feat: support custom tracer when creating run in ts sdk

libs/sdk-js/src/client.ts

@@ -979,6 +979,7 @@ export class RunsClient<
       after_seconds: payload?.afterSeconds,
       if_not_exists: payload?.ifNotExists,
       checkpoint_during: payload?.checkpointDuring,
+      langsmith_tracer: payload?._langsmithTracer,
     };
 
     const [run, response] = await this.fetch<Run>(`/threads/${threadId}/runs`, {
@@ -1059,6 +1060,7 @@ export class RunsClient<
       after_seconds: payload?.afterSeconds,
       if_not_exists: payload?.ifNotExists,
       checkpoint_during: payload?.checkpointDuring,
+      langsmith_tracer: payload?._langsmithTracer,
     };
     const endpoint =
       threadId == null ? `/runs/wait` : `/threads/${threadId}/runs/wait`;

libs/sdk-js/src/types.ts

@@ -140,6 +140,15 @@ interface RunsInvokePayload {
    * Callback when a run is created.
    */
   onRunCreated?: (params: { run_id: string; thread_id?: string }) => void;
+
+  /**
+   * @internal
+   * For LangSmith tracing purposes only. Not part of the public API.
+   */
+  _langsmithTracer?: {
+    project_name: string;
+    example_id: string;
+  };
 }
 
 export interface RunsStreamPayload<