fix(sdk-py): expose ls_user_id on StudioUser

Shows an actionable, docs-linked error when `langgraph deploy` is run
without a `langgraph.json` instead of exposing a traceback.

libs/cli/langgraph_cli/deploy.py

@@ -1603,6 +1603,16 @@ def _deploy_cmd(
 
     # -- 1. Preflight --
     validate_deploy_commands(install_command, build_command)
+    if not config.exists():
+        message = (
+            "We couldn't find a langgraph.json file. Run `langgraph deploy` from "
+            "the root of a LangSmith Deployment project. To get started, visit "
+            "https://docs.langchain.com/langsmith/deployment-quickstart."
+        )
+        if json_output:
+            em.error(message)
+            raise click.exceptions.Exit(1)
+        raise click.ClickException(message)
     config_json = langgraph_cli.config.validate_config_file(config)
     warn_non_wolfi_distro(config_json, emit=em.note)
 

libs/cli/tests/unit_tests/cli/test_cli.py

@@ -320,6 +320,31 @@ def test_top_level_help_truncates_command_descriptions_to_single_line() -> None:
     assert "[Beta] List LangSmith Deployments." in deploy_list_line
 
 
+def test_deploy_missing_config_shows_actionable_error(tmp_path, monkeypatch) -> None:
+    runner = CliRunner()
+    monkeypatch.chdir(tmp_path)
+
+    result = runner.invoke(cli, ["deploy"])
+
+    assert result.exit_code == 1
+    assert "We couldn't find a langgraph.json file." in result.output
+    assert "Run `langgraph deploy` from the root" in result.output
+    assert "https://docs.langchain.com/langsmith/deployment-quickstart" in result.output
+    assert "Traceback" not in result.output
+
+
+def test_deploy_missing_config_emits_json_error(tmp_path, monkeypatch) -> None:
+    runner = CliRunner()
+    monkeypatch.chdir(tmp_path)
+
+    result = runner.invoke(cli, ["deploy", "--json"])
+
+    assert result.exit_code == 1
+    events = [json.loads(line) for line in result.output.splitlines()]
+    assert events[-1]["event"] == "error"
+    assert "We couldn't find a langgraph.json file." in events[-1]["message"]
+
+
 def test_dev_command_requires_ssl_certfile_and_keyfile_together(tmp_path) -> None:
     config_path = tmp_path / "langgraph.json"
     config_path.write_text(

libs/sdk-py/langgraph_sdk/auth/types.py

@@ -218,6 +218,8 @@ class BaseUser(typing.Protocol):
 class StudioUser:
     """A user object that's populated from authenticated requests from the LangGraph studio.
 
+    `ls_user_id` is the canonical LangSmith user ID when supplied by Agent Server.
+
     Note: Studio auth can be disabled in your `langgraph.json` config.
 
     ```json
@@ -250,10 +252,11 @@ class StudioUser:
         ```
     """
 
-    __slots__ = ("_is_authenticated", "_permissions", "username")
+    __slots__ = ("_is_authenticated", "_permissions", "ls_user_id", "username")
 
     def __init__(self, username: str, is_authenticated: bool = False) -> None:
         self.username = username
+        self.ls_user_id: str | None = None
         self._is_authenticated = is_authenticated
         self._permissions = ["authenticated"] if is_authenticated else []
 

libs/sdk-py/tests/test_auth.py

@@ -1,8 +1,22 @@
 import pytest
+from typing_extensions import assert_type
 
 from langgraph_sdk import Auth
 
 
+def test_studio_user_langsmith_id() -> None:
+    def langsmith_id(user: object) -> str | None:
+        if isinstance(user, Auth.types.StudioUser):
+            return assert_type(user.ls_user_id, str | None)
+        return None
+
+    user = Auth.types.StudioUser("login-user", is_authenticated=True)
+    assert langsmith_id(user) is None
+    user.ls_user_id = "langsmith-user"
+    assert langsmith_id(user) == "langsmith-user"
+    assert user.identity == "login-user"
+
+
 def test_handler_multiple_resources_and_actions() -> None:
     auth = Auth()