fix: strip constructor-set sampling fields at construction time (#83)

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.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
 
 ### 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
+- `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 `strip_disabled_fields`.
+
 ## [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

@@ -51,6 +51,7 @@
 )
 from uipath.llm_client.utils.sampling import (
     disabled_params_from_model_details,
+    strip_disabled_fields,
     strip_disabled_kwargs,
 )
 from uipath_langchain_client.settings import (
@@ -172,6 +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:
@@ -188,6 +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

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

@@ -94,3 +94,42 @@ def strip_disabled_kwargs(
                 )
             out.pop(key, None)
     return out
+
+
+def strip_disabled_fields(
+    instance: Any,
+    *,
+    disabled_params: Mapping[str, Any] | None,
+    model_name: str,
+    logger: Logger | None,
+) -> 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; 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. Each strip logs a warning that
+    includes the original value so the caller can see exactly what was dropped.
+    """
+    if not disabled_params:
+        return
+    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,
+                )
+            setattr(instance, key, None)

tests/cassettes.db

@@ -524,6 +524,135 @@ def test_azure_autoinit_parallel_tool_calls_merges_with_our_derivation(
     assert set(llm.disabled_params) == set(DISABLED_SAMPLING_PARAMS) | {"parallel_tool_calls"}
 
 
+# --------------------------------------------------------------------------- #
+# constructor-level field stripping (the second leak)
+# --------------------------------------------------------------------------- #
+#
+# Per-call ``temperature`` lands in ``**kwargs`` and is removed by
+# ``strip_disabled_kwargs``. But ``UiPathChat(..., temperature=0.5)`` stores
+# the value on ``self.temperature``, and vendor SDKs that don't honor
+# langchain-openai's ``_filter_disabled_params`` (langchain-anthropic,
+# langchain-aws) read ``self.<field>`` when building the request body —
+# leaking the disabled value into the wire payload. ``strip_disabled_fields``
+# eagerly nulls matching fields once, inside ``setup_model_info``, so the
+# gateway never sees a value the caller already declared disabled. The strip
+# is permanent and logs a warning per field so the caller can see exactly
+# which value was dropped.
+
+
+def test_constructor_temperature_is_nulled_when_flag_set(
+    client_settings: UiPathBaseSettings,
+) -> None:
+    llm = UiPathChat(
+        model="anthropic.claude-opus-4-7",
+        settings=client_settings,
+        model_details={"shouldSkipTemperature": True},
+        temperature=0.7,
+        top_p=0.9,
+    )
+    # Eager strip: caller-supplied disabled values are nulled before any call.
+    assert llm.temperature is None
+    assert llm.top_p is None
+
+
+def test_constructor_field_strip_skipped_when_flag_absent(
+    client_settings: UiPathBaseSettings,
+) -> None:
+    llm = UiPathChat(
+        model="some-chatty-model",
+        settings=client_settings,
+        model_details={},
+        temperature=0.7,
+    )
+    # No shouldSkipTemperature => no strip.
+    assert llm.temperature == 0.7
+
+
+def test_constructor_field_strip_honors_value_list_spec(
+    client_settings: UiPathBaseSettings,
+) -> None:
+    # Spec list semantics: strip only when the current value is in the list.
+    keep = UiPathChat(
+        model="some-chatty-model",
+        settings=client_settings,
+        model_details={},
+        disabled_params={"temperature": [0.0]},
+        temperature=0.7,  # not in [0.0] -> kept
+    )
+    assert keep.temperature == 0.7
+
+    drop = UiPathChat(
+        model="some-chatty-model",
+        settings=client_settings,
+        model_details={},
+        disabled_params={"temperature": [0.0]},
+        temperature=0.0,  # in [0.0] -> stripped
+    )
+    assert drop.temperature is None
+
+
+def test_constructor_field_strip_skips_fields_already_none(
+    client_settings: UiPathBaseSettings,
+) -> None:
+    # Field not set by caller (default None) => the strip is a no-op for it,
+    # nothing weird happens to other fields. Just confirms the helper's
+    # current=None guard.
+    llm = UiPathChat(
+        model="anthropic.claude-opus-4-7",
+        settings=client_settings,
+        model_details={"shouldSkipTemperature": True},
+    )
+    assert llm.temperature is None  # default, not from strip
+    assert llm.disabled_params is not None
+    assert "temperature" in llm.disabled_params
+
+
+def test_constructor_field_strip_logs_warning_with_original_value(
+    client_settings: UiPathBaseSettings,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    logger = logging.getLogger("uipath.test.skip-sampling-field")
+    with caplog.at_level(logging.WARNING, logger=logger.name):
+        llm = UiPathChat(
+            model="anthropic.claude-opus-4-7",
+            settings=client_settings,
+            model_details={"shouldSkipTemperature": True},
+            temperature=0.7,
+            logger=logger,
+        )
+
+    # Sanity: the strip actually ran.
+    assert llm.temperature is None
+
+    # Warning must include the field name AND the original value so the caller
+    # knows exactly what was dropped.
+    matching = [
+        rec
+        for rec in caplog.records
+        if "'temperature'" in rec.getMessage() and "0.7" in rec.getMessage()
+    ]
+    assert matching, (
+        f"expected a warning mentioning 'temperature' and the original value 0.7; "
+        f"got: {[r.getMessage() for r in caplog.records]}"
+    )
+
+
+def test_constructor_field_strip_silent_when_logger_is_none(
+    client_settings: UiPathBaseSettings,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    with caplog.at_level(logging.DEBUG):
+        llm = UiPathChat(
+            model="anthropic.claude-opus-4-7",
+            settings=client_settings,
+            model_details={"shouldSkipTemperature": True},
+            temperature=0.7,
+            logger=None,
+        )
+    assert llm.temperature is None
+    assert not any("Disabling field" in rec.getMessage() for rec in caplog.records)
+
+
 def test_openai_subclass_runtime_strip_honors_merged_disabled_params(
     monkeypatch: pytest.MonkeyPatch, client_settings: UiPathBaseSettings
 ) -> None:

tests/langchain/test_disabled_sampling_params.py

@@ -0,0 +1,62 @@
+"""End-to-end check: constructor-level ``temperature`` survives ``shouldSkipTemperature``.
+
+Recorded against the live LLM Gateway via the SQLite-backed VCR persister
+(see ``tests/conftest.py`` and ``tests/sqlite_persister.py``). The cassette
+captures a 200 response — which is itself proof that ``strip_disabled_fields``
+nulled the constructor-set field before the vendor SDK serialized the request
+body. Without the fix, the gateway returns 400 for any sampling-knob value on
+``anthropic.claude-opus-4-7`` (modelDetails advertises
+``shouldSkipTemperature: True``), and the ``before_record_response`` filter in
+``conftest.py`` would refuse to persist the failed exchange.
+
+We exercise both vendor SDK families because they read ``self.temperature`` at
+different layers:
+- ``UiPathChatAnthropicBedrock`` -> langchain-anthropic's ``ChatAnthropic``
+- ``UiPathChatBedrockConverse`` -> langchain-aws's ``ChatBedrockConverse``
+"""
+
+import pytest
+from langchain_core.messages import HumanMessage
+from uipath_langchain_client.clients.bedrock.chat_models import (
+    UiPathChatAnthropicBedrock,
+    UiPathChatBedrockConverse,
+)
+
+from uipath.llm_client.settings import UiPathBaseSettings
+
+OPUS_4_7 = "anthropic.claude-opus-4-7"
+
+
+@pytest.mark.vcr
+def test_opus_4_7_constructor_temperature_with_anthropic_bedrock(
+    client_settings: UiPathBaseSettings,
+) -> None:
+    chat = UiPathChatAnthropicBedrock(
+        model=OPUS_4_7,
+        settings=client_settings,
+        # Skip discovery so the cassette only captures the chat completion.
+        model_details={"shouldSkipTemperature": True},
+        temperature=0.7,
+    )
+    # Eager strip: temperature was nulled at construction so the vendor SDK
+    # serializes the request body without it.
+    assert chat.temperature is None
+
+    response = chat.invoke([HumanMessage(content="Reply with the single word: pong")])
+    assert response.content, "expected a non-empty response from the gateway"
+
+
+@pytest.mark.vcr
+def test_opus_4_7_constructor_temperature_with_bedrock_converse(
+    client_settings: UiPathBaseSettings,
+) -> None:
+    chat = UiPathChatBedrockConverse(
+        model=OPUS_4_7,
+        settings=client_settings,
+        model_details={"shouldSkipTemperature": True},
+        temperature=0.7,
+    )
+    assert chat.temperature is None
+
+    response = chat.invoke([HumanMessage(content="Reply with the single word: pong")])
+    assert response.content