fix: strip constructor-set sampling fields at invoke time

`UiPathChatAnthropicBedrock(model="anthropic.claude-opus-4-7", temperature=0.7)`
previously leaked the disabled field into the request body because langchain-
anthropic and langchain-aws build payloads from `self.<field>`, bypassing the
existing kwargs-level `strip_disabled_kwargs`. The gateway then rejected the
call with 400 (modelDetails.shouldSkipTemperature: true for reasoning models).

Adds `disabled_fields_stripped` context manager in core sampling utils — a
sibling of `strip_disabled_kwargs` that temporarily nulls matching instance
attributes for the duration of the underlying call and restores them on exit.
Wired into the four `_generate`/`_agenerate`/`_stream`/`_astream` wrappers in
`UiPathBaseChatModel`, so caller-visible state (`chat.temperature`) is
unchanged but the vendor SDK reads `None` while building the request.

Plugs the init-time leak called out as a known follow-up in 1.10.0.

Tests:
- 7 new unit tests pin down the during-call/after-call semantics, exception
  restoration, value-list spec handling, and warning logging.
- 2 new VCR-cassetted integration tests against `anthropic.claude-opus-4-7`
  exercise both vendor SDK families (anthropic-bedrock + bedrock-converse).
  The recorded 200 is itself proof of the fix — `before_record_response`
  drops 4xx, so a pre-fix run would have refused to persist the cassette.

Core 1.11.0 -> 1.11.2 (new helper exposed)
Langchain 1.11.1 -> 1.11.2 (wiring + dep floor bump)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: cosminacho

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 All notable changes to `uipath_llm_client` (core package) will be documented in this file.
 
+## [1.11.3] - 2026-05-21
+
+### Added
+- `uipath.llm_client.utils.sampling.disabled_fields_stripped`: a context manager that temporarily nulls instance attributes matching `disabled_params` for the duration of the block, then restores them on exit. Sibling of `strip_disabled_kwargs` for the case where vendor SDKs (langchain-anthropic, langchain-aws) read `self.<field>` rather than per-call `**kwargs` when building request bodies.
+
 ## [1.11.2] - 2026-05-18
 
 ### Changed

packages/uipath_langchain_client/CHANGELOG.md

@@ -2,6 +2,14 @@
 
 All notable changes to `uipath_langchain_client` will be documented in this file.
 
+## [1.11.3] - 2026-05-21
+
+### Fixed
+- `UiPathBaseChatModel` now wraps `_uipath_generate`/`_uipath_agenerate`/`_uipath_stream`/`_uipath_astream` in `disabled_fields_stripped`, so constructor-set sampling fields (e.g. `UiPathChatAnthropicBedrock(model="anthropic.claude-opus-4-7", temperature=0.7)`) are nulled on the instance for the duration of the underlying call and restored on exit. Plugs the init-time leak called out as a known follow-up in 1.10.0 — langchain-anthropic and langchain-aws's Bedrock Converse client read `self.temperature`/`self.top_p`/etc. when serializing the request body, so the existing kwargs-level strip alone wasn't enough.
+
+### Changed
+- Bumped `uipath-llm-client` floor to `>=1.11.3` to match the core release exposing `disabled_fields_stripped`.
+
 ## [1.11.2] - 2026-05-18
 
 ### Changed

packages/uipath_langchain_client/pyproject.toml

@@ -6,7 +6,7 @@ readme = "README.md"
 requires-python = ">=3.11"
 dependencies = [
     "langchain>=1.2.15,<2.0.0",
-    "uipath-llm-client>=1.11.2,<2.0.0",
+    "uipath-llm-client>=1.11.3,<2.0.0",
 ]
 
 [project.optional-dependencies]

packages/uipath_langchain_client/src/uipath_langchain_client/__version__.py

@@ -1,3 +1,3 @@
 __title__ = "UiPath LangChain Client"
 __description__ = "A Python client for interacting with UiPath's LLM services via LangChain."
-__version__ = "1.11.2"
+__version__ = "1.11.3"

packages/uipath_langchain_client/src/uipath_langchain_client/base_client.py

@@ -50,6 +50,7 @@
     set_captured_response_headers,
 )
 from uipath.llm_client.utils.sampling import (
+    disabled_fields_stripped,
     disabled_params_from_model_details,
     strip_disabled_kwargs,
 )
@@ -422,7 +423,15 @@ def _generate(
         )
         set_captured_response_headers({})
         try:
-            result = self._uipath_generate(messages, stop=stop, run_manager=run_manager, **kwargs)
+            with disabled_fields_stripped(
+                self,
+                disabled_params=self.disabled_params,
+                model_name=self.model_name,
+                logger=self.logger,
+            ):
+                result = self._uipath_generate(
+                    messages, stop=stop, run_manager=run_manager, **kwargs
+                )
             self._inject_gateway_headers(result.generations)
             return result
         finally:
@@ -453,9 +462,15 @@ async def _agenerate(
         )
         set_captured_response_headers({})
         try:
-            result = await self._uipath_agenerate(
-                messages, stop=stop, run_manager=run_manager, **kwargs
-            )
+            with disabled_fields_stripped(
+                self,
+                disabled_params=self.disabled_params,
+                model_name=self.model_name,
+                logger=self.logger,
+            ):
+                result = await self._uipath_agenerate(
+                    messages, stop=stop, run_manager=run_manager, **kwargs
+                )
             self._inject_gateway_headers(result.generations)
             return result
         finally:
@@ -486,14 +501,20 @@ def _stream(
         )
         set_captured_response_headers({})
         try:
-            first = True
-            for chunk in self._uipath_stream(
-                messages, stop=stop, run_manager=run_manager, **kwargs
+            with disabled_fields_stripped(
+                self,
+                disabled_params=self.disabled_params,
+                model_name=self.model_name,
+                logger=self.logger,
             ):
-                if first:
-                    self._inject_gateway_headers([chunk])
-                    first = False
-                yield chunk
+                first = True
+                for chunk in self._uipath_stream(
+                    messages, stop=stop, run_manager=run_manager, **kwargs
+                ):
+                    if first:
+                        self._inject_gateway_headers([chunk])
+                        first = False
+                    yield chunk
         finally:
             set_captured_response_headers({})
 
@@ -522,14 +543,20 @@ async def _astream(
         )
         set_captured_response_headers({})
         try:
-            first = True
-            async for chunk in self._uipath_astream(
-                messages, stop=stop, run_manager=run_manager, **kwargs
+            with disabled_fields_stripped(
+                self,
+                disabled_params=self.disabled_params,
+                model_name=self.model_name,
+                logger=self.logger,
             ):
-                if first:
-                    self._inject_gateway_headers([chunk])
-                    first = False
-                yield chunk
+                first = True
+                async for chunk in self._uipath_astream(
+                    messages, stop=stop, run_manager=run_manager, **kwargs
+                ):
+                    if first:
+                        self._inject_gateway_headers([chunk])
+                        first = False
+                    yield chunk
         finally:
             set_captured_response_headers({})
 

src/uipath/llm_client/__version__.py

@@ -1,3 +1,3 @@
 __title__ = "UiPath LLM Client"
 __description__ = "A Python client for interacting with UiPath's LLM services."
-__version__ = "1.11.2"
+__version__ = "1.11.3"

src/uipath/llm_client/utils/sampling.py

@@ -16,7 +16,8 @@
 ``anthropic.claude-opus-4-7``), the entire sampling set gets disabled.
 """
 
-from collections.abc import Mapping
+from collections.abc import Iterator, Mapping
+from contextlib import contextmanager
 from logging import Logger
 from typing import Any
 
@@ -94,3 +95,53 @@ def strip_disabled_kwargs(
                 )
             out.pop(key, None)
     return out
+
+
+@contextmanager
+def disabled_fields_stripped(
+    instance: Any,
+    *,
+    disabled_params: Mapping[str, Any] | None,
+    model_name: str,
+    logger: Logger | None,
+) -> Iterator[None]:
+    """Temporarily wipe matching instance attributes for the duration of the block.
+
+    Sibling of :func:`strip_disabled_kwargs` for fields set at construction time.
+    Vendor SDKs that build request bodies from ``self.<field>`` (e.g. langchain-
+    anthropic's ``ChatAnthropic``, langchain-aws's ``ChatBedrockConverse``) bypass
+    the kwargs-level strip; wrapping the underlying ``_generate`` call in this
+    context manager forces them to read ``None`` for any disabled field, then
+    restores the original value on exit so caller-visible state is unchanged.
+
+    Matching rule mirrors ``strip_disabled_kwargs``: a field is nulled out when
+    its name is in ``disabled_params`` AND its current value is non-None AND
+    ``is_disabled_value`` matches the spec.
+    """
+    if not disabled_params:
+        yield
+        return
+    saved: dict[str, Any] = {}
+    try:
+        for key, spec in disabled_params.items():
+            if not hasattr(instance, key):
+                continue
+            current = getattr(instance, key)
+            if current is None:
+                continue
+            if is_disabled_value(current, spec):
+                saved[key] = current
+                if logger is not None:
+                    logger.warning(
+                        "Stripping disabled field %r for model %r",
+                        key,
+                        model_name,
+                    )
+                # object.__setattr__ bypasses pydantic field validation so we can
+                # always restore the original — even if the field's declared type
+                # rejects None.
+                object.__setattr__(instance, key, None)
+        yield
+    finally:
+        for key, value in saved.items():
+            object.__setattr__(instance, key, value)