diff --git a/cli/src/server/services/backend.ts b/cli/src/server/services/backend.ts
index a32ee17..454ab88 100644
--- a/cli/src/server/services/backend.ts
+++ b/cli/src/server/services/backend.ts
@@ -67,10 +67,16 @@ export function createBackends(opts: {
   macos?: BackendType;
   dockerSocket?: string;
 }): BackendMap {
+  let macos = opts.macos;
+
+  if (macos === "tart" && !TartBackend.isAvailable()) {
+    macos = undefined;
+  }
+
   return {
     linux: createBackend(opts.linux, { dockerSocket: opts.dockerSocket }),
-    macos: opts.macos
-      ? createBackend(opts.macos, { dockerSocket: opts.dockerSocket })
+    macos: macos
+      ? createBackend(macos, { dockerSocket: opts.dockerSocket })
       : undefined,
   };
 }
diff --git a/cli/src/server/services/tart.ts b/cli/src/server/services/tart.ts
index f33a53e..166b311 100644
--- a/cli/src/server/services/tart.ts
+++ b/cli/src/server/services/tart.ts
@@ -27,6 +27,7 @@ function tartExec(args: string[], timeoutMs = 10_000): string {
   return execSync(`tart ${args.join(" ")}`, {
     encoding: "utf-8",
     timeout: timeoutMs,
+    stdio: ["ignore", "pipe", "pipe"],
   }).trim();
 }
 
@@ -92,6 +93,15 @@ export class TartBackend implements ContainerBackend {
   readonly supportsPause = true;
   private instances = new Map<string, TartInstance>();
 
+  static isAvailable(): boolean {
+    try {
+      execSync("tart --version", { stdio: "ignore", timeout: 5_000 });
+      return true;
+    } catch {
+      return false;
+    }
+  }
+
   private vmIsSuspended(vmName: string): boolean {
     const vms = tartList();
     const vm = vms.find((v) => v.name === vmName);
diff --git a/cli/test/unit/server/services/backend.spec.ts b/cli/test/unit/server/services/backend.spec.ts
index 8c4d1c3..42a67b6 100644
--- a/cli/test/unit/server/services/backend.spec.ts
+++ b/cli/test/unit/server/services/backend.spec.ts
@@ -1,4 +1,4 @@
-import { describe, expect, it, vi } from "vitest";
+import { afterEach, describe, expect, it, vi } from "vitest";
 
 vi.mock("../../../../src/server/config.ts", () => ({
   config: {
@@ -8,9 +8,13 @@ vi.mock("../../../../src/server/config.ts", () => ({
   },
 }));
 
-import { createBackend } from "../../../../src/server/services/backend.ts";
+import {
+  createBackend,
+  createBackends,
+} from "../../../../src/server/services/backend.ts";
 import { DockerService } from "../../../../src/server/services/docker.ts";
 import { ShuruBackend } from "../../../../src/server/services/shuru.ts";
+import { TartBackend } from "../../../../src/server/services/tart.ts";
 
 describe("createBackend", () => {
   it("returns DockerService for 'docker'", () => {
@@ -34,3 +38,38 @@ describe("createBackend", () => {
     );
   });
 });
+
+describe("createBackends", () => {
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it("creates the tart macOS backend when tart is installed", () => {
+    vi.spyOn(TartBackend, "isAvailable").mockReturnValue(true);
+
+    const backends = createBackends({ linux: "docker", macos: "tart" });
+
+    expect(backends.linux).toBeInstanceOf(DockerService);
+    expect(backends.macos).toBeInstanceOf(TartBackend);
+  });
+
+  it("disables the tart macOS backend when tart is not installed", () => {
+    vi.spyOn(TartBackend, "isAvailable").mockReturnValue(false);
+    const warn = vi.spyOn(console, "warn").mockImplementation(() => {});
+
+    const backends = createBackends({ linux: "docker", macos: "tart" });
+
+    expect(backends.macos).toBeUndefined();
+    expect(backends.linux).toBeInstanceOf(DockerService);
+    expect(warn).not.toHaveBeenCalled();
+  });
+
+  it("never probes for tart when no macOS backend is requested", () => {
+    const isAvailable = vi.spyOn(TartBackend, "isAvailable");
+
+    const backends = createBackends({ linux: "docker" });
+
+    expect(backends.macos).toBeUndefined();
+    expect(isAvailable).not.toHaveBeenCalled();
+  });
+});
diff --git a/cli/test/unit/server/services/tart.spec.ts b/cli/test/unit/server/services/tart.spec.ts
index fef43aa..3a37e89 100644
--- a/cli/test/unit/server/services/tart.spec.ts
+++ b/cli/test/unit/server/services/tart.spec.ts
@@ -164,4 +164,40 @@ describe("TartBackend", () => {
       expect(list).toHaveLength(0);
     });
   });
+
+  describe("isAvailable", () => {
+    it("returns true when the tart CLI runs", () => {
+      execSyncMock.mockReturnValue("tart 2.0.0");
+      expect(TartBackend.isAvailable()).toBe(true);
+    });
+
+    it("returns false when the tart CLI is not installed", () => {
+      execSyncMock.mockImplementation(() => {
+        throw new Error("/bin/sh: tart: command not found");
+      });
+      expect(TartBackend.isAvailable()).toBe(false);
+    });
+
+    it("probes without leaking output to the console", () => {
+      execSyncMock.mockReturnValue("");
+      TartBackend.isAvailable();
+      expect(execSyncMock).toHaveBeenCalledWith(
+        "tart --version",
+        expect.objectContaining({ stdio: "ignore" }),
+      );
+    });
+  });
+
+  describe("tart command execution", () => {
+    it("captures stderr instead of leaking it to the parent console", async () => {
+      execSyncMock.mockReturnValue(JSON.stringify([]));
+
+      await backend.listSandboxes();
+
+      expect(execSyncMock).toHaveBeenCalledWith(
+        "tart list --format json",
+        expect.objectContaining({ stdio: ["ignore", "pipe", "pipe"] }),
+      );
+    });
+  });
 });