feat(langchain): add provider inference metadata to init_chat_model

2026-02-21 06:33:41 +00:00 · 2026-02-08 23:28:10 -05:00
parent 06a7d079b0
commit 316d812ecb
3 changed files with 97 additions and 16 deletions
--- a/libs/langchain_v1/langchain/chat_models/base.py
+++ b/libs/langchain_v1/langchain/chat_models/base.py
@@ -322,6 +322,19 @@ def init_chat_model(
            chat model emulator that initializes the underlying model at runtime once a
            config is passed in.

+            When a concrete `BaseChatModel` is returned (non-configurable path), two
+            extra attributes are set on the instance:
+
+            - `provider_was_inferred` (`bool`): `True` when the provider was guessed
+                from the model name rather than explicitly specified via the
+                `model_provider` kwarg or the `'provider:model'` prefix format.
+            - `resolved_provider` (`str`): The normalized provider string used to
+                look up the model class (e.g., `'openai'`).
+
+            These attributes are **not** Pydantic fields — they won't appear in
+            `model_dump()` / `dict()` and won't survive `model_copy()`. Use
+            `getattr(model, 'provider_was_inferred', None)` for safe access.
+
    Raises:
        ValueError: If `model_provider` cannot be inferred or isn't supported.
        ImportError: If the model provider integration package is not installed.
@@ -471,9 +484,12 @@ def _init_chat_model_helper(
    model_provider: str | None = None,
    **kwargs: Any,
 ) -> BaseChatModel:
-    model, model_provider = _parse_model(model, model_provider)
+    model, model_provider, provider_inferred = _parse_model(model, model_provider)
    creator_func = _get_chat_model_creator(model_provider)
-    return creator_func(model=model, **kwargs)
+    chat_model = creator_func(model=model, **kwargs)
+    object.__setattr__(chat_model, "provider_was_inferred", provider_inferred)
+    object.__setattr__(chat_model, "resolved_provider", model_provider)
+    return chat_model


 def _attempt_infer_model_provider(model_name: str) -> str | None:
@@ -543,8 +559,21 @@ def _attempt_infer_model_provider(model_name: str) -> str | None:
    return None


-def _parse_model(model: str, model_provider: str | None) -> tuple[str, str]:
-    """Parse model name and provider, inferring provider if necessary."""
+def _parse_model(model: str, model_provider: str | None) -> tuple[str, str, bool]:
+    """Parse model name and provider, inferring provider if necessary.
+
+    Args:
+        model: The model name, optionally with a provider prefix (e.g., `'openai:gpt-4o'`).
+        model_provider: Explicit provider name, or `None` to infer.
+
+    Returns:
+        A 3-tuple of `(model_name, provider, provider_was_inferred)` where
+            `provider_was_inferred` is `True` only when the provider was
+            determined by `_attempt_infer_model_provider` (not from an explicit
+            kwarg or a colon-prefix format).
+    """
+    provider_inferred = False
+
    # Handle provider:model format
    if (
        not model_provider
@@ -555,7 +584,10 @@ def _parse_model(model: str, model_provider: str | None) -> tuple[str, str]:
        model = ":".join(model.split(":")[1:])

    # Attempt to infer provider if not specified
-    model_provider = model_provider or _attempt_infer_model_provider(model)
+    if not model_provider:
+        model_provider = _attempt_infer_model_provider(model)
+        if model_provider:
+            provider_inferred = True

    if not model_provider:
        # Enhanced error message with suggestions
@@ -571,7 +603,7 @@ def _parse_model(model: str, model_provider: str | None) -> tuple[str, str]:

    # Normalize provider name
    model_provider = model_provider.replace("-", "_").lower()
-    return model, model_provider
+    return model, model_provider, provider_inferred


 def _remove_prefix(s: str, prefix: str) -> str:
--- a/libs/langchain_v1/tests/unit_tests/chat_models/test_chat_models.py
+++ b/libs/langchain_v1/tests/unit_tests/chat_models/test_chat_models.py
@@ -8,7 +8,11 @@ from langchain_core.runnables import RunnableConfig, RunnableSequence
 from pydantic import SecretStr

 from langchain.chat_models import __all__, init_chat_model
-from langchain.chat_models.base import _SUPPORTED_PROVIDERS, _attempt_infer_model_provider
+from langchain.chat_models.base import (
+    _SUPPORTED_PROVIDERS,
+    _attempt_infer_model_provider,
+    _parse_model,
+)

 if TYPE_CHECKING:
    from langchain_core.language_models import BaseChatModel
@@ -335,3 +339,53 @@ def test_configurable_with_default() -> None:
    prompt = ChatPromptTemplate.from_messages([("system", "foo")])
    chain = prompt | model_with_config
    assert isinstance(chain, RunnableSequence)
+
+
+@pytest.mark.parametrize(
+    ("model", "provider", "expected_inferred"),
+    [
+        # Explicit provider kwarg -> not inferred
+        ("gpt-4o", "openai", False),
+        # Colon-prefix format -> not inferred
+        ("openai:gpt-4o", None, False),
+        # Inferred from model name -> inferred
+        ("gpt-4o", None, True),
+        ("claude-sonnet-4-5-20250929", None, True),
+    ],
+)
+def test_parse_model_returns_inference_flag(
+    model: str,
+    provider: str | None,
+    expected_inferred: bool,  # noqa: FBT001
+) -> None:
+    """Test that `_parse_model` tracks whether the provider was inferred."""
+    _model, _provider, inferred = _parse_model(model, provider)
+    assert inferred is expected_inferred
+    assert _provider in {"openai", "anthropic"}
+
+
+@pytest.mark.requires("langchain_openai")
+@mock.patch.dict(os.environ, {"OPENAI_API_KEY": "foo"}, clear=True)
+def test_provider_inference_metadata_inferred() -> None:
+    """When provider is inferred from model name, `provider_was_inferred` is True."""
+    llm = init_chat_model("gpt-4o")
+    assert llm.provider_was_inferred is True  # type: ignore[attr-defined]
+    assert llm.resolved_provider == "openai"  # type: ignore[attr-defined]
+
+
+@pytest.mark.requires("langchain_openai")
+@mock.patch.dict(os.environ, {"OPENAI_API_KEY": "foo"}, clear=True)
+def test_provider_inference_metadata_explicit() -> None:
+    """When provider is explicitly given, `provider_was_inferred` is False."""
+    llm = init_chat_model("gpt-4o", model_provider="openai")
+    assert llm.provider_was_inferred is False  # type: ignore[attr-defined]
+    assert llm.resolved_provider == "openai"  # type: ignore[attr-defined]
+
+
+@pytest.mark.requires("langchain_openai")
+@mock.patch.dict(os.environ, {"OPENAI_API_KEY": "foo"}, clear=True)
+def test_provider_inference_metadata_prefix_format() -> None:
+    """When provider is given via colon prefix, `provider_was_inferred` is False."""
+    llm = init_chat_model("openai:gpt-4o")
+    assert llm.provider_was_inferred is False  # type: ignore[attr-defined]
+    assert llm.resolved_provider == "openai"  # type: ignore[attr-defined]
--- a/libs/langchain_v1/uv.lock
+++ b/libs/langchain_v1/uv.lock
@@ -1,5 +1,5 @@
 version = 1
-revision = 2
+revision = 3
 requires-python = ">=3.10.0, <4.0.0"
 resolution-markers = [
    "python_full_version >= '3.14' and platform_python_implementation == 'PyPy'",
@@ -1384,7 +1384,6 @@ wheels = [
    { url = "https://files.pythonhosted.org/packages/7d/ed/6bfa4109fcb23a58819600392564fea69cdc6551ffd5e69ccf1d52a40cbc/greenlet-3.2.4-cp310-cp310-macosx_11_0_universal2.whl", hash = "sha256:8c68325b0d0acf8d91dde4e6f930967dd52a5302cd4062932a6b2e7c2969f47c", size = 271061, upload-time = "2025-08-07T13:17:15.373Z" },
    { url = "https://files.pythonhosted.org/packages/2a/fc/102ec1a2fc015b3a7652abab7acf3541d58c04d3d17a8d3d6a44adae1eb1/greenlet-3.2.4-cp310-cp310-manylinux2014_aarch64.manylinux_2_17_aarch64.whl", hash = "sha256:94385f101946790ae13da500603491f04a76b6e4c059dab271b3ce2e283b2590", size = 629475, upload-time = "2025-08-07T13:42:54.009Z" },
    { url = "https://files.pythonhosted.org/packages/c5/26/80383131d55a4ac0fb08d71660fd77e7660b9db6bdb4e8884f46d9f2cc04/greenlet-3.2.4-cp310-cp310-manylinux2014_ppc64le.manylinux_2_17_ppc64le.whl", hash = "sha256:f10fd42b5ee276335863712fa3da6608e93f70629c631bf77145021600abc23c", size = 640802, upload-time = "2025-08-07T13:45:25.52Z" },
-    { url = "https://files.pythonhosted.org/packages/9f/7c/e7833dbcd8f376f3326bd728c845d31dcde4c84268d3921afcae77d90d08/greenlet-3.2.4-cp310-cp310-manylinux2014_s390x.manylinux_2_17_s390x.whl", hash = "sha256:c8c9e331e58180d0d83c5b7999255721b725913ff6bc6cf39fa2a45841a4fd4b", size = 636703, upload-time = "2025-08-07T13:53:12.622Z" },
    { url = "https://files.pythonhosted.org/packages/e9/49/547b93b7c0428ede7b3f309bc965986874759f7d89e4e04aeddbc9699acb/greenlet-3.2.4-cp310-cp310-manylinux2014_x86_64.manylinux_2_17_x86_64.whl", hash = "sha256:58b97143c9cc7b86fc458f215bd0932f1757ce649e05b640fea2e79b54cedb31", size = 635417, upload-time = "2025-08-07T13:18:25.189Z" },
    { url = "https://files.pythonhosted.org/packages/7f/91/ae2eb6b7979e2f9b035a9f612cf70f1bf54aad4e1d125129bef1eae96f19/greenlet-3.2.4-cp310-cp310-manylinux_2_24_x86_64.manylinux_2_28_x86_64.whl", hash = "sha256:c2ca18a03a8cfb5b25bc1cbe20f3d9a4c80d8c3b13ba3df49ac3961af0b1018d", size = 584358, upload-time = "2025-08-07T13:18:23.708Z" },
    { url = "https://files.pythonhosted.org/packages/f7/85/433de0c9c0252b22b16d413c9407e6cb3b41df7389afc366ca204dbc1393/greenlet-3.2.4-cp310-cp310-musllinux_1_1_aarch64.whl", hash = "sha256:9fe0a28a7b952a21e2c062cd5756d34354117796c6d9215a87f55e38d15402c5", size = 1113550, upload-time = "2025-08-07T13:42:37.467Z" },
@@ -1395,7 +1394,6 @@ wheels = [
    { url = "https://files.pythonhosted.org/packages/a4/de/f28ced0a67749cac23fecb02b694f6473f47686dff6afaa211d186e2ef9c/greenlet-3.2.4-cp311-cp311-macosx_11_0_universal2.whl", hash = "sha256:96378df1de302bc38e99c3a9aa311967b7dc80ced1dcc6f171e99842987882a2", size = 272305, upload-time = "2025-08-07T13:15:41.288Z" },
    { url = "https://files.pythonhosted.org/packages/09/16/2c3792cba130000bf2a31c5272999113f4764fd9d874fb257ff588ac779a/greenlet-3.2.4-cp311-cp311-manylinux2014_aarch64.manylinux_2_17_aarch64.whl", hash = "sha256:1ee8fae0519a337f2329cb78bd7a8e128ec0f881073d43f023c7b8d4831d5246", size = 632472, upload-time = "2025-08-07T13:42:55.044Z" },
    { url = "https://files.pythonhosted.org/packages/ae/8f/95d48d7e3d433e6dae5b1682e4292242a53f22df82e6d3dda81b1701a960/greenlet-3.2.4-cp311-cp311-manylinux2014_ppc64le.manylinux_2_17_ppc64le.whl", hash = "sha256:94abf90142c2a18151632371140b3dba4dee031633fe614cb592dbb6c9e17bc3", size = 644646, upload-time = "2025-08-07T13:45:26.523Z" },
-    { url = "https://files.pythonhosted.org/packages/d5/5e/405965351aef8c76b8ef7ad370e5da58d57ef6068df197548b015464001a/greenlet-3.2.4-cp311-cp311-manylinux2014_s390x.manylinux_2_17_s390x.whl", hash = "sha256:4d1378601b85e2e5171b99be8d2dc85f594c79967599328f95c1dc1a40f1c633", size = 640519, upload-time = "2025-08-07T13:53:13.928Z" },
    { url = "https://files.pythonhosted.org/packages/25/5d/382753b52006ce0218297ec1b628e048c4e64b155379331f25a7316eb749/greenlet-3.2.4-cp311-cp311-manylinux2014_x86_64.manylinux_2_17_x86_64.whl", hash = "sha256:0db5594dce18db94f7d1650d7489909b57afde4c580806b8d9203b6e79cdc079", size = 639707, upload-time = "2025-08-07T13:18:27.146Z" },
    { url = "https://files.pythonhosted.org/packages/1f/8e/abdd3f14d735b2929290a018ecf133c901be4874b858dd1c604b9319f064/greenlet-3.2.4-cp311-cp311-manylinux_2_24_x86_64.manylinux_2_28_x86_64.whl", hash = "sha256:2523e5246274f54fdadbce8494458a2ebdcdbc7b802318466ac5606d3cded1f8", size = 587684, upload-time = "2025-08-07T13:18:25.164Z" },
    { url = "https://files.pythonhosted.org/packages/5d/65/deb2a69c3e5996439b0176f6651e0052542bb6c8f8ec2e3fba97c9768805/greenlet-3.2.4-cp311-cp311-musllinux_1_1_aarch64.whl", hash = "sha256:1987de92fec508535687fb807a5cea1560f6196285a4cde35c100b8cd632cc52", size = 1116647, upload-time = "2025-08-07T13:42:38.655Z" },
@@ -1406,7 +1404,6 @@ wheels = [
    { url = "https://files.pythonhosted.org/packages/44/69/9b804adb5fd0671f367781560eb5eb586c4d495277c93bde4307b9e28068/greenlet-3.2.4-cp312-cp312-macosx_11_0_universal2.whl", hash = "sha256:3b67ca49f54cede0186854a008109d6ee71f66bd57bb36abd6d0a0267b540cdd", size = 274079, upload-time = "2025-08-07T13:15:45.033Z" },
    { url = "https://files.pythonhosted.org/packages/46/e9/d2a80c99f19a153eff70bc451ab78615583b8dac0754cfb942223d2c1a0d/greenlet-3.2.4-cp312-cp312-manylinux2014_aarch64.manylinux_2_17_aarch64.whl", hash = "sha256:ddf9164e7a5b08e9d22511526865780a576f19ddd00d62f8a665949327fde8bb", size = 640997, upload-time = "2025-08-07T13:42:56.234Z" },
    { url = "https://files.pythonhosted.org/packages/3b/16/035dcfcc48715ccd345f3a93183267167cdd162ad123cd93067d86f27ce4/greenlet-3.2.4-cp312-cp312-manylinux2014_ppc64le.manylinux_2_17_ppc64le.whl", hash = "sha256:f28588772bb5fb869a8eb331374ec06f24a83a9c25bfa1f38b6993afe9c1e968", size = 655185, upload-time = "2025-08-07T13:45:27.624Z" },
-    { url = "https://files.pythonhosted.org/packages/31/da/0386695eef69ffae1ad726881571dfe28b41970173947e7c558d9998de0f/greenlet-3.2.4-cp312-cp312-manylinux2014_s390x.manylinux_2_17_s390x.whl", hash = "sha256:5c9320971821a7cb77cfab8d956fa8e39cd07ca44b6070db358ceb7f8797c8c9", size = 649926, upload-time = "2025-08-07T13:53:15.251Z" },
    { url = "https://files.pythonhosted.org/packages/68/88/69bf19fd4dc19981928ceacbc5fd4bb6bc2215d53199e367832e98d1d8fe/greenlet-3.2.4-cp312-cp312-manylinux2014_x86_64.manylinux_2_17_x86_64.whl", hash = "sha256:c60a6d84229b271d44b70fb6e5fa23781abb5d742af7b808ae3f6efd7c9c60f6", size = 651839, upload-time = "2025-08-07T13:18:30.281Z" },
    { url = "https://files.pythonhosted.org/packages/19/0d/6660d55f7373b2ff8152401a83e02084956da23ae58cddbfb0b330978fe9/greenlet-3.2.4-cp312-cp312-manylinux_2_24_x86_64.manylinux_2_28_x86_64.whl", hash = "sha256:3b3812d8d0c9579967815af437d96623f45c0f2ae5f04e366de62a12d83a8fb0", size = 607586, upload-time = "2025-08-07T13:18:28.544Z" },
    { url = "https://files.pythonhosted.org/packages/8e/1a/c953fdedd22d81ee4629afbb38d2f9d71e37d23caace44775a3a969147d4/greenlet-3.2.4-cp312-cp312-musllinux_1_1_aarch64.whl", hash = "sha256:abbf57b5a870d30c4675928c37278493044d7c14378350b3aa5d484fa65575f0", size = 1123281, upload-time = "2025-08-07T13:42:39.858Z" },
@@ -1417,7 +1414,6 @@ wheels = [
    { url = "https://files.pythonhosted.org/packages/49/e8/58c7f85958bda41dafea50497cbd59738c5c43dbbea5ee83d651234398f4/greenlet-3.2.4-cp313-cp313-macosx_11_0_universal2.whl", hash = "sha256:1a921e542453fe531144e91e1feedf12e07351b1cf6c9e8a3325ea600a715a31", size = 272814, upload-time = "2025-08-07T13:15:50.011Z" },
    { url = "https://files.pythonhosted.org/packages/62/dd/b9f59862e9e257a16e4e610480cfffd29e3fae018a68c2332090b53aac3d/greenlet-3.2.4-cp313-cp313-manylinux2014_aarch64.manylinux_2_17_aarch64.whl", hash = "sha256:cd3c8e693bff0fff6ba55f140bf390fa92c994083f838fece0f63be121334945", size = 641073, upload-time = "2025-08-07T13:42:57.23Z" },
    { url = "https://files.pythonhosted.org/packages/f7/0b/bc13f787394920b23073ca3b6c4a7a21396301ed75a655bcb47196b50e6e/greenlet-3.2.4-cp313-cp313-manylinux2014_ppc64le.manylinux_2_17_ppc64le.whl", hash = "sha256:710638eb93b1fa52823aa91bf75326f9ecdfd5e0466f00789246a5280f4ba0fc", size = 655191, upload-time = "2025-08-07T13:45:29.752Z" },
-    { url = "https://files.pythonhosted.org/packages/f2/d6/6adde57d1345a8d0f14d31e4ab9c23cfe8e2cd39c3baf7674b4b0338d266/greenlet-3.2.4-cp313-cp313-manylinux2014_s390x.manylinux_2_17_s390x.whl", hash = "sha256:c5111ccdc9c88f423426df3fd1811bfc40ed66264d35aa373420a34377efc98a", size = 649516, upload-time = "2025-08-07T13:53:16.314Z" },
    { url = "https://files.pythonhosted.org/packages/7f/3b/3a3328a788d4a473889a2d403199932be55b1b0060f4ddd96ee7cdfcad10/greenlet-3.2.4-cp313-cp313-manylinux2014_x86_64.manylinux_2_17_x86_64.whl", hash = "sha256:d76383238584e9711e20ebe14db6c88ddcedc1829a9ad31a584389463b5aa504", size = 652169, upload-time = "2025-08-07T13:18:32.861Z" },
    { url = "https://files.pythonhosted.org/packages/ee/43/3cecdc0349359e1a527cbf2e3e28e5f8f06d3343aaf82ca13437a9aa290f/greenlet-3.2.4-cp313-cp313-manylinux_2_24_x86_64.manylinux_2_28_x86_64.whl", hash = "sha256:23768528f2911bcd7e475210822ffb5254ed10d71f4028387e5a99b4c6699671", size = 610497, upload-time = "2025-08-07T13:18:31.636Z" },
    { url = "https://files.pythonhosted.org/packages/b8/19/06b6cf5d604e2c382a6f31cafafd6f33d5dea706f4db7bdab184bad2b21d/greenlet-3.2.4-cp313-cp313-musllinux_1_1_aarch64.whl", hash = "sha256:00fadb3fedccc447f517ee0d3fd8fe49eae949e1cd0f6a611818f4f6fb7dc83b", size = 1121662, upload-time = "2025-08-07T13:42:41.117Z" },
@@ -1428,7 +1424,6 @@ wheels = [
    { url = "https://files.pythonhosted.org/packages/22/5c/85273fd7cc388285632b0498dbbab97596e04b154933dfe0f3e68156c68c/greenlet-3.2.4-cp314-cp314-macosx_11_0_universal2.whl", hash = "sha256:49a30d5fda2507ae77be16479bdb62a660fa51b1eb4928b524975b3bde77b3c0", size = 273586, upload-time = "2025-08-07T13:16:08.004Z" },
    { url = "https://files.pythonhosted.org/packages/d1/75/10aeeaa3da9332c2e761e4c50d4c3556c21113ee3f0afa2cf5769946f7a3/greenlet-3.2.4-cp314-cp314-manylinux2014_aarch64.manylinux_2_17_aarch64.whl", hash = "sha256:299fd615cd8fc86267b47597123e3f43ad79c9d8a22bebdce535e53550763e2f", size = 686346, upload-time = "2025-08-07T13:42:59.944Z" },
    { url = "https://files.pythonhosted.org/packages/c0/aa/687d6b12ffb505a4447567d1f3abea23bd20e73a5bed63871178e0831b7a/greenlet-3.2.4-cp314-cp314-manylinux2014_ppc64le.manylinux_2_17_ppc64le.whl", hash = "sha256:c17b6b34111ea72fc5a4e4beec9711d2226285f0386ea83477cbb97c30a3f3a5", size = 699218, upload-time = "2025-08-07T13:45:30.969Z" },
-    { url = "https://files.pythonhosted.org/packages/dc/8b/29aae55436521f1d6f8ff4e12fb676f3400de7fcf27fccd1d4d17fd8fecd/greenlet-3.2.4-cp314-cp314-manylinux2014_s390x.manylinux_2_17_s390x.whl", hash = "sha256:b4a1870c51720687af7fa3e7cda6d08d801dae660f75a76f3845b642b4da6ee1", size = 694659, upload-time = "2025-08-07T13:53:17.759Z" },
    { url = "https://files.pythonhosted.org/packages/92/2e/ea25914b1ebfde93b6fc4ff46d6864564fba59024e928bdc7de475affc25/greenlet-3.2.4-cp314-cp314-manylinux2014_x86_64.manylinux_2_17_x86_64.whl", hash = "sha256:061dc4cf2c34852b052a8620d40f36324554bc192be474b9e9770e8c042fd735", size = 695355, upload-time = "2025-08-07T13:18:34.517Z" },
    { url = "https://files.pythonhosted.org/packages/72/60/fc56c62046ec17f6b0d3060564562c64c862948c9d4bc8aa807cf5bd74f4/greenlet-3.2.4-cp314-cp314-manylinux_2_24_x86_64.manylinux_2_28_x86_64.whl", hash = "sha256:44358b9bf66c8576a9f57a590d5f5d6e72fa4228b763d0e43fee6d3b06d3a337", size = 657512, upload-time = "2025-08-07T13:18:33.969Z" },
    { url = "https://files.pythonhosted.org/packages/23/6e/74407aed965a4ab6ddd93a7ded3180b730d281c77b765788419484cdfeef/greenlet-3.2.4-cp314-cp314-musllinux_1_2_aarch64.whl", hash = "sha256:2917bdf657f5859fbf3386b12d68ede4cf1f04c90c3a6bc1f013dd68a22e2269", size = 1612508, upload-time = "2025-11-04T12:42:23.427Z" },
@@ -2028,7 +2023,7 @@ typing = [

 [[package]]
 name = "langchain-anthropic"
-version = "1.3.1"
+version = "1.3.2"
 source = { editable = "../partners/anthropic" }
 dependencies = [
    { name = "anthropic" },
@@ -2038,7 +2033,7 @@ dependencies = [

 [package.metadata]
 requires-dist = [
-    { name = "anthropic", specifier = ">=0.75.0,<1.0.0" },
+    { name = "anthropic", specifier = ">=0.78.0,<1.0.0" },
    { name = "langchain-core", editable = "../core" },
    { name = "pydantic", specifier = ">=2.7.4,<3.0.0" },
 ]
@@ -2404,7 +2399,7 @@ wheels = [

 [[package]]
 name = "langchain-tests"
-version = "1.1.3"
+version = "1.1.4"
 source = { editable = "../standard-tests" }
 dependencies = [
    { name = "httpx" },