Follow-up to #8540, which turned on `PLC0415` (import-outside-top-level)
for checkpoint-postgres and checkpoint-sqlite. This does the remaining
six packages: checkpoint, checkpoint-conformance, langgraph, prebuilt,
cli, sdk-py.
Scoped to tests, per @sydney-runkle's call on #8540: library code is
exempted with `per-file-ignores`, since it still has deferred imports
nobody has reviewed and mixing that in would make this hard to read.
## What changed
Function-level imports across 56 test files moved to module level. Nine
could not move and carry an explicit `# noqa: PLC0415` with a reason:
| File | Why it stays local |
|---|---|
| `libs/langgraph/tests/test_deprecation.py` (4) | the import has to run
inside `pytest.warns` for the warning to be observed |
| `libs/langgraph/tests/test_serde_allowlist.py` | try/except guard,
skips when langchain_core is absent |
| `libs/langgraph/tests/test_delta_channel_benchmark.py` | optional
psycopg probe |
| `libs/checkpoint/tests/test_conformance_delta.py` (3) | protected by a
module-level `pytest.importorskip`; hoisting past the guard turns a skip
into a collection error |
That last one is the trap: an import moved above `pytest.importorskip`
silently defeats the guard. I hit it locally and it turned the skip into
a `ModuleNotFoundError` at collection. Every file with an `importorskip`
or `except ImportError` was checked by hand for this.
## Verification
`make lint` and `make test` in each of the six:
| Package | Tests |
|---|---|
| checkpoint | 156 passed, 17 skipped |
| checkpoint-conformance | 1 passed |
| langgraph | 1968 passed, 4 skipped |
| prebuilt | 284 passed |
| cli | 336 passed |
| sdk-py | 493 passed |
Also confirmed the rule actually fires: a throwaway test file with a
function-level import is flagged in all six packages, and the source
exemption holds.
Makes `ToolRuntime.tools` default to an empty list when not provided,
which avoids requiring callers and tests to pass it explicitly. Adds a
focused regression test covering direct `ToolRuntime` construction
without `tools`.
Created with [Deep Agents
CLI](https://docs.langchain.com/oss/python/deepagents/cli/overview)
using gpt-5.4 (provider: openai).
## Summary
Extends `ToolNode` so that a single tool invocation can return
`list[Command | ToolMessage]` instead of only a single `Command` or
`ToolMessage`. This brings `ToolNode`'s per-tool-call contract in line
with the rest of LangGraph, where nodes can already return multiple
Commands.
Depends on langchain-ai/langchain#36963 which allows
`list[ToolOutputMixin]` to pass through `BaseTool._format_output`
unchanged.
## Changes
### `libs/prebuilt/langgraph/prebuilt/tool_node.py`
**New list-return gate in `_execute_tool_sync` / `_execute_tool_async`**
— After the existing `Command` and `ToolMessage` checks, a new branch
accepts `list[Command | ToolMessage]` and routes it through
`_validate_tool_command_list`. Lists with non-`Command`/`ToolMessage`
elements raise `TypeError`. Both sync and async paths are updated
symmetrically.
**`_validate_tool_command_list`** — Enforces the terminating-ToolMessage
rule: exactly one `ToolMessage` in the list must carry `tool_call_id ==
<outer_id>` (top-level or nested inside a `Command.update["messages"]`).
Zero or multiple terminators raise `_MissingToolMessageError`.
Individual Commands in the list are validated via the existing
`_validate_tool_command`; when a Command lacks the terminator (which is
allowed since the list-level check handles it), the
`_MissingToolMessageError` is caught and the already-normalized command
from the exception is used.
**`_MissingToolMessageError`** — A `ValueError` subclass raised by
`_validate_tool_command` (and `_validate_tool_command_list`) when no
matching `ToolMessage` is found. Carries the already-normalized command
so callers can recover without re-doing deepcopy/message-conversion
work. Using a typed exception avoids brittle string-matching on error
messages.
**`_combine_tool_outputs`** — Flattens list entries at the top of the
method so downstream combiner logic (parent-`goto` accumulation,
ToolMessage wrapping) is unchanged.
**Response processing moved inside try/except** — In both sync and async
execute methods, the response validation (Command/ToolMessage/list
checks) now runs inside the existing error-handling try block, so
validation errors from the list path go through `_handle_tool_errors`
like other tool errors.
**Return type signatures** widened on `_execute_tool_sync`,
`_execute_tool_async`, `_run_one`, `_arun_one` to include `list[Command
| ToolMessage]`.
### `libs/prebuilt/tests/test_tool_node.py`
New tests covering: valid list returns (top-level terminator, nested
terminator, parent-goto + terminator), regression tests for single
Command/ToolMessage returns, invalid cases (no terminator, multiple
terminators), async parity, integration with mixed list/non-list tool
calls, and `_handle_tool_errors` interaction.
---------
Co-authored-by: Sydney Runkle <sydneymarierunkle@gmail.com>
## Summary
Enhances `ExecutionInfo` and `Runtime` to surface richer execution
context and introduces `ServerInfo` for LangGraph Server metadata.
### `ExecutionInfo` expansion
Converted from `NamedTuple` to a frozen `dataclass`. Added identity
fields populated during task preparation in `_algo.py`:
| Field | Type | Default | Description |
|-------|------|---------|-------------|
| `checkpoint_id` | `str` | required | Checkpoint ID for the current
execution |
| `checkpoint_ns` | `str` | required | Checkpoint namespace for the
current execution |
| `task_id` | `str` | required | Task ID for the current execution |
| `thread_id` | `str \| None` | `None` | Thread ID (None without a
checkpointer) |
| `run_id` | `str \| None` | `None` | Run ID (None when not provided in
config) |
| `node_attempt` | `int` | `1` | Current node execution attempt number
(1-indexed) |
| `node_first_attempt_time` | `float \| None` | `None` | Unix timestamp
for when the first attempt started |
`checkpoint_id`, `checkpoint_ns`, and `task_id` are required (no
defaults) — they are always populated during task preparation in
`_algo.py`. `Runtime.execution_info` is `None` until that point.
### New `ServerInfo` type
Frozen dataclass with `assistant_id: str`, `graph_id: str`, and optional
`user: BaseUser | None`. Populated from config metadata (`assistant_id`,
`graph_id`) and `configurable["langgraph_auth_user"]` via
`_build_server_info()` in `pregel/main.py`.
User detection uses `isinstance(BaseUser)` with a `hasattr("identity")`
fallback — needed because the server's `ProxyUser` provides
`permissions` via `__getattr__`, which Python's `runtime_checkable`
Protocol check doesn't see.
### `Runtime` changes
- `execution_info` is now `ExecutionInfo | None` (default `None`), set
during task prep
- Added `server_info: ServerInfo | None` field, wired through `merge()`
and `override()`
### `ToolNode` / `ToolRuntime` forwarding
`execution_info` and `server_info` are forwarded from `Runtime` to
`ToolRuntime` so tools can access execution and server context.
### New public API surface
```python
from langgraph.runtime import BaseUser, ExecutionInfo, Runtime, ServerInfo, get_runtime
```
## Test plan
- [x] `ExecutionInfo` defaults, patch, and frozen behavior
- [x] Integration tests verifying identity fields are populated in sync
and async execution
- [x] Retry tests confirming identity fields persist and `node_attempt`
increments
- [x] `ServerInfo` construction, frozen behavior, and `Runtime.merge`
precedence
- [x] `server_info` populated from config metadata and
`langgraph_auth_user` (including starlette-style proxy user)
- [x] `server_info` is `None` when no server metadata present
- [x] `ToolRuntime` forwarding of `execution_info` and `server_info`
🤖 Generated with [Claude Code](https://claude.com/claude-code)
ensuring that injected args can only be injected by LC code, not LLMs :)
this does not appear to be an actual security concern because it falls
outside of documented usage, the tool node doesn't inject arbitrary args
**Description:**
This PR fixes an issue where injection types (like `ToolRuntime`) were
not recognized by `ToolNode` when used with generic type arguments
(e.g., `ToolRuntime[MyContext]`).
Previously, the `_is_injection` check relied solely on `isinstance` and
`issubclass`, which fail for `typing._GenericAlias` objects. This update
adds a check using `typing.get_origin()` to correctly identify the base
class of generic types, ensuring the runtime is injected correctly even
when type hints are present.
**Issue:** Fixes#6465
**Dependencies:** None
**Twitter handle:** @SidharthRajmoh2
---------
Co-authored-by: Sydney Runkle <54324534+sydney-runkle@users.noreply.github.com>
## overview
The main purpose of this is to respect tool signatures that request
injected args (like `ToolRuntime`) even when the explicitly specified
`args_schema` does not.
Ex in the following example, we should still inject `runtime` despite
its absence in `ArgsSchema`
```py
class ArgsSchema(BaseModel):
some_arg: int = Field(...)
@tool(args_schema=ArgsSchema)
def my_tool(some_arg: int, runtime: ToolRuntime): ...
```
This is accompanied by
https://github.com/langchain-ai/langchain/pull/34051 which has tests
that pass w/ this change. This tests injection w/ `create_agent` (more
end to end than tests added in
https://github.com/langchain-ai/langchain/pull/33999.
This unblocks the injection of `ToolRuntime` into MCP tools which is
exciting bc that exposes tool call id and state, which we previously
were unable to do.
## other benefits
* Cleaner code structure w/ more helpful docs about injected args.
* Nice perf boost, we're no longer inspecting the annotations of a
tool's schema 3 different times to detect store, state, and runtime
injections.
## additional notes
1. I could see a world where we want more of this logic to reside on the
tools themselves, but tools don't now about LG specific injection types
(like `ToolRuntime`, hence having this logic here for now).
2. We could separately add validation for the case where something is
specified in `args_schema` and not in the function signature (probably
at the tool level though).
namespace decisions
```
langgraph.prebuilt
├── ToolRuntime # new
# all of the other stuff that was already there
langgraph.prebuilt.tool_node
├── ToolNode
├── ToolCallRequest # new
├── ToolRuntime # new
├── InjectedState
├── InjectedStore
├── ToolCallWrapper
├── AsyncToolCallWrapper
├── tools_condition
```
```
langchain.tools
├── ToolRuntime # now from langgraph.prebuilt
├── InjectedState # now from langgraph.prebuilt
├── InjectedStore # now from langgraph.prebuilt
├── ToolException
├── tool
├── BaseTool
├── InjectedToolArg
├── InjectedToolCallId
```
This PR updates the dependencies in all Python packages using `uv lock
--upgrade`.
This is an automated PR created by the UV Lock Upgrade workflow.
To make tests pass:
* linting fixes
* whitespace fixes in snapshots
---------
Co-authored-by: sydney-runkle <54324534+sydney-runkle@users.noreply.github.com>
Co-authored-by: Sydney Runkle <sydneymarierunkle@gmail.com>
## Description
Previously, when a tool returned `Command` to update the graph's state,
the `_validate_tool_command` method in `ToolNode` would raise a
`ValueError` if the `messages_update` list contained only a
`RemoveMessage(id=REMOVE_ALL_MESSAGES)` object. This was because the
validation logic expected a matching `ToolMessage` for the tool call and
did not account for this specific state-clearing scenario.
This commit modifies the validation logic to check if the
`messages_update` list contains a single
`RemoveMessage(id=REMOVE_ALL_MESSAGES)` element. If this condition is
met, the `ToolMessage` validation is bypassed, allowing a tool to clear
the entire message history without causing a validation error.
A new test case, `test_tool_node_command_remove_all_messages`, has been
added to `tests/test_tool_node.py` to verify this change and prevent
future regressions.
## Example
Here is a self-contained example that illustrates the problem and the
fix. Without this change, the code block for `Example 2` would raise a
`ValueError`.
```python
from typing import Annotated, List
from langchain_core.messages import (
AIMessage,
AnyMessage,
HumanMessage,
RemoveMessage,
ToolMessage,
)
from langchain_core.tools import InjectedToolCallId, tool
from langchain_openai import ChatOpenAI
from langgraph.graph import END, StateGraph, add_messages
from langgraph.graph.message import REMOVE_ALL_MESSAGES
from langgraph.prebuilt import InjectedState, ToolNode
from langgraph.types import Command
from pydantic import BaseModel, Field
# Agent state tracks current and all messages
class AgentState(BaseModel):
messages: Annotated[List[AnyMessage], add_messages] = Field(
default_factory=list, description="Current conversation messages."
)
all_messages: Annotated[List[AnyMessage], add_messages] = Field(
default_factory=list, description="All messages, including removed ones."
)
# Tool to clear history if long enough, otherwise returns a warning
@tool
def clear_history_tool(
state: Annotated[AgentState, InjectedState],
tool_call_id: Annotated[str, InjectedToolCallId],
):
"""Clears message history if it's long enough."""
if len(state.messages) < 3:
return Command(
update={
"messages": [
ToolMessage(
"History is not long enough to be cleared. Please try again.",
tool_call_id=tool_call_id,
)
]
}
)
else:
return Command(
update={
"messages": [RemoveMessage(id=REMOVE_ALL_MESSAGES)],
"all_messages": state.messages
+ [
ToolMessage(
"History has been successfully cleared.",
tool_call_id=tool_call_id,
)
],
}
)
# Bind the tool to the model
model = ChatOpenAI(model="gpt-4o-mini").bind_tools([clear_history_tool])
def model_node(state: AgentState):
return {"messages": [model.invoke(state.messages)]}
# Build the agent graph
graph_builder = StateGraph(AgentState)
graph_builder.add_node("model", model_node)
graph_builder.add_node("tools", ToolNode([clear_history_tool]))
graph_builder.set_entry_point("model")
graph_builder.add_edge("model", "tools")
graph_builder.add_edge("tools", END)
graph = graph_builder.compile()
def print_messages(header, messages):
print(f"\n{header}")
for message in messages:
message.pretty_print()
### Example 1: Not enough history to clear
state_1 = AgentState(
messages=[HumanMessage(content="Please clear my message history.")]
)
output_1 = graph.invoke(state_1)
print_messages("First call: State 'messages'", output_1["messages"])
print_messages("First call: State 'all_messages'", output_1["all_messages"])
### Example 2: History is cleared
state_2 = AgentState(
messages=[
HumanMessage(content="Will this PR get merged?"),
AIMessage(content="Maybe, if it's good enough."),
HumanMessage(content="Please clear my message history."),
]
)
# Without the changes in this PR, the following line will raise a ValueError
output_2 = graph.invoke(state_2)
print_messages("Second call: State 'messages'", output_2["messages"])
print_messages("Second call: State 'all_messages'", output_2["all_messages"])
```
### Outputs
*Without the changes in this PR:*
```
First call: State 'messages'
================================ Human Message =================================
Please clear my message history.
================================== Ai Message ==================================
Tool Calls:
clear_history_tool (ba421ac3-1e1a-4208-a8f6-c5500ee0abcc)
Call ID: ba421ac3-1e1a-4208-a8f6-c5500ee0abcc
Args:
================================= Tool Message =================================
Name: clear_history_tool
History is not long enough to be cleared. Please try again.
First call: State 'all_messages'
Traceback (most recent call last):
File "main.py", line 114, in <module>
output_2 = graph.invoke(state_2)
^^^^^^^^^^^^^^^^^^^^^
File ".venv/lib/python3.11/site-packages/langgraph/pregel/__init__.py", line 2844, in invoke
for chunk in self.stream(
File ".venv/lib/python3.11/site-packages/langgraph/pregel/__init__.py", line 2534, in stream
for _ in runner.tick(
File ".venv/lib/python3.11/site-packages/langgraph/prebuilt/tool_node.py", line 241, in _func
outputs = [
^
File ".venv/lib/python3.11/concurrent/futures/_base.py", line 619, in result_iterator
yield _result_or_cancel(fs.pop())
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File ".venv/lib/python3.11/concurrent/futures/_base.py", line 317, in _result_or_cancel
return fut.result(timeout)
^^^^^^^^^^^^^^^^^^^
File ".venv/lib/python3.11/concurrent/futures/_base.py", line 449, in result
return self.__get_result()
^^^^^^^^^^^^^^^^^^^
File ".venv/lib/python3.11/concurrent/futures/_base.py", line 401, in __get_result
raise self._exception
File ".venv/lib/python3.11/concurrent/futures/thread.py", line 58, in run
result = self.fn(*self.args, **self.kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File ".venv/lib/python3.11/site-packages/langchain_core/runnables/config.py", line 555, in _wrapped_fn
return contexts.pop().run(fn, *args)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File ".venv/lib/python3.11/site-packages/langgraph/prebuilt/tool_node.py", line 353, in _run_one
return self._validate_tool_command(response, call, input_type)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File ".venv/lib/python3.11/site-packages/langgraph/prebuilt/tool_node.py", line 616, in _validate_tool_command
raise ValueError(
ValueError: Expected to have a matching ToolMessage in Command.update for tool 'clear_history_tool', got: [RemoveMessage(content='', additional_kwargs={}, response_metadata={}, id='__remove_all__')]. Every tool call (LLM requesting to call a tool) in the message history MUST have a corresponding ToolMessage. You can fix it by modifying the tool to return `Command(update={"messages": [ToolMessage("Success", tool_call_id=tool_call_id), ...]}, ...)`.
```
*With the changes in this PR:*
```
First call: State 'messages'
================================ Human Message =================================
Please clear my message history.
================================== Ai Message ==================================
Tool Calls:
clear_history_tool (ba421ac3-1e1a-4208-a8f6-c5500ee0abcc)
Call ID: ba421ac3-1e1a-4208-a8f6-c5500ee0abcc
Args:
================================= Tool Message =================================
Name: clear_history_tool
History is not long enough to be cleared. Please try again.
First call: State 'all_messages'
Second call: State 'messages'
Second call: State 'all_messages'
================================ Human Message =================================
Will this PR get merged?
================================== Ai Message ==================================
Maybe, if it's good enough.
================================ Human Message =================================
Please clear my message history.
================================== Ai Message ==================================
Tool Calls:
clear_history_tool (499b1be3-6df1-493f-85e5-8d7e429dead8)
Call ID: 499b1be3-6df1-493f-85e5-8d7e429dead8
Args:
================================= Tool Message =================================
Name: clear_history_tool
History has been successfully cleared.
```
## Twitter handle
[@samuelpullely](https://x.com/samuelpullely)
---------
Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>
- Now all tests fully migrated to more recent sync_checkpointer and async_checkpointer fixtures for parametrising on checkpointer
- Use sync/async_store fixtures where tests used only in memory store
- Remove unused "should snapshot" check for older versions of langchain core no longer tested against
