fix(cli): isolate claude MCP config

CHANGELOG.md

@@ -40,6 +40,7 @@ Docs: https://docs.openclaw.ai
 - Agents/status: use provider-aware context window lookup for fresh Anthropic 4.6 model overrides so `/status` shows the correct 1.0m window instead of an underreported shared-cache minimum. (#54796) Thanks @neeravmakwana.
 - Agents/errors: surface provider quota/reset details when available, but keep HTML/Cloudflare rate-limit pages on the generic fallback so raw error pages are not shown to users. (#54512) Thanks @bugkill3r.
 - Claude CLI: switch the bundled Claude CLI backend to `stream-json` output so watchdogs see progress on long runs, and keep session/usage metadata even when Claude finishes with an empty result line. (#49698) Thanks @felear2022.
+- Claude CLI/MCP: always pass a strict generated `--mcp-config` overlay for background Claude CLI runs, including the empty-server case, so Claude does not inherit ambient user/global MCP servers. (#54961) Thanks @markojak.
 - Agents/embedded replies: surface mid-turn 429 and overload failures when embedded runs end without a user-visible reply, while preserving successful media-only replies that still use legacy `mediaUrl`. (#50930) Thanks @infichen.
 - WhatsApp/allowFrom: show a specific allowFrom policy error for valid blocked targets instead of the misleading `<E.164|group JID>` format hint. Thanks @mcaxtr.
 - Agents/cooldowns: scope rate-limit cooldowns per model so one 429 no longer blocks every model on the same auth profile, replace the exponential 1 min -> 1 h escalation with a stepped 30 s / 1 min / 5 min ladder, and surface a user-facing countdown message when all models are rate-limited. (#49834) Thanks @kiranvk-2011.

src/agents/cli-runner.test.ts

@@ -272,6 +272,56 @@ describe("runCliAgent with process supervisor", () => {
     expect(allArgs).toContain("You are a helpful assistant.");
   });
 
+  it("injects a strict empty MCP config for bundle-MCP-enabled Claude CLI runs", async () => {
+    supervisorSpawnMock.mockResolvedValueOnce(
+      createManagedRun({
+        reason: "exit",
+        exitCode: 0,
+        exitSignal: null,
+        durationMs: 50,
+        stdout: JSON.stringify({
+          session_id: "session-123",
+          message: "ok",
+        }),
+        stderr: "",
+        timedOut: false,
+        noOutputTimedOut: false,
+      }),
+    );
+
+    await runCliAgent({
+      sessionId: "s1",
+      sessionFile: "/tmp/session.jsonl",
+      workspaceDir: "/tmp",
+      config: {
+        agents: {
+          defaults: {
+            cliBackends: {
+              "claude-cli": {
+                command: "node",
+                args: ["/tmp/fake-claude.mjs"],
+                clearEnv: [],
+              },
+            },
+          },
+        },
+      } satisfies OpenClawConfig,
+      prompt: "hi",
+      provider: "claude-cli",
+      model: "claude-sonnet-4-6",
+      timeoutMs: 1_000,
+      runId: "run-bundle-mcp-empty",
+    });
+
+    const input = supervisorSpawnMock.mock.calls[0]?.[0] as { argv?: string[] };
+    expect(input.argv?.[0]).toBe("node");
+    expect(input.argv).toContain("/tmp/fake-claude.mjs");
+    expect(input.argv).toContain("--strict-mcp-config");
+    const configFlagIndex = input.argv?.indexOf("--mcp-config") ?? -1;
+    expect(configFlagIndex).toBeGreaterThanOrEqual(0);
+    expect(input.argv?.[configFlagIndex + 1]).toMatch(/^\/.+\/mcp\.json$/);
+  });
+
   it("runs CLI through supervisor and returns payload", async () => {
     supervisorSpawnMock.mockResolvedValueOnce(
       createManagedRun({

src/agents/cli-runner/bundle-mcp.test.ts

@@ -15,6 +15,32 @@ afterEach(async () => {
 });
 
 describe("prepareCliBundleMcpConfig", () => {
+  it("injects a strict empty --mcp-config overlay for bundle-MCP-enabled backends without servers", async () => {
+    const workspaceDir = await tempHarness.createTempDir("openclaw-cli-bundle-mcp-empty-");
+
+    const prepared = await prepareCliBundleMcpConfig({
+      enabled: true,
+      backend: {
+        command: "node",
+        args: ["./fake-claude.mjs"],
+      },
+      workspaceDir,
+      config: {},
+    });
+
+    const configFlagIndex = prepared.backend.args?.indexOf("--mcp-config") ?? -1;
+    expect(configFlagIndex).toBeGreaterThanOrEqual(0);
+    expect(prepared.backend.args).toContain("--strict-mcp-config");
+    const generatedConfigPath = prepared.backend.args?.[configFlagIndex + 1];
+    expect(typeof generatedConfigPath).toBe("string");
+    const raw = JSON.parse(await fs.readFile(generatedConfigPath as string, "utf-8")) as {
+      mcpServers?: Record<string, unknown>;
+    };
+    expect(raw.mcpServers).toEqual({});
+
+    await prepared.cleanup?.();
+  });
+
   it("injects a merged --mcp-config overlay for bundle-MCP-enabled backends", async () => {
     const env = captureEnv(["HOME"]);
     try {

src/agents/cli-runner/bundle-mcp.ts

@@ -98,10 +98,9 @@ export async function prepareCliBundleMcpConfig(params: {
   }
   mergedConfig = applyMergePatch(mergedConfig, bundleConfig.config) as BundleMcpConfig;
 
-  if (Object.keys(mergedConfig.mcpServers).length === 0) {
-    return { backend: params.backend };
-  }
-
+  // Always pass an explicit strict MCP config for background claude-cli runs.
+  // Otherwise Claude may inherit ambient user/global MCP servers (for example
+  // Playwright) and spawn unexpected background processes.
   const tempDir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-cli-mcp-"));
   const mcpConfigPath = path.join(tempDir, "mcp.json");
   const serializedConfig = `${JSON.stringify(mergedConfig, null, 2)}\n`;