diff --git a/src/commands/provider.ts b/src/commands/provider.ts
index 8a3066e50..e7b0ff101 100644
--- a/src/commands/provider.ts
+++ b/src/commands/provider.ts
@@ -4,6 +4,7 @@ import { getAPIProvider } from '../utils/model/providers.js'
 import { updateSettingsForSource } from '../utils/settings/settings.js'
 import { getSettings_DEPRECATED } from '../utils/settings/settings.js'
 import { applyConfigEnvironmentVariables } from '../utils/managedEnv.js'
+import { getDefaultSonnetModel, getDefaultOpusModel, getDefaultHaikuModel } from '../utils/model/model.js'
 
 function getEnvVarForProvider(provider: string): string {
   switch (provider) {
@@ -43,6 +44,28 @@ const call: LocalCommandCall = async (args, context) => {
     return { type: 'text', value: `Current API provider: ${current}` }
   }
 
+  // Helper function to set default model based on provider
+  const setDefaultModel = (provider: string) => {
+    const settings = getSettings_DEPRECATED() || {}
+    const currentModel = settings.model
+
+    // Only set default if no model has been explicitly set
+    if (!currentModel) {
+      let defaultModel: string
+      switch (provider) {
+        case 'anthropic':
+          defaultModel = getDefaultSonnetModel()
+          break
+        case 'openai':
+        case 'gemini':
+        case 'grok':
+        default:
+          defaultModel = getDefaultSonnetModel()
+      }
+      updateSettingsForSource('userSettings', { model: defaultModel })
+    }
+  }
+
   // unset - clear settings, fallback to env vars
   if (arg === 'unset') {
     updateSettingsForSource('userSettings', { modelType: undefined })
@@ -84,6 +107,7 @@ const call: LocalCommandCall = async (args, context) => {
     const hasUrl = !!mergedEnv.OPENAI_BASE_URL
     if (!hasKey || !hasUrl) {
       updateSettingsForSource('userSettings', { modelType: 'openai' })
+      setDefaultModel('openai')
       const missing = []
       if (!hasKey) missing.push('OPENAI_API_KEY')
       if (!hasUrl) missing.push('OPENAI_BASE_URL')
@@ -100,6 +124,7 @@ const call: LocalCommandCall = async (args, context) => {
     const hasKey = !!(mergedEnv.GROK_API_KEY || mergedEnv.XAI_API_KEY)
     if (!hasKey) {
       updateSettingsForSource('userSettings', { modelType: 'grok' })
+      setDefaultModel('grok')
       return {
         type: 'text',
         value: `Switched to Grok provider.\nWarning: Missing env var: GROK_API_KEY (or XAI_API_KEY)\nConfigure it via settings.json env or set manually.`,
@@ -114,6 +139,7 @@ const call: LocalCommandCall = async (args, context) => {
     // GEMINI_BASE_URL is optional (has default)
     if (!hasKey) {
       updateSettingsForSource('userSettings', { modelType: 'gemini' })
+      setDefaultModel('gemini')
       return {
         type: 'text',
         value: `Switched to Gemini provider.\nWarning: Missing env var: GEMINI_API_KEY\nConfigure it via /login or set manually.`,
@@ -135,6 +161,8 @@ const call: LocalCommandCall = async (args, context) => {
     delete process.env.CLAUDE_CODE_USE_COSTRICT
     // Update settings.json
     updateSettingsForSource('userSettings', { modelType: arg })
+    // Set default model for the provider
+    setDefaultModel(arg)
     // Ensure settings.env gets applied to process.env
     applyConfigEnvironmentVariables()
     return { type: 'text', value: `API provider set to ${arg}.` }
diff --git a/src/components/ConsoleOAuthFlow.tsx b/src/components/ConsoleOAuthFlow.tsx
index 73bb98ae8..0f6acd502 100644
--- a/src/components/ConsoleOAuthFlow.tsx
+++ b/src/components/ConsoleOAuthFlow.tsx
@@ -13,6 +13,7 @@ import { OAuthService } from '../services/oauth/index.js'
 import { getOauthAccountInfo, validateForceLoginOrg } from '../utils/auth.js'
 import { logError } from '../utils/log.js'
 import { getSettings_DEPRECATED, updateSettingsForSource } from '../utils/settings/settings.js'
+import { getDefaultSonnetModel } from '../utils/model/model.js'
 import { Select } from './CustomSelect/select.js'
 import { Spinner } from './Spinner.js'
 import TextInput from './TextInput.js'
@@ -283,6 +284,8 @@ export function ConsoleOAuthFlow({
         }
         // Reset modelType to anthropic when using OAuth login
         updateSettingsForSource('userSettings', { modelType: 'anthropic' } as any)
+        // Set default model to sonnet for Anthropic provider
+        updateSettingsForSource('userSettings', { model: getDefaultSonnetModel() } as any)
         // Clear costrict env var to prevent conflicts
         delete process.env.CLAUDE_CODE_USE_COSTRICT
 
@@ -729,6 +732,8 @@ function OAuthStatusMessage({
             for (const [k, v] of Object.entries(env)) process.env[k] = v
             // Clear costrict env var to prevent conflicts when using custom platform
             delete process.env.CLAUDE_CODE_USE_COSTRICT
+            // Set default model to sonnet for this provider
+            updateSettingsForSource('userSettings', { model: getDefaultSonnetModel() } as any)
             setOAuthStatus({ state: 'success' })
             void onDone()
           }
@@ -951,6 +956,8 @@ function OAuthStatusMessage({
             for (const [k, v] of Object.entries(env)) process.env[k] = v
             // Clear costrict env var to prevent conflicts when using OpenAI
             delete process.env.CLAUDE_CODE_USE_COSTRICT
+            // Set default model to sonnet for this provider
+            updateSettingsForSource('userSettings', { model: getDefaultSonnetModel() } as any)
             setOAuthStatus({ state: 'success' })
             void onDone()
           }
@@ -1186,6 +1193,8 @@ function OAuthStatusMessage({
             for (const [k, v] of Object.entries(env)) process.env[k] = v
             // Clear costrict env var to prevent conflicts when using Gemini
             delete process.env.CLAUDE_CODE_USE_COSTRICT
+            // Set default model to sonnet for this provider
+            updateSettingsForSource('userSettings', { model: getDefaultSonnetModel() } as any)
             setOAuthStatus({ state: 'success' })
             void onDone()
           }