The `draw_png()` method currently does not support drawing subgraphs.
This PR adds the ability to render subgraph outlines, improving
visualization clarity when working with nested structures.
This PR fixes#32234 and improves HuggingFace chat model integration by:
Ensuring ChatHuggingFace inherits key parameters (temperature,
max_tokens, top_p, streaming, etc.) from the underlying LLM when not
explicitly set.
Adding and updating unit tests to verify property inheritance.
No breaking changes; these updates enhance reliability and
maintainability.
---------
Co-authored-by: Mason Daugherty <mason@langchain.dev>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Mason Daugherty <github@mdrxy.com>
- **Description:** Updated Function Signature of `create_agent`, the
system prompt can be both a list and string. I see no harm in doing
this, since SystemMessage accepts both.
- **Issue:** #33630
---------
Co-authored-by: Sydney Runkle <54324534+sydney-runkle@users.noreply.github.com>
The `@shielded` decorator in async callback managers was not preserving
context variables, breaking OpenTelemetry instrumentation and other
context-dependent functionality.
## Problem
When using async callbacks with the `@shielded` decorator (applied to
methods like `on_llm_end`, `on_chain_end`, etc.), context variables were
not being preserved across the shield boundary. This caused issues with:
- OpenTelemetry span context propagation
- Other instrumentation that relies on context variables
- Inconsistent context behavior between sync and async execution
The issue was reproducible with:
```python
from contextvars import copy_context
import asyncio
from langgraph.graph import StateGraph
# Sync case: context remains consistent
print("SYNC")
print(copy_context()) # Same object
graph.invoke({"result": "init"})
print(copy_context()) # Same object
# Async case: context was inconsistent (before fix)
print("ASYNC")
asyncio.run(graph.ainvoke({"result": "init"}))
print(copy_context()) # Different object than expected
```
## Root Cause
The original `shielded` decorator implementation:
```python
async def wrapped(*args: Any, **kwargs: Any) -> Any:
return await asyncio.shield(func(*args, **kwargs))
```
Used `asyncio.shield()` directly without preserving the current
execution context, causing context variables to be lost.
## Solution
Modified the `shielded` decorator to:
1. Capture the current context using `copy_context()`
2. Create a task with explicit context using `asyncio.create_task(coro,
context=ctx)` for Python 3.11+
3. Shield the context-aware task
4. Fallback to regular task creation for Python < 3.11
```python
async def wrapped(*args: Any, **kwargs: Any) -> Any:
# Capture the current context to preserve context variables
ctx = copy_context()
coro = func(*args, **kwargs)
try:
# Create a task with the captured context to preserve context variables
task = asyncio.create_task(coro, context=ctx)
return await asyncio.shield(task)
except TypeError:
# Python < 3.11 fallback
task = asyncio.create_task(coro)
return await asyncio.shield(task)
```
## Testing
- Added comprehensive test
`test_shielded_callback_context_preservation()` that validates context
variables are preserved across shielded callback boundaries
- Verified the fix resolves the original LangGraph context consistency
issue
- Confirmed all existing callback manager tests still pass
- Validated OpenTelemetry-like instrumentation scenarios work correctly
The fix is minimal, maintains backward compatibility, and ensures proper
context preservation for both modern Python versions and older ones.
Fixes#31398.
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---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: mdrxy <61371264+mdrxy@users.noreply.github.com>
Co-authored-by: Mason Daugherty <github@mdrxy.com>
Co-authored-by: Mason Daugherty <mason@langchain.dev>
# Description
This submission is a part of a school project from our team of 4
@EminGul @williamzhu54 @annay54 @donttouch22.
Our pull request fixes the issue with RunnableParallel scheme being
empty by returning the correct schema output when children runnable
input schemas use TypedDicts.
# Issue
Fixes#24326
# Dependencies
No extra dependencies required for this fix.
# Feedback
Any feedback and advice is gladly welcomed. Please feel free to let us
know what we can change or improve upon regarding this issue.
---------
Co-authored-by: Mason Daugherty <mason@langchain.dev>
Co-authored-by: Mason Daugherty <github@mdrxy.com>
* for run count + thread count overflow we should warn model not to call
again
* don't tally mocked tool calls in thread limit -- consider the
following
* run limit is 1
* thread limit is 3
* first run calls the tool 2 times, 1 executes, 1 is blocked
* we should only count the successful execution above towards the total
thread count
* raise more helpful warnings on invalid config
* improving typing (covariance)
* adding in support for continuing w/ tool calls not yet at threshold,
switching default to continue
* moving all logic into after model
```py
ExitBehavior = Literal["continue", "error", "end"]
"""How to handle execution when tool call limits are exceeded.
- `"continue"`: Block exceeded tools with error messages, let other tools continue (default)
- `"error"`: Raise a `ToolCallLimitExceededError` exception
- `"end"`: Stop execution immediately, injecting a ToolMessage and an AI message
for the single tool call that exceeded the limit. Raises `NotImplementedError`
if there are multiple tool calls
"""
```
To fix nondeterministic results causing integration testing to sometimes
fail
Also speeds up from 10s to 0.5
---------
Co-authored-by: ccurme <chester.curme@gmail.com>
