🤖 feat: add Grok 4.5 priority processing

.github/workflows/pr.yml

@@ -277,6 +277,7 @@ jobs:
           fi
         env:
           OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
+          XAI_API_KEY: ${{ secrets.XAI_API_KEY }}
           ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
           BACKEND: ${{ needs.changes.outputs.backend }}
           BROWSER: ${{ needs.changes.outputs.browser }}

docs/config/models.mdx

@@ -30,8 +30,7 @@ Mux ships with curated models kept up to date with the frontier. Use any custom
 | Codex Max 5.1          | openai:gpt-5.1-codex-max      | `codex-max`                                                  |         |
 | Gemini 3.1 Pro Preview | google:gemini-3.1-pro-preview | `gemini`, `gemini-pro`                                       |         |
 | Gemini 3.6 Flash       | google:gemini-3.6-flash       | `gemini-flash`                                               |         |
-| Grok 4 1 Fast          | xai:grok-4-1-fast             | `grok`, `grok-4`, `grok-4.1`, `grok-4-1`                     |         |
-| Grok Code Fast 1       | xai:grok-code-fast-1          | `grok-code`                                                  |         |
+| Grok 4.5               | xai:grok-4.5                  | `grok`, `grok-4.5`                                           |         |
 | DeepSeek V4 Pro        | deepseek:deepseek-v4-pro      | `deepseek`, `deepseek-pro`, `deepseek-v4`, `deepseek-v4-pro` |         |
 | DeepSeek V4 Flash      | deepseek:deepseek-v4-flash    | `deepseek-flash`, `deepseek-v4-flash`                        |         |
 | Kimi K3                | moonshotai:kimi-k3            | `kimi`, `k3`, `kimi-k3`                                      |         |

flake.nix

@@ -46,15 +46,16 @@
             stdenv.cc.cc.lib # Provides libstdc++ for native modules like sharp
           ];
 
-          # Fetch dependencies in a separate fixed-output derivation
-          # Use only package.json and bun.lock to ensure consistent hashing
-          # regardless of how the flake is evaluated (local vs remote)
+          # Fetch dependencies in a separate fixed-output derivation.
+          # Include Bun patch files alongside package.json and bun.lock so patched
+          # dependencies install identically in local and remote Nix evaluations.
           offlineCache = pkgs.stdenvNoCC.mkDerivation {
             name = "mux-deps-${version}";
 
             src = pkgs.runCommand "mux-lock-files" { } ''
               mkdir -p $out
               cp ${./package.json} $out/package.json
+              cp -r ${./patches} $out/patches
               cp ${./bun.lock} $out/bun.lock
             '';
 
@@ -83,7 +84,7 @@
 
             outputHashMode = "recursive";
             # Marker used by scripts/update_flake_hash.sh to update this hash in place.
-            outputHash = "sha256-hK0zwN0pShMv8NlfMXud+9Jx2J32hz5+qtLMqzunZF8="; # mux-offline-cache-hash
+            outputHash = "sha256-ufRtgBViq/5RAGzL/f79pIYK/+3BCQNNAD1nCz/edRg="; # mux-offline-cache-hash
           };
 
           configurePhase = ''

package.json

@@ -57,7 +57,7 @@
     "@ai-sdk/moonshotai": "^3.0.15",
     "@ai-sdk/openai": "^4.0.11",
     "@ai-sdk/openai-compatible": "^3.0.7",
-    "@ai-sdk/xai": "^4.0.10",
+    "@ai-sdk/xai": "^4.0.28",
     "@aws-sdk/credential-providers": "^3.940.0",
     "@dnd-kit/core": "^6.3.1",
     "@dnd-kit/sortable": "^10.0.0",
@@ -252,6 +252,7 @@
     "dist/**/*.json",
     "dist/**/*.png",
     "dist/assets/**/*",
+    "patches/**/*",
     "scripts/postinstall.sh",
     "npm-shrinkwrap.json",
     "README.md",
@@ -331,5 +332,8 @@
     "sharp",
     "ssh2",
     "unrs-resolver"
-  ]
+  ],
+  "patchedDependencies": {
+    "@ai-sdk/xai@4.0.28": "patches/@ai-sdk%2Fxai@4.0.28.patch"
+  }
 }

patches/@ai-sdk%2Fxai@4.0.28.patch

@@ -0,0 +1,30 @@
+diff --git a/dist/index.js b/dist/index.js
+index ea833a84c3323dcc72534e076d68473dfdb77128..41568478bea4246ff9acd7943bbd4d4ee6bd28e3 100644
+--- a/dist/index.js
++++ b/dist/index.js
+@@ -2096,8 +2096,8 @@ import { z as z12 } from "zod/v4";
+ var xSearchArgsSchema = lazySchema4(
+   () => zodSchema4(
+     z12.object({
+-      allowedXHandles: z12.array(z12.string()).max(10).optional(),
+-      excludedXHandles: z12.array(z12.string()).max(10).optional(),
++      allowedXHandles: z12.array(z12.string()).max(20).optional(),
++      excludedXHandles: z12.array(z12.string()).max(20).optional(),
+       fromDate: z12.string().optional(),
+       toDate: z12.string().optional(),
+       enableImageUnderstanding: z12.boolean().optional(),
+diff --git a/src/tool/x-search.ts b/src/tool/x-search.ts
+index 5566aa9c391f67cab60fe50ff2a2b55ca71b0b73..6d0dd586f07c5ea9d2bd2dcbed4be211be2e3c8a 100644
+--- a/src/tool/x-search.ts
++++ b/src/tool/x-search.ts
+@@ -8,8 +8,8 @@ import { z } from 'zod/v4';
+ export const xSearchArgsSchema = lazySchema(() =>
+   zodSchema(
+     z.object({
+-      allowedXHandles: z.array(z.string()).max(10).optional(),
+-      excludedXHandles: z.array(z.string()).max(10).optional(),
++      allowedXHandles: z.array(z.string()).max(20).optional(),
++      excludedXHandles: z.array(z.string()).max(20).optional(),
+       fromDate: z.string().optional(),
+       toDate: z.string().optional(),
+       enableImageUnderstanding: z.boolean().optional(),

scripts/check-bench-agent.sh

@@ -95,6 +95,7 @@ trap 'rm -rf "$CHECK_DIR"' EXIT
 
 # Copy built dist and package.json — but NO lockfile, shrinkwrap, or node_modules.
 cp -r "$REPO_ROOT/dist" "$CHECK_DIR/dist"
+cp -r "$REPO_ROOT/patches" "$CHECK_DIR/patches"
 cp "$REPO_ROOT/package.json" "$CHECK_DIR/package.json"
 
 # Strip devDependencies so bun only resolves production deps (matching published package).

src/browser/App.tsx

@@ -17,7 +17,7 @@ import {
 } from "./hooks/usePersistedState";
 import { useResizableSidebar } from "./hooks/useResizableSidebar";
 import { matchesKeybind, KEYBINDS } from "./utils/ui/keybinds";
-import { applyFastModeServiceTierChange } from "./utils/fastModeServiceTier";
+import { applyFastModeServiceTierChange, getFastModeProvider } from "./utils/fastModeServiceTier";
 import { handleLayoutSlotHotkeys } from "./utils/ui/layoutSlotHotkeys";
 import { buildSortedWorkspacesByProject } from "./utils/ui/workspaceFiltering";
 import {
@@ -76,7 +76,6 @@ import {
   LEFT_SIDEBAR_WIDTH_KEY,
 } from "@/common/constants/storage";
 import { normalizeToCanonical } from "@/common/utils/ai/models";
-import { openaiDirectProviderOptionsAvailable } from "@/common/utils/ai/openaiProviderOptionsAvailability";
 import { getDefaultModel } from "@/browser/hooks/useModelsFromSettings";
 import type { BranchListResult } from "@/common/orpc/types";
 import { useTelemetry } from "./hooks/useTelemetry";
@@ -680,8 +679,19 @@ function AppInner() {
     [api, getModelForWorkspace, getReasoningModeForWorkspace, getThinkingLevelForWorkspace]
   );
 
+  const getFastModeActive = useCallback(() => {
+    const scopeId = selectedWorkspace?.workspaceId ?? creationScopeId;
+    if (!scopeId || providersConfig == null) return false;
+
+    const model = getModelForWorkspace(scopeId);
+    const provider = getFastModeProvider(model, {
+      providersConfig,
+      resolvedRouteProvider: getRouteForModel(normalizeToCanonical(model)),
+    });
+    return provider != null && providersConfig[provider]?.serviceTier === "priority";
+  }, [creationScopeId, getModelForWorkspace, getRouteForModel, providersConfig, selectedWorkspace]);
+
   const fastModeToggleInFlightRef = useRef(false);
-  const fastModeActive = providersConfig?.openai?.serviceTier === "priority";
   const toggleFastMode = useCallback(async () => {
     const scopeId = selectedWorkspace?.workspaceId ?? creationScopeId;
     if (!api || !scopeId || providersConfig == null || fastModeToggleInFlightRef.current) return;
@@ -691,25 +701,25 @@ function AppInner() {
     // Serialize requests so a quick double press cannot compute two writes from stale config.
     fastModeToggleInFlightRef.current = true;
     const model = getModelForWorkspace(scopeId);
-    const route = getRouteForModel(normalizeToCanonical(model));
-    if (
-      !openaiDirectProviderOptionsAvailable(model, {
-        providersConfig,
-        resolvedRouteProvider: route,
-      })
-    ) {
+    const provider = getFastModeProvider(model, {
+      providersConfig,
+      resolvedRouteProvider: getRouteForModel(normalizeToCanonical(model)),
+    });
+    if (provider == null) {
       fastModeToggleInFlightRef.current = false;
       return;
     }
 
     try {
+      const providerConfig = providersConfig[provider];
       const change = await applyFastModeServiceTierChange(
         api.providers,
-        providersConfig.openai?.serviceTier,
-        providersConfig.openai?.fastModePreviousServiceTier
+        provider,
+        providerConfig?.serviceTier,
+        providerConfig?.fastModePreviousServiceTier
       );
       if (change) {
-        updateOptimistically("openai", {
+        updateOptimistically(provider, {
           serviceTier: change.serviceTier,
           fastModePreviousServiceTier: change.previousServiceTier,
         });
@@ -972,7 +982,7 @@ function AppInner() {
     onSetThinkingLevel: setThinkingLevelFromPalette,
     getReasoningMode: getReasoningModeForWorkspace,
     onToggleReasoningMode: toggleReasoningModeFromPalette,
-    getFastMode: () => fastModeActive,
+    getFastMode: getFastModeActive,
     onToggleFastMode: toggleFastMode,
     getEffectiveComposerModel: getModelForWorkspace,
     providersConfig,

src/browser/components/ModelSelector/modelFilter.test.ts

@@ -10,7 +10,6 @@ describe("modelMatchesQuery", () => {
   test("matches documented aliases that are not model string substrings", () => {
     expect(modelMatchesQuery("google:gemini-3.6-flash", "gemini-flash")).toBe(true);
     expect(modelMatchesQuery("deepseek:deepseek-v4-pro", "deepseek-pro")).toBe(true);
-    expect(modelMatchesQuery("xai:grok-4-1-fast", "grok-4.1")).toBe(true);
   });
 
   test("matches aliases for gateway-prefixed model strings", () => {

src/browser/components/ThinkingSelector/ThinkingSelector.tsx

@@ -8,11 +8,13 @@ import { useReasoningMode } from "@/browser/hooks/useReasoningMode";
 import { useRouting } from "@/browser/hooks/useRouting";
 import { useThinkingLevel } from "@/browser/hooks/useThinkingLevel";
 import { stopKeyboardPropagation } from "@/browser/utils/events";
-import { applyFastModeServiceTierChange } from "@/browser/utils/fastModeServiceTier";
+import {
+  applyFastModeServiceTierChange,
+  getFastModeProvider,
+} from "@/browser/utils/fastModeServiceTier";
 import { formatKeybind, KEYBINDS } from "@/browser/utils/ui/keybinds";
 import { cn } from "@/common/lib/utils";
 import { getThinkingDisplayLabel, type ThinkingLevel } from "@/common/types/thinking";
-import { openaiDirectProviderOptionsAvailable } from "@/common/utils/ai/openaiProviderOptionsAvailability";
 import { openaiProModeAvailable } from "@/common/utils/ai/proMode";
 import { normalizeToCanonical } from "@/common/utils/ai/models";
 import { enforceThinkingPolicy, getAvailableThinkingLevels } from "@/common/utils/thinking/policy";
@@ -60,20 +62,23 @@ export const ThinkingSelector: React.FC<ThinkingSelectorProps> = (props) => {
   );
   const displayLabel = getThinkingDisplayLabel(effectiveThinkingLevel, props.modelString);
   const resolvedRoute = routing.resolveRoute(normalizeToCanonical(props.modelString)).route;
-  const directOpenAIOptionsAvailable = openaiDirectProviderOptionsAvailable(props.modelString, {
-    providersConfig,
-    resolvedRouteProvider: resolvedRoute,
-  });
   const proModeAvailable =
     props.allowProMode !== false &&
     openaiProModeAvailable(props.modelString, {
       providersConfig,
       resolvedRouteProvider: resolvedRoute,
     });
-  const fastModeAvailable =
-    props.allowFastMode !== false && providersConfig != null && directOpenAIOptionsAvailable;
+  const fastModeProvider =
+    props.allowFastMode !== false && providersConfig != null
+      ? getFastModeProvider(props.modelString, {
+          providersConfig,
+          resolvedRouteProvider: resolvedRoute,
+        })
+      : null;
+  const fastModeAvailable = fastModeProvider != null;
   const proModeActive = proModeAvailable && reasoningMode === "pro";
-  const fastModeActive = fastModeAvailable && providersConfig?.openai?.serviceTier === "priority";
+  const fastModeActive =
+    fastModeProvider != null && providersConfig?.[fastModeProvider]?.serviceTier === "priority";
   const hasMenu = allowed.length > 1 || proModeAvailable || fastModeAvailable;
 
   // The menu is rendered inline for happy-dom coverage, so a document listener is the
@@ -92,17 +97,19 @@ export const ThinkingSelector: React.FC<ThinkingSelectorProps> = (props) => {
   }, [isOpen]);
 
   const handleFastModeToggle = async () => {
-    if (!api || fastModeSaving || providersConfig == null) return;
+    if (!api || fastModeSaving || providersConfig == null || fastModeProvider == null) return;
 
     setFastModeSaving(true);
     try {
+      const providerConfig = providersConfig[fastModeProvider];
       const change = await applyFastModeServiceTierChange(
         api.providers,
-        providersConfig.openai?.serviceTier,
-        providersConfig.openai?.fastModePreviousServiceTier
+        fastModeProvider,
+        providerConfig?.serviceTier,
+        providerConfig?.fastModePreviousServiceTier
       );
       if (change) {
-        updateOptimistically("openai", {
+        updateOptimistically(fastModeProvider, {
           serviceTier: change.serviceTier,
           fastModePreviousServiceTier: change.previousServiceTier,
         });

src/browser/features/Settings/Sections/ProvidersSection.stories.tsx

@@ -103,6 +103,33 @@ export const ProvidersEnvSourced: Story = {
   },
 };
 
+export const XAIProcessingMode: Story = {
+  render: () => (
+    <SettingsSectionStory
+      setup={() =>
+        setupSettingsStory({
+          providersConfig: {
+            xai: {
+              apiKeySet: true,
+              isEnabled: true,
+              isConfigured: true,
+              serviceTier: "priority",
+            },
+          },
+        })
+      }
+    >
+      <ProvidersSection />
+    </SettingsSectionStory>
+  ),
+  play: async ({ canvasElement }) => {
+    const canvas = within(canvasElement);
+    const xaiButton = await canvas.findByRole("button", { name: /xAI/i });
+    await userEvent.click(xaiButton);
+    await canvas.findByText("fast (priority)");
+  },
+};
+
 export const ProvidersExpanded: Story = {
   render: () => (
     <SettingsSectionStory

src/browser/features/Settings/Sections/ProvidersSection.test.tsx

@@ -105,6 +105,11 @@ function createProvidersConfig(): ProvidersConfigMap {
       isEnabled: true,
       isConfigured: true,
     },
+    xai: {
+      apiKeySet: true,
+      isEnabled: true,
+      isConfigured: true,
+    },
     [CUSTOM_PROVIDER_ID]: {
       apiKeySet: true,
       isEnabled: true,