diff --git a/trios/agent-server/apps/agent/entrypoints/app/ai-settings/AISettingsPage.test.ts b/trios/agent-server/apps/agent/entrypoints/app/ai-settings/AISettingsPage.test.ts
new file mode 100644
index 0000000000..43dec337a1
--- /dev/null
+++ b/trios/agent-server/apps/agent/entrypoints/app/ai-settings/AISettingsPage.test.ts
@@ -0,0 +1,141 @@
+/**
+ * @license
+ * Copyright 2025 BrowserOS
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ *
+ * The AI settings page, held against its contract
+ * (gHashTag/trios#1504): the one export of
+ * entrypoints/app/ai-settings/AISettingsPage.tsx - AISettingsPage -
+ * pinned as it behaves today, so the next change to that file has
+ * something to fail against.
+ *
+ * The page reads the provider store, the session, the agent server
+ * URL and two graphql queries, so each seam is stubbed with a full
+ * stand-in: the providers hook (empty list, no default), the
+ * graphql query and mutation hooks (no data, idle mutation), the
+ * session info (no user), the agent server URL (no base URL), the
+ * metrics track (a no-op - its real module pulls the adapter graph
+ * other suites stub incompletely), and the storage fake underneath
+ * the graph's own items. Measured, the static render goes through
+ * and shows the page as it first mounts.
+ *
+ * Not pinned, and why (issue User Story 2): the settings flow
+ * itself - adding, editing, testing and deleting providers, the
+ * remote incomplete-provider sync, the dialogs - they live in
+ * handlers that need a live document and window. The port env
+ * seam is seeded before any import can reach the env module (its
+ * one-time snapshot - the trap the agent-outputs suite
+ * documented), with the subject imported dynamically for that
+ * reason.
+ */
+
+import { describe, expect, it, mock } from 'bun:test'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { createElement } from 'react'
+import { renderToStaticMarkup } from 'react-dom/server'
+
+// biome-ignore lint/style/noProcessEnv: the env seam is the only way to reach the port helpers before the env module's one-time snapshot freezes (see suite header)
+process.env.VITE_BROWSEROS_SERVER_PORT ??= '43210'
+
+const values = new Map<string, unknown>()
+
+const fakeItem = (key: string, opts: unknown) => ({
+  getValue: async () => {
+    if (values.has(key)) {
+      return values.get(key)
+    }
+    const fallback = (opts as { fallback?: unknown } | undefined)?.fallback
+    return fallback ?? null
+  },
+  setValue: async (value: unknown) => {
+    values.set(key, value)
+  },
+  watch: () => () => {},
+})
+
+mock.module('@wxt-dev/storage', () => ({
+  storage: {
+    defineItem: (key: string, opts?: unknown) => fakeItem(key, opts),
+  },
+}))
+
+mock.module('@/lib/llm-providers/useLlmProviders', () => ({
+  useLlmProviders: () => ({
+    providers: [],
+    defaultProviderId: '',
+    selectedProvider: null,
+    isLoading: false,
+    saveProvider: async () => {},
+    setDefaultProvider: async () => {},
+    deleteProvider: async () => {},
+  }),
+}))
+
+// The session seam is re-registered as a spread of the real module
+// (query-imported, so it never collides with the mock registry)
+// with only the hook stubbed: earlier suites of this group link the
+// facade with a stand-in that carries no useSessionInfo, and bun
+// freezes the facade's export set at that first link - a spread of
+// the real module restores the full export set for this suite's
+// import.
+const realSessionUrl = '@/lib/auth/sessionStorage?ai-settings-real'
+const realSession = (await import(realSessionUrl)) as Record<string, unknown>
+mock.module('@/lib/auth/sessionStorage', () => ({
+  ...realSession,
+  useSessionInfo: () => ({ sessionInfo: {}, isLoading: false }),
+}))
+
+mock.module('@/lib/browseros/useBrowserOSProviders', () => ({
+  useAgentServerUrl: () => ({
+    baseUrl: null,
+    isLoading: false,
+    error: null,
+  }),
+}))
+
+mock.module('@/lib/graphql/useGraphqlQuery', () => ({
+  useGraphqlQuery: () => ({ data: undefined, isLoading: false }),
+}))
+
+mock.module('@/lib/graphql/useGraphqlMutation', () => ({
+  useGraphqlMutation: () => ({ mutate: () => {}, isPending: false }),
+}))
+
+mock.module('@/lib/metrics/track', () => ({
+  track: () => {},
+}))
+
+// Some child of the page reads the router context - the real module
+// is spread with only the hook replaced.
+const realRouterUrl = 'react-router?ai-settings-real'
+const realRouter = (await import(realRouterUrl)) as Record<string, unknown>
+mock.module('react-router', () => ({
+  ...realRouter,
+  useNavigate: () => () => {},
+}))
+
+// The subject is read through a query-qualified specifier so this
+// suite's page graph loads as its own fresh module instances - the
+// shared session-storage seam keeps whichever mock an earlier suite
+// of this group registered for ITS consumers, instead of colliding
+// through a shared cache.
+const subjectUrl = './AISettingsPage?ai-settings-suite-real'
+const { AISettingsPage } = (await import(
+  subjectUrl
+)) as typeof import('./AISettingsPage')
+
+describe('AISettingsPageTsxContract', () => {
+  describe('AISettingsPage', () => {
+    it('answers the settings page as it first mounts: the framed page with its providers heading', () => {
+      const markup = renderToStaticMarkup(
+        createElement(
+          QueryClientProvider,
+          { client: new QueryClient() },
+          createElement(AISettingsPage),
+        ),
+      )
+      expect(markup).toContain('fade-in')
+      expect(markup).toContain('LLM Providers')
+    })
+  })
+})