List recent runs from LangSmith (root-only by default).

Args: project_name: LangSmith project name (required) is_root: Only return root runs when true (default: True) run_type: Filter by run type (e.g., 'llm', 'chain', 'tool') error: Filter by error status - True=failed only, False=successful only, None=all start_minutes_ago: Lookback window in minutes (default: 1440 = 24 hours, min: 1) limit: Maximum runs to return (default: 50, range: 1-200) select: List of fields to return (default: id, name, run_type, start_time, end_time, error, tags, extra)

Read a single run with optional children hydration.

Args: run_id: Run ID to fetch (required) hydrate_children: Include child spans in response (default: False) child_limit: Maximum children to return when hydrate_children=True (default: 100, range: 1-500)

Generate a shareable LangSmith UI URL for a run.

Args: run_id: Run ID to generate URL for (required)

Returns: Shareable LangSmith URL (e.g., https://smith.langchain.com/o/.../runs/...)

List child spans for a given parent run.

Args: parent_run_id: Parent run ID (required) limit: Maximum children to return (default: 100, range: 1-500)

Returns: List of child run objects with id, name, run_type, timing, and error info

List projects from LangSmith workspace.

Args: limit: Maximum projects to return (default: 10, range: 1-200)

Returns: List of project objects with id, name, start_time, tenant_id, and optional statistics