnables/test_fallbacks.py b/libs/core/tests/unit_tests/runnables/test_fallbacks.py
index 01b6b1a363..11e02f3939 100644
--- a/libs/core/tests/unit_tests/runnables/test_fallbacks.py
+++ b/libs/core/tests/unit_tests/runnables/test_fallbacks.py
@@ -335,14 +335,16 @@ class FakeStructuredOutputModel(BaseChatModel):
     @override
     def bind_tools(
         self,
-        tools: Sequence[dict[str, Any] | type[BaseModel] | Callable | BaseTool],
+        tools: Sequence[
+            dict[str, Any] | type[BaseModel] | Callable[..., Any] | BaseTool
+        ],
         **kwargs: Any,
     ) -> Runnable[LanguageModelInput, AIMessage]:
         return self.bind(tools=tools)
 
     @override
     def with_structured_output(
-        self, schema: dict | type[BaseModel], **kwargs: Any
+        self, schema: dict[str, Any] | type[BaseModel], **kwargs: Any
     ) -> Runnable[LanguageModelInput, dict[str, int] | BaseModel]:
         return RunnableLambda(lambda _: {"foo": self.foo})
 
@@ -368,7 +370,9 @@ class FakeModel(BaseChatModel):
     @override
     def bind_tools(
         self,
-        tools: Sequence[dict[str, Any] | type[BaseModel] | Callable | BaseTool],
+        tools: Sequence[
+            dict[str, Any] | type[BaseModel] | Callable[..., Any] | BaseTool
+        ],
         **kwargs: Any,
     ) -> Runnable[LanguageModelInput, AIMessage]:
         return self.bind(tools=tools)
diff --git a/libs/core/tests/unit_tests/runnables/test_graph.py b/libs/core/tests/unit_tests/runnables/test_graph.py
index c7d705cfd6..ffd90a0779 100644
--- a/libs/core/tests/unit_tests/runnables/test_graph.py
+++ b/libs/core/tests/unit_tests/runnables/test_graph.py
@@ -226,7 +226,9 @@ def test_graph_sequence_map(snapshot: SnapshotAssertion) -> None:
     str_parser = StrOutputParser()
     xml_parser = XMLOutputParser()
 
-    def conditional_str_parser(value: str) -> Runnable[BaseMessage | str, str]:
+    def conditional_str_parser(
+        value: str,
+    ) -> Runnable[BaseMessage | str, str | dict[str, Any]]:
         if value == "a":
             return str_parser
         return xml_parser
diff --git a/libs/core/tests/unit_tests/runnables/test_runnable.py b/libs/core/tests/unit_tests/runnables/test_runnable.py
index da648b0031..1cccc2743b 100644
--- a/libs/core/tests/unit_tests/runnables/test_runnable.py
+++ b/libs/core/tests/unit_tests/runnables/test_runnable.py
@@ -3770,6 +3770,40 @@ async def test_deep_astream_assign() -> None:
     }
 
 
+def _empty_mapper_assign() -> RunnableAssign:
+    """Build an assign whose mapper yields zero chunks.
+
+    The map output stream is started with `next(map_output, None)` /
+    `anext(map_output, None)`, so `None` is the exhaustion sentinel rather than
+    a real chunk. Both `stream` and `astream` must guard against yielding that
+    sentinel into the output stream.
+    """
+
+    def empty_gen(it: Iterator[Any]) -> Iterator[dict[str, Any]]:
+        for _ in it:
+            pass
+        yield from ()  # consume input, yield nothing
+
+    async def aempty_gen(it: AsyncIterator[Any]) -> AsyncIterator[dict[str, Any]]:
+        async for _ in it:
+            pass
+        return
+        yield  # pragma: no cover  # make this an async generator function
+
+    return RunnablePassthrough.assign(foo=RunnableGenerator(empty_gen, aempty_gen))
+
+
+def test_stream_assign_empty_mapper() -> None:
+    """An assign whose mapper yields no chunks must not emit `None` (sync)."""
+    assert list(_empty_mapper_assign().stream({"a": 1})) == [{"a": 1}]
+
+
+async def test_astream_assign_empty_mapper() -> None:
+    """An assign whose mapper yields no chunks must not emit `None` (async)."""
+    chunks = [chunk async for chunk in _empty_mapper_assign().astream({"a": 1})]
+    assert chunks == [{"a": 1}]
+
+
 def test_runnable_sequence_transform() -> None:
     llm = FakeStreamingListLLM(responses=["foo-lish"])
 
@@ -5374,7 +5408,7 @@ async def test_ainvoke_on_returned_runnable() -> None:
 
 
 def test_invoke_stream_passthrough_assign_trace() -> None:
-    def idchain_sync(_input: dict, /) -> bool:
+    def idchain_sync(_input: dict[str, Any], /) -> bool:
         return False
 
     chain = RunnablePassthrough.assign(urls=idchain_sync)
@@ -5394,7 +5428,7 @@ def test_invoke_stream_passthrough_assign_trace() -> None:
 
 
 async def test_ainvoke_astream_passthrough_assign_trace() -> None:
-    def idchain_sync(_input: dict, /) -> bool:
+    def idchain_sync(_input: dict[str, Any], /) -> bool:
         return False
 
     chain = RunnablePassthrough.assign(urls=idchain_sync)
diff --git a/libs/core/tests/unit_tests/runnables/test_runnable_events_v1.py b/libs/core/tests/unit_tests/runnables/test_runnable_events_v1.py
index 06f13e035b..1165382399 100644
--- a/libs/core/tests/unit_tests/runnables/test_runnable_events_v1.py
+++ b/libs/core/tests/unit_tests/runnables/test_runnable_events_v1.py
@@ -78,7 +78,7 @@ def _assert_events_equal_allow_superset_metadata(
 async def test_event_stream_with_simple_function_tool() -> None:
     """Test the event stream with a function and tool."""
 
-    def foo(_: int) -> dict:
+    def foo(_: int) -> dict[str, Any]:
         """Foo."""
         return {"x": 5}
 
@@ -1076,12 +1076,14 @@ async def test_event_streaming_with_tools() -> None:
         return "world"
 
     @tool
-    def with_parameters(x: int, y: str) -> dict:
+    def with_parameters(x: int, y: str) -> dict[str, Any]:
         """A tool that does nothing."""
         return {"x": x, "y": y}
 
     @tool
-    def with_parameters_and_callbacks(x: int, y: str, callbacks: Callbacks) -> dict:
+    def with_parameters_and_callbacks(
+        x: int, y: str, callbacks: Callbacks
+    ) -> dict[str, Any]:
         """A tool that does nothing."""
         _ = callbacks
         return {"x": x, "y": y}
diff --git a/libs/core/tests/unit_tests/runnables/test_runnable_events_v2.py b/libs/core/tests/unit_tests/runnables/test_runnable_events_v2.py
index f36dc87cbd..f59500dba4 100644
--- a/libs/core/tests/unit_tests/runnables/test_runnable_events_v2.py
+++ b/libs/core/tests/unit_tests/runnables/test_runnable_events_v2.py
@@ -93,7 +93,7 @@ async def _collect_events(
 async def test_event_stream_with_simple_function_tool() -> None:
     """Test the event stream with a function and tool."""
 
-    def foo(x: int) -> dict:
+    def foo(x: int) -> dict[str, Any]:
         """Foo."""
         _ = x
         return {"x": 5}
@@ -1097,12 +1097,14 @@ async def test_event_streaming_with_tools() -> None:
         return "world"
 
     @tool
-    def with_parameters(x: int, y: str) -> dict:
+    def with_parameters(x: int, y: str) -> dict[str, Any]:
         """A tool that does nothing."""
         return {"x": x, "y": y}
 
     @tool
-    def with_parameters_and_callbacks(x: int, y: str, callbacks: Callbacks) -> dict:
+    def with_parameters_and_callbacks(
+        x: int, y: str, callbacks: Callbacks
+    ) -> dict[str, Any]:
         """A tool that does nothing."""
         _ = callbacks
         return {"x": x, "y": y}
diff --git a/libs/core/tests/unit_tests/runnables/test_tracing_interops.py b/libs/core/tests/unit_tests/runnables/test_tracing_interops.py
index 029e3bcb8e..c1f11d9c2a 100644
--- a/libs/core/tests/unit_tests/runnables/test_tracing_interops.py
+++ b/libs/core/tests/unit_tests/runnables/test_tracing_interops.py
@@ -421,7 +421,8 @@ class TestRunnableSequenceParallelTraceNesting:
         ids=["invoke", "stream", "batch"],
     )
     def test_sync(
-        self, method: Callable[[RunnableLambda, list[BaseCallbackHandler]], int]
+        self,
+        method: Callable[[RunnableLambda[int, int], list[BaseCallbackHandler]], int],
     ) -> None:
         def other_thing(_: int) -> Generator[int, None, None]:
             yield 1
@@ -458,7 +459,8 @@ class TestRunnableSequenceParallelTraceNesting:
     async def test_async(
         self,
         method: Callable[
-            [RunnableLambda, list[BaseCallbackHandler]], Coroutine[Any, Any, int]
+            [RunnableLambda[int, int], list[BaseCallbackHandler]],
+            Coroutine[Any, Any, int],
         ],
     ) -> None:
         async def other_thing(_: int) -> AsyncGenerator[int, None]:
diff --git a/libs/core/tests/unit_tests/runnables/test_utils.py b/libs/core/tests/unit_tests/runnables/test_utils.py
index 37c19ca1a1..031bb5aa23 100644
--- a/libs/core/tests/unit_tests/runnables/test_utils.py
+++ b/libs/core/tests/unit_tests/runnables/test_utils.py
@@ -56,7 +56,7 @@ def test_nonlocals() -> None:
     def my_func4(value: str) -> str:
         return global_agent.invoke(value)
 
-    def my_func5() -> tuple[Callable[[str], str], RunnableLambda]:
+    def my_func5() -> tuple[Callable[[str], str], RunnableLambda[str, str]]:
         global_agent = RunnableLambda[str, str](lambda x: x * 3)
 
         def my_func6(value: str) -> str:
diff --git a/libs/core/tests/unit_tests/stores/test_in_memory.py b/libs/core/tests/unit_tests/stores/test_in_memory.py
index 6c24ebe463..4602777b85 100644
--- a/libs/core/tests/unit_tests/stores/test_in_memory.py
+++ b/libs/core/tests/unit_tests/stores/test_in_memory.py
@@ -23,7 +23,7 @@ class TestSyncInMemoryStore(BaseStoreSyncTests[Any]):
         return "value1", "value2", "value3"
 
 
-class TestAsyncInMemoryStore(BaseStoreAsyncTests):
+class TestAsyncInMemoryStore(BaseStoreAsyncTests[Any]):
     @pytest.fixture
     @override
     async def kv_store(self) -> InMemoryStore:
diff --git a/libs/core/tests/unit_tests/test_messages.py b/libs/core/tests/unit_tests/test_messages.py
index a13fdc62a6..c6e4f5b50b 100644
--- a/libs/core/tests/unit_tests/test_messages.py
+++ b/libs/core/tests/unit_tests/test_messages.py
@@ -1,5 +1,5 @@
 import uuid
-from typing import get_args
+from typing import Any, get_args
 
 import pytest
 
@@ -488,7 +488,7 @@ def test_message_chunk_to_message() -> None:
 
 
 def test_tool_calls_merge() -> None:
-    chunks: list[dict] = [
+    chunks: list[dict[str, Any]] = [
         {"content": ""},
         {
             "content": "",
@@ -1092,7 +1092,11 @@ def test_tool_message_str() -> None:
         ),
     ],
 )
-def test_merge_content(first: list | str, others: list, expected: list | str) -> None:
+def test_merge_content(
+    first: str | list[str | dict[str, Any]],
+    others: str | list[str | dict[str, Any]],
+    expected: str | list[str | dict[str, Any]],
+) -> None:
     actual = merge_content(first, *others)
     assert actual == expected
 
diff --git a/libs/core/tests/unit_tests/test_prompt_values.py b/libs/core/tests/unit_tests/test_prompt_values.py
index 6a08a4270a..187ca9f7b3 100644
--- a/libs/core/tests/unit_tests/test_prompt_values.py
+++ b/libs/core/tests/unit_tests/test_prompt_values.py
@@ -12,7 +12,7 @@ from langchain_core.prompt_values import ChatPromptValueConcrete
 
 
 def test_chat_prompt_value_concrete() -> None:
-    messages: list = [
+    messages = [
         AIMessage("foo"),
         HumanMessage("foo"),
         SystemMessage("foo"),
diff --git a/libs/core/tests/unit_tests/test_tools.py b/libs/core/tests/unit_tests/test_tools.py
index 274b25874f..43c23a109b 100644
--- a/libs/core/tests/unit_tests/test_tools.py
+++ b/libs/core/tests/unit_tests/test_tools.py
@@ -113,7 +113,7 @@ class _MockSchema(BaseModel):
 
     arg1: int
     arg2: bool
-    arg3: dict | None = None
+    arg3: dict[str, Any] | None = None
 
 
 class _MockStructuredTool(BaseTool):
@@ -122,10 +122,12 @@ class _MockStructuredTool(BaseTool):
     description: str = "A Structured Tool"
 
     @override
-    def _run(self, *, arg1: int, arg2: bool, arg3: dict | None = None) -> str:
+    def _run(self, *, arg1: int, arg2: bool, arg3: dict[str, Any] | None = None) -> str:
         return f"{arg1} {arg2} {arg3}"
 
-    async def _arun(self, *, arg1: int, arg2: bool, arg3: dict | None = None) -> str:
+    async def _arun(
+        self, *, arg1: int, arg2: bool, arg3: dict[str, Any] | None = None
+    ) -> str:
         raise NotImplementedError
 
 
@@ -166,11 +168,13 @@ def test_misannotated_base_tool_raises_error() -> None:
             description: str = "A Structured Tool"
 
             @override
-            def _run(self, *, arg1: int, arg2: bool, arg3: dict | None = None) -> str:
+            def _run(
+                self, *, arg1: int, arg2: bool, arg3: dict[str, Any] | None = None
+            ) -> str:
                 return f"{arg1} {arg2} {arg3}"
 
             async def _arun(
-                self, *, arg1: int, arg2: bool, arg3: dict | None = None
+                self, *, arg1: int, arg2: bool, arg3: dict[str, Any] | None = None
             ) -> str:
                 raise NotImplementedError
 
@@ -184,11 +188,13 @@ def test_forward_ref_annotated_base_tool_accepted() -> None:
         description: str = "A Structured Tool"
 
         @override
-        def _run(self, *, arg1: int, arg2: bool, arg3: dict | None = None) -> str:
+        def _run(
+            self, *, arg1: int, arg2: bool, arg3: dict[str, Any] | None = None
+        ) -> str:
             return f"{arg1} {arg2} {arg3}"
 
         async def _arun(
-            self, *, arg1: int, arg2: bool, arg3: dict | None = None
+            self, *, arg1: int, arg2: bool, arg3: dict[str, Any] | None = None
         ) -> str:
             raise NotImplementedError
 
@@ -202,11 +208,13 @@ def test_subclass_annotated_base_tool_accepted() -> None:
         description: str = "A Structured Tool"
 
         @override
-        def _run(self, *, arg1: int, arg2: bool, arg3: dict | None = None) -> str:
+        def _run(
+            self, *, arg1: int, arg2: bool, arg3: dict[str, Any] | None = None
+        ) -> str:
             return f"{arg1} {arg2} {arg3}"
 
         async def _arun(
-            self, *, arg1: int, arg2: bool, arg3: dict | None = None
+            self, *, arg1: int, arg2: bool, arg3: dict[str, Any] | None = None
         ) -> str:
             raise NotImplementedError
 
@@ -219,7 +227,7 @@ def test_decorator_with_specified_schema() -> None:
     """Test that manually specified schemata are passed through to the tool."""
 
     @tool(args_schema=_MockSchema)
-    def tool_func(*, arg1: int, arg2: bool, arg3: dict | None = None) -> str:
+    def tool_func(*, arg1: int, arg2: bool, arg3: dict[str, Any] | None = None) -> str:
         return f"{arg1} {arg2} {arg3}"
 
     assert isinstance(tool_func, BaseTool)
@@ -238,10 +246,12 @@ def test_decorator_with_specified_schema_pydantic_v1() -> None:
 
         arg1: int
         arg2: bool
-        arg3: dict | None = None
+        arg3: dict[str, Any] | None = None
 
     @tool(args_schema=cast("ArgsSchema", _MockSchemaV1))
-    def tool_func_v1(*, arg1: int, arg2: bool, arg3: dict | None = None) -> str:
+    def tool_func_v1(
+        *, arg1: int, arg2: bool, arg3: dict[str, Any] | None = None
+    ) -> str:
         return f"{arg1} {arg2} {arg3}"
 
     assert isinstance(tool_func_v1, BaseTool)
@@ -253,7 +263,7 @@ def test_decorated_function_schema_equivalent() -> None:
 
     @tool
     def structured_tool_input(
-        *, arg1: int, arg2: bool, arg3: dict | None = None
+        *, arg1: int, arg2: bool, arg3: dict[str, Any] | None = None
     ) -> str:
         """Return the arguments directly."""
         return f"{arg1} {arg2} {arg3}"
@@ -322,7 +332,7 @@ def test_structured_args_decorator_no_infer_schema() -> None:
 
     @tool(infer_schema=False)
     def structured_tool_input(
-        arg1: int, arg2: float | datetime, opt_arg: dict | None = None
+        arg1: int, arg2: float | datetime, opt_arg: dict[str, Any] | None = None
     ) -> str:
         """Return the arguments directly."""
         return f"{arg1}, {arg2}, {opt_arg}"
@@ -362,7 +372,7 @@ def test_structured_tool_types_parsed() -> None:
     def structured_tool(
         some_enum: SomeEnum,
         some_base_model: SomeBaseModel,
-    ) -> dict:
+    ) -> dict[str, Any]:
         """Return the arguments directly."""
         return {
             "some_enum": some_enum,
@@ -1032,7 +1042,7 @@ def test_validation_error_handling_non_validation_error(
 
         def _parse_input(
             self,
-            tool_input: str | dict,
+            tool_input: str | dict[str, Any],
             tool_call_id: str | None,
         ) -> str | dict[str, Any]:
             raise NotImplementedError
@@ -1098,7 +1108,7 @@ async def test_async_validation_error_handling_non_validation_error(
 
         def _parse_input(
             self,
-            tool_input: str | dict,
+            tool_input: str | dict[str, Any],
             tool_call_id: str | None,
         ) -> str | dict[str, Any]:
             raise NotImplementedError
@@ -1145,9 +1155,11 @@ def test_optional_subset_model_rewrite() -> None:
         ({"bar": "bar", "baz": None}, {"bar": "bar", "baz": None, "buzz": "buzz"}),
     ],
 )
-def test_tool_invoke_optional_args(inputs: dict, expected: dict | None) -> None:
+def test_tool_invoke_optional_args(
+    inputs: dict[str, Any], expected: dict[str, Any] | None
+) -> None:
     @tool
-    def foo(bar: str, baz: int | None = 3, buzz: str | None = "buzz") -> dict:
+    def foo(bar: str, baz: int | None = 3, buzz: str | None = "buzz") -> dict[str, Any]:
         """The foo."""
         return {
             "bar": bar,
@@ -2283,9 +2295,13 @@ def test__get_all_basemodel_annotations_v2(*, use_v1_namespace: bool) -> None:
             return "foo"
 
     class ModelC(Mixin, ModelB):
-        c: dict
+        c: dict[str, Any]
 
-    expected = {"a": str, "b": Annotated[ModelA[dict[str, Any]], "foo"], "c": dict}
+    expected = {
+        "a": str,
+        "b": Annotated[ModelA[dict[str, Any]], "foo"],
+        "c": dict[str, Any],
+    }
     actual = get_all_basemodel_annotations(ModelC)
     assert actual == expected
 
@@ -2309,7 +2325,7 @@ def test__get_all_basemodel_annotations_v2(*, use_v1_namespace: bool) -> None:
     expected = {
         "a": str,
         "b": Annotated[ModelA[dict[str, Any]], "foo"],
-        "c": dict,
+        "c": dict[str, Any],
         "d": str | int | None,
     }
     actual = get_all_basemodel_annotations(ModelD)
@@ -2318,7 +2334,7 @@ def test__get_all_basemodel_annotations_v2(*, use_v1_namespace: bool) -> None:
     expected = {
         "a": str,
         "b": Annotated[ModelA[dict[str, Any]], "foo"],
-        "c": dict,
+        "c": dict[str, Any],
         "d": int | None,
     }
     actual = get_all_basemodel_annotations(ModelD[int])
@@ -2342,7 +2358,7 @@ def test_tool_annotations_preserved() -> None:
     """Test that annotations are preserved when creating a tool."""
 
     @tool
-    def my_tool(val: int, other_val: Annotated[dict, "my annotation"]) -> str:
+    def my_tool(val: int, other_val: Annotated[dict[str, Any], "my annotation"]) -> str:
         """Tool docstring."""
         return "foo"
 
@@ -3080,7 +3096,7 @@ def test_tool_args_schema_with_annotated_type() -> None:
 class CallbackHandlerWithInputCapture(FakeCallbackHandler):
     """Callback handler that captures inputs passed to on_tool_start."""
 
-    captured_inputs: list[dict | None] = Field(default_factory=list)
+    captured_inputs: list[dict[str, Any] | None] = Field(default_factory=list)
 
     def on_tool_start(
         self,
@@ -3114,7 +3130,7 @@ def test_filter_injected_args_from_callbacks() -> None:
     @tool
     def search_tool(
         query: str,
-        state: Annotated[dict, InjectedToolArg()],
+        state: Annotated[dict[str, Any], InjectedToolArg()],
     ) -> str:
         """Search with injected state.
 
@@ -3182,7 +3198,7 @@ def test_filter_multiple_injected_args() -> None:
     def complex_tool(
         query: str,
         limit: int,
-        state: Annotated[dict, InjectedToolArg()],
+        state: Annotated[dict[str, Any], InjectedToolArg()],
         context: Annotated[str, InjectedToolArg()],
         run_manager: CallbackManagerForToolRun | None = None,
     ) -> str:
@@ -3250,7 +3266,7 @@ async def test_filter_injected_args_async() -> None:
     @tool
     async def async_search_tool(
         query: str,
-        state: Annotated[dict, InjectedToolArg()],
+        state: Annotated[dict[str, Any], InjectedToolArg()],
     ) -> str:
         """Async search with injected state.
 
diff --git a/libs/core/tests/unit_tests/tracers/test_memory_stream.py b/libs/core/tests/unit_tests/tracers/test_memory_stream.py
index ba9daa913c..c0840a3c19 100644
--- a/libs/core/tests/unit_tests/tracers/test_memory_stream.py
+++ b/libs/core/tests/unit_tests/tracers/test_memory_stream.py
@@ -12,7 +12,7 @@ async def test_same_event_loop() -> None:
     This is the easy case.
     """
     reader_loop = asyncio.get_event_loop()
-    channel = _MemoryStream[dict](reader_loop)
+    channel = _MemoryStream[dict[str, int | float]](reader_loop)
     writer = channel.get_send_stream()
     reader = channel.get_receive_stream()
 
@@ -30,7 +30,7 @@ async def test_same_event_loop() -> None:
             )
         await writer.aclose()
 
-    async def consumer() -> AsyncIterator[dict]:
+    async def consumer() -> AsyncIterator[dict[str, int | float]]:
         tic = time.time()
         async for item in reader:
             toc = time.time()
@@ -63,7 +63,7 @@ async def test_same_event_loop() -> None:
 async def test_queue_for_streaming_via_sync_call() -> None:
     """Test via async -> sync -> async path."""
     reader_loop = asyncio.get_event_loop()
-    channel = _MemoryStream[dict](reader_loop)
+    channel = _MemoryStream[dict[str, int | float]](reader_loop)
     writer = channel.get_send_stream()
     reader = channel.get_receive_stream()
 
@@ -85,7 +85,7 @@ async def test_queue_for_streaming_via_sync_call() -> None:
         """Blocking sync call."""
         asyncio.run(producer())
 
-    async def consumer() -> AsyncIterator[dict]:
+    async def consumer() -> AsyncIterator[dict[str, int | float]]:
         tic = time.time()
         async for item in reader:
             toc = time.time()
diff --git a/libs/core/tests/unit_tests/utils/test_function_calling.py b/libs/core/tests/unit_tests/utils/test_function_calling.py
index d2906f59e3..e6e46fd450 100644
--- a/libs/core/tests/unit_tests/utils/test_function_calling.py
+++ b/libs/core/tests/unit_tests/utils/test_function_calling.py
@@ -26,7 +26,7 @@ from pydantic import BaseModel, ConfigDict, Field
 from pydantic.errors import PydanticInvalidForJsonSchema
 
 from langchain_core.messages import AIMessage, HumanMessage, ToolMessage
-from langchain_core.runnables import Runnable, RunnableLambda
+from langchain_core.runnables import RunnableLambda
 from langchain_core.tools import BaseTool, StructuredTool, Tool, tool
 from langchain_core.utils.function_calling import (
     _convert_typed_dict_to_openai_function,
@@ -49,7 +49,7 @@ def pydantic() -> type[BaseModel]:
 
 
 @pytest.fixture
-def annotated_function() -> Callable:
+def annotated_function() -> Callable[[int, Literal["bar", "baz"]], None]:
     def dummy_function(
         arg1: ExtensionsAnnotated[int, "foo"],
         arg2: ExtensionsAnnotated[Literal["bar", "baz"], "one of 'bar', 'baz'"],
@@ -60,7 +60,7 @@ def annotated_function() -> Callable:
 
 
 @pytest.fixture
-def function() -> Callable:
+def function() -> Callable[[int, Literal["bar", "baz"]], None]:
     def dummy_function(arg1: int, arg2: Literal["bar", "baz"]) -> None:
         """Dummy function.
 
@@ -73,7 +73,7 @@ def function() -> Callable:
 
 
 @pytest.fixture
-def function_docstring_annotations() -> Callable:
+def function_docstring_annotations() -> Callable[[int, Literal["bar", "baz"]], None]:
     def dummy_function(arg1: int, arg2: Literal["bar", "baz"]) -> None:
         """Dummy function.
 
@@ -85,13 +85,14 @@ def function_docstring_annotations() -> Callable:
     return dummy_function
 
 
-@pytest.fixture
-def runnable() -> Runnable:
-    class Args(ExtensionsTypedDict):
-        arg1: ExtensionsAnnotated[int, "foo"]
-        arg2: ExtensionsAnnotated[Literal["bar", "baz"], "one of 'bar', 'baz'"]
+class _Args(ExtensionsTypedDict):
+    arg1: ExtensionsAnnotated[int, "foo"]
+    arg2: ExtensionsAnnotated[Literal["bar", "baz"], "one of 'bar', 'baz'"]
 
-    def dummy_function(input_dict: Args) -> None:
+
+@pytest.fixture
+def runnable() -> RunnableLambda[_Args, None]:
+    def dummy_function(input_dict: _Args) -> None:
         pass
 
     return RunnableLambda(dummy_function)
@@ -229,7 +230,7 @@ def dummy_extensions_typed_dict_docstring() -> type:
 
 
 @pytest.fixture
-def json_schema() -> dict:
+def json_schema() -> dict[str, Any]:
     return {
         "title": "dummy_function",
         "description": "Dummy function.",
@@ -247,7 +248,7 @@ def json_schema() -> dict:
 
 
 @pytest.fixture
-def anthropic_tool() -> dict:
+def anthropic_tool() -> dict[str, Any]:
     return {
         "name": "dummy_function",
         "description": "Dummy function.",
@@ -267,7 +268,7 @@ def anthropic_tool() -> dict:
 
 
 @pytest.fixture
-def bedrock_converse_tool() -> dict:
+def bedrock_converse_tool() -> dict[str, Any]:
     return {
         "toolSpec": {
             "name": "dummy_function",
@@ -313,17 +314,17 @@ class DummyWithClassMethod:
 
 def test_convert_to_openai_function(
     pydantic: type[BaseModel],
-    function: Callable,
-    function_docstring_annotations: Callable,
+    function: Callable[[int, Literal["bar", "baz"]], None],
+    function_docstring_annotations: Callable[[int, Literal["bar", "baz"]], None],
     dummy_structured_tool: StructuredTool,
     dummy_structured_tool_args_schema_dict: StructuredTool,
     dummy_tool: BaseTool,
-    json_schema: dict,
-    anthropic_tool: dict,
-    bedrock_converse_tool: dict,
-    annotated_function: Callable,
+    json_schema: dict[str, Any],
+    anthropic_tool: dict[str, Any],
+    bedrock_converse_tool: dict[str, Any],
+    annotated_function: Callable[[int, Literal["bar", "baz"]], None],
     dummy_pydantic: type[BaseModel],
-    runnable: Runnable,
+    runnable: RunnableLambda[_Args, None],
     dummy_typing_typed_dict: type,
     dummy_typing_typed_dict_docstring: type,
     dummy_extensions_typed_dict: type,
@@ -643,7 +644,7 @@ openai_function_no_description_no_params = {
         openai_function_no_description,
     ],
 )
-def test_convert_to_openai_function_no_description(func: dict) -> None:
+def test_convert_to_openai_function_no_description(func: dict[str, Any]) -> None:
     expected = {
         "name": "dummy_function",
         "parameters": {
@@ -670,7 +671,9 @@ def test_convert_to_openai_function_no_description(func: dict) -> None:
         openai_function_no_description_no_params,
     ],
 )
-def test_convert_to_openai_function_no_description_no_params(func: dict) -> None:
+def test_convert_to_openai_function_no_description_no_params(
+    func: dict[str, Any],
+) -> None:
     expected = {
         "name": "dummy_function",
     }
@@ -1040,7 +1043,9 @@ def test__convert_typed_dict_to_openai_function(
 @pytest.mark.parametrize("typed_dict", [ExtensionsTypedDict, TypingTypedDict])
 def test__convert_typed_dict_to_openai_function_fail(typed_dict: type) -> None:
     class Tool(typed_dict):  # type: ignore[misc]
-        arg1: typing.MutableSet  # Pydantic 2 supports this, but pydantic v1 does not.
+        arg1: typing.MutableSet[
+            Any
+        ]  # Pydantic 2 supports this, but pydantic v1 does not.
 
     # Error should be raised since we're using v1 code path here
     with pytest.raises(TypeError):
@@ -1081,15 +1086,15 @@ def test_convert_to_openai_function_no_args() -> None:
 
 def test_convert_to_json_schema(
     pydantic: type[BaseModel],
-    function: Callable,
-    function_docstring_annotations: Callable,
+    function: Callable[[int, Literal["bar", "baz"]], None],
+    function_docstring_annotations: Callable[[int, Literal["bar", "baz"]], None],
     dummy_structured_tool: StructuredTool,
     dummy_structured_tool_args_schema_dict: StructuredTool,
     dummy_tool: BaseTool,
-    json_schema: dict,
-    anthropic_tool: dict,
-    bedrock_converse_tool: dict,
-    annotated_function: Callable,
+    json_schema: dict[str, Any],
+    anthropic_tool: dict[str, Any],
+    bedrock_converse_tool: dict[str, Any],
+    annotated_function: Callable[[int, Literal["bar", "baz"]], None],
     dummy_pydantic: type[BaseModel],
     dummy_typing_typed_dict: type,
     dummy_typing_typed_dict_docstring: type,
@@ -1123,10 +1128,10 @@ def test_convert_to_json_schema(
 
 
 def test_convert_to_openai_function_nested_strict_2() -> None:
-    def my_function(arg1: dict, arg2: dict | None) -> None:
+    def my_function(arg1: dict[str, Any], arg2: dict[str, Any] | None) -> None:
         """Dummy function."""
 
-    expected: dict = {
+    expected: dict[str, Any] = {
         "name": "my_function",
         "description": "Dummy function.",
         "parameters": {
diff --git a/libs/core/tests/unit_tests/utils/test_rm_titles.py b/libs/core/tests/unit_tests/utils/test_rm_titles.py
index ead63cfab4..285ce35987 100644
--- a/libs/core/tests/unit_tests/utils/test_rm_titles.py
+++ b/libs/core/tests/unit_tests/utils/test_rm_titles.py
@@ -1,3 +1,5 @@
+from typing import Any
+
 import pytest
 
 from langchain_core.utils.function_calling import _rm_titles
@@ -229,5 +231,5 @@ output5 = {
         (schema5, output5),
     ],
 )
-def test_rm_titles(schema: dict, output: dict) -> None:
+def test_rm_titles(schema: dict[str, Any], output: dict[str, Any]) -> None:
     assert _rm_titles(schema) == output
diff --git a/libs/core/tests/unit_tests/utils/test_utils.py b/libs/core/tests/unit_tests/utils/test_utils.py
index 815296f888..7799c9c9df 100644
--- a/libs/core/tests/unit_tests/utils/test_utils.py
+++ b/libs/core/tests/unit_tests/utils/test_utils.py
@@ -132,7 +132,9 @@ def test_check_package_version(
     ],
 )
 def test_merge_dicts(
-    left: dict, right: dict, expected: dict | AbstractContextManager
+    left: dict[str, Any],
+    right: dict[str, Any],
+    expected: dict[str, Any] | AbstractContextManager[BaseException],
 ) -> None:
     err = expected if isinstance(expected, AbstractContextManager) else nullcontext()
 
@@ -160,7 +162,9 @@ def test_merge_dicts(
 )
 @pytest.mark.xfail(reason="Refactors to make in 0.3")
 def test_merge_dicts_0_3(
-    left: dict, right: dict, expected: dict | AbstractContextManager
+    left: dict[str, Any],
+    right: dict[str, Any],
+    expected: dict[str, Any] | AbstractContextManager[BaseException],
 ) -> None:
     err = expected if isinstance(expected, AbstractContextManager) else nullcontext()
 
diff --git a/libs/core/tests/unit_tests/vectorstores/test_utils.py b/libs/core/tests/unit_tests/vectorstores/test_utils.py
index 2ff9817f5b..d97348c347 100644
--- a/libs/core/tests/unit_tests/vectorstores/test_utils.py
+++ b/libs/core/tests/unit_tests/vectorstores/test_utils.py
@@ -6,6 +6,7 @@ import pytest
 
 pytest.importorskip("numpy")
 import numpy as np
+import numpy.typing as npt
 
 from langchain_core.vectorstores.utils import _cosine_similarity
 
@@ -61,8 +62,8 @@ class TestCosineSimilarity:
 
     def test_numpy_array_input(self) -> None:
         """Test with numpy array inputs."""
-        x: np.ndarray = np.array([[1, 0], [0, 1]])
-        y: np.ndarray = np.array([[1, 0], [0, 1]])
+        x: npt.NDArray[np.floating] = np.array([[1, 0], [0, 1]])
+        y: npt.NDArray[np.floating] = np.array([[1, 0], [0, 1]])
         result = _cosine_similarity(x, y)
         expected = np.array([[1.0, 0.0], [0.0, 1.0]])
         np.testing.assert_array_almost_equal(result, expected)
@@ -70,7 +71,7 @@ class TestCosineSimilarity:
     def test_mixed_input_types(self) -> None:
         """Test with mixed input types (list and numpy array)."""
         x: list[list[float]] = [[1, 0], [0, 1]]
-        y: np.ndarray = np.array([[1, 0], [0, 1]])
+        y: npt.NDArray[np.floating] = np.array([[1, 0], [0, 1]])
         result = _cosine_similarity(x, y)
         expected = np.array([[1.0, 0.0], [0.0, 1.0]])
         np.testing.assert_array_almost_equal(result, expected)
diff --git a/libs/core/tests/unit_tests/vectorstores/test_vectorstore.py b/libs/core/tests/unit_tests/vectorstores/test_vectorstore.py
index f8af00ee79..5ba467767f 100644
--- a/libs/core/tests/unit_tests/vectorstores/test_vectorstore.py
+++ b/libs/core/tests/unit_tests/vectorstores/test_vectorstore.py
@@ -30,7 +30,7 @@ class CustomAddTextsVectorstore(VectorStore):
     def add_texts(
         self,
         texts: Iterable[str],
-        metadatas: list[dict] | None = None,
+        metadatas: list[dict[str, Any]] | None = None,
         ids: list[str] | None = None,
         **kwargs: Any,
     ) -> list[str]:
@@ -58,7 +58,7 @@ class CustomAddTextsVectorstore(VectorStore):
         cls,
         texts: list[str],
         embedding: Embeddings,
-        metadatas: list[dict] | None = None,
+        metadatas: list[dict[str, Any]] | None = None,
         **kwargs: Any,
     ) -> CustomAddTextsVectorstore:
         vectorstore = CustomAddTextsVectorstore()
@@ -104,7 +104,7 @@ class CustomAddDocumentsVectorstore(VectorStore):
         cls,
         texts: list[str],
         embedding: Embeddings,
-        metadatas: list[dict] | None = None,
+        metadatas: list[dict[str, Any]] | None = None,
         **kwargs: Any,
     ) -> CustomAddDocumentsVectorstore:
         vectorstore = CustomAddDocumentsVectorstore()
diff --git a/libs/text-splitters/langchain_text_splitters/markdown.py b/libs/text-splitters/langchain_text_splitters/markdown.py
index f4c2b05530..7eee94e9c5 100644
--- a/libs/text-splitters/langchain_text_splitters/markdown.py
+++ b/libs/text-splitters/langchain_text_splitters/markdown.py
@@ -455,7 +455,8 @@ class ExperimentalMarkdownSyntaxTextSplitter:
             # Apply the header stack as metadata
             for depth, value in self.current_header_stack:
                 header_key = self.splittable_headers.get("#" * depth)
-                self.current_chunk.metadata[header_key] = value
+                if header_key is not None:
+                    self.current_chunk.metadata[header_key] = value
             self.chunks.append(self.current_chunk)
         # Reset the current chunk
         self.current_chunk = Document(page_content="")