Switch to eager construction-time strip instead of invoke-time context manager

Prior approach used a context manager that temporarily nulled matching fields
for the duration of each call and restored them on exit, so `chat.temperature`
read the caller's original value between invocations. That's sneaky: the
gateway will never accept the value, so reporting 0.7 on the instance is a lie
that hides the truth from the user.

Replace `disabled_fields_stripped` (context manager) with `strip_disabled_fields`
(eager, one-shot). Wire it into `UiPathBaseLLMClient.setup_model_info` so the
strip happens once, immediately after `disabled_params` resolves. Each strip
logs a warning that includes the original value, so the caller sees exactly
what was dropped at construction time rather than being silently surprised
later. The four `_generate`/`_agenerate`/`_stream`/`_astream` wrappers are now
plain again — no context-manager wrapping, no save/restore, no exception edge
cases, no generator subtlety.

Net effect for callers:
- `UiPathChatAnthropicBedrock(model="anthropic.claude-opus-4-7", temperature=0.7)`
  now logs a warning and leaves `chat.temperature is None`.
- Per-call `chat.invoke(..., temperature=0.7)` still gets stripped by the
  existing `strip_disabled_kwargs` filter, unchanged.

Tests updated to assert the field is None after construction (not "restored
after call"). Restore-on-exception test removed (no longer applicable). VCR
cassettes still replay — the gateway request body is unchanged.

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

Author: cosminacho

CHANGELOG.md

@@ -5,7 +5,7 @@ All notable changes to `uipath_llm_client` (core package) will be documented in
 ## [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.
+- `uipath.llm_client.utils.sampling.strip_disabled_fields`: eagerly nulls instance attributes whose names appear in `disabled_params` and whose current values match `is_disabled_value`. 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. Each strip logs a warning that includes the original value so callers can see exactly what was dropped.
 
 ## [1.11.2] - 2026-05-18
 

packages/uipath_langchain_client/CHANGELOG.md

@@ -5,10 +5,10 @@ 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.
+- `UiPathBaseLLMClient.setup_model_info` now calls `strip_disabled_fields` after merging `disabled_params`, so constructor-set sampling fields (e.g. `UiPathChatAnthropicBedrock(model="anthropic.claude-opus-4-7", temperature=0.7)`) are nulled on the instance once `disabled_params` is resolved. 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. A warning is logged per stripped field with the original value so the caller can see what was dropped.
 
 ### Changed
-- Bumped `uipath-llm-client` floor to `>=1.11.3` to match the core release exposing `disabled_fields_stripped`.
+- Bumped `uipath-llm-client` floor to `>=1.11.3` to match the core release exposing `strip_disabled_fields`.
 
 ## [1.11.2] - 2026-05-18
 

packages/uipath_langchain_client/src/uipath_langchain_client/base_client.py

@@ -50,8 +50,8 @@
     set_captured_response_headers,
 )
 from uipath.llm_client.utils.sampling import (
-    disabled_fields_stripped,
     disabled_params_from_model_details,
+    strip_disabled_fields,
     strip_disabled_kwargs,
 )
 from uipath_langchain_client.settings import (
@@ -173,6 +173,13 @@ def setup_model_info(self) -> Self:
         can derive from ``model_details`` (via
         ``disabled_params_from_model_details``). User-provided keys win on
         conflicts, so callers can override a derived entry by name.
+
+        Once ``disabled_params`` is resolved, any matching instance field set at
+        construction time is nulled via ``strip_disabled_fields``. Vendor SDKs
+        that read ``self.<field>`` when serializing requests (langchain-
+        anthropic, langchain-aws) would otherwise leak disabled values past the
+        per-call ``strip_disabled_kwargs`` filter. The strip logs a warning per
+        field so the caller knows what was dropped.
         """
         if self.model_details is None:
             try:
@@ -189,6 +196,13 @@ def setup_model_info(self) -> Self:
         merged = {**derived, **user_provided}
         self.disabled_params = merged or None
 
+        strip_disabled_fields(
+            self,
+            disabled_params=self.disabled_params,
+            model_name=self.model_name,
+            logger=self.logger,
+        )
+
         return self
 
     @cached_property
@@ -423,15 +437,7 @@ def _generate(
         )
         set_captured_response_headers({})
         try:
-            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
-                )
+            result = self._uipath_generate(messages, stop=stop, run_manager=run_manager, **kwargs)
             self._inject_gateway_headers(result.generations)
             return result
         finally:
@@ -462,15 +468,9 @@ async def _agenerate(
         )
         set_captured_response_headers({})
         try:
-            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
-                )
+            result = await self._uipath_agenerate(
+                messages, stop=stop, run_manager=run_manager, **kwargs
+            )
             self._inject_gateway_headers(result.generations)
             return result
         finally:
@@ -501,20 +501,14 @@ def _stream(
         )
         set_captured_response_headers({})
         try:
-            with disabled_fields_stripped(
-                self,
-                disabled_params=self.disabled_params,
-                model_name=self.model_name,
-                logger=self.logger,
+            first = True
+            for chunk in self._uipath_stream(
+                messages, stop=stop, run_manager=run_manager, **kwargs
             ):
-                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
+                if first:
+                    self._inject_gateway_headers([chunk])
+                    first = False
+                yield chunk
         finally:
             set_captured_response_headers({})
 
@@ -543,20 +537,14 @@ async def _astream(
         )
         set_captured_response_headers({})
         try:
-            with disabled_fields_stripped(
-                self,
-                disabled_params=self.disabled_params,
-                model_name=self.model_name,
-                logger=self.logger,
+            first = True
+            async for chunk in self._uipath_astream(
+                messages, stop=stop, run_manager=run_manager, **kwargs
             ):
-                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
+                if first:
+                    self._inject_gateway_headers([chunk])
+                    first = False
+                yield chunk
         finally:
             set_captured_response_headers({})
 

src/uipath/llm_client/utils/sampling.py

@@ -16,8 +16,7 @@
 ``anthropic.claude-opus-4-7``), the entire sampling set gets disabled.
 """
 
-from collections.abc import Iterator, Mapping
-from contextlib import contextmanager
+from collections.abc import Mapping
 from logging import Logger
 from typing import Any
 
@@ -97,51 +96,42 @@ def strip_disabled_kwargs(
     return out
 
 
-@contextmanager
-def disabled_fields_stripped(
+def strip_disabled_fields(
     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.
+) -> None:
+    """Null instance attributes that match ``disabled_params``.
 
     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.
+    the kwargs-level strip; this helper neutralizes them once, eagerly, so they
+    can't leak into any subsequent request.
 
     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.
+    ``is_disabled_value`` matches the spec. Each strip logs a warning that
+    includes the original value so the caller can see exactly what was dropped.
     """
     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)
+    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):
+            if logger is not None:
+                logger.warning(
+                    "Disabling field %r (was %r) for model %r — parameter is in disabled_params",
+                    key,
+                    current,
+                    model_name,
+                )
+            # object.__setattr__ bypasses pydantic field validation in case the
+            # field's declared type forbids None.
+            object.__setattr__(instance, key, None)