diff --git a/src/lib/messaging-bridge-health.test.ts b/src/lib/messaging-bridge-health.test.ts
new file mode 100644
index 0000000000..ffbaa0e193
--- /dev/null
+++ b/src/lib/messaging-bridge-health.test.ts
@@ -0,0 +1,134 @@
+// SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+vi.mock("./resolve-openshell.js", () => ({
+  resolveOpenshell: vi.fn(() => "/usr/local/bin/openshell"),
+}));
+
+vi.mock("node:child_process", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("node:child_process")>();
+  return { ...actual, spawnSync: vi.fn() };
+});
+
+import { checkMessagingBridgeHealth } from "./messaging-bridge-health.js";
+import { spawnSync } from "node:child_process";
+import { resolveOpenshell } from "./resolve-openshell.js";
+
+const spawnSyncMock = vi.mocked(spawnSync);
+const resolveOpenshellMock = vi.mocked(resolveOpenshell);
+
+type SpawnResult = ReturnType<typeof spawnSync>;
+function mockSpawn(overrides: Partial<SpawnResult> = {}): void {
+  spawnSyncMock.mockReturnValue({
+    pid: 0,
+    output: [],
+    stdout: "",
+    stderr: "",
+    status: 0,
+    signal: null,
+    ...overrides,
+  } as unknown as SpawnResult);
+}
+
+beforeEach(() => {
+  vi.clearAllMocks();
+  resolveOpenshellMock.mockReturnValue("/usr/local/bin/openshell");
+});
+
+describe("checkMessagingBridgeHealth", () => {
+  it("returns empty and does not spawn when channels does not include telegram", () => {
+    const result = checkMessagingBridgeHealth("alpha", ["discord", "slack"]);
+    expect(result).toEqual([]);
+    expect(spawnSyncMock).not.toHaveBeenCalled();
+  });
+
+  it("returns empty and does not spawn when channels is null/undefined", () => {
+    expect(checkMessagingBridgeHealth("alpha", null)).toEqual([]);
+    expect(checkMessagingBridgeHealth("alpha", undefined)).toEqual([]);
+    expect(spawnSyncMock).not.toHaveBeenCalled();
+  });
+
+  it("returns empty when openshell binary cannot be resolved", () => {
+    resolveOpenshellMock.mockReturnValue(null);
+    const result = checkMessagingBridgeHealth("alpha", ["telegram"]);
+    expect(result).toEqual([]);
+    expect(spawnSyncMock).not.toHaveBeenCalled();
+  });
+
+  it("returns a conflict entry when gateway log reports N conflicts", () => {
+    mockSpawn({ stdout: "32\n" });
+    expect(checkMessagingBridgeHealth("alpha", ["telegram"])).toEqual([
+      { channel: "telegram", conflicts: 32 },
+    ]);
+  });
+
+  it("returns empty when the conflict count is zero", () => {
+    mockSpawn({ stdout: "0\n" });
+    expect(checkMessagingBridgeHealth("alpha", ["telegram"])).toEqual([]);
+  });
+
+  it("returns empty when the count is non-numeric", () => {
+    mockSpawn({ stdout: "\n" });
+    expect(checkMessagingBridgeHealth("alpha", ["telegram"])).toEqual([]);
+  });
+
+  it("returns empty when spawnSync throws", () => {
+    spawnSyncMock.mockImplementation(() => {
+      throw new Error("spawn EPIPE");
+    });
+    expect(checkMessagingBridgeHealth("alpha", ["telegram"])).toEqual([]);
+  });
+
+  it("returns empty when spawnSync reports a non-zero exit status (exec failed)", () => {
+    mockSpawn({ stderr: "/bin/bash: alpha: command not found\n", status: 127 });
+    expect(checkMessagingBridgeHealth("alpha", ["telegram"])).toEqual([]);
+  });
+
+  it("returns empty when spawnSync returns an error object (e.g. timeout)", () => {
+    mockSpawn({
+      stdout: null as unknown as string,
+      stderr: null as unknown as string,
+      status: null,
+      signal: "SIGTERM",
+      error: new Error("spawnSync timed out"),
+    });
+    expect(checkMessagingBridgeHealth("alpha", ["telegram"])).toEqual([]);
+  });
+
+  // Regression for #2018: `openshell sandbox exec` requires the --name/-n
+  // flag. Passing the sandbox name as a positional causes the name to be
+  // interpreted as the first word of the command and fails with exit 127.
+  describe("argv shape (#2018 regression)", () => {
+    beforeEach(() => mockSpawn({ stdout: "5\n" }));
+
+    it("passes the sandbox name via --name/-n, not as a positional", () => {
+      checkMessagingBridgeHealth("tele-brev", ["telegram"]);
+
+      expect(spawnSyncMock).toHaveBeenCalledTimes(1);
+      const [binary, args] = spawnSyncMock.mock.calls[0];
+      expect(binary).toBe("/usr/local/bin/openshell");
+
+      const argsArray = args as string[];
+      const nameFlagIdx = argsArray.indexOf("-n");
+      expect(nameFlagIdx).toBeGreaterThan(-1);
+      expect(argsArray[nameFlagIdx + 1]).toBe("tele-brev");
+
+      // Pre-fix, args were ["sandbox", "exec", "<name>", "sh", "-c", <script>].
+      // Ensure the sandbox name is not directly adjacent to "exec" (positional).
+      const execIdx = argsArray.indexOf("exec");
+      expect(argsArray[execIdx + 1]).not.toBe("tele-brev");
+    });
+
+    it("separates the command from flags with `--`", () => {
+      checkMessagingBridgeHealth("tele-brev", ["telegram"]);
+      const [, args] = spawnSyncMock.mock.calls[0];
+      const argsArray = args as string[];
+      const sepIdx = argsArray.indexOf("--");
+      expect(sepIdx).toBeGreaterThan(-1);
+      expect(argsArray[sepIdx + 1]).toBe("sh");
+      expect(argsArray[sepIdx + 2]).toBe("-c");
+    });
+  });
+});
diff --git a/src/lib/messaging-bridge-health.ts b/src/lib/messaging-bridge-health.ts
new file mode 100644
index 0000000000..97179d8ad2
--- /dev/null
+++ b/src/lib/messaging-bridge-health.ts
@@ -0,0 +1,38 @@
+// SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import { spawnSync } from "node:child_process";
+import type { MessagingBridgeHealth } from "./inventory-commands.js";
+import { resolveOpenshell } from "./resolve-openshell.js";
+
+const CONFLICT_SCRIPT =
+  'tail -n 200 /tmp/gateway.log 2>/dev/null | grep -cE "getUpdates conflict|409[[:space:]:]+Conflict" || true';
+
+export function checkMessagingBridgeHealth(
+  sandboxName: string,
+  channels: readonly string[] | null | undefined,
+): MessagingBridgeHealth[] {
+  if (!Array.isArray(channels) || !channels.includes("telegram")) return [];
+
+  const binary = resolveOpenshell();
+  if (!binary) return [];
+
+  // `openshell sandbox exec` requires --name/-n for the sandbox name; a
+  // positional there gets parsed as the first word of the command and
+  // fails with exit 127 (#2018).
+  const args = ["sandbox", "exec", "-n", sandboxName, "--", "sh", "-c", CONFLICT_SCRIPT];
+
+  try {
+    const result = spawnSync(binary, args, {
+      encoding: "utf-8",
+      timeout: 3000,
+      stdio: ["ignore", "pipe", "pipe"],
+    });
+    if (result.error || result.status !== 0) return [];
+    const count = Number.parseInt((result.stdout || "").trim(), 10);
+    if (!Number.isFinite(count) || count === 0) return [];
+    return [{ channel: "telegram", conflicts: count }];
+  } catch {
+    return [];
+  }
+}
diff --git a/src/nemoclaw.ts b/src/nemoclaw.ts
index d01885f058..c22630b1ef 100644
--- a/src/nemoclaw.ts
+++ b/src/nemoclaw.ts
@@ -1047,27 +1047,7 @@ async function credentialsCommand(args) {
   process.exit(1);
 }
 
-function checkMessagingBridgeHealth(sandboxName, channels) {
-  // Only Telegram currently emits a recognizable conflict signature in the
-  // gateway log. Discord/Slack have similar single-consumer constraints but
-  // log differently; we can extend the regex when those patterns are known.
-  if (!Array.isArray(channels) || !channels.includes("telegram")) return [];
-  const { spawnSync } = require("child_process");
-  const script =
-    'tail -n 200 /tmp/gateway.log 2>/dev/null | grep -cE "getUpdates conflict|409[[:space:]:]+Conflict" || true';
-  try {
-    const result = spawnSync(
-      getOpenshellBinary(),
-      ["sandbox", "exec", sandboxName, "sh", "-c", script],
-      { encoding: "utf-8", timeout: 3000, stdio: ["ignore", "pipe", "pipe"] },
-    );
-    const count = Number.parseInt((result.stdout || "").trim(), 10);
-    if (!Number.isFinite(count) || count === 0) return [];
-    return [{ channel: "telegram", conflicts: count }];
-  } catch {
-    return [];
-  }
-}
+const { checkMessagingBridgeHealth } = require("./lib/messaging-bridge-health");
 
 function makeConflictProbe() {
   // Upfront liveness check so we can distinguish "provider not attached" from
@@ -1111,9 +1091,10 @@ function readGatewayLog(sandboxName) {
   try {
     const result = spawnSync(
       getOpenshellBinary(),
-      ["sandbox", "exec", sandboxName, "sh", "-c", "tail -n 10 /tmp/gateway.log 2>/dev/null"],
+      ["sandbox", "exec", "-n", sandboxName, "--", "sh", "-c", "tail -n 10 /tmp/gateway.log 2>/dev/null"],
       { encoding: "utf-8", timeout: 3000, stdio: ["ignore", "pipe", "pipe"] },
     );
+    if (result.error || result.status !== 0) return null;
     const output = (result.stdout || "").trim();
     return output || null;
   } catch {