diff --git a/internal/cloud/otel-trace.ts b/internal/cloud/otel-trace.ts
index 1c6a9ab9..53ca3ed4 100644
--- a/internal/cloud/otel-trace.ts
+++ b/internal/cloud/otel-trace.ts
@@ -273,6 +273,7 @@ export async function emitHttpServerRequestSpan(context, env = process.env, opti
     "http.response.status_code": statusCode || null,
     "http.response.status_class": statusClassValue,
     "hwlab.http.stage": "http.server.request",
+    ...options.attributes,
     ...(errorCode ? { "error.code": errorCode, "error.category": options.errorCategory ?? null, "error.layer": options.errorLayer ?? null } : {})
   };
   const body = {
diff --git a/internal/cloud/server-workbench-http.ts b/internal/cloud/server-workbench-http.ts
index f072d69e..a46f6f48 100644
--- a/internal/cloud/server-workbench-http.ts
+++ b/internal/cloud/server-workbench-http.ts
@@ -124,6 +124,13 @@ export async function handleWorkbenchRealtimeHttp(request, response, url, option
   const activeTraceId = requestedTraceId
     ?? safeTraceId(initialSession?.lastTraceId ?? initialSessionSnapshot.lastTraceId ?? initialSessionSnapshot.currentTraceId)
     ?? null;
+  attachWorkbenchRealtimeOtelContext(request, {
+    sessionId: streamSessionId ?? requestedSessionId,
+    traceId: activeTraceId,
+    threadId: streamThreadId,
+    heartbeatMs,
+    outboxMode: typeof (options.runtimeStore ?? null)?.readWorkbenchProjectionOutbox === "function"
+  });
   if (activeTraceId) {
     await (perf ? perf.measure("workbench_initial_trace", () => writeTraceRealtimeSnapshot({ writeEvent, options, actor: auth.actor, traceId: activeTraceId, reason: "initial" })) : writeTraceRealtimeSnapshot({ writeEvent, options, actor: auth.actor, traceId: activeTraceId, reason: "initial" }));
     const runtimeStore = options.runtimeStore ?? null;
@@ -222,6 +229,22 @@ export async function handleWorkbenchRealtimeHttp(request, response, url, option
   });
 }
 
+function attachWorkbenchRealtimeOtelContext(request, fields = {}) {
+  const context = request?.hwlabHttpRequestContext;
+  if (!context) return;
+  context.route = "/v1/workbench/events";
+  context.otelAttributes = {
+    ...(context.otelAttributes ?? {}),
+    "workbench.route": "events",
+    "workbench.session_id": fields.sessionId ?? null,
+    traceId: fields.traceId ?? null,
+    "workbench.trace_id": fields.traceId ?? null,
+    "workbench.thread_id": fields.threadId ?? null,
+    "workbench.sse.heartbeat_ms": fields.heartbeatMs ?? null,
+    "workbench.sse.outbox_mode": fields.outboxMode === true
+  };
+}
+
 function realtimeEventCreatedAt(payload) {
   const candidates = [payload?.event?.createdAt, payload?.snapshot?.lastEvent?.createdAt, payload?.turn?.updatedAt];
   for (const value of candidates) {
diff --git a/internal/cloud/server.ts b/internal/cloud/server.ts
index 050d3c0b..28c56d0b 100644
--- a/internal/cloud/server.ts
+++ b/internal/cloud/server.ts
@@ -131,23 +131,32 @@ export function createCloudApiServer(options = {}) {
     const requestContext = buildHttpRequestContext(request);
     attachHttpRequestContext(request, response, requestContext);
     const backendPerformance = backendPerformanceStore.beginHttpRequest(request, response);
-    response.once("finish", () => {
+    let otelHttpSpanEmitted = false;
+    const emitHttpSpan = (closedBy) => {
+      if (otelHttpSpanEmitted) return;
+      otelHttpSpanEmitted = true;
       const httpCtx = request.hwlabHttpRequestContext;
       if (!httpCtx?.traceId) return;
       if (isOtelNoisyProbeRoute(httpCtx.route)) return;
       const lastError = httpCtx.lastHttpError;
       void emitHttpServerRequestSpan(httpCtx, env, {
-        startTimeMs: backendPerformance.startedAt,
+        startTimeMs: httpCtx.startedAtMs,
         endTimeMs: Date.now(),
         statusCode: Number(response.statusCode ?? backendPerformance.statusCode ?? 0),
         method: backendPerformance.method || httpCtx.method,
         route: backendPerformance.route || httpCtx.route,
+        attributes: {
+          "http.closed_by": closedBy,
+          ...(httpCtx.otelAttributes ?? {})
+        },
         errorCode: lastError?.code,
         errorCategory: lastError?.category,
         errorLayer: lastError?.layer,
         statusMessage: lastError?.code
       }).catch(() => undefined);
-    });
+    };
+    response.once("finish", () => emitHttpSpan("finish"));
+    response.once("close", () => emitHttpSpan("close"));
     await withBackendPerformanceContext(backendPerformance, async () => {
       try {
         await routeRequest(request, response, { ...options, env, runtimeStore, gatewayRegistry, hwpodNodeWsRegistry, accessController, sessionRegistry, traceStore, codexStdioManager, codeAgentChatResults, webPerformanceStore, backendPerformanceStore, backendPerformance });
@@ -178,6 +187,7 @@ function buildHttpRequestContext(request) {
   });
   return {
     requestId: safeRequestId(getHeader(request, "x-request-id")) || `req_${randomUUID()}`,
+    startedAtMs: Date.now(),
     traceId: otelContext.traceId,
     parentSpanId: otelContext.parentSpanId,
     spanId: otelContext.spanId,