feat: implement platform-specific provider visibility for cursor agent

server/modules/providers/services/mcp.service.ts

@@ -1,7 +1,18 @@
+import os from 'node:os';
+
 import { providerRegistry } from '@/modules/providers/provider.registry.js';
 import type { LLMProvider, McpScope, ProviderMcpServer, UpsertProviderMcpServerInput } from '@/shared/types.js';
 import { AppError } from '@/shared/utils.js';
 
+/** Cursor MCP is not supported on Windows hosts (no Cursor CLI integration). */
+function includeProviderInGlobalMcp(providerId: LLMProvider): boolean {
+  if (providerId === 'cursor' && os.platform() === 'win32') {
+    return false;
+  }
+
+  return true;
+}
+
 
 export const providerMcpService = {
   /**
@@ -83,7 +94,7 @@ export const providerMcpService = {
 
     const scope = input.scope ?? 'project';
     const results: Array<{ provider: LLMProvider; created: boolean; error?: string }> = [];
-    const providers = providerRegistry.listProviders();
+    const providers = providerRegistry.listProviders().filter((p) => includeProviderInGlobalMcp(p.id));
     for (const provider of providers) {
       try {
         await provider.mcp.upsertServer({ ...input, scope });

server/modules/providers/tests/mcp.test.ts

@@ -255,7 +255,8 @@ test('providerMcpService global adder writes to all providers and rejects unsupp
       workspacePath,
     });
 
-    assert.equal(globalResult.length, 4);
+    const expectCursorGlobal = process.platform !== 'win32';
+    assert.equal(globalResult.length, expectCursorGlobal ? 4 : 3);
     assert.ok(globalResult.every((entry) => entry.created === true));
 
     const claudeProject = await readJson(path.join(workspacePath, '.mcp.json'));
@@ -267,8 +268,10 @@ test('providerMcpService global adder writes to all providers and rejects unsupp
     const geminiProject = await readJson(path.join(workspacePath, '.gemini', 'settings.json'));
     assert.ok((geminiProject.mcpServers as Record<string, unknown>)['global-http']);
 
-    const cursorProject = await readJson(path.join(workspacePath, '.cursor', 'mcp.json'));
-    assert.ok((cursorProject.mcpServers as Record<string, unknown>)['global-http']);
+    if (expectCursorGlobal) {
+      const cursorProject = await readJson(path.join(workspacePath, '.cursor', 'mcp.json'));
+      assert.ok((cursorProject.mcpServers as Record<string, unknown>)['global-http']);
+    }
 
     await assert.rejects(
       providerMcpService.addMcpServerToAllProviders({

server/routes/settings.js

@@ -273,4 +273,14 @@ router.post('/push/unsubscribe', async (req, res) => {
   }
 });
 
+// Host OS for UI (e.g. hide Cursor agent when the backend runs on Windows).
+router.get('/server-env', async (req, res) => {
+  try {
+    res.json({ platform: process.platform });
+  } catch (error) {
+    console.error('Error reading server environment:', error);
+    res.status(500).json({ error: 'Failed to read server environment' });
+  }
+});
+
 export default router;

src/components/chat/view/subcomponents/ProviderSelectionEmptyState.tsx

@@ -1,6 +1,7 @@
-import React from "react";
+import React, { useEffect, useMemo } from "react";
 import { Check, ChevronDown } from "lucide-react";
 import { useTranslation } from "react-i18next";
+import { useServerPlatform } from "../../../../hooks/useServerPlatform";
 import SessionProviderLogo from "../../../llm-logo-provider/SessionProviderLogo";
 import {
   CLAUDE_MODELS,
@@ -115,6 +116,23 @@ export default function ProviderSelectionEmptyState({
   setInput,
 }: ProviderSelectionEmptyStateProps) {
   const { t } = useTranslation("chat");
+  const { isWindowsServer } = useServerPlatform();
+
+  const visibleProviders = useMemo(
+    () =>
+      isWindowsServer
+        ? PROVIDERS.filter((p) => p.id !== "cursor")
+        : PROVIDERS,
+    [isWindowsServer],
+  );
+
+  useEffect(() => {
+    if (isWindowsServer && provider === "cursor") {
+      setProvider("claude");
+      localStorage.setItem("selected-provider", "claude");
+    }
+  }, [isWindowsServer, provider, setProvider]);
+
   const nextTaskPrompt = t("tasks.nextTaskPrompt", {
     defaultValue: "Start the next task",
   });
@@ -166,8 +184,10 @@ export default function ProviderSelectionEmptyState({
           </div>
 
           {/* Provider cards — horizontal row, equal width */}
-          <div className="mb-6 grid grid-cols-2 gap-2 sm:grid-cols-4 sm:gap-2.5">
-            {PROVIDERS.map((p) => {
+          <div
+            className={`mb-6 grid grid-cols-2 gap-2 sm:gap-2.5 ${visibleProviders.length >= 4 ? "sm:grid-cols-4" : "sm:grid-cols-3"}`}
+          >
+            {visibleProviders.map((p) => {
               const active = provider === p.id;
               return (
                 <button

src/components/settings/view/tabs/agents-settings/AgentsSettingsTab.tsx

@@ -1,5 +1,6 @@
-import { useMemo, useState } from 'react';
+import { useEffect, useMemo, useState } from 'react';
 
+import { useServerPlatform } from '../../../../../hooks/useServerPlatform';
 import type { AgentCategory, AgentProvider } from '../../../types/types';
 
 import type { AgentContext, AgentsSettingsTabProps } from './types';
@@ -22,6 +23,22 @@ export default function AgentsSettingsTab({
 }: AgentsSettingsTabProps) {
   const [selectedAgent, setSelectedAgent] = useState<AgentProvider>('claude');
   const [selectedCategory, setSelectedCategory] = useState<AgentCategory>('account');
+  const { isWindowsServer } = useServerPlatform();
+
+  const visibleAgents = useMemo<AgentProvider[]>(() => {
+    const all: AgentProvider[] = ['claude', 'cursor', 'codex', 'gemini'];
+    if (isWindowsServer) {
+      return all.filter((id) => id !== 'cursor');
+    }
+
+    return all;
+  }, [isWindowsServer]);
+
+  useEffect(() => {
+    if (isWindowsServer && selectedAgent === 'cursor') {
+      setSelectedAgent('claude');
+    }
+  }, [isWindowsServer, selectedAgent]);
 
   const agentContextById = useMemo<Record<AgentProvider, AgentContext>>(() => ({
     claude: {
@@ -51,6 +68,7 @@ export default function AgentsSettingsTab({
   return (
     <div className="-mx-4 -mb-4 -mt-2 flex min-h-[300px] flex-col overflow-hidden md:-mx-6 md:-mb-6 md:-mt-2 md:min-h-[500px]">
       <AgentSelectorSection
+        agents={visibleAgents}
         selectedAgent={selectedAgent}
         onSelectAgent={setSelectedAgent}
         agentContextById={agentContextById}

src/components/settings/view/tabs/agents-settings/sections/AgentSelectorSection.tsx

@@ -3,8 +3,6 @@ import SessionProviderLogo from '../../../../../llm-logo-provider/SessionProvide
 import type { AgentProvider } from '../../../../types/types';
 import type { AgentSelectorSectionProps } from '../types';
 
-const AGENT_PROVIDERS: AgentProvider[] = ['claude', 'cursor', 'codex', 'gemini'];
-
 const AGENT_NAMES: Record<AgentProvider, string> = {
   claude: 'Claude',
   cursor: 'Cursor',
@@ -13,6 +11,7 @@ const AGENT_NAMES: Record<AgentProvider, string> = {
 };
 
 export default function AgentSelectorSection({
+  agents,
   selectedAgent,
   onSelectAgent,
   agentContextById,
@@ -20,7 +19,7 @@ export default function AgentSelectorSection({
   return (
     <div className="flex-shrink-0 border-b border-border px-3 py-2 md:px-4 md:py-3">
       <PillBar className="w-full md:w-auto">
-        {AGENT_PROVIDERS.map((agent) => {
+        {agents.map((agent) => {
           const dotColor =
             agent === 'claude' ? 'bg-blue-500' :
             agent === 'cursor' ? 'bg-purple-500' :

src/components/settings/view/tabs/agents-settings/types.ts

@@ -37,6 +37,7 @@ export type AgentCategoryTabsSectionProps = {
 };
 
 export type AgentSelectorSectionProps = {
+  agents: AgentProvider[];
   selectedAgent: AgentProvider;
   onSelectAgent: (agent: AgentProvider) => void;
   agentContextById: AgentContextByProvider;

src/hooks/useServerPlatform.ts

@@ -0,0 +1,40 @@
+import { useEffect, useState } from 'react';
+
+import { authenticatedFetch } from '../utils/api';
+
+/**
+ * Node `process.platform` from the API host (e.g. win32, darwin, linux).
+ * Null until loaded or if the request fails.
+ */
+export function useServerPlatform(): {
+  serverPlatform: string | null;
+  isWindowsServer: boolean;
+} {
+  const [serverPlatform, setServerPlatform] = useState<string | null>(null);
+
+  useEffect(() => {
+    let cancelled = false;
+    (async () => {
+      try {
+        const response = await authenticatedFetch('/api/settings/server-env');
+        if (!response.ok) {
+          return;
+        }
+        const body = (await response.json()) as { platform?: string };
+        if (!cancelled && typeof body.platform === 'string') {
+          setServerPlatform(body.platform);
+        }
+      } catch {
+        // Keep null: treat as unknown host.
+      }
+    })();
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+
+  return {
+    serverPlatform,
+    isWindowsServer: serverPlatform === 'win32',
+  };
+}