diff --git a/docs/cli/status.md b/docs/cli/status.md
index 0cb7a06a48b0..33275eca80c3 100644
--- a/docs/cli/status.md
+++ b/docs/cli/status.md
@@ -47,6 +47,14 @@ Channels without a probe, such as WhatsApp, report lifecycle health instead.
 In the Health table, `healthy` is `OK`; degraded lifecycle states and failed
 probes remain `WARN`. A lifecycle `OK` does not mean a live probe ran.
 
+`--deep` also asks the running Gateway whether the Node executable it still holds can be started. A Homebrew upgrade can delete that Cellar path while the LaunchAgent plist still points at a valid symlink and the Gateway port stays reachable. Status then warns:
+
+```text
+Gateway runtime is stale after Node upgrade: child workers are using <path>, which no longer exists. Restart the Gateway.
+```
+
+The check does not restart the Gateway. Run `openclaw gateway restart` after the warning.
+
 `--deep` and `--all` also show delivery queue warnings for dead-lettered messages
 and pressured inbound lanes. These warnings include pending, claimed, and blocked
 message counts even when a channel connection is healthy. See
diff --git a/packages/gateway-protocol/src/schema/snapshot.ts b/packages/gateway-protocol/src/schema/snapshot.ts
index c5b48ee06a11..4420f37f6ae2 100644
--- a/packages/gateway-protocol/src/schema/snapshot.ts
+++ b/packages/gateway-protocol/src/schema/snapshot.ts
@@ -177,6 +177,14 @@ const HealthSnapshotSchema = closedObject({
       hotReloadStatus: Type.Union([Type.Literal("active"), Type.Literal("disabled")]),
     }),
   ),
+  // The running process reports the Node binary it will use for child workers.
+  // A deleted Homebrew Cellar path stays reachable at the Gateway port.
+  childRuntime: Type.Optional(
+    closedObject({
+      execPath: Type.String(),
+      available: Type.Boolean(),
+    }),
+  ),
   // Channel plugins own their nested account/probe summaries, so this is the
   // one provider-contributed bag that deliberately remains unknown.
   channels: Type.Optional(Type.Record(Type.String(), Type.Unknown())),
diff --git a/src/commands/doctor-gateway-health.test.ts b/src/commands/doctor-gateway-health.test.ts
index a2a57ada30a0..0370800be5e2 100644
--- a/src/commands/doctor-gateway-health.test.ts
+++ b/src/commands/doctor-gateway-health.test.ts
@@ -281,6 +281,21 @@ describe("checkGatewayHealth", () => {
     },
   );
 
+  it("reports a deleted Gateway Node path without marking the gateway unhealthy", async () => {
+    const execPath = "/opt/homebrew/Cellar/node@24/24.20.0/bin/node";
+    callGateway
+      .mockResolvedValueOnce({
+        childRuntime: { execPath, available: false },
+      })
+      .mockResolvedValue({});
+    const runtime = { log: vi.fn(), error: vi.fn(), exit: vi.fn() };
+    await expect(checkGatewayHealth({ runtime, cfg })).resolves.toMatchObject({ healthOk: true });
+    expect(note).toHaveBeenCalledWith(
+      `Gateway runtime is stale after Node upgrade: child workers are using ${execPath}, which no longer exists. Restart the Gateway.`,
+      "Gateway runtime",
+    );
+  });
+
   it.each([
     ["startupMigrationWarning", "Startup migration warnings"],
     ["startupRecoveryWarning", "Startup session recovery"],
diff --git a/src/commands/doctor-gateway-health.ts b/src/commands/doctor-gateway-health.ts
index eb1689e32a4c..03fb73ddf0b4 100644
--- a/src/commands/doctor-gateway-health.ts
+++ b/src/commands/doctor-gateway-health.ts
@@ -30,6 +30,7 @@ import type {
   DoctorMemoryStatusPayload,
 } from "../gateway/server-methods/doctor.js";
 import { collectChannelStatusIssues } from "../infra/channels-status-issues.js";
+import { formatMissingChildRuntimeWarning } from "../infra/child-runtime-viability.js";
 import { formatErrorMessage } from "../infra/errors.js";
 import { formatDurationSeconds } from "../infra/format-time/format-duration.js";
 import { readGatewayLastInstallationReplacement } from "../infra/gateway-boot-lifecycle.js";
@@ -342,6 +343,12 @@ export async function checkGatewayHealth(params: {
     if (status.startupRecoveryWarning) {
       note(sanitizeTerminalText(status.startupRecoveryWarning), "Startup session recovery");
     }
+    const childRuntimeWarning = status.childRuntime
+      ? formatMissingChildRuntimeWarning(status.childRuntime)
+      : undefined;
+    if (childRuntimeWarning) {
+      note(sanitizeTerminalText(childRuntimeWarning), "Gateway runtime");
+    }
     if (status.installationReplacementWarning) {
       note(sanitizeTerminalText(status.installationReplacementWarning), "Installation replaced");
     }
diff --git a/src/commands/status-overview-rows.test.ts b/src/commands/status-overview-rows.test.ts
index 8a01fd992bb6..0d06d6d07fbd 100644
--- a/src/commands/status-overview-rows.test.ts
+++ b/src/commands/status-overview-rows.test.ts
@@ -221,6 +221,16 @@ describe("status-overview-rows", () => {
     expect(findRowValue(rows, label)).toContain(params.summary[field]);
   });
 
+  it("surfaces a deleted Gateway Node path in the overview", () => {
+    const execPath = "/opt/homebrew/Cellar/node@24/24.20.0/bin/node";
+    const params = createStatusCommandOverviewRowsParams();
+    params.summary.childRuntime = { execPath, available: false };
+    const rows = buildStatusCommandOverviewRows(params);
+    expect(findRowValue(rows, "Gateway runtime")).toBe(
+      `warn(Gateway runtime is stale after Node upgrade: child workers are using ${execPath}, which no longer exists. Restart the Gateway.)`,
+    );
+  });
+
   it("builds status-all overview rows from the shared surface", () => {
     const summary = createStatusCommandOverviewRowsParams().summary;
     const rows = buildStatusAllOverviewRows({
diff --git a/src/commands/status-overview-rows.ts b/src/commands/status-overview-rows.ts
index 6fa460a8ad4e..3d53a700ea03 100644
--- a/src/commands/status-overview-rows.ts
+++ b/src/commands/status-overview-rows.ts
@@ -3,6 +3,7 @@
 
 import { formatCliCommand } from "../cli/command-format.js";
 import { resolveIsNixMode } from "../config/paths.js";
+import { formatMissingChildRuntimeWarning } from "../infra/child-runtime-viability.js";
 import { isTruthyEnvValue } from "../infra/env.js";
 import type { HeartbeatEventPayload } from "../infra/heartbeat-events.js";
 import type { PluginCompatibilityNotice } from "../plugins/status.js";
@@ -40,6 +41,7 @@ type StatusDegradationSummary = Pick<
   | "startupMigrationWarning"
   | "startupRecoveryWarning"
   | "installationReplacementWarning"
+  | "childRuntime"
   | "secretEgressProxy"
 >;
 
@@ -54,6 +56,12 @@ function buildStatusDegradationRows(
   if (summary.startupRecoveryWarning) {
     rows.push({ Item: "Session recovery", Value: decorate(summary.startupRecoveryWarning) });
   }
+  const childRuntimeWarning = summary.childRuntime
+    ? formatMissingChildRuntimeWarning(summary.childRuntime)
+    : undefined;
+  if (childRuntimeWarning) {
+    rows.push({ Item: "Gateway runtime", Value: decorate(childRuntimeWarning) });
+  }
   if (summary.installationReplacementWarning) {
     rows.push({
       Item: "Installation replaced",
diff --git a/src/commands/status.command-sections.test.ts b/src/commands/status.command-sections.test.ts
index 0f30fe583491..78ca4611f32d 100644
--- a/src/commands/status.command-sections.test.ts
+++ b/src/commands/status.command-sections.test.ts
@@ -293,6 +293,27 @@ describe("status.command-sections", () => {
     ]);
   });
 
+  it("warns when deep health says the retained Node executable is gone", () => {
+    const execPath = "/opt/homebrew/Cellar/node@24/24.20.0/bin/node";
+    const rows = buildStatusHealthRows({
+      health: {
+        durationMs: 42,
+        childRuntime: { execPath, available: false },
+      } as HealthSummary,
+      formatHealthChannelLines: () => ["Discord: OK"],
+      ok: (value) => `ok(${value})`,
+      warn: (value) => `warn(${value})`,
+      muted: (value) => `muted(${value})`,
+    });
+
+    expect(rows[0]).toEqual({ Item: "Gateway", Status: "ok(reachable)", Detail: "42ms" });
+    expect(rows[1]).toEqual({
+      Item: "Gateway runtime",
+      Status: "warn(WARN)",
+      Detail: `Gateway runtime is stale after Node upgrade: child workers are using ${execPath}, which no longer exists. Restart the Gateway.`,
+    });
+  });
+
   it.each([
     { account: {}, status: "ok(OK)", detail: "healthy" },
     {
diff --git a/src/commands/status.command-sections.ts b/src/commands/status.command-sections.ts
index 14a23412f797..f8913d4e5c86 100644
--- a/src/commands/status.command-sections.ts
+++ b/src/commands/status.command-sections.ts
@@ -6,6 +6,7 @@ import {
 } from "../../packages/gateway-protocol/src/connect-error-details.js";
 import type { TableColumn } from "../../packages/terminal-core/src/table.js";
 import { areRuntimeModelRefsEquivalent } from "../agents/model-runtime-aliases.js";
+import { formatMissingChildRuntimeWarning } from "../infra/child-runtime-viability.js";
 import { formatDurationCompact } from "../infra/format-time/format-duration.js";
 import type { HeartbeatEventPayload } from "../infra/heartbeat-events.js";
 import type { Tone } from "../memory-host-sdk/status.js";
@@ -252,6 +253,16 @@ export function buildStatusHealthRows(params: {
       Detail: `${params.health.durationMs}ms`,
     },
   ];
+  const childRuntimeWarning = params.health.childRuntime
+    ? formatMissingChildRuntimeWarning(params.health.childRuntime)
+    : undefined;
+  if (childRuntimeWarning) {
+    rows.push({
+      Item: "Gateway runtime",
+      Status: params.warn("WARN"),
+      Detail: childRuntimeWarning,
+    });
+  }
   const sqliteWalWarning = formatSqliteWalHealthWarning(params.sqliteWal);
   if (sqliteWalWarning) {
     rows.push({ Item: "SQLite WAL", Status: params.warn("WARN"), Detail: sqliteWalWarning });
diff --git a/src/commands/status.scan-overview.test.ts b/src/commands/status.scan-overview.test.ts
index 7585bb3f67ac..83fb4051b90f 100644
--- a/src/commands/status.scan-overview.test.ts
+++ b/src/commands/status.scan-overview.test.ts
@@ -164,6 +164,10 @@ describe("collectStatusScanOverview", () => {
             degradedPlugins: [],
             startupMigrationWarning: "Retained legacy state; run openclaw doctor --fix.",
             installationReplacementWarning: "Installation replaced; draining before handoff.",
+            childRuntime: {
+              execPath: "/opt/homebrew/Cellar/node@24/24.20.0/bin/node",
+              available: false,
+            },
             sqliteWal,
           }
         : { channelAccounts: {} },
@@ -175,7 +179,7 @@ describe("collectStatusScanOverview", () => {
   it("uses gateway fallback overrides for channels.status when requested", async () => {
     const result = await collectStatusScanOverview({
       commandName: "status --all",
-      opts: createStatusGatewayProbeBudget(1234),
+      opts: { ...createStatusGatewayProbeBudget(1234), deep: true },
       showSecrets: false,
       useGatewayCallOverridesForChannelsStatus: true,
     });
@@ -202,6 +206,10 @@ describe("collectStatusScanOverview", () => {
     expect(result.runtimeDegradation?.installationReplacementWarning).toBe(
       "Installation replaced; draining before handoff.",
     );
+    expect(result.runtimeDegradation?.childRuntime).toEqual({
+      execPath: "/opt/homebrew/Cellar/node@24/24.20.0/bin/node",
+      available: false,
+    });
   });
 
   it("can keep channel overview on metadata-only status paths", async () => {
@@ -222,6 +230,7 @@ describe("collectStatusScanOverview", () => {
     expect(channelTableCall?.[1]?.showSecrets).toBe(false);
     expect(channelTableCall?.[1]?.sourceConfig).toStrictEqual({ session: { raw: true } });
     expect(result.channelIssues).toStrictEqual([]);
+    expect(result.runtimeDegradation).not.toHaveProperty("childRuntime");
   });
 
   it("skips channels.status when the gateway is unreachable", async () => {
diff --git a/src/commands/status.scan-overview.ts b/src/commands/status.scan-overview.ts
index fb6eae38b38c..1f354b74299c 100644
--- a/src/commands/status.scan-overview.ts
+++ b/src/commands/status.scan-overview.ts
@@ -104,6 +104,7 @@ export type StatusScanOverviewResult = {
         | "degradedPlugins"
         | "startupMigrationWarning"
         | "installationReplacementWarning"
+        | "childRuntime"
         | "secretEgressProxy"
         | "sqliteWal"
       > &
@@ -120,7 +121,7 @@ export type StatusScanOverviewResult = {
 export async function collectStatusScanOverview(params: {
   env?: NodeJS.ProcessEnv;
   commandName: string;
-  opts: StatusGatewayProbeBudget & { all?: boolean };
+  opts: StatusGatewayProbeBudget & { all?: boolean; deep?: boolean };
   showSecrets: boolean;
   runtime?: RuntimeEnv;
   allowMissingConfigFastPath?: boolean;
@@ -304,6 +305,7 @@ export async function collectStatusScanOverview(params: {
           degradedPlugins: status.degradedPlugins ?? [],
           startupMigrationWarning: status.startupMigrationWarning,
           installationReplacementWarning: status.installationReplacementWarning,
+          ...(params.opts.deep && status.childRuntime ? { childRuntime: status.childRuntime } : {}),
           secretEgressProxy: status.secretEgressProxy,
           sqliteWal: status.sqliteWal,
           // The Gateway owns route readiness; CLI channel runtimes stay unloaded.
diff --git a/src/gateway/server-methods/health.owner-routing.test.ts b/src/gateway/server-methods/health.owner-routing.test.ts
index 76c02c75cfe4..faacecf7ea4a 100644
--- a/src/gateway/server-methods/health.owner-routing.test.ts
+++ b/src/gateway/server-methods/health.owner-routing.test.ts
@@ -9,6 +9,7 @@ import {
   getAgentEventLifecycleGeneration,
   rotateAgentEventLifecycleGeneration,
 } from "../../infra/agent-events.js";
+import * as childRuntime from "../../infra/child-runtime-viability.js";
 import { beginLifecycleWriteCustody } from "../../infra/lifecycle-write-custody.js";
 import { recordStartupMigrationWarnings } from "../../infra/state-migrations.messages.js";
 import { withStateDirEnv } from "../../test-helpers/state-dir-env.js";
@@ -211,6 +212,46 @@ describe("Gateway status owner routing", () => {
     },
   );
 
+  it("reports a deleted child runtime executable without storing it on cached health", async () => {
+    const removed = "/opt/homebrew/Cellar/node@24/24.20.0/bin/node";
+    const read = vi.spyOn(childRuntime, "readChildRuntimeViability").mockReturnValue({
+      execPath: removed,
+      available: false,
+    });
+    const cached: HealthSummary = {
+      ok: true,
+      ts: Date.now(),
+      durationMs: 1,
+      channels: {},
+      channelOrder: [],
+      channelLabels: {},
+      heartbeatSeconds: 0,
+      agents: [],
+      sessions: { path: "/tmp/sessions.json", count: 0, recent: [] },
+    };
+    const respond = vi.fn();
+    await healthHandlers.health!({
+      req: {} as never,
+      params: {},
+      respond: respond as never,
+      context: {
+        getHealthCache: () => cached,
+        refreshHealthSnapshot: vi.fn(async () => cached),
+        getRuntimeSnapshot: () => ({ channels: {}, channelAccounts: {} }),
+        logHealth: { error: vi.fn() },
+      } as never,
+      client: { connect: { role: "operator", scopes: ["operator.read"] } } as never,
+      isWebchatConnect: () => false,
+    });
+    expect(read).toHaveBeenCalled();
+    expect(respond.mock.calls[0]?.[1].childRuntime).toEqual({
+      execPath: removed,
+      available: false,
+    });
+    expect(cached).not.toHaveProperty("childRuntime");
+    expect(respond.mock.calls[0]?.[3]).toEqual({ cached: true });
+  });
+
   it("projects requested CLI facts without choosing a fleet owner or widening read scopes", async () => {
     await withStateDirEnv("openclaw-gateway-cli-status-", async ({ stateDir }) => {
       const config = {
diff --git a/src/gateway/server-methods/health.ts b/src/gateway/server-methods/health.ts
index 0764d72ae988..81522d701442 100644
--- a/src/gateway/server-methods/health.ts
+++ b/src/gateway/server-methods/health.ts
@@ -3,6 +3,7 @@
 import { isFutureDateTimestampMs } from "@openclaw/normalization-core/number-coercion";
 import { getPreparedModelRuntimeStartupStatus } from "../../agents/prepared-model-runtime.startup-status.js";
 import type { ChannelAccountSnapshot } from "../../channels/plugins/types.public.js";
+import { readChildRuntimeViability } from "../../infra/child-runtime-viability.js";
 import { formatErrorMessage as formatError } from "../../infra/errors.js";
 import { readGatewayMaintenanceWork } from "../../infra/gateway-active-work.js";
 import { getStatusSummary } from "../../status/summary.js";
@@ -150,11 +151,15 @@ export const healthHandlers: GatewayRequestHandlers = {
     ) {
       respond(
         true,
-        await mergeCachedHealthRuntimeState({
-          cached,
-          getEventLoopHealth: context.getEventLoopHealth,
-          configReloadHotReloadStatus: context.getConfigReloaderHotReloadStatus?.(),
-        }),
+        {
+          ...(await mergeCachedHealthRuntimeState({
+            cached,
+            getEventLoopHealth: context.getEventLoopHealth,
+            configReloadHotReloadStatus: context.getConfigReloaderHotReloadStatus?.(),
+          })),
+          // Live check. The cache must not keep a path that disappeared after it was stored.
+          childRuntime: readChildRuntimeViability(),
+        },
         undefined,
         { cached: true },
       );
@@ -167,7 +172,15 @@ export const healthHandlers: GatewayRequestHandlers = {
     }
     await respondUnavailableOnThrow(respond, async () => {
       const snap = await refreshHealthSnapshot({ probe: wantsProbe, includeSensitive });
-      respond(true, { ...snap, modelRuntime: getPreparedModelRuntimeStartupStatus() }, undefined);
+      respond(
+        true,
+        {
+          ...snap,
+          modelRuntime: getPreparedModelRuntimeStartupStatus(),
+          childRuntime: readChildRuntimeViability(),
+        },
+        undefined,
+      );
     });
   },
   status: async ({ respond, client, params, context }) => {
@@ -202,6 +215,7 @@ export const healthHandlers: GatewayRequestHandlers = {
         workerPools,
         pid: process.pid,
         shutdownBudget: shutdownStatus,
+        childRuntime: readChildRuntimeViability(),
       },
       undefined,
     );
diff --git a/src/gateway/server-methods/server-methods.test.ts b/src/gateway/server-methods/server-methods.test.ts
index 4450b58a6da7..732cbdc1cdc3 100644
--- a/src/gateway/server-methods/server-methods.test.ts
+++ b/src/gateway/server-methods/server-methods.test.ts
@@ -30,6 +30,7 @@ import {
   resetContextEngineRuntimeQuarantineForTests,
 } from "../../context-engine/registry.test-support.js";
 import { emitAgentEvent } from "../../infra/agent-events.js";
+import * as childRuntime from "../../infra/child-runtime-viability.js";
 import {
   buildSystemRunApprovalBinding,
   buildSystemRunApprovalEnvBinding,
@@ -4138,6 +4139,8 @@ describe("gateway healthHandlers.health cache freshness", () => {
   let healthHandlers: typeof import("./health.js").healthHandlers;
   let restoreContextEngineRegistryState: () => void;
   const contextEngineTestOwner = "plugin:health-test";
+  const healthyChildRuntime = { execPath: "/test/node", available: true };
+  let restoreChildRuntime: () => void;
 
   function createHealthSnapshot<T extends Record<string, unknown>>(overrides: T) {
     return {
@@ -4235,12 +4238,17 @@ describe("gateway healthHandlers.health cache freshness", () => {
   });
 
   beforeEach(() => {
+    const runtimeSpy = vi
+      .spyOn(childRuntime, "readChildRuntimeViability")
+      .mockReturnValue(healthyChildRuntime);
+    restoreChildRuntime = () => runtimeSpy.mockRestore();
     restoreContextEngineRegistryState = captureContextEngineRegistryStateForTests();
     registerLegacyContextEngine();
     resetContextEngineRuntimeQuarantineForTests();
   });
 
   afterEach(() => {
+    restoreChildRuntime();
     vi.useRealTimers();
     restoreContextEngineRegistryState();
   });
@@ -4284,7 +4292,11 @@ describe("gateway healthHandlers.health cache freshness", () => {
     const { respond, refreshHealthSnapshot } = await requestHealthSnapshot({ cached, fresh });
 
     expect(refreshHealthSnapshot).toHaveBeenCalledOnce();
-    expect(respond).toHaveBeenCalledWith(true, fresh, undefined);
+    expect(respond).toHaveBeenCalledWith(
+      true,
+      { ...fresh, childRuntime: healthyChildRuntime },
+      undefined,
+    );
   });
 
   it("restarts request-driven health refreshes when the clock moves backward", async () => {
@@ -4316,7 +4328,11 @@ describe("gateway healthHandlers.health cache freshness", () => {
       probe: true,
       includeSensitive: true,
     });
-    expect(respond).toHaveBeenCalledWith(true, fresh, undefined);
+    expect(respond).toHaveBeenCalledWith(
+      true,
+      { ...fresh, childRuntime: healthyChildRuntime },
+      undefined,
+    );
   });
 
   it("maps health collection failures to UNAVAILABLE", async () => {
@@ -4378,7 +4394,11 @@ describe("gateway healthHandlers.health cache freshness", () => {
       probe: false,
       includeSensitive: false,
     });
-    expect(respond).toHaveBeenCalledWith(true, fresh, undefined);
+    expect(respond).toHaveBeenCalledWith(
+      true,
+      { ...fresh, childRuntime: healthyChildRuntime },
+      undefined,
+    );
   });
 
   it("refreshes cached health when runtime channel lifecycle has changed", async () => {
@@ -4412,7 +4432,11 @@ describe("gateway healthHandlers.health cache freshness", () => {
       probe: false,
       includeSensitive: false,
     });
-    expect(respond).toHaveBeenCalledWith(true, fresh, undefined);
+    expect(respond).toHaveBeenCalledWith(
+      true,
+      { ...fresh, childRuntime: healthyChildRuntime },
+      undefined,
+    );
   });
 
   it("refreshes cached health when recorded lifecycle changes without socket churn", async () => {
@@ -4738,7 +4762,11 @@ describe("gateway healthHandlers.health cache freshness", () => {
         probe: false,
         includeSensitive: false,
       });
-      expect(respond).toHaveBeenCalledWith(true, fresh, undefined);
+      expect(respond).toHaveBeenCalledWith(
+        true,
+        { ...fresh, childRuntime: healthyChildRuntime },
+        undefined,
+      );
     },
   );
 });
diff --git a/src/infra/child-runtime-viability.test.ts b/src/infra/child-runtime-viability.test.ts
new file mode 100644
index 000000000000..c1b598bd1f21
--- /dev/null
+++ b/src/infra/child-runtime-viability.test.ts
@@ -0,0 +1,45 @@
+import { describe, expect, it } from "vitest";
+import {
+  formatMissingChildRuntimeWarning,
+  readChildRuntimeViability,
+} from "./child-runtime-viability.ts";
+
+const removedCellarPath = "/opt/homebrew/Cellar/node@24/24.20.0/bin/node";
+
+describe("child runtime viability", () => {
+  it("treats a missing executable as a stale runtime", () => {
+    const viability = readChildRuntimeViability({
+      execPath: removedCellarPath,
+      access: () => {
+        throw Object.assign(new Error("spawn ENOENT"), { code: "ENOENT" });
+      },
+    });
+
+    expect(viability).toEqual({ execPath: removedCellarPath, available: false });
+    expect(formatMissingChildRuntimeWarning(viability)).toBe(
+      `Gateway runtime is stale after Node upgrade: child workers are using ${removedCellarPath}, which no longer exists. Restart the Gateway.`,
+    );
+  });
+
+  it("stays quiet when the retained executable can still be started", () => {
+    const viability = readChildRuntimeViability({
+      execPath: process.execPath,
+      access: () => undefined,
+    });
+
+    expect(viability).toEqual({ execPath: process.execPath, available: true });
+    expect(formatMissingChildRuntimeWarning(viability)).toBeUndefined();
+  });
+
+  it("does not call a permission error a deleted Node path", () => {
+    const viability = readChildRuntimeViability({
+      execPath: removedCellarPath,
+      access: () => {
+        throw Object.assign(new Error("permission denied"), { code: "EACCES" });
+      },
+    });
+
+    expect(viability.available).toBe(true);
+    expect(formatMissingChildRuntimeWarning(viability)).toBeUndefined();
+  });
+});
diff --git a/src/infra/child-runtime-viability.ts b/src/infra/child-runtime-viability.ts
new file mode 100644
index 000000000000..8dd9a0e3be5d
--- /dev/null
+++ b/src/infra/child-runtime-viability.ts
@@ -0,0 +1,54 @@
+// The running Gateway keeps the Node path it was launched with.
+// A Homebrew upgrade can delete that Cellar binary while the process stays up.
+
+import { accessSync, constants } from "node:fs";
+import { sanitizeTerminalText } from "../../packages/terminal-core/src/safe-text.js";
+
+export type ChildRuntimeViability = {
+  execPath: string;
+  available: boolean;
+};
+
+function errnoCode(error: unknown): string | undefined {
+  if (!(error instanceof Error) || !("code" in error)) {
+    return undefined;
+  }
+  const code = error.code;
+  return typeof code === "string" ? code : undefined;
+}
+
+function accessExecutable(execPath: string): void {
+  accessSync(execPath, constants.X_OK);
+}
+
+/** Reports whether this process can still spawn children with its own Node binary. */
+export function readChildRuntimeViability(params?: {
+  execPath?: string;
+  access?: (execPath: string) => void;
+}): ChildRuntimeViability {
+  const execPath = params?.execPath ?? process.execPath;
+  const access = params?.access ?? accessExecutable;
+  try {
+    access(execPath);
+    return { execPath, available: true };
+  } catch (error) {
+    const code = errnoCode(error);
+    // Only a removed path matches the Homebrew Cellar failure. Other access
+    // errors are not this diagnostic.
+    if (code === "ENOENT" || code === "ENOTDIR") {
+      return { execPath, available: false };
+    }
+    return { execPath, available: true };
+  }
+}
+
+/** Operator text for a Gateway whose retained Node binary is gone. */
+export function formatMissingChildRuntimeWarning(
+  viability: ChildRuntimeViability,
+): string | undefined {
+  if (viability.available) {
+    return undefined;
+  }
+  const execPath = sanitizeTerminalText(viability.execPath);
+  return `Gateway runtime is stale after Node upgrade: child workers are using ${execPath}, which no longer exists. Restart the Gateway.`;
+}
diff --git a/src/status/summary.ts b/src/status/summary.ts
index 04ae06780a8d..48535ed1acf7 100644
--- a/src/status/summary.ts
+++ b/src/status/summary.ts
@@ -574,6 +574,10 @@ export type StatusSummary = Omit<
     "heartbeat" | "channelSummary" | "queuedSystemEvents" | "sessions"
   > & {
     runtimeVersion?: string | null;
+    childRuntime?: {
+      execPath: string;
+      available: boolean;
+    };
     eventLoop?: NonNullable<SystemInfoResult["eventLoop"]>;
     processMemory?: NonNullable<SystemInfoResult["processMemory"]>;
     degradedSecretOwners?: Array<