Nhan Nguyen 6affec92ce fix(core): pass tool_call_id to on_tool_start callback (#34235) ...

## Summary

When invoking a tool with a `ToolCall`, the `tool_call_id` is extracted
but was **not forwarded** to callback handlers in `on_tool_start`. This
made it impossible for callback handlers to correlate tool executions
with the original LLM tool calls.

This fix adds `tool_call_id=tool_call_id` to both:
- Sync `run()` method's `on_tool_start` call
- Async `arun()` method's `on_tool_start` call

## Changes

- **`libs/core/langchain_core/tools/base.py`**: Added `tool_call_id`
parameter to `on_tool_start` calls (2 lines)
- **`libs/core/tests/unit_tests/test_tools.py`**: Added 6 comprehensive
tests covering:
  - Sync tool invocation via `invoke()`
  - Async tool invocation via `ainvoke()`
  - `tool_call_id` is `None` when invoked without a ToolCall
  - Empty string `tool_call_id` edge case
  - Direct `run()` method
  - Direct `arun()` method

## Test plan

- [x] All 147 existing tests pass
- [x] 6 new tests added and passing
- [x] Linting passes

Fixes #34168

---

This PR was developed with AI assistance (Claude).

---------

Co-authored-by: Mason Daugherty <github@mdrxy.com>
Co-authored-by: Mason Daugherty <mason@langchain.dev>

2025-12-08 10:15:18 -05:00

..

benchmarks

feat: Use uuid7 for run ids (#34172)

2025-12-03 10:09:10 -08:00

integration_tests

core: Add ruff rules for PIE (#26939)

2024-09-27 12:08:35 -04:00

unit_tests

fix(core): pass tool_call_id to on_tool_start callback (#34235)

2025-12-08 10:15:18 -05:00

__init__.py

Separate out langchain_core package (#13577)

2023-11-20 13:09:30 -08:00