langchain: default to langsmith sdk for pulling prompts, fallback to langchainhub (#24156)

**Description:** Deprecating langchainhub, replacing with langsmith sdk

libs/langchain/langchain/hub.py

@@ -3,28 +3,38 @@
 from __future__ import annotations
 
 import json
-from typing import TYPE_CHECKING, Any, Optional
+from typing import Any, Optional, Sequence
 
 from langchain_core.load.dump import dumps
 from langchain_core.load.load import loads
 from langchain_core.prompts import BasePromptTemplate
 
-if TYPE_CHECKING:
-    from langchainhub import Client
 
-
-def _get_client(api_url: Optional[str] = None, api_key: Optional[str] = None) -> Client:
+def _get_client(
+    api_key: Optional[str] = None,
+    api_url: Optional[str] = None,
+) -> Any:
     try:
-        from langchainhub import Client
+        from langsmith import Client as LangSmithClient
+
+        ls_client = LangSmithClient(api_url, api_key=api_key)
+        if hasattr(ls_client, "push_prompt") and hasattr(ls_client, "pull_prompt"):
+            return ls_client
+        else:
+            from langchainhub import Client as LangChainHubClient
+
+            return LangChainHubClient(api_url, api_key=api_key)
+    except ImportError:
+        try:
+            from langchainhub import Client as LangChainHubClient
+
+            return LangChainHubClient(api_url, api_key=api_key)
         except ImportError as e:
             raise ImportError(
-            "Could not import langchainhub, please install with `pip install "
-            "langchainhub`."
+                "Could not import langsmith or langchainhub (deprecated),"
+                "please install with `pip install langsmith`."
             ) from e
 
-    # Client logic will also attempt to load URL/key from environment variables
-    return Client(api_url, api_key=api_key)
-
 
 def push(
     repo_full_name: str,
@@ -32,27 +42,43 @@ def push(
     *,
     api_url: Optional[str] = None,
     api_key: Optional[str] = None,
-    parent_commit_hash: Optional[str] = "latest",
-    new_repo_is_public: bool = True,
-    new_repo_description: str = "",
+    parent_commit_hash: Optional[str] = None,
+    new_repo_is_public: bool = False,
+    new_repo_description: Optional[str] = None,
+    readme: Optional[str] = None,
+    tags: Optional[Sequence[str]] = None,
 ) -> str:
     """
     Push an object to the hub and returns the URL it can be viewed at in a browser.
 
-    :param repo_full_name: The full name of the repo to push to in the format of
-        `owner/repo`.
+    :param repo_full_name: The full name of the prompt to push to in the format of
+        `owner/prompt_name` or `prompt_name`.
     :param object: The LangChain to serialize and push to the hub.
     :param api_url: The URL of the LangChain Hub API. Defaults to the hosted API service
         if you have an api key set, or a localhost instance if not.
     :param api_key: The API key to use to authenticate with the LangChain Hub API.
     :param parent_commit_hash: The commit hash of the parent commit to push to. Defaults
         to the latest commit automatically.
-    :param new_repo_is_public: Whether the repo should be public. Defaults to
-        True (Public by default).
-    :param new_repo_description: The description of the repo. Defaults to an empty
+    :param new_repo_is_public: Whether the prompt should be public. Defaults to
+        False (Private by default).
+    :param new_repo_description: The description of the prompt. Defaults to an empty
         string.
     """
-    client = _get_client(api_url=api_url, api_key=api_key)
+    client = _get_client(api_key=api_key, api_url=api_url)
+
+    # Then it's langsmith
+    if hasattr(client, "push_prompt"):
+        return client.push_prompt(
+            repo_full_name,
+            object=object,
+            parent_commit_hash=parent_commit_hash,
+            is_public=new_repo_is_public,
+            description=new_repo_description,
+            readme=readme,
+            tags=tags,
+        )
+
+    # Then it's langchainhub
     manifest_json = dumps(object)
     message = client.push(
         repo_full_name,
@@ -67,20 +93,28 @@ def push(
 def pull(
     owner_repo_commit: str,
     *,
+    include_model: Optional[bool] = None,
     api_url: Optional[str] = None,
     api_key: Optional[str] = None,
 ) -> Any:
     """
     Pull an object from the hub and returns it as a LangChain object.
 
-    :param owner_repo_commit: The full name of the repo to pull from in the format of
-        `owner/repo:commit_hash`.
+    :param owner_repo_commit: The full name of the prompt to pull from in the format of
+        `owner/prompt_name:commit_hash` or `owner/prompt_name`
+        or just `prompt_name` if it's your own prompt.
     :param api_url: The URL of the LangChain Hub API. Defaults to the hosted API service
         if you have an api key set, or a localhost instance if not.
     :param api_key: The API key to use to authenticate with the LangChain Hub API.
     """
-    client = _get_client(api_url=api_url, api_key=api_key)
+    client = _get_client(api_key=api_key, api_url=api_url)
 
+    # Then it's langsmith
+    if hasattr(client, "pull_prompt"):
+        response = client.pull_prompt(owner_repo_commit, include_model=include_model)
+        return response
+
+    # Then it's langchainhub
     if hasattr(client, "pull_repo"):
         # >= 0.1.15
         res_dict = client.pull_repo(owner_repo_commit)
@@ -93,6 +127,6 @@ def pull(
             obj.metadata["lc_hub_commit_hash"] = res_dict["commit_hash"]
         return obj
 
-    # Then it's < 0.1.15
+    # Then it's < 0.1.15 langchainhub
     resp: str = client.pull(owner_repo_commit)
     return loads(resp)