diff --git a/cmd/hwlab-workbench-api/main.ts b/cmd/hwlab-workbench-api/main.ts
index 06ebea33..03915edd 100644
--- a/cmd/hwlab-workbench-api/main.ts
+++ b/cmd/hwlab-workbench-api/main.ts
@@ -3,7 +3,7 @@ import { createWorkbenchHttpApp } from "../../internal/workbench/http.ts";
 import { workbenchRuntime } from "../../internal/workbench/runtime.ts";
 import { startHwlabKafkaEventBridge } from "../../internal/cloud/kafka-event-bridge.ts";
 
-const runtime = workbenchRuntime();
+const runtime = workbenchRuntime(process.env, { eventPublisher: null });
 const kafkaEventBridge = runtime.mode === "agentrun-native" ? startHwlabKafkaEventBridge({ env: process.env }) : null;
 const app = createWorkbenchHttpApp({ dispatch: runtime.dispatch, snapshot: runtime.application.snapshot?.bind(runtime.application), authorization: process.env.WORKBENCH_API_AUTHORIZATION, mode: runtime.mode, kafkaEventBridge, close: async () => { await kafkaEventBridge?.stop?.(); await runtime.close(); } });
 const host = process.env.WORKBENCH_API_HOST || "0.0.0.0";
diff --git a/internal/workbench/runtime.ts b/internal/workbench/runtime.ts
index f4970e94..1e5ffa13 100644
--- a/internal/workbench/runtime.ts
+++ b/internal/workbench/runtime.ts
@@ -9,11 +9,15 @@ import { createWorkbenchTemporalGateway } from "./temporal.ts";
 import { createWorkbenchKafkaEventPublisher } from "./kafka-event-publisher.ts";
 import type { WorkbenchEventPublisher } from "./contracts.ts";
 
-export function workbenchRuntime(env: Record<string, string | undefined> = process.env, options: { eventPublisher?: WorkbenchEventPublisher } = {}) {
+export function workbenchRuntime(env: Record<string, string | undefined> = process.env, options: { eventPublisher?: WorkbenchEventPublisher | null } = {}) {
   const mode = String(env.WORKBENCH_MODE ?? "").trim();
   if (mode !== "native-test" && mode !== "agentrun-native" && mode !== "temporal") throw codedError("workbench_mode_required", "WORKBENCH_MODE must be native-test, agentrun-native, or temporal");
   const stateFile = path.resolve(String(env.WORKBENCH_NATIVE_STATE_FILE ?? ".state/workbench-native/state.json"));
-  const eventPublisher = mode === "native-test" ? null : options.eventPublisher ?? createWorkbenchKafkaEventPublisher({ env });
+  const eventPublisher = mode === "native-test"
+    ? null
+    : Object.hasOwn(options, "eventPublisher")
+      ? options.eventPublisher ?? null
+      : createWorkbenchKafkaEventPublisher({ env });
   const application = mode === "native-test"
     ? createNativeTestWorkbenchApplication({ stateFile })
     : mode === "agentrun-native"
diff --git a/internal/workbench/workbench.test.ts b/internal/workbench/workbench.test.ts
index 00901d8d..f62010fc 100644
--- a/internal/workbench/workbench.test.ts
+++ b/internal/workbench/workbench.test.ts
@@ -5,8 +5,26 @@ import { createWorkbenchActivities } from "./activities.ts";
 import { createWorkbenchDispatcher } from "./dispatcher.ts";
 import { createCloudWorkbenchApplication } from "./cloud-application.ts";
 import { createWorkbenchHttpApp } from "./http.ts";
+import { workbenchRuntime } from "./runtime.ts";
 import { runWorkbenchCli } from "../../tools/src/workbench-cli.ts";
 
+test("temporal API runtime does not require worker Kafka publisher configuration", async () => {
+  const runtime = workbenchRuntime({
+    WORKBENCH_MODE: "temporal",
+    WORKBENCH_CLOUD_API_URL: "http://cloud.internal",
+    WORKBENCH_CLOUD_API_AUTHORIZATION: "internal-key",
+    WORKBENCH_TEMPORAL_ADDRESS: "127.0.0.1:7233",
+    WORKBENCH_TEMPORAL_NAMESPACE: "unidesk",
+    WORKBENCH_TEMPORAL_TASK_QUEUE: "hwlab-v03-workbench",
+    WORKBENCH_ACTIVITY_START_TO_CLOSE_TIMEOUT_MS: "30000",
+    WORKBENCH_ACTIVITY_RETRY_INITIAL_INTERVAL_MS: "1000",
+    WORKBENCH_ACTIVITY_RETRY_MAXIMUM_INTERVAL_MS: "30000",
+    WORKBENCH_ACTIVITY_RETRY_MAXIMUM_ATTEMPTS: "5"
+  }, { eventPublisher: null });
+  expect(runtime.eventPublisher).toBeNull();
+  await runtime.close();
+});
+
 describe("Workbench dispatcher", () => {
   test("submits through Temporal without synthesizing terminal state", async () => {
     const calls: string[] = [];