fix: bound anthropic<1.0.0 on the bedrock extra

The bedrock extra received the anthropic SDK only transitively via
langchain-aws[anthropic] (unbounded above); langchain-anthropic 1.7.0
also lifted its own <1.0.0 pin. Fresh resolutions therefore picked
anthropic 1.x, which moved to httpx2 and rejects UiPath's httpx clients
at Bedrock chat-model construction.

Add an explicit anthropic[bedrock]>=0.96.0,<1.0.0 to the bedrock extra
(anthropic and all already carry the bound; no other extra pulls
anthropic transitively), plus a guard test that fails if any extra's
dependency closure includes anthropic without an explicit <1.0.0 bound.

Interim pin — widen to <2.0.0 once httpx2-compatible clients land in
uipath-llm-client.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: andreibalas-uipath

packages/uipath_langchain_client/CHANGELOG.md

@@ -2,6 +2,11 @@
 
 All notable changes to `uipath_langchain_client` will be documented in this file.
 
+## [1.18.1] - 2026-08-31
+
+### Fixed
+- Bound `anthropic[bedrock]>=0.96.0,<1.0.0` explicitly on the `bedrock` extra. The extra previously received the anthropic SDK only transitively (via `langchain-aws[anthropic]`, unbounded above; `langchain-anthropic>=1.7.0` also lifted its own `<1.0.0` pin), so fresh resolutions picked anthropic 1.x — which moved to httpx2 and rejects UiPath's httpx clients at Bedrock chat-model construction (`TypeError: Invalid http_client argument`). Interim pin: to be widened to `<2.0.0` once httpx2-compatible clients land in `uipath-llm-client`. Audited the remaining extras — no other extra pulls `anthropic` without the bound (`anthropic` and `all` already carry it) — and added a guard test enforcing the bound on any extra whose dependency closure includes `anthropic`.
+
 ## [1.18.0] - 2026-08-13
 
 ### Changed

packages/uipath_langchain_client/pyproject.toml

@@ -22,6 +22,10 @@ anthropic = [
 ]
 bedrock = [
     "langchain-aws[anthropic]>=1.4.5,<2.0.0",
+    # Interim: langchain-aws[anthropic] and langchain-anthropic>=1.7.0 admit
+    # anthropic 1.x, which requires httpx2 and rejects UiPath's httpx clients.
+    # Widen to <2.0.0 once httpx2-compatible clients land in uipath-llm-client.
+    "anthropic[bedrock]>=0.96.0,<1.0.0",
 ]
 vertexai = [
     "langchain-google-vertexai>=3.2.2,<4.0.0",

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__ = "1.18.0"
+__version__ = "1.18.1"

tests/langchain/test_extras_anthropic_bound.py

@@ -0,0 +1,98 @@
+"""Guard: every extra whose dependency closure includes `anthropic` must carry
+an explicit `anthropic` bound excluding 1.x.
+
+The anthropic 1.x SDK moved to httpx2 and rejects UiPath's httpx-based clients
+at construction time, so until httpx2-compatible clients land the bound must be
+declared directly on each affected extra — transitive requirements
+(langchain-aws[anthropic], langchain-anthropic>=1.7.0) admit anthropic 1.x.
+
+The closure is computed from the checked-in uv.lock (no network), and the bound
+is asserted against the extras declared in the langchain package's pyproject.
+When httpx2-compatible clients land and the pins are widened to <2.0.0, update
+EXCLUDED_ANTHROPIC_VERSION accordingly.
+"""
+
+import tomllib
+from pathlib import Path
+from typing import Any
+
+import pytest
+from packaging.requirements import Requirement
+
+REPO_ROOT = Path(__file__).parents[2]
+LANGCHAIN_PYPROJECT = REPO_ROOT / "packages" / "uipath_langchain_client" / "pyproject.toml"
+UV_LOCK = REPO_ROOT / "uv.lock"
+
+PACKAGE_NAME = "uipath-langchain-client"
+EXCLUDED_ANTHROPIC_VERSION = "1.0.0"
+
+
+def _load_extras() -> dict[str, list[Requirement]]:
+    with LANGCHAIN_PYPROJECT.open("rb") as f:
+        pyproject = tomllib.load(f)
+    extras: dict[str, list[str]] = pyproject["project"]["optional-dependencies"]
+    return {name: [Requirement(dep) for dep in deps] for name, deps in extras.items()}
+
+
+def _expand_self_references(extra: str, extras: dict[str, list[Requirement]]) -> list[Requirement]:
+    """Flatten extras composed from the package's own extras (e.g. `all`)."""
+    requirements: list[Requirement] = []
+    for requirement in extras[extra]:
+        if requirement.name == PACKAGE_NAME:
+            for referenced in requirement.extras:
+                requirements.extend(_expand_self_references(referenced, extras))
+        else:
+            requirements.append(requirement)
+    return requirements
+
+
+def _load_lock_graph() -> dict[str, dict[str, Any]]:
+    with UV_LOCK.open("rb") as f:
+        lock = tomllib.load(f)
+    return {pkg["name"]: pkg for pkg in lock["package"]}
+
+
+def _closure(requirements: list[Requirement]) -> set[str]:
+    """Transitive dependency closure per uv.lock, honoring requirement extras."""
+    graph = _load_lock_graph()
+    reached: set[str] = set()
+    visited: set[tuple[str, frozenset[str]]] = set()
+    stack: list[tuple[str, frozenset[str]]] = [
+        (req.name, frozenset(req.extras)) for req in requirements
+    ]
+    while stack:
+        name, extras = stack.pop()
+        if (name, extras) in visited:
+            continue
+        visited.add((name, extras))
+        reached.add(name)
+        pkg = graph.get(name)
+        if pkg is None:
+            continue
+        deps: list[dict[str, Any]] = list(pkg.get("dependencies", []))
+        optional = pkg.get("optional-dependencies", {})
+        for extra in extras:
+            deps.extend(optional.get(extra, []))
+        for dep in deps:
+            stack.append((dep["name"], frozenset(dep.get("extra", []))))
+    return reached
+
+
+@pytest.mark.parametrize("extra", sorted(_load_extras()))
+def test_extras_with_anthropic_in_closure_carry_explicit_bound(extra: str) -> None:
+    extras = _load_extras()
+    requirements = _expand_self_references(extra, extras)
+    if "anthropic" not in _closure(requirements):
+        return
+
+    anthropic_requirements = [req for req in requirements if req.name == "anthropic"]
+    assert anthropic_requirements, (
+        f"Extra '{extra}' pulls `anthropic` transitively but declares no explicit "
+        f"`anthropic` requirement; add an `anthropic<{EXCLUDED_ANTHROPIC_VERSION}` "
+        "bound to the extra in packages/uipath_langchain_client/pyproject.toml."
+    )
+    for requirement in anthropic_requirements:
+        assert not requirement.specifier.contains(EXCLUDED_ANTHROPIC_VERSION, prereleases=True), (
+            f"Extra '{extra}' admits anthropic=={EXCLUDED_ANTHROPIC_VERSION} via "
+            f"'{requirement}'; the anthropic 1.x SDK (httpx2) is not yet supported."
+        )