diff --git a/src/cliproxy/cliproxy-executor.ts b/src/cliproxy/cliproxy-executor.ts
index 695adace..df768b0d 100644
--- a/src/cliproxy/cliproxy-executor.ts
+++ b/src/cliproxy/cliproxy-executor.ts
@@ -26,6 +26,8 @@ import {
 } from './config-generator';
 import { isAuthenticated } from './auth-handler';
 import { CLIProxyProvider, ExecutorConfig } from './types';
+import { configureProviderModel } from './model-config';
+import { supportsModelConfig } from './model-catalog';
 
 /** Default executor configuration */
 const DEFAULT_CONFIG: ExecutorConfig = {
@@ -116,10 +118,17 @@ export async function execClaudeWithCLIProxy(
     throw error;
   }
 
-  // 2. Handle authentication flags
+  // 2. Handle special flags
   const forceAuth = args.includes('--auth');
   const forceHeadless = args.includes('--headless');
   const forceLogout = args.includes('--logout');
+  const forceConfig = args.includes('--config');
+
+  // Handle --config: configure model selection and exit
+  if (forceConfig && supportsModelConfig(provider)) {
+    await configureProviderModel(provider, true);
+    process.exit(0);
+  }
 
   // Handle --logout: clear auth and exit
   if (forceLogout) {
@@ -155,10 +164,16 @@ export async function execClaudeWithCLIProxy(
     }
   }
 
-  // 4. Ensure user settings file exists (creates from defaults if not)
+  // 4. First-run model configuration (interactive)
+  // For supported providers, prompt user to select model on first run
+  if (supportsModelConfig(provider)) {
+    await configureProviderModel(provider, false); // false = only if not configured
+  }
+
+  // 5. Ensure user settings file exists (creates from defaults if not)
   ensureProviderSettings(provider);
 
-  // 5. Generate config file
+  // 6. Generate config file
   log(`Generating config for ${provider}`);
   const configPath = generateConfig(provider, cfg.port);
   log(`Config written: ${configPath}`);
@@ -226,7 +241,7 @@ export async function execClaudeWithCLIProxy(
   log(`Claude env: ANTHROPIC_MODEL=${envVars.ANTHROPIC_MODEL}`);
 
   // Filter out CCS-specific flags before passing to Claude CLI
-  const ccsFlags = ['--auth', '--headless', '--logout'];
+  const ccsFlags = ['--auth', '--headless', '--logout', '--config'];
   const claudeArgs = args.filter((arg) => !ccsFlags.includes(arg));
 
   const isWindows = process.platform === 'win32';
diff --git a/src/cliproxy/index.ts b/src/cliproxy/index.ts
index 27837e32..eeffe239 100644
--- a/src/cliproxy/index.ts
+++ b/src/cliproxy/index.ts
@@ -70,6 +70,16 @@ export {
   clearConfigCache,
 } from './base-config-loader';
 
+// Model catalog and configuration
+export type { ModelEntry, ProviderCatalog } from './model-catalog';
+export { MODEL_CATALOG, supportsModelConfig, getProviderCatalog, findModel } from './model-catalog';
+export {
+  hasUserSettings,
+  getCurrentModel,
+  configureProviderModel,
+  showCurrentConfig,
+} from './model-config';
+
 // Executor
 export { execClaudeWithCLIProxy, isPortAvailable, findAvailablePort } from './cliproxy-executor';
 
diff --git a/src/cliproxy/model-catalog.ts b/src/cliproxy/model-catalog.ts
new file mode 100644
index 00000000..557cf828
--- /dev/null
+++ b/src/cliproxy/model-catalog.ts
@@ -0,0 +1,81 @@
+/**
+ * Model Catalog - Available models for CLI Proxy providers
+ *
+ * Ships with CCS to provide users with interactive model selection.
+ * Models are mapped to their internal names used by the proxy backend.
+ */
+
+import { CLIProxyProvider } from './types';
+
+/**
+ * Model entry definition
+ */
+export interface ModelEntry {
+  /** Literal model name to put in settings.json */
+  id: string;
+  /** Human-readable name for display */
+  name: string;
+  /** Access tier indicator */
+  tier?: 'free' | 'paid';
+}
+
+/**
+ * Provider catalog definition
+ */
+export interface ProviderCatalog {
+  provider: CLIProxyProvider;
+  displayName: string;
+  models: ModelEntry[];
+  defaultModel: string;
+}
+
+/**
+ * Model catalog for providers that support interactive configuration
+ *
+ * Models listed in order of recommendation (top = best)
+ */
+export const MODEL_CATALOG: Partial<Record<CLIProxyProvider, ProviderCatalog>> = {
+  agy: {
+    provider: 'agy',
+    displayName: 'Antigravity',
+    defaultModel: 'gemini-3-pro-preview',
+    models: [
+      { id: 'gemini-claude-opus-4-5-thinking', name: 'Claude Opus 4.5 Thinking' },
+      { id: 'gemini-claude-sonnet-4-5-thinking', name: 'Claude Sonnet 4.5 Thinking' },
+      { id: 'gemini-claude-sonnet-4-5', name: 'Claude Sonnet 4.5' },
+      { id: 'gemini-3-pro-preview', name: 'Gemini 3 Pro', tier: 'paid' },
+    ],
+  },
+  gemini: {
+    provider: 'gemini',
+    displayName: 'Gemini',
+    defaultModel: 'gemini-2.5-pro',
+    models: [
+      { id: 'gemini-3-pro-preview', name: 'Gemini 3 Pro', tier: 'paid' },
+      { id: 'gemini-2.5-pro', name: 'Gemini 2.5 Pro' },
+    ],
+  },
+};
+
+/**
+ * Check if provider supports interactive model configuration
+ */
+export function supportsModelConfig(provider: CLIProxyProvider): boolean {
+  return provider in MODEL_CATALOG;
+}
+
+/**
+ * Get catalog for provider
+ */
+export function getProviderCatalog(provider: CLIProxyProvider): ProviderCatalog | undefined {
+  return MODEL_CATALOG[provider];
+}
+
+/**
+ * Find model entry by ID
+ */
+export function findModel(provider: CLIProxyProvider, modelId: string): ModelEntry | undefined {
+  const catalog = MODEL_CATALOG[provider];
+  if (!catalog) return undefined;
+  return catalog.models.find((m) => m.id === modelId);
+}
diff --git a/src/cliproxy/model-config.ts b/src/cliproxy/model-config.ts
new file mode 100644
index 00000000..1ff67b97
--- /dev/null
+++ b/src/cliproxy/model-config.ts
@@ -0,0 +1,168 @@
+/**
+ * Model Configuration - Interactive model selection for CLI Proxy providers
+ *
+ * Handles first-run configuration and explicit --config flag.
+ * Persists user selection to ~/.ccs/{provider}.settings.json
+ */
+
+import * as fs from 'fs';
+import * as path from 'path';
+import { InteractivePrompt } from '../utils/prompt';
+import { getProviderCatalog, supportsModelConfig, ModelEntry } from './model-catalog';
+import { getProviderSettingsPath, getClaudeEnvVars } from './config-generator';
+import { CLIProxyProvider } from './types';
+
+/** CCS directory */
+const CCS_DIR = path.join(process.env.HOME || process.env.USERPROFILE || '', '.ccs');
+
+/**
+ * Check if provider has user settings configured
+ */
+export function hasUserSettings(provider: CLIProxyProvider): boolean {
+  const settingsPath = getProviderSettingsPath(provider);
+  return fs.existsSync(settingsPath);
+}
+
+/**
+ * Get current model from user settings
+ */
+export function getCurrentModel(provider: CLIProxyProvider): string | undefined {
+  const settingsPath = getProviderSettingsPath(provider);
+  if (!fs.existsSync(settingsPath)) return undefined;
+
+  try {
+    const settings = JSON.parse(fs.readFileSync(settingsPath, 'utf8'));
+    return settings.env?.ANTHROPIC_MODEL;
+  } catch {
+    return undefined;
+  }
+}
+
+/**
+ * Format model entry for display
+ */
+function formatModelOption(model: ModelEntry): string {
+  const tierLabel = model.tier === 'paid' ? ' [paid]' : '';
+  return `${model.name} (${model.id})${tierLabel}`;
+}
+
+/**
+ * Configure model for provider (interactive)
+ *
+ * @param provider CLIProxy provider (agy, gemini)
+ * @param force Force reconfiguration even if settings exist
+ * @returns true if configuration was performed, false if skipped
+ */
+export async function configureProviderModel(
+  provider: CLIProxyProvider,
+  force: boolean = false
+): Promise<boolean> {
+  // Check if provider supports model configuration
+  if (!supportsModelConfig(provider)) {
+    return false;
+  }
+
+  const catalog = getProviderCatalog(provider);
+  if (!catalog) return false;
+
+  const settingsPath = getProviderSettingsPath(provider);
+
+  // Skip if already configured (unless --config flag)
+  if (!force && fs.existsSync(settingsPath)) {
+    return false;
+  }
+
+  // Build options list
+  const options = catalog.models.map((m) => ({
+    id: m.id,
+    label: formatModelOption(m),
+  }));
+
+  // Find default index
+  const defaultIdx = catalog.models.findIndex((m) => m.id === catalog.defaultModel);
+  const safeDefaultIdx = defaultIdx >= 0 ? defaultIdx : 0;
+
+  // Show header
+  console.error('');
+  console.error(`[i] Configure ${catalog.displayName} model`);
+
+  // Interactive selection
+  const selectedModel = await InteractivePrompt.selectFromList('Select model:', options, {
+    defaultIndex: safeDefaultIdx,
+  });
+
+  // Get base env vars to preserve haiku model and base URL
+  const baseEnv = getClaudeEnvVars(provider);
+
+  // Build settings with selected model
+  const settings = {
+    env: {
+      ...baseEnv,
+      ANTHROPIC_MODEL: selectedModel,
+      ANTHROPIC_DEFAULT_OPUS_MODEL: selectedModel,
+      ANTHROPIC_DEFAULT_SONNET_MODEL: selectedModel,
+      // Keep haiku as-is from base config (usually flash model)
+    },
+  };
+
+  // Ensure CCS directory exists
+  if (!fs.existsSync(CCS_DIR)) {
+    fs.mkdirSync(CCS_DIR, { recursive: true });
+  }
+
+  // Write settings file
+  fs.writeFileSync(settingsPath, JSON.stringify(settings, null, 2));
+
+  // Find display name
+  const selectedEntry = catalog.models.find((m) => m.id === selectedModel);
+  const displayName = selectedEntry?.name || selectedModel;
+
+  console.error('');
+  console.error(`[OK] Model set to: ${displayName} (${selectedModel})`);
+  console.error(`[i] Saved to: ${settingsPath}`);
+  console.error('');
+
+  return true;
+}
+
+/**
+ * Show current model configuration
+ */
+export function showCurrentConfig(provider: CLIProxyProvider): void {
+  if (!supportsModelConfig(provider)) {
+    console.error(`[i] Provider ${provider} does not support model configuration`);
+    return;
+  }
+
+  const catalog = getProviderCatalog(provider);
+  if (!catalog) return;
+
+  const currentModel = getCurrentModel(provider);
+  const settingsPath = getProviderSettingsPath(provider);
+
+  console.error('');
+  console.error(`[i] ${catalog.displayName} Model Configuration`);
+  console.error('');
+
+  if (currentModel) {
+    const entry = catalog.models.find((m) => m.id === currentModel);
+    const displayName = entry?.name || 'Unknown';
+    console.error(`  Current: ${displayName} (${currentModel})`);
+    console.error(`  Config:  ${settingsPath}`);
+  } else {
+    console.error(`  Current: (using defaults)`);
+    console.error(`  Default: ${catalog.defaultModel}`);
+  }
+
+  console.error('');
+  console.error('Available models:');
+  catalog.models.forEach((m) => {
+    const isCurrent = m.id === currentModel;
+    const marker = isCurrent ? '>' : ' ';
+    console.error(`  ${marker} ${formatModelOption(m)}`);
+  });
+
+  console.error('');
+  console.error(`Run "ccs ${provider} --config" to change`);
+  console.error('');
+}
diff --git a/tests/unit/cliproxy/model-catalog.test.js b/tests/unit/cliproxy/model-catalog.test.js
new file mode 100644
index 00000000..2a3c67d5
--- /dev/null
+++ b/tests/unit/cliproxy/model-catalog.test.js
@@ -0,0 +1,216 @@
+/**
+ * Tests for CLIProxy Model Catalog
+ * Verifies model database structure and lookup functions
+ */
+
+const assert = require('assert');
+
+describe('Model Catalog', () => {
+  const modelCatalog = require('../../../dist/cliproxy/model-catalog');
+
+  describe('MODEL_CATALOG structure', () => {
+    it('contains AGY provider catalog', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      assert(MODEL_CATALOG.agy, 'Should have agy provider');
+      assert.strictEqual(MODEL_CATALOG.agy.provider, 'agy');
+      assert.strictEqual(MODEL_CATALOG.agy.displayName, 'Antigravity');
+    });
+
+    it('contains Gemini provider catalog', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      assert(MODEL_CATALOG.gemini, 'Should have gemini provider');
+      assert.strictEqual(MODEL_CATALOG.gemini.provider, 'gemini');
+      assert.strictEqual(MODEL_CATALOG.gemini.displayName, 'Gemini');
+    });
+
+    it('does not contain codex or qwen (not configurable)', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      assert.strictEqual(MODEL_CATALOG.codex, undefined);
+      assert.strictEqual(MODEL_CATALOG.qwen, undefined);
+    });
+  });
+
+  describe('AGY models', () => {
+    it('has correct default model', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      assert.strictEqual(MODEL_CATALOG.agy.defaultModel, 'gemini-3-pro-preview');
+    });
+
+    it('includes Claude Opus 4.5 Thinking', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      const opus = MODEL_CATALOG.agy.models.find(
+        (m) => m.id === 'gemini-claude-opus-4-5-thinking'
+      );
+      assert(opus, 'Should include Claude Opus 4.5 Thinking');
+      assert.strictEqual(opus.name, 'Claude Opus 4.5 Thinking');
+    });
+
+    it('includes Claude Sonnet 4.5 Thinking', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      const sonnetThinking = MODEL_CATALOG.agy.models.find(
+        (m) => m.id === 'gemini-claude-sonnet-4-5-thinking'
+      );
+      assert(sonnetThinking, 'Should include Claude Sonnet 4.5 Thinking');
+      assert.strictEqual(sonnetThinking.name, 'Claude Sonnet 4.5 Thinking');
+    });
+
+    it('includes Claude Sonnet 4.5', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      const sonnet = MODEL_CATALOG.agy.models.find((m) => m.id === 'gemini-claude-sonnet-4-5');
+      assert(sonnet, 'Should include Claude Sonnet 4.5');
+      assert.strictEqual(sonnet.name, 'Claude Sonnet 4.5');
+    });
+
+    it('includes Gemini 3 Pro with paid tier', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      const gem3 = MODEL_CATALOG.agy.models.find((m) => m.id === 'gemini-3-pro-preview');
+      assert(gem3, 'Should include Gemini 3 Pro');
+      assert.strictEqual(gem3.name, 'Gemini 3 Pro');
+      assert.strictEqual(gem3.tier, 'paid');
+    });
+
+    it('has 4 models total', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      assert.strictEqual(MODEL_CATALOG.agy.models.length, 4);
+    });
+  });
+
+  describe('Gemini models', () => {
+    it('has correct default model', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      assert.strictEqual(MODEL_CATALOG.gemini.defaultModel, 'gemini-2.5-pro');
+    });
+
+    it('includes Gemini 3 Pro with paid tier', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      const gem3 = MODEL_CATALOG.gemini.models.find((m) => m.id === 'gemini-3-pro-preview');
+      assert(gem3, 'Should include Gemini 3 Pro');
+      assert.strictEqual(gem3.name, 'Gemini 3 Pro');
+      assert.strictEqual(gem3.tier, 'paid');
+    });
+
+    it('includes Gemini 2.5 Pro without tier (free)', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      const gem25 = MODEL_CATALOG.gemini.models.find((m) => m.id === 'gemini-2.5-pro');
+      assert(gem25, 'Should include Gemini 2.5 Pro');
+      assert.strictEqual(gem25.name, 'Gemini 2.5 Pro');
+      assert.strictEqual(gem25.tier, undefined);
+    });
+
+    it('has 2 models total', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      assert.strictEqual(MODEL_CATALOG.gemini.models.length, 2);
+    });
+  });
+
+  describe('supportsModelConfig', () => {
+    it('returns true for agy', () => {
+      const { supportsModelConfig } = modelCatalog;
+      assert.strictEqual(supportsModelConfig('agy'), true);
+    });
+
+    it('returns true for gemini', () => {
+      const { supportsModelConfig } = modelCatalog;
+      assert.strictEqual(supportsModelConfig('gemini'), true);
+    });
+
+    it('returns false for codex', () => {
+      const { supportsModelConfig } = modelCatalog;
+      assert.strictEqual(supportsModelConfig('codex'), false);
+    });
+
+    it('returns false for qwen', () => {
+      const { supportsModelConfig } = modelCatalog;
+      assert.strictEqual(supportsModelConfig('qwen'), false);
+    });
+  });
+
+  describe('getProviderCatalog', () => {
+    it('returns catalog for agy', () => {
+      const { getProviderCatalog } = modelCatalog;
+      const catalog = getProviderCatalog('agy');
+      assert(catalog, 'Should return catalog');
+      assert.strictEqual(catalog.provider, 'agy');
+      assert(Array.isArray(catalog.models));
+    });
+
+    it('returns catalog for gemini', () => {
+      const { getProviderCatalog } = modelCatalog;
+      const catalog = getProviderCatalog('gemini');
+      assert(catalog, 'Should return catalog');
+      assert.strictEqual(catalog.provider, 'gemini');
+    });
+
+    it('returns undefined for codex', () => {
+      const { getProviderCatalog } = modelCatalog;
+      const catalog = getProviderCatalog('codex');
+      assert.strictEqual(catalog, undefined);
+    });
+  });
+
+  describe('findModel', () => {
+    it('finds Claude Opus 4.5 Thinking in agy', () => {
+      const { findModel } = modelCatalog;
+      const model = findModel('agy', 'gemini-claude-opus-4-5-thinking');
+      assert(model, 'Should find model');
+      assert.strictEqual(model.name, 'Claude Opus 4.5 Thinking');
+    });
+
+    it('finds Gemini 2.5 Pro in gemini', () => {
+      const { findModel } = modelCatalog;
+      const model = findModel('gemini', 'gemini-2.5-pro');
+      assert(model, 'Should find model');
+      assert.strictEqual(model.name, 'Gemini 2.5 Pro');
+    });
+
+    it('returns undefined for unknown model', () => {
+      const { findModel } = modelCatalog;
+      const model = findModel('agy', 'unknown-model');
+      assert.strictEqual(model, undefined);
+    });
+
+    it('returns undefined for unsupported provider', () => {
+      const { findModel } = modelCatalog;
+      const model = findModel('codex', 'any-model');
+      assert.strictEqual(model, undefined);
+    });
+  });
+
+  describe('Model entry structure', () => {
+    it('all models have required fields', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+
+      for (const [provider, catalog] of Object.entries(MODEL_CATALOG)) {
+        for (const model of catalog.models) {
+          assert(model.id, `Model in ${provider} should have id`);
+          assert(typeof model.id === 'string', `Model id should be string`);
+          assert(model.name, `Model ${model.id} should have name`);
+          assert(typeof model.name === 'string', `Model name should be string`);
+          // tier is optional
+          if (model.tier !== undefined) {
+            assert(['free', 'paid'].includes(model.tier), `Invalid tier: ${model.tier}`);
+          }
+        }
+      }
+    });
+
+    it('all model IDs are unique within provider', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+
+      for (const [provider, catalog] of Object.entries(MODEL_CATALOG)) {
+        const ids = catalog.models.map((m) => m.id);
+        const uniqueIds = new Set(ids);
+        assert.strictEqual(ids.length, uniqueIds.size, `Duplicate model IDs in ${provider}`);
+      }
+    });
+
+    it('default model exists in models array', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+
+      for (const [provider, catalog] of Object.entries(MODEL_CATALOG)) {
+        const defaultExists = catalog.models.some((m) => m.id === catalog.defaultModel);
+        assert(defaultExists, `Default model ${catalog.defaultModel} not found in ${provider}`);
+      }
+    });
+  });
+});
diff --git a/tests/unit/cliproxy/model-config.test.js b/tests/unit/cliproxy/model-config.test.js
new file mode 100644
index 00000000..24118bd7
--- /dev/null
+++ b/tests/unit/cliproxy/model-config.test.js
@@ -0,0 +1,162 @@
+/**
+ * Tests for CLIProxy Model Configuration
+ * Verifies model configuration logic and settings management
+ */
+
+const assert = require('assert');
+const fs = require('fs');
+const path = require('path');
+const os = require('os');
+
+describe('Model Config', () => {
+  const modelConfig = require('../../../dist/cliproxy/model-config');
+  const modelCatalog = require('../../../dist/cliproxy/model-catalog');
+
+  describe('hasUserSettings', () => {
+    it('returns false when settings file does not exist', () => {
+      // Ensure we're checking a non-existent path
+      const { hasUserSettings } = modelConfig;
+      // Since we can't easily mock getCcsDir, we test the function logic
+      // by checking it doesn't throw
+      const result = hasUserSettings('agy');
+      assert(typeof result === 'boolean', 'Should return boolean');
+    });
+  });
+
+  describe('getCurrentModel', () => {
+    it('returns undefined when settings file does not exist', () => {
+      const { getCurrentModel } = modelConfig;
+      // Test with a provider that likely has no settings in test env
+      const result = getCurrentModel('agy');
+      // Result depends on whether ~/.ccs/agy.settings.json exists
+      // Just verify it returns string or undefined
+      assert(
+        result === undefined || typeof result === 'string',
+        'Should return string or undefined'
+      );
+    });
+  });
+
+  describe('configureProviderModel', () => {
+    it('returns false for unsupported provider (codex)', async () => {
+      const { configureProviderModel } = modelConfig;
+      const result = await configureProviderModel('codex', true);
+      assert.strictEqual(result, false);
+    });
+
+    it('returns false for unsupported provider (qwen)', async () => {
+      const { configureProviderModel } = modelConfig;
+      const result = await configureProviderModel('qwen', true);
+      assert.strictEqual(result, false);
+    });
+
+    // Note: Full interactive tests require mocking stdin
+    // These are smoke tests to verify basic logic
+  });
+
+  describe('showCurrentConfig', () => {
+    it('does not throw for agy provider', () => {
+      const { showCurrentConfig } = modelConfig;
+      // Just verify it doesn't throw
+      assert.doesNotThrow(() => showCurrentConfig('agy'));
+    });
+
+    it('does not throw for gemini provider', () => {
+      const { showCurrentConfig } = modelConfig;
+      assert.doesNotThrow(() => showCurrentConfig('gemini'));
+    });
+
+    it('does not throw for unsupported provider', () => {
+      const { showCurrentConfig } = modelConfig;
+      assert.doesNotThrow(() => showCurrentConfig('codex'));
+    });
+  });
+
+  describe('Model catalog integration', () => {
+    it('configureProviderModel uses correct catalog for agy', async () => {
+      const { getProviderCatalog } = modelCatalog;
+      const catalog = getProviderCatalog('agy');
+
+      // Verify catalog structure is what configureProviderModel expects
+      assert(catalog.models, 'Should have models array');
+      assert(catalog.defaultModel, 'Should have defaultModel');
+      assert(catalog.displayName, 'Should have displayName');
+    });
+
+    it('configureProviderModel uses correct catalog for gemini', async () => {
+      const { getProviderCatalog } = modelCatalog;
+      const catalog = getProviderCatalog('gemini');
+
+      assert(catalog.models, 'Should have models array');
+      assert(catalog.defaultModel, 'Should have defaultModel');
+      assert(catalog.displayName, 'Should have displayName');
+    });
+  });
+
+  describe('Settings file format', () => {
+    it('should generate correct settings structure', () => {
+      // Test the expected settings structure
+      const expectedStructure = {
+        env: {
+          ANTHROPIC_BASE_URL: expect.any(String),
+          ANTHROPIC_AUTH_TOKEN: expect.any(String),
+          ANTHROPIC_MODEL: 'gemini-claude-opus-4-5-thinking',
+          ANTHROPIC_DEFAULT_OPUS_MODEL: 'gemini-claude-opus-4-5-thinking',
+          ANTHROPIC_DEFAULT_SONNET_MODEL: 'gemini-claude-opus-4-5-thinking',
+          ANTHROPIC_DEFAULT_HAIKU_MODEL: expect.any(String),
+        },
+      };
+
+      // Verify the structure is valid JSON
+      const testSettings = {
+        env: {
+          ANTHROPIC_BASE_URL: 'http://127.0.0.1:8317/api/provider/agy',
+          ANTHROPIC_AUTH_TOKEN: 'ccs-internal-managed',
+          ANTHROPIC_MODEL: 'gemini-claude-opus-4-5-thinking',
+          ANTHROPIC_DEFAULT_OPUS_MODEL: 'gemini-claude-opus-4-5-thinking',
+          ANTHROPIC_DEFAULT_SONNET_MODEL: 'gemini-claude-opus-4-5-thinking',
+          ANTHROPIC_DEFAULT_HAIKU_MODEL: 'gemini-2.5-flash',
+        },
+      };
+
+      const json = JSON.stringify(testSettings, null, 2);
+      const parsed = JSON.parse(json);
+
+      assert(parsed.env, 'Should have env object');
+      assert(parsed.env.ANTHROPIC_MODEL, 'Should have ANTHROPIC_MODEL');
+      assert.strictEqual(
+        parsed.env.ANTHROPIC_MODEL,
+        'gemini-claude-opus-4-5-thinking'
+      );
+    });
+
+    it('all env values should be strings (PowerShell safety)', () => {
+      const testSettings = {
+        env: {
+          ANTHROPIC_BASE_URL: 'http://127.0.0.1:8317/api/provider/agy',
+          ANTHROPIC_AUTH_TOKEN: 'ccs-internal-managed',
+          ANTHROPIC_MODEL: 'gemini-claude-opus-4-5-thinking',
+          ANTHROPIC_DEFAULT_OPUS_MODEL: 'gemini-claude-opus-4-5-thinking',
+          ANTHROPIC_DEFAULT_SONNET_MODEL: 'gemini-claude-opus-4-5-thinking',
+          ANTHROPIC_DEFAULT_HAIKU_MODEL: 'gemini-2.5-flash',
+        },
+      };
+
+      for (const [key, value] of Object.entries(testSettings.env)) {
+        assert.strictEqual(
+          typeof value,
+          'string',
+          `env.${key} should be string, got ${typeof value}`
+        );
+      }
+    });
+  });
+});
+
+// Helper for expect-like assertions
+const expect = {
+  any: (type) => ({
+    _type: type,
+    toString: () => `expect.any(${type.name})`,
+  }),
+};