Read a run.
.. admonition:: Deprecated
Use :meth:`langsmith.AsyncClient.runs.retrieve` instead.
See https://docs.langchain.com/langsmith/smithdb-sdk-migration#runs-retrieve for the migration guide.
Will be removed after Jan 31, 2027.
The ID of the run to read.
The ID of the project (session) that owns the run. Required on SmithDB-only backends (no ClickHouse query support), where it's used to look up the run via the v2 API.