feat(anthropic,fireworks,openai): use LangSmith gateway keys

libs/partners/anthropic/langchain_anthropic/chat_models.py

@@ -6,6 +6,7 @@
 import datetime
 import hashlib
 import json
+import os
 import re
 import warnings
 from collections.abc import AsyncIterator, Callable, Iterator, Mapping, Sequence
@@ -76,6 +77,27 @@
 
 _MODEL_PROFILES = cast(ModelProfileRegistry, _PROFILES)
 
+_LANGSMITH_GATEWAY_DEFAULT_URL = "https://gateway.smith.langchain.com/anthropic"
+_LANGSMITH_GATEWAY_API_KEY_ENV_VARS = (
+    "LANGSMITH_GATEWAY_API_KEY",
+    "LANGSMITH_API_KEY",
+    "LANGCHAIN_API_KEY",
+)
+
+
+def _resolve_gateway_base_url() -> str | None:
+    raw = os.getenv("LANGSMITH_GATEWAY")
+    if raw is None or raw.lower() in ("false", "0", "no"):
+        return None
+    if raw.lower() in ("true", "1", "yes"):
+        return _LANGSMITH_GATEWAY_DEFAULT_URL
+    return raw
+
+
+def _resolve_gateway_api_key() -> SecretStr | None:
+    return secret_from_env(_LANGSMITH_GATEWAY_API_KEY_ENV_VARS, default=None)()
+
+
 _USER_AGENT: Final[str] = f"langchain-anthropic/{__version__}"
 
 
@@ -945,22 +967,34 @@ class ChatAnthropic(BaseChatModel):
 
     anthropic_api_url: str | None = Field(
         alias="base_url",
-        default_factory=from_env(
+        default_factory=lambda: _resolve_gateway_base_url()
+        or from_env(
             ["ANTHROPIC_API_URL", "ANTHROPIC_BASE_URL"],
             default="https://api.anthropic.com",
-        ),
+        )(),
     )
     """Base URL for API requests. Only specify if using a proxy or service emulator.
 
     If a value isn't passed in, will attempt to read the value first from
     `ANTHROPIC_API_URL` and if that is not set, `ANTHROPIC_BASE_URL`.
+
+    If `LANGSMITH_GATEWAY` is set, it takes precedence over both env vars.
     """
 
     anthropic_api_key: SecretStr = Field(
         alias="api_key",
-        default_factory=secret_from_env("ANTHROPIC_API_KEY", default=""),
+        default_factory=lambda: (
+            _resolve_gateway_api_key()
+            if _resolve_gateway_base_url() is not None
+            else None
+        )
+        or secret_from_env("ANTHROPIC_API_KEY", default="")(),
     )
-    """Automatically read from env var `ANTHROPIC_API_KEY` if not provided."""
+    """Automatically read from env var `ANTHROPIC_API_KEY` if not provided.
+
+    If `LANGSMITH_GATEWAY` is enabled, `LANGSMITH_GATEWAY_API_KEY`,
+    `LANGSMITH_API_KEY`, and `LANGCHAIN_API_KEY` take precedence.
+    """
 
     anthropic_proxy: str | None = Field(
         default_factory=from_env("ANTHROPIC_PROXY", default=None)

libs/partners/anthropic/tests/unit_tests/test_chat_models.py

@@ -3574,3 +3574,86 @@ def mock_create(_payload: Any) -> list:
     message_finish = cast("dict[str, Any]", stream_events[-1])
     assert message_finish["event"] == "message-finish"
     assert message_finish["metadata"]["stop_reason"] == "tool_use"
+
+
+def test_langsmith_gateway_true(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "true")
+    monkeypatch.delenv("ANTHROPIC_API_URL", raising=False)
+    monkeypatch.delenv("ANTHROPIC_BASE_URL", raising=False)
+    llm = ChatAnthropic(model=MODEL_NAME, api_key="test")
+    assert llm.anthropic_api_url == "https://gateway.smith.langchain.com/anthropic"
+
+
+def test_langsmith_gateway_false(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "false")
+    monkeypatch.delenv("ANTHROPIC_API_URL", raising=False)
+    monkeypatch.delenv("ANTHROPIC_BASE_URL", raising=False)
+    llm = ChatAnthropic(model=MODEL_NAME, api_key="test")
+    assert llm.anthropic_api_url == "https://api.anthropic.com"
+
+
+def test_langsmith_gateway_unset(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.delenv("LANGSMITH_GATEWAY", raising=False)
+    monkeypatch.delenv("ANTHROPIC_API_URL", raising=False)
+    monkeypatch.delenv("ANTHROPIC_BASE_URL", raising=False)
+    llm = ChatAnthropic(model=MODEL_NAME, api_key="test")
+    assert llm.anthropic_api_url == "https://api.anthropic.com"
+
+
+def test_langsmith_gateway_api_key(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "true")
+    monkeypatch.setenv("LANGSMITH_GATEWAY_API_KEY", "gateway-key")
+    monkeypatch.delenv("ANTHROPIC_API_KEY", raising=False)
+    llm = ChatAnthropic(model=MODEL_NAME)
+    assert llm.anthropic_api_key.get_secret_value() == "gateway-key"
+
+
+@pytest.mark.parametrize(
+    ("env_var", "expected"),
+    [
+        ("LANGSMITH_API_KEY", "langsmith-key"),
+        ("LANGCHAIN_API_KEY", "langchain-key"),
+    ],
+)
+def test_langsmith_gateway_api_key_langsmith_fallbacks(
+    monkeypatch: pytest.MonkeyPatch, env_var: str, expected: str
+) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "true")
+    monkeypatch.delenv("LANGSMITH_GATEWAY_API_KEY", raising=False)
+    monkeypatch.delenv("LANGSMITH_API_KEY", raising=False)
+    monkeypatch.delenv("LANGCHAIN_API_KEY", raising=False)
+    monkeypatch.delenv("ANTHROPIC_API_KEY", raising=False)
+    monkeypatch.setenv(env_var, expected)
+    llm = ChatAnthropic(model=MODEL_NAME)
+    assert llm.anthropic_api_key.get_secret_value() == expected
+
+
+def test_langsmith_gateway_api_key_precedence(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "true")
+    monkeypatch.setenv("LANGSMITH_GATEWAY_API_KEY", "gateway-key")
+    monkeypatch.setenv("LANGSMITH_API_KEY", "langsmith-key")
+    monkeypatch.setenv("LANGCHAIN_API_KEY", "langchain-key")
+    monkeypatch.setenv("ANTHROPIC_API_KEY", "provider-key")
+    llm = ChatAnthropic(model=MODEL_NAME)
+    assert llm.anthropic_api_key.get_secret_value() == "gateway-key"
+
+
+def test_langsmith_gateway_explicit_api_key_takes_precedence(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "true")
+    monkeypatch.setenv("LANGSMITH_GATEWAY_API_KEY", "gateway-key")
+    llm = ChatAnthropic(model=MODEL_NAME, api_key="explicit-key")
+    assert llm.anthropic_api_key.get_secret_value() == "explicit-key"
+
+
+def test_langsmith_gateway_api_key_not_used_without_gateway(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.delenv("LANGSMITH_GATEWAY", raising=False)
+    monkeypatch.setenv("LANGSMITH_GATEWAY_API_KEY", "gateway-key")
+    monkeypatch.setenv("ANTHROPIC_API_KEY", "provider-key")
+    llm = ChatAnthropic(model=MODEL_NAME)
+    assert llm.anthropic_api_key.get_secret_value() == "provider-key"

libs/partners/fireworks/langchain_fireworks/chat_models.py

@@ -5,6 +5,7 @@
 import contextlib
 import json
 import logging
+import os
 from collections.abc import AsyncIterator, Callable, Iterator, Mapping, Sequence
 from operator import itemgetter
 from typing import (
@@ -108,6 +109,26 @@
 
 _MODEL_PROFILES = cast("ModelProfileRegistry", _PROFILES)
 
+_LANGSMITH_GATEWAY_DEFAULT_URL = "https://gateway.smith.langchain.com/fireworks"
+_LANGSMITH_GATEWAY_API_KEY_ENV_VARS = (
+    "LANGSMITH_GATEWAY_API_KEY",
+    "LANGSMITH_API_KEY",
+    "LANGCHAIN_API_KEY",
+)
+
+
+def _resolve_gateway_base_url() -> str | None:
+    raw = os.getenv("LANGSMITH_GATEWAY")
+    if raw is None or raw.lower() in ("false", "0", "no"):
+        return None
+    if raw.lower() in ("true", "1", "yes"):
+        return _LANGSMITH_GATEWAY_DEFAULT_URL
+    return raw
+
+
+def _resolve_gateway_api_key() -> SecretStr | None:
+    return secret_from_env(_LANGSMITH_GATEWAY_API_KEY_ENV_VARS, default=None)()
+
 
 def _get_default_model_profile(model_name: str) -> ModelProfile:
     default = _MODEL_PROFILES.get(model_name) or {}
@@ -756,25 +777,37 @@ def model(self) -> str:
 
     fireworks_api_key: SecretStr = Field(
         alias="api_key",
-        default_factory=secret_from_env(
+        default_factory=lambda: (
+            _resolve_gateway_api_key()
+            if _resolve_gateway_base_url() is not None
+            else None
+        )
+        or secret_from_env(
             "FIREWORKS_API_KEY",
             error_message=(
                 "You must specify an api key. "
                 "You can pass it an argument as `api_key=...` or "
                 "set the environment variable `FIREWORKS_API_KEY`."
             ),
-        ),
+        )(),
     )
     """Fireworks API key.
 
     Automatically read from env variable `FIREWORKS_API_KEY` if not provided.
+
+    If `LANGSMITH_GATEWAY` is enabled, `LANGSMITH_GATEWAY_API_KEY`,
+    `LANGSMITH_API_KEY`, and `LANGCHAIN_API_KEY` take precedence.
     """
 
     fireworks_api_base: str | None = Field(
-        alias="base_url", default_factory=from_env("FIREWORKS_API_BASE", default=None)
+        alias="base_url",
+        default_factory=lambda: _resolve_gateway_base_url()
+        or from_env("FIREWORKS_API_BASE", default=None)(),
     )
     """Base URL path for API requests, leave blank if not using a proxy or service
     emulator.
+
+    If `LANGSMITH_GATEWAY` is set, it takes precedence over `FIREWORKS_API_BASE`.
     """
 
     request_timeout: float | tuple[float, float] | Any | None = Field(

libs/partners/fireworks/tests/unit_tests/test_chat_models.py

@@ -1591,3 +1591,82 @@ def test_request_timeout_tuple_normalized_to_httpx_timeout(
     assert forwarded.connect == 5.0
     assert forwarded.read == 30.0
     assert async_mock.call_args.kwargs["timeout"] == forwarded
+
+
+def test_langsmith_gateway_true(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "true")
+    llm = _make_model()
+    assert llm.fireworks_api_base == "https://gateway.smith.langchain.com/fireworks"
+
+
+def test_langsmith_gateway_false(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "false")
+    monkeypatch.delenv("FIREWORKS_API_BASE", raising=False)
+    llm = _make_model()
+    assert llm.fireworks_api_base is None
+
+
+def test_langsmith_gateway_unset(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.delenv("LANGSMITH_GATEWAY", raising=False)
+    monkeypatch.delenv("FIREWORKS_API_BASE", raising=False)
+    llm = _make_model()
+    assert llm.fireworks_api_base is None
+
+
+def test_langsmith_gateway_api_key(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "true")
+    monkeypatch.setenv("LANGSMITH_GATEWAY_API_KEY", "gateway-key")
+    monkeypatch.delenv("FIREWORKS_API_KEY", raising=False)
+    llm = ChatFireworks(model=MODEL_NAME)  # type: ignore[call-arg]
+    assert llm.fireworks_api_key.get_secret_value() == "gateway-key"
+
+
+@pytest.mark.parametrize(
+    ("env_var", "expected"),
+    [
+        ("LANGSMITH_API_KEY", "langsmith-key"),
+        ("LANGCHAIN_API_KEY", "langchain-key"),
+    ],
+)
+def test_langsmith_gateway_api_key_langsmith_fallbacks(
+    monkeypatch: pytest.MonkeyPatch, env_var: str, expected: str
+) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "true")
+    monkeypatch.delenv("LANGSMITH_GATEWAY_API_KEY", raising=False)
+    monkeypatch.delenv("LANGSMITH_API_KEY", raising=False)
+    monkeypatch.delenv("LANGCHAIN_API_KEY", raising=False)
+    monkeypatch.delenv("FIREWORKS_API_KEY", raising=False)
+    monkeypatch.setenv(env_var, expected)
+    llm = ChatFireworks(model=MODEL_NAME)  # type: ignore[call-arg]
+    assert llm.fireworks_api_key.get_secret_value() == expected
+
+
+def test_langsmith_gateway_api_key_precedence(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "true")
+    monkeypatch.setenv("LANGSMITH_GATEWAY_API_KEY", "gateway-key")
+    monkeypatch.setenv("LANGSMITH_API_KEY", "langsmith-key")
+    monkeypatch.setenv("LANGCHAIN_API_KEY", "langchain-key")
+    monkeypatch.setenv("FIREWORKS_API_KEY", "provider-key")
+    llm = ChatFireworks(model=MODEL_NAME)  # type: ignore[call-arg]
+    assert llm.fireworks_api_key.get_secret_value() == "gateway-key"
+
+
+def test_langsmith_gateway_explicit_api_key_takes_precedence(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setenv("LANGSMITH_GATEWAY", "true")
+    monkeypatch.setenv("LANGSMITH_GATEWAY_API_KEY", "gateway-key")
+    llm = ChatFireworks(model=MODEL_NAME, api_key="explicit-key")  # type: ignore[call-arg]
+    assert llm.fireworks_api_key.get_secret_value() == "explicit-key"
+
+
+def test_langsmith_gateway_api_key_not_used_without_gateway(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.delenv("LANGSMITH_GATEWAY", raising=False)
+    monkeypatch.setenv("LANGSMITH_GATEWAY_API_KEY", "gateway-key")
+    monkeypatch.setenv("FIREWORKS_API_KEY", "provider-key")
+    llm = ChatFireworks(model=MODEL_NAME)  # type: ignore[call-arg]
+    assert llm.fireworks_api_key.get_secret_value() == "provider-key"