hub push/pull (#9225)

Description: Adds push/pull functions to interact with the hub
Issue: n/a
Dependencies: `langchainhub`

---------

Co-authored-by: Bagatur <baskaryan@gmail.com>

libs/langchain/langchain/hub.py

@@ -0,0 +1,60 @@
+"""Push and pull to the LangChain Hub."""
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any, Optional
+
+from langchain.load.dump import dumps
+from langchain.load.load import loads
+from langchain.utils import get_from_env
+
+if TYPE_CHECKING:
+    from langchainhub import Client
+
+
+def _get_client(api_url: Optional[str] = None, api_key: Optional[str] = None) -> Client:
+    try:
+        from langchainhub import Client
+    except ImportError as e:
+        raise ImportError(
+            "Could not import langchainhub, please install with `pip install "
+            "langchainhub`."
+        ) from e
+
+    api_url = api_url or get_from_env("api_url", "LANGCHAIN_HUB_API_URL")
+    api_key = api_key or get_from_env("api_key", "LANGCHAIN_HUB_API_KEY", default="")
+    api_key = api_key or get_from_env("api_key", "LANGCHAIN_API_KEY")
+    return Client(api_url, api_key=api_key)
+
+
+def push(
+    repo_full_name: str,
+    object: Any,
+    *,
+    api_url: Optional[str] = None,
+    api_key: Optional[str] = None,
+    parent_commit_hash: Optional[str] = "latest",
+) -> str:
+    """
+    Pushes an object to the hub and returns the URL.
+    """
+    client = _get_client(api_url=api_url, api_key=api_key)
+    manifest_json = dumps(object)
+    resp = client.push(
+        repo_full_name, manifest_json, parent_commit_hash=parent_commit_hash
+    )
+    commit_hash: str = resp["commit"]["commit_hash"]
+    return commit_hash
+
+
+def pull(
+    owner_repo_commit: str,
+    *,
+    api_url: Optional[str] = None,
+    api_key: Optional[str] = None,
+) -> Any:
+    """
+    Pulls an object from the hub and returns it.
+    """
+    client = _get_client(api_url=api_url, api_key=api_key)
+    resp: str = client.pull(owner_repo_commit)
+    return loads(resp)