diff --git a/desktop/src/api/hahaOAuth.ts b/desktop/src/api/hahaOAuth.ts
new file mode 100644
index 00000000..65b3de40
--- /dev/null
+++ b/desktop/src/api/hahaOAuth.ts
@@ -0,0 +1,38 @@
+// desktop/src/api/hahaOAuth.ts
+
+import { api, getBaseUrl } from './client'
+
+export type HahaOAuthStatus =
+  | { loggedIn: false }
+  | {
+      loggedIn: true
+      expiresAt: number | null
+      scopes: string[]
+      subscriptionType: 'pro' | 'max' | 'team' | 'enterprise' | null
+    }
+
+function currentServerPort(): number {
+  const port = new URL(getBaseUrl()).port
+  const parsed = Number.parseInt(port, 10)
+  if (!Number.isFinite(parsed) || parsed <= 0) {
+    throw new Error(`Cannot determine server port from baseUrl: ${getBaseUrl()}`)
+  }
+  return parsed
+}
+
+export const hahaOAuthApi = {
+  start() {
+    return api.post<{ authorizeUrl: string; state: string }>(
+      '/api/haha-oauth/start',
+      { serverPort: currentServerPort() },
+    )
+  },
+
+  status() {
+    return api.get<HahaOAuthStatus>('/api/haha-oauth')
+  },
+
+  logout() {
+    return api.delete<{ ok: true }>('/api/haha-oauth')
+  },
+}
diff --git a/desktop/src/stores/hahaOAuthStore.ts b/desktop/src/stores/hahaOAuthStore.ts
new file mode 100644
index 00000000..d6f3e49a
--- /dev/null
+++ b/desktop/src/stores/hahaOAuthStore.ts
@@ -0,0 +1,89 @@
+// desktop/src/stores/hahaOAuthStore.ts
+
+import { create } from 'zustand'
+import { hahaOAuthApi, type HahaOAuthStatus } from '../api/hahaOAuth'
+
+const POLL_INTERVAL_MS = 2_000
+
+type HahaOAuthState = {
+  status: HahaOAuthStatus | null
+  isPolling: boolean
+  isLoading: boolean
+  error: string | null
+
+  fetchStatus: () => Promise<void>
+  login: () => Promise<{ authorizeUrl: string }>
+  logout: () => Promise<void>
+  startPolling: () => void
+  stopPolling: () => void
+}
+
+export const useHahaOAuthStore = create<HahaOAuthState>((set, get) => {
+  let pollTimer: ReturnType<typeof setInterval> | null = null
+
+  return {
+    status: null,
+    isPolling: false,
+    isLoading: false,
+    error: null,
+
+    fetchStatus: async () => {
+      try {
+        const status = await hahaOAuthApi.status()
+        set({ status, error: null })
+      } catch (err) {
+        set({ error: err instanceof Error ? err.message : String(err) })
+      }
+    },
+
+    login: async () => {
+      set({ isLoading: true, error: null })
+      try {
+        const res = await hahaOAuthApi.start()
+        set({ isLoading: false })
+        get().startPolling()
+        return { authorizeUrl: res.authorizeUrl }
+      } catch (err) {
+        set({
+          isLoading: false,
+          error: err instanceof Error ? err.message : String(err),
+        })
+        throw err
+      }
+    },
+
+    logout: async () => {
+      set({ isLoading: true })
+      try {
+        await hahaOAuthApi.logout()
+        set({ status: { loggedIn: false }, isLoading: false })
+      } catch (err) {
+        set({
+          isLoading: false,
+          error: err instanceof Error ? err.message : String(err),
+        })
+        throw err
+      }
+    },
+
+    startPolling: () => {
+      if (pollTimer) return
+      set({ isPolling: true })
+      pollTimer = setInterval(async () => {
+        await get().fetchStatus()
+        const cur = get().status
+        if (cur && cur.loggedIn) {
+          get().stopPolling()
+        }
+      }, POLL_INTERVAL_MS)
+    },
+
+    stopPolling: () => {
+      if (pollTimer) {
+        clearInterval(pollTimer)
+        pollTimer = null
+      }
+      set({ isPolling: false })
+    },
+  }
+})