The file-based and title-based labeler workflows were conflicting,
causing the bot to add and remove identical labels in the same
operation. Hopefully this fixes
- Removes Codespell from deps, docs, and `Makefile`s
- Python version requirements in all `pyproject.toml` files now use the
`~=` (compatible release) specifier
- All dependency groups and main dependencies now use explicit lower and
upper bounds, reducing potential for breaking changes
We want state schema as the input schema to middleware nodes because the
conditional edges after these nodes need access to the full state.
Also, we just generally want all state passed to middleware nodes, so we
should be specifying this explicitly. If we don't, the state annotations
used by users in their node signatures are used (so they might be
missing fields).
# Changes
## Adds support for `DynamicSystemPromptMiddleware`
```py
from langchain.agents.middleware import DynamicSystemPromptMiddleware
from langgraph.runtime import Runtime
from typing_extensions import TypedDict
class Context(TypedDict):
user_name: str
def system_prompt(state: AgentState, runtime: Runtime[Context]) -> str:
user_name = runtime.context.get("user_name", "n/a")
return f"You are a helpful assistant. Always address the user by their name: {user_name}"
middleware = DynamicSystemPromptMiddleware(system_prompt)
```
## Adds support for `runtime` in middleware hooks
```py
class AgentMiddleware(Generic[StateT, ContextT]):
def modify_model_request(
self,
request: ModelRequest,
state: StateT,
runtime: Runtime[ContextT], # Optional runtime parameter
) -> ModelRequest:
# upgrade model if runtime.context.subscription is `top-tier` or whatever
```
## Adds support for omitting state attributes from input / output
schemas
```py
from typing import Annotated, NotRequired
from langchain.agents.middleware.types import PrivateStateAttr, OmitFromInput, OmitFromOutput
class CustomState(AgentState):
# Private field - not in input or output schemas
internal_counter: NotRequired[Annotated[int, PrivateStateAttr]]
# Input-only field - not in output schema
user_input: NotRequired[Annotated[str, OmitFromOutput]]
# Output-only field - not in input schema
computed_result: NotRequired[Annotated[str, OmitFromInput]]
```
## Additionally
* Removes filtering of state before passing into middleware hooks
Typing is not foolproof here, still need to figure out some of the
generics stuff w/ state and context schema extensions for middleware.
TODO:
* More docs for middleware, should hold off on this until other prios
like MCP and deepagents are met
---------
Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>
## Summary
This PR fixes several bugs and improves the example code in
`BaseChatMessageHistory` docstring that would prevent it from working
correctly.
### Bugs Fixed
- **Critical bug**: Fixed `json.dump(messages, f)` →
`json.dump(serialized, f)` - was using wrong variable
- **NameError**: Fixed bare variable references to use
`self.storage_path` and `self.session_id`
- **Missing imports**: Added required imports (`json`, `os`, message
converters) to make example runnable
### Improvements
- Added missing type hints following project standards (`messages() ->
list[BaseMessage]`, `clear() -> None`)
- Added robust error handling with `FileNotFoundError` exception
handling
- Added directory creation with `os.makedirs(exist_ok=True)` to prevent
path errors
- Improved performance: `json.load(f)` instead of `json.loads(f.read())`
- Added explicit UTF-8 encoding to all file operations
- Updated stores.py to use modern union syntax (`int | None` vs
`Optional[int]`)
### Test Plan
- [x] Code passes linting (`ruff check`)
- [x] Example code now has all required imports and proper syntax
- [x] Fixed variable references prevent runtime errors
- [x] Follows project's type annotation standards
The example code in the docstring is now fully functional and follows
LangChain's coding standards.
---------
Co-authored-by: sadiqkhzn <sadiqkhzn@users.noreply.github.com>
- **Description:** Updated the dead/unreachable links to Docling from
the additional resources section of the langchain-docling docs
- **Issue:** Fixes langchain-ai/docs/issues/574
- **Dependencies:** None
# Main changes / new features
## Better support for parallel tool calls
1. Support for multiple tool calls requiring human input
2. Support for combination of tool calls requiring human input + those
that are auto-approved
3. Support structured output w/ tool calls requiring human input
4. Support structured output w/ standard tool calls
## Shortcut for allowed actions
Adds a shortcut where tool config can be specified as a `bool`, meaning
"all actions allowed"
```py
HumanInTheLoopMiddleware(tool_configs={"expensive_tool": True})
```
## A few design decisions here
* We only raise one interrupt w/ all `HumanInterrupt`s, currently we
won't be able to execute all tools until all of these are resolved. This
isn't super blocking bc we can't re-invoke the model until all tools
have finished execution. That being said, if you have a long running
auto-approved tool, this could slow things down.
## TODOs
* Ideally, we would rename `accept` -> `approve`
* Ideally, we would rename `respond` -> `reject`
* Docs update (@sydney-runkle to own)
* In another PR I'd like to refactor testing to have one file for each
prebuilt middleware :)
Fast follow to https://github.com/langchain-ai/langchain/pull/32962
which was deemed as too breaking
The standard PDF input test was creating file content blocks without a
filename field.
This caused a warning when the OpenAI block translator processed the
message for LangSmith tracing, since OpenAI requires filenames for file
inputs.
