Fix several docstring inaccuracies in langchain-core and update outdated
LangSmith URLs across three README files.
**Docstring fixes (libs/core):**
- `tap_output_iter`: docstring says "async iterator" but method accepts
sync `Iterator`
- `agenerate_from_stream`: docstring says "Iterator" but method accepts
`AsyncIterator`
- `BaseLLM.OutputType`: docstring says "input type" but property returns
output type
- Grammar: "or deprecated" → "or be deprecated", "relies" → "rely",
"whose the" → "whose"
**URL fixes (libs/core, libs/langchain, libs/langchain_v1):**
- Updated `smith.langchain.com` → `www.langchain.com/langsmith` (root
README already uses the correct URL)
Verified with `make lint` and `make format` in libs/core — no new issues
introduced. Changes are docs-only with no code logic impact.
*This PR was created with assistance from an AI coding tool.*
## Description
This PR replaces a bare `except:` clause with `except Exception:` in
`libs/core/langchain_core/tracers/core.py`.
The previous implementation caught `BaseException`, which includes
`SystemExit` and `KeyboardInterrupt`. This meant that if a user tried to
interrupt the program (Ctrl+C) during a traceback formatting error, the
signal would be suppressed, potentially making the process un-killable.
This change ensures that standard runtime errors are still caught and
logged, but system control signals are allowed to propagate correctly.
## Verification
- Verified via code inspection.
- This is a standard safety fix for exception handling patterns in
Python to avoid suppressing system exit signals.
it looks scary but i promise it is not
improving documentation consistency across core. primarily update
docstrings and comments for better formatting, readability, and
accuracy, as well as add minor clarifications and formatting
improvements to user-facing documentation.
# Add `tool_call_id` to `on_tool_error` event data
## Summary
This PR addresses issue #33597 by adding `tool_call_id` to the
`on_tool_error` callback event data. This enables users to link tool
errors to specific tool calls in stateless agent implementations, which
is essential for building OpenAI-compatible APIs and tracking tool
execution flows.
## Problem
When streaming events using `astream_events` with `version="v2"`, the
`on_tool_error` event only included the error and input data, but lacked
the `tool_call_id`. This made it difficult to:
- Link errors to specific tool calls in stateless agent scenarios
- Implement OpenAI-compatible APIs that require tool call tracking
- Track tool execution flows when using `run_id` is not sufficient
## Solution
The fix adds `tool_call_id` propagation through the callback chain:
1. **Pass `tool_call_id` to callbacks**: Updated `BaseTool.run()` and
`BaseTool.arun()` to pass `tool_call_id` to both `on_tool_start` and
`on_tool_error` callbacks
2. **Store in event stream handler**: Modified
`_AstreamEventsCallbackHandler` to store `tool_call_id` in run info
during `on_tool_start`
3. **Include in error events**: Updated `on_tool_error` handler to
extract and include `tool_call_id` in the event data
## Changes
- **`libs/core/langchain_core/tools/base.py`**:
- Pass `tool_call_id` to `on_tool_start` in both sync and async methods
- Pass `tool_call_id` to `on_tool_error` when errors occur
- **`libs/core/langchain_core/tracers/event_stream.py`**:
- Store `tool_call_id` in run info during `on_tool_start`
- Extract `tool_call_id` from kwargs or run info in `on_tool_error`
- Include `tool_call_id` in the `on_tool_error` event data
## Testing
The fix was verified by:
1. Direct tool invocation: Confirmed `tool_call_id` appears in
`on_tool_error` event data when calling tools directly
2. Agent integration: Tested with `create_agent` to ensure
`tool_call_id` is present in error events during agent execution
```python
# Example verification
async for event in agent.astream_events(
{"messages": "Please demonstrate a tool error"},
version="v2",
):
if event["event"] == "on_tool_error":
assert "tool_call_id" in event["data"] # ✓ Now passes
print(event["data"]["tool_call_id"])
```
## Backward Compatibility
- ✅ Fully backward compatible: `tool_call_id` is optional (can be
`None`)
- ✅ No breaking changes: All changes are additive
- ✅ Existing code continues to work without modification
## Related Issues
Fixes#33597
---------
Co-authored-by: Mason Daugherty <github@mdrxy.com>
* FIxed where possible
* Used `cast` when not possible to fix
---------
Co-authored-by: Mason Daugherty <github@mdrxy.com>
Co-authored-by: Mason Daugherty <mason@langchain.dev>
* Fixed a few TC
* Added a few Pydantic classes to
`flake8-type-checking.runtime-evaluated-base-classes` (not as much as I
would have imagined)
* Added a few `noqa: TC`
* Activated TC rules
Adds automatic tool call counting to tracing by means of a new
`store_tool_call_count_in_run()`, which calls on newly added
`count_tool_calls_in_run()`.
Runs on successful LLM completion. Does not run on errored runs.
Adds `usage_metadata` (token counts, etc.) to the run metadata in
`LangChainTracer`.
When an LLM run ends, usage metadata is extracted from all generations
and aggregated using the existing `add_usage` helper, then stored in
`run.extra["metadata"]["usage_metadata"]`.
The original data in outputs remains unchanged.
Also, see #34415
---------
Co-authored-by: Mason Daugherty <github@mdrxy.com>
Co-authored-by: Mason Daugherty <mason@langchain.dev>
ref https://github.com/langchain-ai/langchainjs/pull/9665
Fixes trace persistence for iterator/generator inputs (like
`RunnableGenerator`) where the full input isn't available at chain
start. Instead of POSTing a run with incomplete inputs on start and
PATCHing later, this defers the POST until chain end when inputs are
fully realized.
---------
Co-authored-by: Mason Daugherty <github@mdrxy.com>
* Fix detection of support of context in `asyncio.create_task`
* Fix: in Python 3.14 `asyncio.get_event_loop()` raises an exception if
there's no running loop
* Bump pydantic to version 2.12
* Skips tests with pydantic v1 models as they are not supported with
Python 3.14
* Run core tests with Python 3.14 in CI.
---------
Co-authored-by: Mason Daugherty <mason@langchain.dev>
Co-authored-by: Sydney Runkle <54324534+sydney-runkle@users.noreply.github.com>
Largely:
- Remove explicit `"Default is x"` since new refs show default inferred
from sig
- Inline code (useful for eventual parsing)
- Fix code block rendering (indentations)
Removed:
- `libs/core/langchain_core/chat_history.py`: `add_user_message` and
`add_ai_message` in favor of `add_messages` and `aadd_messages`
- `libs/core/langchain_core/language_models/base.py`: `predict`,
`predict_messages`, and async versions in favor of `invoke`. removed
`_all_required_field_names` since it was a wrapper on
`get_pydantic_field_names`
- `libs/core/langchain_core/language_models/chat_models.py`:
`callback_manager` param in favor of `callbacks`. `__call__` and
`call_as_llm` method in favor of `invoke`
- `libs/core/langchain_core/language_models/llms.py`: `callback_manager`
param in favor of `callbacks`. `__call__`, `predict`, `apredict`, and
`apredict_messages` methods in favor of `invoke`
- `libs/core/langchain_core/prompts/chat.py`: `from_role_strings` and
`from_strings` in favor of `from_messages`
- `libs/core/langchain_core/prompts/pipeline.py`: removed
`PipelinePromptTemplate`
- `libs/core/langchain_core/prompts/prompt.py`: `input_variables` param
on `from_file` as it wasn't used
- `libs/core/langchain_core/tools/base.py`: `callback_manager` param in
favor of `callbacks`
- `libs/core/langchain_core/tracers/context.py`: `tracing_enabled` in
favor of `tracing_enabled_v2`
- `libs/core/langchain_core/tracers/langchain_v1.py`: entire module
- `libs/core/langchain_core/utils/loading.py`: entire module,
`try_load_from_hub`
- `libs/core/langchain_core/vectorstores/in_memory.py`: `upsert` in
favor of `add_documents`
- `libs/standard-tests/langchain_tests/integration_tests/chat_models.py`
and `libs/standard-tests/langchain_tests/unit_tests/chat_models.py`:
`tool_choice_value` as models should accept `tool_choice="any"`
- `langchain` will consequently no longer expose these items if it was
previously
---------
Co-authored-by: Mohammad Mohtashim <45242107+keenborder786@users.noreply.github.com>
Co-authored-by: Caspar Broekhuizen <caspar@langchain.dev>
Co-authored-by: ccurme <chester.curme@gmail.com>
Co-authored-by: Christophe Bornet <cbornet@hotmail.com>
Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>
Co-authored-by: Sadra Barikbin <sadraqazvin1@yahoo.com>
Co-authored-by: Vadym Barda <vadim.barda@gmail.com>
**TL;DR much of the provided `Makefile` targets were broken, and any
time I wanted to preview changes locally I either had to refer to a
command Chester gave me or try waiting on a Vercel preview deployment.
With this PR, everything should behave like normal.**
Significant updates to the `Makefile` and documentation files, focusing
on improving usability, adding clear messaging, and fixing/enhancing
documentation workflows.
### Updates to `Makefile`:
#### Enhanced build and cleaning processes:
- Added informative messages (e.g., "📚 Building LangChain
documentation...") to makefile targets like `docs_build`, `docs_clean`,
and `api_docs_build` for better user feedback during execution.
- Introduced a `clean-cache` target to the `docs` `Makefile` to clear
cached dependencies and ensure clean builds.
#### Improved dependency handling:
- Modified `install-py-deps` to create a `.venv/deps_installed` marker,
preventing redundant/duplicate dependency installations and improving
efficiency.
#### Streamlined file generation and infrastructure setup:
- Added caching for the LangServe README download and parallelized
feature table generation
- Added user-friendly completion messages for targets like `copy-infra`
and `render`.
#### Documentation server updates:
- Enhanced the `start` target with messages indicating server start and
URL for local documentation viewing.
---
### Documentation Improvements:
#### Content clarity and consistency:
- Standardized section titles for consistency across documentation
files.
[[1]](diffhunk://#diff-9b1a85ea8a9dcf79f58246c88692cd7a36316665d7e05a69141cfdc50794c82aL1-R1)
[[2]](diffhunk://#diff-944008ad3a79d8a312183618401fcfa71da0e69c75803eff09b779fc8e03183dL1-R1)
- Refined phrasing and formatting in sections like "Dependency
management" and "Formatting and linting" for better readability.
[[1]](diffhunk://#diff-2069d4f956ab606ae6d51b191439283798adaf3a6648542c409d258131617059L6-R6)
[[2]](diffhunk://#diff-2069d4f956ab606ae6d51b191439283798adaf3a6648542c409d258131617059L84-R82)
#### Enhanced workflows:
- Updated instructions for building and viewing documentation locally,
including tips for specifying server ports and handling API reference
previews.
[[1]](diffhunk://#diff-048deddcfd44b242e5b23aed9f2e9ec73afc672244ce14df2a0a316d95840c87L60-R94)
[[2]](diffhunk://#diff-048deddcfd44b242e5b23aed9f2e9ec73afc672244ce14df2a0a316d95840c87L82-R126)
- Expanded guidance on cleaning documentation artifacts and using
linting tools effectively.
[[1]](diffhunk://#diff-048deddcfd44b242e5b23aed9f2e9ec73afc672244ce14df2a0a316d95840c87L82-R126)
[[2]](diffhunk://#diff-048deddcfd44b242e5b23aed9f2e9ec73afc672244ce14df2a0a316d95840c87L107-R142)
#### API reference documentation:
- Improved instructions for generating and formatting in-code
documentation, highlighting best practices for docstring writing.
[[1]](diffhunk://#diff-048deddcfd44b242e5b23aed9f2e9ec73afc672244ce14df2a0a316d95840c87L107-R142)
[[2]](diffhunk://#diff-048deddcfd44b242e5b23aed9f2e9ec73afc672244ce14df2a0a316d95840c87L144-R186)
---
### Minor Changes:
- Added support for a new package name (`langchain_v1`) in the API
documentation generation script.
- Fixed minor capitalization and formatting issues in documentation
files.
[[1]](diffhunk://#diff-2069d4f956ab606ae6d51b191439283798adaf3a6648542c409d258131617059L40-R40)
[[2]](diffhunk://#diff-2069d4f956ab606ae6d51b191439283798adaf3a6648542c409d258131617059L166-R160)
---------
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* Simplified Pydantic handling since Pydantic v1 is not supported
anymore.
* Replace use of deprecated v1 methods by corresponding v2 methods.
* Remove use of other deprecated methods.
* Activate mypy errors on deprecated methods use.
---------
Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>
