PR #35788 added 7 new fields to the `langchain-profiles` CLI output
(`name`, `status`, `release_date`, `last_updated`, `open_weights`,
`attachment`, `temperature`) but didn't update `ModelProfile` in
`langchain-core`. Partner packages like `langchain-aws` that set
`extra="forbid"` on their Pydantic models hit `extra_forbidden`
validation errors when Pydantic encountered undeclared TypedDict keys at
construction time. This adds the missing fields, makes `ModelProfile`
forward-compatible, provides a base-class hook so partners can stop
duplicating model-profile validator boilerplate, migrates all in-repo
partners to the new hook, and adds runtime + CI-time warnings for schema
drift.
## Changes
### `langchain-core`
- Add `__pydantic_config__ = ConfigDict(extra="allow")` to
`ModelProfile` so unknown profile keys pass Pydantic validation even on
models with `extra="forbid"` — forward-compatibility for when the CLI
schema evolves ahead of core
- Declare the 7 missing fields on `ModelProfile`: `name`, `status`,
`release_date`, `last_updated`, `open_weights` (metadata) and
`attachment`, `temperature` (capabilities)
- Add `_warn_unknown_profile_keys()` in `model_profile.py` — emits a
`UserWarning` when a profile dict contains keys not in `ModelProfile`,
suggesting a core upgrade. Wrapped in a bare `except` so introspection
failures never crash model construction
- Add `BaseChatModel._resolve_model_profile()` hook that returns `None`
by default. Partners can override this single method instead of
redefining the full `_set_model_profile` validator — the base validator
calls it automatically
- Add `BaseChatModel._check_profile_keys` as a separate
`model_validator` that calls `_warn_unknown_profile_keys`. Uses a
distinct method name so partner overrides of `_set_model_profile` don't
inadvertently suppress the check
### `langchain-profiles` CLI
- Add `_warn_undeclared_profile_keys()` to the CLI (`cli.py`), called
after merging augmentations in `refresh()` — warns at profile-generation
time (not just runtime) when emitted keys aren't declared in
`ModelProfile`. Gracefully skips if `langchain-core` isn't installed
- Add guard test
`test_model_data_to_profile_keys_subset_of_model_profile` in
model-profiles — feeds a fully-populated model dict to
`_model_data_to_profile()` and asserts every emitted key exists in
`ModelProfile.__annotations__`. CI fails before any release if someone
adds a CLI field without updating the TypedDict
### Partner packages
- Migrate all 10 in-repo partners to the `_resolve_model_profile()`
hook, replacing duplicated `@model_validator` / `_set_model_profile`
overrides: anthropic, deepseek, fireworks, groq, huggingface, mistralai,
openai (base + azure), openrouter, perplexity, xai
- Anthropic retains custom logic (context-1m beta → `max_input_tokens`
override); all others reduce to a one-liner
- Add `pr_lint.yml` scope for the new `model-profiles` package
Fixes missing `run.metadata.usage_metadata` population in
`LangChainTracer` for real LLM/chat traces following #34414
- Fix extraction to read usage from serialized tracer message shape:
`outputs.generations[*][*].message.kwargs.usage_metadata`
- Remove non-serialized direct message shape handling
(`message.usage_metadata`) from extractor to match real tracer output
path
- Clarify tracer docstrings around chat callback naming
(`on_chat_model_start` + shared `on_llm_end`) to reduce ambiguity
## Why
#34414 introduced usage duplication into `run.metadata.usage_metadata`,
but the extractor read `message.usage_metadata`.
In real tracer flow, messages are serialized with `dumpd(...)` during
run completion, so usage metadata lives under
`message.kwargs.usage_metadata`. Because of this mismatch, duplication
did not trigger in real traces.
Defer `langsmith` and tracer imports in `callbacks/manager.py` and
`runnables/config.py` from module-level to function-level.
These imports pull in the full `langsmith` package (~132ms) at import
time but are only used inside `_configure()`, `trace_as_chain_group()`,
`_set_config_context()`, and `set_config_context()` — none of which run
during module initialization.
## Summary
- Replace `claude-3-5-haiku-20241022` and `claude-3-7-sonnet-20250219`
with `claude-haiku-4-5-20251001` and `claude-sonnet-4-5-20250929`
respectively
- Both models were retired by Anthropic on February 19, 2026, causing
all anthropic integration tests to fail
- Updates integration tests, a unit test, and docstring examples in
`langchain-core`
See:
https://platform.claude.com/docs/en/docs/resources/model-deprecations
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.*
## Summary
- The inline comment at `langchain_core/prompts/string.py:67-69`
incorrectly states that `SandboxedEnvironment` "blocks ALL
attribute/method access" and that "only simple variable lookups like
`{{variable}}` are allowed."
- In reality, Jinja2's `SandboxedEnvironment` only blocks access to
dunder attributes (`__class__`, `__globals__`, etc.) to prevent sandbox
escapes. Regular attribute access like `{{obj.content}}` and method
calls remain allowed.
- This misleading comment was left behind when a
`_RestrictedSandboxedEnvironment` class was reverted in commit
395c8d0bd4. Updated to accurately describe the actual behavior.
## Why this matters
The comment could mislead developers into trusting partially-untrusted
templates, believing attribute access is blocked when it is not. The
function's docstring already correctly warns against untrusted
templates.
## Test plan
- [ ] No behavioral change — comment-only fix
- [ ] Verified `SandboxedEnvironment` behavior matches updated comment
> This PR was authored with the help of AI tools.
## Description
Fixes#35046
Two minor cleanups in `langchain-core`:
1. **Fix docstring mismatch in `mustache.render()`**: The docstring
incorrectly documented `partials_path` and `partials_ext` parameters
that do not exist in the function signature. These were likely carried
over from the original
[chevron](https://github.com/noahmorrison/chevron) library but were
never part of this adapted implementation.
2. **Remove redundant logic in `Blob.from_path()`**: The expression
`mimetypes.guess_type(path)[0] if guess_type else None` had a redundant
`if guess_type` ternary since the outer condition `if mime_type is None
and guess_type:` already guarantees `guess_type` is `True` at that
point. Simplified to just `mimetypes.guess_type(path)[0]`.
## AI Disclaimer
An AI coding assistant was used to help identify and implement these
changes.
## 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.
