fix(copilot): use gpt-4.1 as default model and 127.0.0.1 for local connections

Key changes:
- Changed default model from claude-sonnet-4.5 to gpt-4.1 (free tier compatible)
- Updated all Claude models to minPlan: 'pro' (requires paid Copilot subscription)
- Replaced 'localhost' with '127.0.0.1' for more reliable local connections
  (bypasses DNS resolution and potential IPv6 issues)
- Updated UI presets: replaced Claude Haiku with Raptor Mini in free tier
- Fixed FREE_PRESETS to only include actually free models

This fixes the "model_not_supported" error when using free tier GitHub Copilot
subscription, which doesn't have access to Claude models.

src/config/unified-config-types.ts

@@ -253,6 +253,7 @@ export interface SecretsConfig {
 /**
  * Default Copilot configuration.
  * Strictly opt-in - disabled by default.
+ * Uses gpt-4.1 as default model (free tier compatible).
  */
 export const DEFAULT_COPILOT_CONFIG: CopilotConfig = {
   enabled: false,
@@ -261,7 +262,7 @@ export const DEFAULT_COPILOT_CONFIG: CopilotConfig = {
   account_type: 'individual',
   rate_limit: null,
   wait_on_limit: true,
-  model: 'claude-sonnet-4.5',
+  model: 'gpt-4.1', // Free tier compatible
 };
 
 /**

src/copilot/copilot-daemon.ts

@@ -17,12 +17,13 @@ const PID_FILE = path.join(getCopilotDir(), 'daemon.pid');
 
 /**
  * Check if copilot-api daemon is running on the specified port.
+ * Uses 127.0.0.1 instead of localhost for more reliable local connections.
  */
 export async function isDaemonRunning(port: number): Promise<boolean> {
   return new Promise((resolve) => {
     const req = http.request(
       {
-        hostname: 'localhost',
+        hostname: '127.0.0.1',
         port,
         path: '/usage',
         method: 'GET',

src/copilot/copilot-executor.ts

@@ -40,8 +40,10 @@ export function generateCopilotEnv(config: CopilotConfig): Record<string, string
   const sonnetModel = config.sonnet_model || config.model;
   const haikuModel = config.haiku_model || config.model;
 
+  // Use 127.0.0.1 instead of localhost for more reliable local connections
+  // (bypasses DNS resolution and potential IPv6 issues)
   return {
-    ANTHROPIC_BASE_URL: `http://localhost:${config.port}`,
+    ANTHROPIC_BASE_URL: `http://127.0.0.1:${config.port}`,
     ANTHROPIC_AUTH_TOKEN: 'dummy', // copilot-api handles auth internally
     ANTHROPIC_MODEL: config.model,
     // Model tier mapping - allows different models for opus/sonnet/haiku

src/copilot/copilot-models.ts

@@ -18,12 +18,11 @@ import { CopilotModel } from './types';
  * Multipliers: 0 = free tier, 0.25-0.33 = cheap, 1 = standard, 3-10 = premium
  */
 export const DEFAULT_COPILOT_MODELS: CopilotModel[] = [
-  // Anthropic Models
+  // Anthropic Models - All require paid Copilot subscription
   {
     id: 'claude-sonnet-4.5',
     name: 'Claude Sonnet 4.5',
     provider: 'anthropic',
-    isDefault: true,
     minPlan: 'pro',
     multiplier: 1,
   },
@@ -53,7 +52,7 @@ export const DEFAULT_COPILOT_MODELS: CopilotModel[] = [
     id: 'claude-haiku-4.5',
     name: 'Claude Haiku 4.5',
     provider: 'anthropic',
-    minPlan: 'free',
+    minPlan: 'pro', // Requires paid Copilot subscription
     multiplier: 0.33,
   },
 
@@ -93,7 +92,14 @@ export const DEFAULT_COPILOT_MODELS: CopilotModel[] = [
   },
   { id: 'gpt-5', name: 'GPT-5', provider: 'openai', minPlan: 'pro', multiplier: 1 },
   { id: 'gpt-5-mini', name: 'GPT-5 Mini', provider: 'openai', minPlan: 'free', multiplier: 0 },
-  { id: 'gpt-4.1', name: 'GPT-4.1', provider: 'openai', minPlan: 'free', multiplier: 0 },
+  {
+    id: 'gpt-4.1',
+    name: 'GPT-4.1',
+    provider: 'openai',
+    isDefault: true,
+    minPlan: 'free',
+    multiplier: 0,
+  },
 
   // Google Models
   {
@@ -150,7 +156,8 @@ export async function fetchModelsFromDaemon(port: number): Promise<CopilotModel[
   return new Promise((resolve) => {
     const req = http.request(
       {
-        hostname: 'localhost',
+        // Use 127.0.0.1 instead of localhost for more reliable local connections
+        hostname: '127.0.0.1',
         port,
         path: '/v1/models',
         method: 'GET',
@@ -171,7 +178,7 @@ export async function fetchModelsFromDaemon(port: number): Promise<CopilotModel[
                 id: m.id,
                 name: formatModelName(m.id),
                 provider: detectProvider(m.id),
-                isDefault: m.id === 'claude-sonnet-4.5',
+                isDefault: m.id === 'gpt-4.1', // Free tier default
               }));
               resolve(models.length > 0 ? models : DEFAULT_COPILOT_MODELS);
             } else {
@@ -206,9 +213,10 @@ export async function getAvailableModels(port: number): Promise<CopilotModel[]>
 
 /**
  * Get the default model.
+ * Uses gpt-4.1 as it's available on free tier.
  */
 export function getDefaultModel(): string {
-  return 'claude-sonnet-4.5';
+  return 'gpt-4.1';
 }
 
 /**

src/web-server/routes.ts

@@ -1826,9 +1826,10 @@ apiRoutes.get('/copilot/settings/raw', (_req: Request, res: Response): void => {
     // If file doesn't exist, return default structure with all model mappings
     if (!fs.existsSync(settingsPath)) {
       // Create settings structure matching CLIProxy pattern - always include all model mappings
+      // Use 127.0.0.1 instead of localhost for more reliable local connections
       const defaultSettings = {
         env: {
-          ANTHROPIC_BASE_URL: `http://localhost:${copilotConfig.port}`,
+          ANTHROPIC_BASE_URL: `http://127.0.0.1:${copilotConfig.port}`,
           ANTHROPIC_AUTH_TOKEN: 'copilot-managed',
           ANTHROPIC_MODEL: defaultModel,
           ANTHROPIC_DEFAULT_OPUS_MODEL: copilotConfig.opus_model || defaultModel,

ui/src/components/copilot/copilot-config-form.tsx

@@ -39,6 +39,7 @@ const CodeEditor = lazy(() =>
 
 // Model presets for quick configuration
 // Grouped by tier: Free (available to all) and Paid (requires Pro+)
+// Note: ALL Claude models require paid Copilot subscription
 const FREE_PRESETS = [
   {
     name: 'GPT-4.1 (Free)',
@@ -57,12 +58,12 @@ const FREE_PRESETS = [
     haiku: 'gpt-5-mini',
   },
   {
-    name: 'Claude Haiku 4.5 (Free)',
-    description: 'Free tier - fast Anthropic model',
-    default: 'claude-haiku-4.5',
-    opus: 'claude-haiku-4.5',
-    sonnet: 'claude-haiku-4.5',
-    haiku: 'claude-haiku-4.5',
+    name: 'Raptor Mini (Free)',
+    description: 'Free tier - fine-tuned for coding',
+    default: 'raptor-mini',
+    opus: 'raptor-mini',
+    sonnet: 'raptor-mini',
+    haiku: 'raptor-mini',
   },
 ];