fix(core): Release LS trace clients on run finalization (no-changelog) (#28254)

Signed-off-by: Oleg Ivaniv <me@olegivaniv.com>

Author: OlegIvaniv

packages/@n8n/instance-ai/src/index.ts

@@ -17,6 +17,7 @@ export type { DomainAccessTracker } from './domain-access';
 export {
 	createInstanceAiTraceContext,
 	continueInstanceAiTraceContext,
+	releaseTraceClient,
 	withCurrentTraceSpan,
 } from './tracing/langsmith-tracing';
 export { createInstanceAgent } from './agent/instance-agent';

packages/@n8n/instance-ai/src/tracing/langsmith-tracing.ts

@@ -423,6 +423,15 @@ function mergeRunTreeInputs(
 	};
 }
 
+/**
+ * Unconditionally remove the cached LangSmith Client for a trace.
+ * Call after run finalization (success or failure) so the Client and
+ * its RunTree hierarchy can be garbage-collected.
+ */
+export function releaseTraceClient(traceId: string): void {
+	traceClients.delete(traceId);
+}
+
 export function getTraceParentRun(): RunTree | undefined {
 	const overrideRun = traceParentOverrideStorage.getStore()?.current;
 	if (overrideRun) {

packages/cli/src/modules/instance-ai/instance-ai.service.ts

@@ -34,6 +34,7 @@ import {
 	PlannedTaskCoordinator,
 	PlannedTaskStorage,
 	applyPlannedTaskPermissions,
+	releaseTraceClient,
 	resumeAgentRun,
 	RunStateRegistry,
 	startBuildWorkflowAgentTask,
@@ -544,6 +545,8 @@ export class InstanceAiService {
 				threadId: tracing.rootRun.metadata?.thread_id,
 				error: getErrorMessage(error),
 			});
+		} finally {
+			releaseTraceClient(tracing.rootRun.traceId);
 		}
 	}
 
@@ -574,6 +577,7 @@ export class InstanceAiService {
 	private deleteTraceContextsForThread(threadId: string): void {
 		for (const [runId, entry] of this.traceContextsByRunId) {
 			if (entry.threadId === threadId) {
+				releaseTraceClient(entry.tracing.rootRun.traceId);
 				this.traceContextsByRunId.delete(runId);
 			}
 		}
@@ -609,6 +613,8 @@ export class InstanceAiService {
 				traceRunId: traceContext.rootRun.id,
 				error: getErrorMessage(error),
 			});
+		} finally {
+			releaseTraceClient(traceContext.rootRun.traceId);
 		}
 	}