Make /model provider switch activate selected tier in minimal TUI

docs/plans/state.json

@@ -57,6 +57,18 @@
       "test_status": "pnpm test:run src/daemon/clientFactory.test.ts src/models/openai.test.ts + pnpm typecheck passing (updated to cover textual 401 without status field)"
     },
 
+    "tui-model-provider-switch-activates-tier": {
+      "status": "completed",
+      "date": "2026-02-16",
+      "updated": "2026-02-16",
+      "summary": "Fixed minimal TUI /model <tier> <provider/model> behavior to also activate the selected tier and sync agent tier immediately. This prevents confusing cases where provider/model changes are applied to one tier while prompts still run on another tier.",
+      "files_modified": [
+        "src/frontends/tui/minimal.ts",
+        "src/frontends/tui/minimal.test.ts"
+      ],
+      "test_status": "pnpm test:run src/frontends/tui/minimal.test.ts src/models/openai.test.ts src/daemon/clientFactory.test.ts + pnpm typecheck passing"
+    },
+
     "deployment-port-env-override": {
       "status": "completed",
       "date": "2026-02-16",

src/frontends/tui/minimal.test.ts

@@ -163,6 +163,67 @@ describe('MinimalTui backend command', () => {
 
       expect(mockRouter.setClient).toHaveBeenCalledOnce();
       expect(mockRouter.setTierStrict).toHaveBeenCalledWith('default', true);
+      expect(mockRouter.setTier).toHaveBeenCalledWith('default');
+    } finally {
+      if (prevOpenRouterKey) {
+        process.env.OPENROUTER_API_KEY = prevOpenRouterKey;
+      } else {
+        delete process.env.OPENROUTER_API_KEY;
+      }
+    }
+  });
+
+  it('switches active tier and syncs agent for /model <tier> <provider/model>', () => {
+    const prevOpenRouterKey = process.env.OPENROUTER_API_KEY;
+    delete process.env.OPENROUTER_API_KEY;
+
+    try {
+      const mockSession = {
+        id: 'test',
+        getHistory: () => [],
+        addMessage: vi.fn(),
+        clear: vi.fn(),
+        replaceHistory: vi.fn(),
+      };
+
+      const mockRouter = {
+        getTier: () => 'fast' as const,
+        getAvailableTiers: () => ['default', 'fast', 'local'],
+        setTier: vi.fn(() => true),
+        getLocalProviderName: () => 'ollama',
+        setLocalClient: vi.fn(),
+        setClient: vi.fn(),
+        setTierStrict: vi.fn(),
+        chat: vi.fn(),
+        getClient: vi.fn(),
+      };
+
+      const mockAgent = {
+        setModelTier: vi.fn(),
+        getModelTier: vi.fn(() => 'fast'),
+        process: vi.fn(),
+      };
+
+      const tui = new MinimalTui({
+        session: mockSession as any,
+        modelClient: mockRouter as any,
+        modelRouter: mockRouter as any,
+        agent: mockAgent as any,
+        systemPrompt: 'test',
+        modelProviderConfigs: {
+          openrouter: {
+            provider: 'openrouter',
+            model: 'seed-model',
+            api_key: 'test-key',
+            endpoint: 'https://openrouter.ai/api/v1',
+          },
+        },
+      });
+
+      (tui as any).handleModelCommand('default', 'openrouter/deepseek/deepseek-chat');
+
+      expect(mockRouter.setTier).toHaveBeenCalledWith('default');
+      expect(mockAgent.setModelTier).toHaveBeenCalledWith('default');
     } finally {
       if (prevOpenRouterKey) {
         process.env.OPENROUTER_API_KEY = prevOpenRouterKey;

src/frontends/tui/minimal.ts

@@ -287,12 +287,14 @@ export class MinimalTui {
         });
         router.setClient(tier, client, providerModel);
         router.setTierStrict(tier, true);
+        router.setTier(tier);
 
-        if (this.config.agent && tier === router.getTier()) {
+        if (this.config.agent) {
           this.config.agent.setModelTier(tier);
         }
 
         console.log(`${colors.gray}Set ${tier} to:${colors.reset} ${providerModel}`);
+        console.log(`${colors.gray}Switched to model:${colors.reset} ${tier}`);
         console.log(`${colors.gray}Fallbacks for ${tier} disabled (strict tier mode).${colors.reset}\n`);
       } catch (error) {
         const message = error instanceof Error ? error.message : String(error);