diff --git a/src/daemon/__tests__/request-router-cost.test.ts b/src/daemon/__tests__/request-router-cost.test.ts
index d32bf15fe..1e79a9b4b 100644
--- a/src/daemon/__tests__/request-router-cost.test.ts
+++ b/src/daemon/__tests__/request-router-cost.test.ts
@@ -17,6 +17,7 @@ vi.mock('../device-ready.ts', () => ({ ensureDeviceReady: vi.fn(async () => {})
 
 import { dispatchCommand } from '../../core/dispatch.ts';
 import { createRequestHandler } from '../request-router.ts';
+import { emitDiagnostic } from '../../utils/diagnostics.ts';
 import type { DaemonRequest, SessionState } from '../types.ts';
 import { LeaseRegistry } from '../lease-registry.ts';
 import { makeSessionStore } from '../../__tests__/test-utils/store-factory.ts';
@@ -110,9 +111,12 @@ test('(b) flag-on additive-only: cost block is the ONLY delta vs flag-off', asyn
   expect(respFlagOn.ok).toBe(true);
   if (!respFlagOff.ok || !respFlagOn.ok) return;
 
+  // The cost block carries BOTH wallClockMs and runnerRoundTrips, both numbers
+  // ≥ 0. A request that never touches the iOS runner reports 0 — honest.
   const cost = respFlagOn.data?.cost;
   expect(cost).toMatchObject({
     wallClockMs: expect.any(Number),
+    runnerRoundTrips: 0,
   });
   expect(cost?.wallClockMs).toBeGreaterThanOrEqual(0);
   // This payload has no node tree, so nodeCount is omitted entirely.
@@ -123,7 +127,30 @@ test('(b) flag-on additive-only: cost block is the ONLY delta vs flag-off', asyn
   expect(respFlagOn.data).toEqual(respFlagOff.data);
 });
 
-test('(c) nodeCount reports the node-tree size whenever data carries a nodes array, additive-only', async () => {
+test('(c) runnerRoundTrips counts real iOS-runner round-trip diagnostics in scope', async () => {
+  const { sessionStore, handler } = makeHandler();
+  sessionStore.set('cost-session', makeIosSession('cost-session'));
+
+  // The mocked dispatch runs inside the request's diagnostics scope, so emitting
+  // here is equivalent to the runner-session emitting these phases per round-trip.
+  mockDispatch.mockImplementation(async () => {
+    emitDiagnostic({ phase: 'ios_runner_readiness_preflight' }); // real round-trip
+    emitDiagnostic({ phase: 'ios_runner_command_send' }); // real round-trip
+    emitDiagnostic({ phase: 'ios_runner_command_send' }); // real round-trip
+    emitDiagnostic({ level: 'debug', phase: 'ios_runner_readiness_preflight_skipped' }); // NOT
+    emitDiagnostic({ phase: 'some_other_phase' }); // NOT
+    return { ...REPRESENTATIVE_PAYLOAD };
+  });
+
+  const resp = await handler(baseRequest({ meta: { includeCost: true } }));
+  expect(resp.ok).toBe(true);
+  if (!resp.ok) return;
+  // 1 preflight + 2 command_send = 3; the _skipped marker and unrelated phases
+  // are excluded.
+  expect(resp.data?.cost?.runnerRoundTrips).toBe(3);
+});
+
+test('(c2) nodeCount reports the node-tree size whenever data carries a nodes array, additive-only', async () => {
   const { sessionStore, handler } = makeHandler();
   sessionStore.set('cost-session', makeIosSession('cost-session'));
 
diff --git a/src/daemon/request-router.ts b/src/daemon/request-router.ts
index 53e5210d4..dd6f0bd3c 100644
--- a/src/daemon/request-router.ts
+++ b/src/daemon/request-router.ts
@@ -22,6 +22,7 @@ import {
   withRequestPlatformProviderScope,
 } from './request-platform-providers.ts';
 import {
+  countDiagnosticEventsByPhase,
   emitDiagnostic,
   flushDiagnosticsToSessionFile,
   getDiagnosticsMeta,
@@ -344,12 +345,26 @@ function applyResponseLevelView(
   return view ? { ok: true, data: view(response.data ?? {}, level) } : response;
 }
 
+// Diagnostic phases emitted once per real iOS-runner round-trip. `..._command_send`
+// is the command itself; `..._readiness_preflight` is the pre-command uptime probe
+// (a real network round-trip). The `..._skipped` / `..._recovered` markers do NOT
+// hit the runner and are intentionally excluded.
+const RUNNER_ROUND_TRIP_PHASES = [
+  'ios_runner_command_send',
+  'ios_runner_readiness_preflight',
+] as const;
+
 function buildResponseCost(
   originalData: DaemonResponseData | undefined,
   startedAt: number,
 ): ResponseCost {
   const cost: ResponseCost = {
     wallClockMs: Date.now() - startedAt,
+    // Counts this request's real runner round-trips from the flush-surviving
+    // diagnostics phase tally. Reads 0 when no runner was hit (e.g. a no-op or a
+    // command served entirely from the daemon). Must run inside the request's
+    // diagnostics scope (see `applyAgentCostGrafts` call site).
+    runnerRoundTrips: countDiagnosticEventsByPhase(RUNNER_ROUND_TRIP_PHASES),
   };
   // nodeCount reads the ORIGINAL node tree (the digest view may have already
   // collapsed `data.nodes`), so the count stays accurate.
diff --git a/src/kernel/contracts.ts b/src/kernel/contracts.ts
index 56a19a75d..c1509423d 100644
--- a/src/kernel/contracts.ts
+++ b/src/kernel/contracts.ts
@@ -120,6 +120,10 @@ export type DaemonArtifact = {
 
 export type ResponseCost = {
   wallClockMs: number;
+  // Number of real iOS-runner round-trips made while serving the request (the
+  // `ios_runner_command_send` + `ios_runner_readiness_preflight` diagnostic
+  // phases). Always present when cost is included; 0 when no runner was hit.
+  runnerRoundTrips: number;
   // Number of UI/accessibility nodes in the response, when the command returns a
   // node tree (e.g. snapshot). Absent for commands that produce no nodes, so an
   // agent can size a snapshot before re-fetching at a different depth/scope.
diff --git a/src/utils/diagnostics.ts b/src/utils/diagnostics.ts
index 5e176e690..f3e2daf45 100644
--- a/src/utils/diagnostics.ts
+++ b/src/utils/diagnostics.ts
@@ -86,6 +86,22 @@ export function getDiagnosticsMeta(): {
   };
 }
 
+/**
+ * Sum the number of diagnostic events emitted in the current scope whose phase
+ * is one of `phases`. Backed by the flush-surviving `phaseCounts` tally, so it
+ * stays accurate for the whole request even under `--debug` (where `events` is
+ * streamed out and reset). Returns 0 when called outside a diagnostics scope.
+ */
+export function countDiagnosticEventsByPhase(phases: readonly string[]): number {
+  const scope = diagnosticsStorage.getStore();
+  if (!scope) return 0;
+  let total = 0;
+  for (const phase of phases) {
+    total += scope.phaseCounts.get(phase) ?? 0;
+  }
+  return total;
+}
+
 export function emitDiagnostic(event: {
   level?: DiagnosticLevel;
   phase: string;