diff --git a/src/mgr/server.ts b/src/mgr/server.ts
index 0cc1265..342e441 100644
--- a/src/mgr/server.ts
+++ b/src/mgr/server.ts
@@ -908,8 +908,21 @@ async function route({ method, url, body, store, sourceCommit, authSummary, runn
   }
   if (method === "POST" && path === "/api/v1/reconciler/runner-jobs") {
     const record = body === null ? {} : asRecord(body, "runnerReconciler");
-    const limit = Math.max(1, Math.min(numberField(record, "limit", runnerReconcilerOptions?.batchSize ?? 20), 500));
-    const namespace = optionalString(record.namespace) ?? runnerReconcilerOptions?.namespace ?? process.env.AGENTRUN_RUNTIME_NAMESPACE ?? "agentrun-v01";
+    const requestedLimit = Math.max(1, Math.min(numberField(record, "limit", runnerReconcilerOptions.batchSize), 500));
+    const limit = Math.min(requestedLimit, runnerReconcilerOptions.batchSize);
+    const requestedNamespace = optionalString(record.namespace);
+    if (requestedNamespace !== null && requestedNamespace !== runnerReconcilerOptions.namespace) {
+      throw new AgentRunError("tenant-policy-denied", "runner reconciler namespace is fixed by manager runtime configuration", {
+        httpStatus: 403,
+        details: {
+          reason: "runner-reconciler-namespace-override-denied",
+          configuredNamespace: runnerReconcilerOptions.namespace,
+          requestedNamespace,
+          valuesPrinted: false,
+        },
+      });
+    }
+    const namespace = runnerReconcilerOptions.namespace;
     return await reconcileRunnerJobsOnce({
       store,
       namespace,
diff --git a/src/selftest/cases/22-runner-retention-stale-pending.ts b/src/selftest/cases/22-runner-retention-stale-pending.ts
index 0738388..d7e90ef 100644
--- a/src/selftest/cases/22-runner-retention-stale-pending.ts
+++ b/src/selftest/cases/22-runner-retention-stale-pending.ts
@@ -168,7 +168,7 @@ const selfTest: SelfTestCase = async (context) => {
       "periodic-reconciler-protects-unsafe-runners",
       "periodic-reconciler-cas-conflict-fails-closed",
       "periodic-reconciler-namespace-fence-prevents-duplicate-terminalization",
-      "controlled-reconcile-api-exposes-bounded-retention-result",
+      "controlled-reconcile-api-enforces-yaml-batch-and-namespace",
       "automatic-reconciler-reports-next-schedule",
     ],
   };
@@ -609,15 +609,15 @@ async function assertConcurrentPeriodicReconcileIsSerialized(input: { fixturePat
 }
 
 async function assertControlledReconcileApiExposesRetention(input: { fixturePath: string; statePath: string; kubectlCommand: string }): Promise<void> {
-  const fact = pendingFact(350, new Date(Date.now() - 60 * 60_000).toISOString());
+  const facts = [350, 351].map((index) => pendingFact(index, new Date(Date.now() - 60 * 60_000).toISOString()));
   await writeFixture(input, {
-    jobs: [runnerJob(fact, 350)],
-    pods: [runnerPod(fact, 350, "pending")],
-    events: [failedMountEvent(fact, 350)],
+    jobs: facts.map((fact, index) => runnerJob(fact, index + 350)),
+    pods: facts.map((fact, index) => runnerPod(fact, index + 350, "pending")),
+    events: facts.map((fact, index) => failedMountEvent(fact, index + 350)),
     bumpJobResourceVersionAfterPodDelete: true,
     bumpedJobResourceVersion: "2",
   });
-  const store = new RetentionFactStore([fact]);
+  const store = new RetentionFactStore(facts);
   const retention = retentionOptions(input.kubectlCommand, 20);
   const server = await startManagerServer({
     port: 0,
@@ -644,8 +644,10 @@ async function assertControlledReconcileApiExposesRetention(input: { fixturePath
     },
   });
   try {
-    const summary = await new ManagerClient(server.baseUrl).post("/api/v1/reconciler/runner-jobs", { limit: 1, namespace: "agentrun-nc01-v02" }) as JsonRecord;
+    const client = new ManagerClient(server.baseUrl);
+    const summary = await client.post("/api/v1/reconciler/runner-jobs", { limit: 500 }) as JsonRecord;
     const cleanup = summary.stalePendingRetention as JsonRecord;
+    assert.equal(summary.limit, 1);
     assert.equal(cleanup.enabled, true);
     assert.equal(cleanup.selectedRunnerCount, 1);
     assert.equal(cleanup.terminalizedRunCount, 1);
@@ -654,6 +656,14 @@ async function assertControlledReconcileApiExposesRetention(input: { fixturePath
     assert.equal(cleanup.valuesPrinted, false);
     assert.equal(summary.nextReconcileAt, null);
     assert.equal(JSON.stringify(summary).includes("abc123-secret-value"), false);
+    assert.equal(store.getRun((facts[1] as RetentionFact).run.id).status, "pending");
+    await assert.rejects(
+      () => client.post("/api/v1/reconciler/runner-jobs", { limit: 1, namespace: "another-runtime" }),
+      (error) => error instanceof AgentRunError
+        && error.failureKind === "tenant-policy-denied"
+        && ((((error.details?.error as JsonRecord | undefined)?.details) as JsonRecord | undefined)?.reason) === "runner-reconciler-namespace-override-denied",
+    );
+    assert.equal(store.getRun((facts[1] as RetentionFact).run.id).status, "pending");
   } finally {
     await new Promise<void>((resolve) => server.server.close(() => resolve()));
   }