fix: add deprecation warning for agent.model + e2e model tests

- Warn at startup when agent.model is present in lettabot.yaml (deprecated, now ignored)
- Add e2e tests for model listing and agent model retrieval
- Remove stale model field from existing e2e test (BotConfig no longer has it)

Written by Cameron ◯ Letta Code

"The best way to predict the future is to invent it." -- Alan Kay

e2e/bot.e2e.test.ts

@@ -31,7 +31,6 @@ describe.skipIf(SKIP_E2E)('e2e: LettaBot with Letta Cloud', () => {
     
     // Initialize bot with test config
     bot = new LettaBot({
-      model: 'claude-sonnet-4-20250514', // Good balance of speed/quality
       workingDir: tempDir,
       agentName: 'e2e-test',
     });

e2e/models.e2e.test.ts

@@ -0,0 +1,30 @@
+/**
+ * E2E Tests for Model API
+ * 
+ * Tests model listing and retrieval against Letta Cloud.
+ * Requires LETTA_API_KEY and LETTA_E2E_AGENT_ID environment variables.
+ * 
+ * Run with: npm run test:e2e
+ */
+
+import { describe, it, expect } from 'vitest';
+import { listModels, getAgentModel } from '../src/tools/letta-api.js';
+
+const SKIP_E2E = !process.env.LETTA_API_KEY || !process.env.LETTA_E2E_AGENT_ID;
+
+describe.skipIf(SKIP_E2E)('e2e: Model API', () => {
+  it('lists available models from Letta Cloud', async () => {
+    const models = await listModels();
+    expect(models.length).toBeGreaterThan(0);
+    // Known providers should always exist on Letta Cloud
+    const handles = models.map(m => m.handle);
+    expect(handles.some(h => h.includes('anthropic') || h.includes('openai'))).toBe(true);
+  }, 30000);
+
+  it('retrieves the current agent model', async () => {
+    const agentId = process.env.LETTA_E2E_AGENT_ID!;
+    const model = await getAgentModel(agentId);
+    expect(model).toBeTruthy();
+    expect(typeof model).toBe('string');
+  }, 30000);
+});

src/main.ts

@@ -21,6 +21,9 @@ const yamlConfig = loadConfig();
 const configSource = existsSync(resolveConfigPath()) ? resolveConfigPath() : 'defaults + environment variables';
 console.log(`[Config] Loaded from ${configSource}`);
 console.log(`[Config] Mode: ${yamlConfig.server.mode}, Agent: ${yamlConfig.agent.name}`);
+if (yamlConfig.agent.model) {
+  console.warn('[Config] WARNING: agent.model in lettabot.yaml is deprecated and ignored. Use `lettabot model set <handle>` instead.');
+}
 applyConfigToEnv(yamlConfig);
 
 // Sync BYOK providers on startup (async, don't block)