diff --git a/src/commands/auth-choice-options.ts b/src/commands/auth-choice-options.ts
index f13eef365..3a323a3af 100644
--- a/src/commands/auth-choice-options.ts
+++ b/src/commands/auth-choice-options.ts
@@ -22,7 +22,8 @@ export type AuthChoiceGroupId =
   | "minimax"
   | "synthetic"
   | "venice"
-  | "qwen";
+  | "qwen"
+  | "xai";
 
 export type AuthChoiceGroup = {
   value: AuthChoiceGroupId;
@@ -115,6 +116,12 @@ const AUTH_CHOICE_GROUP_DEFS: {
     hint: "API key",
     choices: ["opencode-zen"],
   },
+  {
+    value: "xai",
+    label: "xAI",
+    hint: "Grok models (API key)",
+    choices: ["xai-api-key"],
+  },
 ];
 
 function formatOAuthHint(expires?: number, opts?: { allowStale?: boolean }): string {
@@ -219,6 +226,7 @@ export function buildAuthChoiceOptions(params: {
     hint: "Uses the bundled Gemini CLI auth plugin",
   });
   options.push({ value: "zai-api-key", label: "Z.AI (GLM 4.7) API key" });
+  options.push({ value: "xai-api-key", label: "xAI API key" });
   options.push({ value: "qwen-portal", label: "Qwen OAuth" });
   options.push({
     value: "copilot-proxy",
diff --git a/src/commands/auth-choice.apply.api-providers.ts b/src/commands/auth-choice.apply.api-providers.ts
index 8be02008b..edbcf8d63 100644
--- a/src/commands/auth-choice.apply.api-providers.ts
+++ b/src/commands/auth-choice.apply.api-providers.ts
@@ -27,6 +27,8 @@ import {
   applyVeniceProviderConfig,
   applyVercelAiGatewayConfig,
   applyVercelAiGatewayProviderConfig,
+  applyXaiConfig,
+  applyXaiProviderConfig,
   applyZaiConfig,
   KIMI_CODE_MODEL_REF,
   MOONSHOT_DEFAULT_MODEL_REF,
@@ -42,7 +44,9 @@ import {
   setSyntheticApiKey,
   setVeniceApiKey,
   setVercelAiGatewayApiKey,
+  setXaiApiKey,
   setZaiApiKey,
+  XAI_DEFAULT_MODEL_REF,
   ZAI_DEFAULT_MODEL_REF,
 } from "./onboard-auth.js";
 import { OPENCODE_ZEN_DEFAULT_MODEL } from "./opencode-zen-model-default.js";
@@ -85,6 +89,8 @@ export async function applyAuthChoiceApiProviders(
       authChoice = "venice-api-key";
     } else if (params.opts.tokenProvider === "opencode") {
       authChoice = "opencode-zen";
+    } else if (params.opts.tokenProvider === "xai") {
+      authChoice = "xai-api-key";
     }
   }
 
@@ -579,5 +585,53 @@ export async function applyAuthChoiceApiProviders(
     return { config: nextConfig, agentModelOverride };
   }
 
+  if (authChoice === "xai-api-key") {
+    let hasCredential = false;
+
+    if (!hasCredential && params.opts?.token && params.opts?.tokenProvider === "xai") {
+      await setXaiApiKey(normalizeApiKeyInput(params.opts.token), params.agentDir);
+      hasCredential = true;
+    }
+
+    const envKey = resolveEnvApiKey("xai");
+    if (envKey) {
+      const useExisting = await params.prompter.confirm({
+        message: `Use existing XAI_API_KEY (${envKey.source}, ${formatApiKeyPreview(envKey.apiKey)})?`,
+        initialValue: true,
+      });
+      if (useExisting) {
+        await setXaiApiKey(envKey.apiKey, params.agentDir);
+        hasCredential = true;
+      }
+    }
+    if (!hasCredential) {
+      const key = await params.prompter.text({
+        message: "Enter xAI API key",
+        validate: validateApiKeyInput,
+      });
+      await setXaiApiKey(normalizeApiKeyInput(String(key)), params.agentDir);
+    }
+    nextConfig = applyAuthProfileConfig(nextConfig, {
+      profileId: "xai:default",
+      provider: "xai",
+      mode: "api_key",
+    });
+    {
+      const applied = await applyDefaultModelChoice({
+        config: nextConfig,
+        setDefaultModel: params.setDefaultModel,
+        defaultModel: XAI_DEFAULT_MODEL_REF,
+        applyDefaultConfig: applyXaiConfig,
+        applyProviderConfig: applyXaiProviderConfig,
+        noteDefault: XAI_DEFAULT_MODEL_REF,
+        noteAgentModel,
+        prompter: params.prompter,
+      });
+      nextConfig = applied.config;
+      agentModelOverride = applied.agentModelOverride ?? agentModelOverride;
+    }
+    return { config: nextConfig, agentModelOverride };
+  }
+
   return null;
 }
diff --git a/src/commands/onboard-auth.config-core.ts b/src/commands/onboard-auth.config-core.ts
index 8e324113e..278fca010 100644
--- a/src/commands/onboard-auth.config-core.ts
+++ b/src/commands/onboard-auth.config-core.ts
@@ -14,6 +14,7 @@ import type { ClawdbotConfig } from "../config/config.js";
 import {
   OPENROUTER_DEFAULT_MODEL_REF,
   VERCEL_AI_GATEWAY_DEFAULT_MODEL_REF,
+  XAI_DEFAULT_MODEL_REF,
   ZAI_DEFAULT_MODEL_REF,
 } from "./onboard-auth.credentials.js";
 import {
@@ -55,6 +56,47 @@ export function applyZaiConfig(cfg: ClawdbotConfig): ClawdbotConfig {
   };
 }
 
+export function applyXaiProviderConfig(cfg: ClawdbotConfig): ClawdbotConfig {
+  const models = { ...cfg.agents?.defaults?.models };
+  models[XAI_DEFAULT_MODEL_REF] = {
+    ...models[XAI_DEFAULT_MODEL_REF],
+    alias: models[XAI_DEFAULT_MODEL_REF]?.alias ?? "Grok",
+  };
+
+  return {
+    ...cfg,
+    agents: {
+      ...cfg.agents,
+      defaults: {
+        ...cfg.agents?.defaults,
+        models,
+      },
+    },
+  };
+}
+
+export function applyXaiConfig(cfg: ClawdbotConfig): ClawdbotConfig {
+  const next = applyXaiProviderConfig(cfg);
+  const existingModel = next.agents?.defaults?.model;
+  return {
+    ...next,
+    agents: {
+      ...next.agents,
+      defaults: {
+        ...next.agents?.defaults,
+        model: {
+          ...(existingModel && "fallbacks" in (existingModel as Record<string, unknown>)
+            ? {
+                fallbacks: (existingModel as { fallbacks?: string[] }).fallbacks,
+              }
+            : undefined),
+          primary: XAI_DEFAULT_MODEL_REF,
+        },
+      },
+    },
+  };
+}
+
 export function applyOpenrouterProviderConfig(cfg: ClawdbotConfig): ClawdbotConfig {
   const models = { ...cfg.agents?.defaults?.models };
   models[OPENROUTER_DEFAULT_MODEL_REF] = {
diff --git a/src/commands/onboard-auth.credentials.ts b/src/commands/onboard-auth.credentials.ts
index 0c7dff409..ba35a1ddf 100644
--- a/src/commands/onboard-auth.credentials.ts
+++ b/src/commands/onboard-auth.credentials.ts
@@ -113,6 +113,7 @@ export async function setVeniceApiKey(key: string, agentDir?: string) {
 }
 
 export const ZAI_DEFAULT_MODEL_REF = "zai/glm-4.7";
+export const XAI_DEFAULT_MODEL_REF = "xai/grok-4.1";
 export const OPENROUTER_DEFAULT_MODEL_REF = "openrouter/auto";
 export const VERCEL_AI_GATEWAY_DEFAULT_MODEL_REF = "vercel-ai-gateway/anthropic/claude-opus-4.5";
 
@@ -164,3 +165,15 @@ export async function setOpencodeZenApiKey(key: string, agentDir?: string) {
     agentDir: resolveAuthAgentDir(agentDir),
   });
 }
+
+export async function setXaiApiKey(key: string, agentDir?: string) {
+  upsertAuthProfile({
+    profileId: "xai:default",
+    credential: {
+      type: "api_key",
+      provider: "xai",
+      key,
+    },
+    agentDir: resolveAuthAgentDir(agentDir),
+  });
+}
diff --git a/src/commands/onboard-auth.ts b/src/commands/onboard-auth.ts
index 3ddeca48c..bb1f4ec00 100644
--- a/src/commands/onboard-auth.ts
+++ b/src/commands/onboard-auth.ts
@@ -20,6 +20,8 @@ export {
   applyVeniceProviderConfig,
   applyVercelAiGatewayConfig,
   applyVercelAiGatewayProviderConfig,
+  applyXaiConfig,
+  applyXaiProviderConfig,
   applyZaiConfig,
 } from "./onboard-auth.config-core.js";
 export {
@@ -47,9 +49,11 @@ export {
   setSyntheticApiKey,
   setVeniceApiKey,
   setVercelAiGatewayApiKey,
+  setXaiApiKey,
   setZaiApiKey,
   writeOAuthCredentials,
   VERCEL_AI_GATEWAY_DEFAULT_MODEL_REF,
+  XAI_DEFAULT_MODEL_REF,
   ZAI_DEFAULT_MODEL_REF,
 } from "./onboard-auth.credentials.js";
 export {
diff --git a/src/commands/onboard-types.ts b/src/commands/onboard-types.ts
index 84c15afc4..0700d2a65 100644
--- a/src/commands/onboard-types.ts
+++ b/src/commands/onboard-types.ts
@@ -31,6 +31,7 @@ export type AuthChoice =
   | "github-copilot"
   | "copilot-proxy"
   | "qwen-portal"
+  | "xai-api-key"
   | "skip";
 export type GatewayAuthChoice = "off" | "token" | "password";
 export type ResetScope = "config" | "config+creds+sessions" | "full";
@@ -71,6 +72,7 @@ export type OnboardOptions = {
   syntheticApiKey?: string;
   veniceApiKey?: string;
   opencodeZenApiKey?: string;
+  xaiApiKey?: string;
   gatewayPort?: number;
   gatewayBind?: GatewayBind;
   gatewayAuth?: GatewayAuthChoice;