# 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>
Changes Created
I have fixed the issue where a generic and misleading error message was
displayed when a JSON schema was missing the top-level
title
key.
[Fix: Improve error message for missing title in JSON schema
functions](https://github.com/Bhavesh007Sharma/langchain/tree/fix-json-schema-title-error)
File Modified:
libs/core/langchain_core/utils/function_calling.py
I updated the
convert_to_openai_function
validation logic to specifically check for
dict
inputs that look like schemas (
type
or
properties
keys present) but are missing the
title
key.
# Before (Generic Error)
raise ValueError(
f"Unsupported function\n\n{function}\n\nFunctions must be passed in"
" as Dict, pydantic.BaseModel, or Callable. If they're a dict they must"
" either be in OpenAI function format or valid JSON schema with
top-level"
" 'title' and 'description' keys."
)
# After (Specific Error)
if isinstance(function, dict) and ("type" in function or "properties" in
function):
msg = (
"Unsupported function\n\nTo use a JSON schema as a function, "
"it must have a top-level 'title' key to be used as the function name."
)
raise ValueError(msg)
Verification Results
Automated Tests
I created a reproduction script
reproduce_issue.py
to confirm the behavior.
Before Fix: The script would have raised the generic "Unsupported
function" error claiming description was also required.
After Fix: The script now confirms that the new, specific error message
is raised when
title
is missing.
(Note: Verification was performed by inspecting the code logic and
running a lightweight reproduction script locally, as full suite
verification had environment dependency issues.)
---------
Co-authored-by: Mason Daugherty <github@mdrxy.com>
This PR fixes a signature mismatch between BaseStore and its concrete
implementations by making the `prefix` parameter keyword-only in
`yield_keys` and `ayield_keys`.
This aligns the implementations with the BaseStore interface contract,
prevents Liskov Substitution Principle violations, and ensures
consistent
method signatures across store backends.
Fixes#32637
Breaking changes
None. This change only enforces the existing abstract interface and does
not modify runtime behavior
Testing
- Verified that existing test suites pass after the signature fix.
Parts of this contribution were assisted by generative AI for
code navigation and drafting. All final design decisions and changes
were
reviewed and validated manually.
---------
Co-authored-by: Khagesh-Anayasmi <khagesh.desai@anayasmi.in>
Co-authored-by: Mason Daugherty <mason@langchain.dev>
Regression introduced in 8e3c6b109f
The commit changed the return annotation of `with_structured_output`
from `typing.Dict | BaseModel` to `builtins.dict[str, Any] | BaseModel`.
Since `BaseModel` refers to `pydantic.BaseModel (v2)`, but the test
`test_structured_output_pydantic_2_v1` uses `pydantic.v1.BaseModel`,
mypy's `warn_unreachable` setting flags the `isinstance` checks as
unreachable (since a class can't be both a `dict` and a different
`BaseModel` type).
Switching to `builtins.dict[str, Any]` made the type more precise, which
exposed this type incompatibility that was always latent but hidden by
the looser `typing.Dict` annotation.
* Making `FakeToolCallingModel` generic on its `structured_response`
doesn't help anywhere in typing.
* There are more than 120 references of `FakeToolCallingModel` in the
code where you get ` error: Need type annotation for "model"
[var-annotated]` because mypy can't resolve the generic type (we don't
see them atm because they are in files temporarily excluded from mypy
checking). We would need to explicitly type them to
`FakeToolCallingModel[Any]`
Co-authored-by: Mason Daugherty <mason@langchain.dev>
Appears `override()`'s docstring in `langgraph` already shows
`state=new_state` as a valid usage pattern
Works since `dataclasses.replace()` accepts any field, but the
`TypedDicts` weren't updated to match. Caused mypy to flag legitimate
usage as an error.
description by @mdrxy
- Enable `test_responses_spec.py` integration tests that were previously
skipped at module level
- Widen `ToolStrategy.schema` type annotation from `type[SchemaT]` to
`type[SchemaT] | dict[str, Any]` to match actual supported usage (JSON
schema dicts were already handled at runtime)
- Fix type annotations and linting issues in test file (modernize to
`dict`/`list`, add return types, prefix unused `_request` param)
- Improve generic typing in `load_spec` utility with bounded `TypeVar`
Co-authored-by: Mason Daugherty <mason@langchain.dev>
# feat(core): add more file extensions to ignore in HTML link extraction
## Description
This PR enhances the HTML link extraction utility in
`libs/core/langchain_core/utils/html.py` by expanding the
`SUFFIXES_TO_IGNORE` list to include additional common binary file
extensions:
- `.webp`
- `.pdf`
- `.docx`
- `.xlsx`
- `.pptx`
- `.pptm`
These file types are non-HTML, non-crawlable resources. Ignoring them
prevents `find_all_links` and `extract_sub_links` from mistakenly
treating such binary assets as navigable links. This improves link
filtering, reduces unnecessary crawling, and aligns behavior with
typical web scraping expectations.
## Summary of Changes
- **Updated** `libs/core/langchain_core/utils/html.py`: Added `.webp`,
`.pdf`, `.docx`, `.xlsx`, `.pptx`, `.pptm` to `SUFFIXES_TO_IGNORE`.
## Related Issues
N/A
## Verification
- `ruff check libs/core/langchain_core/utils/html.py`: **Passed**
- `mypy libs/core/langchain_core/utils/html.py`: **Passed**
- `pytest libs/core/tests/unit_tests/utils/test_html.py`: **Passed** (11
tests)
---------
Co-authored-by: Mason Daugherty <mason@langchain.dev>
# refactor(core): improve docstrings for HTML link extraction utilities
## Description
This PR updates and clarifies the docstrings for `find_all_links` and
`extract_sub_links` in
`libs/core/langchain_core/utils/html.py`.
The previous return-value descriptions were vague (e.g., "all links",
"sub links"). They have now been revised to clearly describe the
behavior and output of each function:
- **find_all_links** → “A list of all links found in the HTML.”
- **extract_sub_links** → “A list of absolute paths to sub links.”
These improvements make the utilities more understandable and
developer-friendly without altering functionality.
## Verification
- `ruff check libs/core/langchain_core/utils/html.py`: **Passed**
- `pytest libs/core/tests/unit_tests/utils/test_html.py`: **Passed**
## Checklists
- PR title follows the required format: `TYPE(SCOPE): DESCRIPTION`
- Changes are limited to the `langchain-core` package
- `make format`, `make lint`, and `make test` pass
Fixes#34282
**Before:** When using agents with tools (like file reading, web search,
etc.), the conversation looks like this:
```
[User] "Read these 10 files and summarize them"
[AI] "I'll read all 10 files" + [tool_call: read_file x 10]
[Tool] "Contents of file1.txt..."
[Tool] "Contents of file2.txt..."
[Tool] "Contents of file3.txt..."
... (7 more tool responses)
```
When the conversation gets too long, `SummarizationMiddleware` kicks in
to compress older messages. The problem was:
If you asked to keep the last 6 messages, you'd get:
```
[Summary] "Here's what happened before..."
[Tool] "Contents of file5.txt..."
[Tool] "Contents of file6.txt..."
[Tool] "Contents of file7.txt..."
[Tool] "Contents of file8.txt..."
[Tool] "Contents of file9.txt..."
[Tool] "Contents of file10.txt..."
```
The AI's original request to read the files (`[AI]` message with
`tool_calls`) was summarized away, but the tool responses remained. This
caused the error:
```
Error code: 400 - "No tool call found for function call output with call_id..."
```
Many APIs require that every tool response has a matching tool request.
Without the AI message, the tool responses are "orphaned."
## The fix
Now when the cutoff lands on tool messages, we **move backward** to
include the AI message that requested those tools:
Same scenario, keeping last 6 messages:
```
[Summary] "Here's what happened before..."
[AI] "I'll read all 10 files" + [tool_call: read_file x 10]
[Tool] "Contents of file1.txt..."
[Tool] "Contents of file2.txt..."
... (all 10 tool responses)
```
The AI message is preserved along with its tool responses, keeping them
paired together.
## Practical examples
### Example 1: Parallel tool calls
**Scenario:** Agent reads 10 files in parallel, summarization triggers
(see above)
### Example 2: Mixed conversation
**Scenario:** User asks question, AI uses tools, user says thanks
```
[User] "What's the weather?"
[AI] "Let me check" + [tool_call: get_weather]
[Tool] "72F and sunny"
[AI] "It's 72F and sunny!"
[User] "Thanks!"
```
Keeping last 2 messages:
| Before (Bug) | After (Fix) |
|--------------|-------------|
| Only `[User] "Thanks!"` kept | `[AI] + [Tool] + [AI] + [User]` all
kept |
| Lost the weather info | Tool pair preserved with response |
### Example 3: Multiple tool sequences
```
[User] "Search for X"
[AI] [tool_call: search]
[Tool] "Results for X"
[User] "Now search for Y"
[AI] [tool_call: search]
[Tool] "Results for Y"
[User] "Great!"
```
**Keeping last 3 messages:** If cutoff lands on `[Tool] "Results for
Y"`, we now include `[AI] [tool_call: search]` to keep the pair
together.
Add unit coverage for chat model provider inference across common model
name prefixes. This improves regression protection without touching
runtime
---------
Co-authored-by: Mason Daugherty <github@mdrxy.com>
Fixes a bug introduced with commit 85f1ba2 (released in `langchain ==
1.2.1`).
Whenever the index embedding of the langgraph-server is configured with
`azure_openai` provider, the wrong class is going to be initialized (and
fails to do so if the now unexpected credentials in environment variable
`OPENAI_API_KEY` is not provided).
Example configuration file `langgraph.json` that will reproduce the
issue:
(see
https://docs.langchain.com/langsmith/cli#adding-semantic-search-to-the-store)
```json
{
"dependencies": ["."],
"graphs": {
"chat": "src/agents/chat/graph.py:graph",
},
"store": {
"index": {
"embed": "azure_openai:text-embedding-3-small",
"dims": 1536
}
},
"python_version": "3.13",
"image_distro": "wolfi"
}
```
