feat(tui): implement live model fetching and enhance model selection menus

src/features/agent/infrastructure/llm/provider.test.ts

@@ -0,0 +1,52 @@
+/**
+ * Tests for LlmClient.listModels() — the live /models fetch backing the TUI
+ * model picker. Mocks global fetch so no network is touched.
+ */
+import { describe, test, expect, mock } from "bun:test";
+import { LlmClient } from "./provider.ts";
+
+/** Replace global fetch once, returning the given JSON body for /models. */
+async function listWith(fetchImpl: (url: string) => Promise<Response>): Promise<string[]> {
+  const orig = globalThis.fetch;
+  globalThis.fetch = fetchImpl as typeof fetch;
+  try {
+    const client = new LlmClient("key", "some-model", "https://api.example.com/v1");
+    return await client.listModels();
+  } finally {
+    globalThis.fetch = orig;
+  }
+}
+
+describe("LlmClient.listModels", () => {
+  test("parses OpenAI-style { data: [{id}] }", async () => {
+    const rows = await listWith(async (url: string) => {
+      expect(url).toBe("https://api.example.com/v1/models");
+      return new Response(JSON.stringify({ data: [{ id: "gpt-5" }, { id: "deepseek-v3" }] }), {
+        status: 200,
+        headers: { "Content-Type": "application/json" },
+      });
+    });
+    expect(rows).toEqual(["gpt-5", "deepseek-v3"]);
+  });
+
+  test("parses { models: [string] } variant", async () => {
+    const rows = await listWith(async () =>
+      new Response(JSON.stringify({ models: ["a", "b"] }), { status: 200 }),
+    );
+    expect(rows).toEqual(["a", "b"]);
+  });
+
+  test("filters out missing ids", async () => {
+    const rows = await listWith(async () =>
+      new Response(JSON.stringify({ data: [{ id: "x" }, {}, { id: "y" }] }), { status: 200 }),
+    );
+    expect(rows).toEqual(["x", "y"]);
+  });
+
+  test("returns [] on non-OK or throw", async () => {
+    const rows = await listWith(async () => new Response("forbidden", { status: 403 }));
+    expect(rows).toEqual([]);
+  });
+});
+
+void mock;

src/features/agent/infrastructure/llm/provider.ts

@@ -123,6 +123,35 @@ export class LlmClient implements ProviderService {
     return `API request failed: ${err?.message ?? String(e)}`;
   }
 
+  /**
+   * List the model ids exposed by the provider's `/models` endpoint
+   * (OpenAI/Anthropic-compatible). Returns an empty array when the endpoint
+   * isn't exposed or the call fails — callers fall back to static catalogs.
+   */
+  async listModels(): Promise<string[]> {
+    const url = `${this.baseUrl}/models`;
+    try {
+      const resp = await fetch(url, {
+        method: "GET",
+        headers: this.headers(),
+        signal: AbortSignal.timeout(REQUEST_TIMEOUT_MS),
+      });
+      if (!resp.ok) return [];
+      const data = (await resp.json()) as {
+        data?: { id?: string }[] | null;
+        models?: (string | { id?: string })[] | null;
+      };
+      const fromData = (data.data ?? []).map((m) => m?.id ?? "").filter(Boolean);
+      if (fromData.length) return fromData;
+      const fromModels = (data.models ?? [])
+        .map((m) => (typeof m === "string" ? m : m?.id ?? ""))
+        .filter(Boolean);
+      return fromModels;
+    } catch {
+      return [];
+    }
+  }
+
   async chat(
     messages: ChatMessage[],
     tools?: ToolDef[],

src/interfaces/cli/compose.ts

@@ -40,6 +40,8 @@ export interface WiredRuntime {
   apiKey: string;
   model: string;
   apiBase?: string;
+  /** Fetch the provider's available model ids (via GET /models). */
+  listModels?: () => Promise<string[]>;
 }
 
 /**
@@ -76,7 +78,15 @@ export async function runSingleProcess(): Promise<WiredRuntime> {
     toolDefs(allTools()) as never,
   );
 
-  return { store, executor, turnService, apiKey, model, apiBase: baseUrl };
+  return {
+    store,
+    executor,
+    turnService,
+    apiKey,
+    model,
+    apiBase: baseUrl,
+    listModels: () => llmClient.listModels(),
+  };
 }
 
 /** Rooted, long-lived event sink that collects events into an array. */

src/interfaces/tui/menu.ts

@@ -35,24 +35,30 @@ export function modelProviderMenu(state: AppStateRest): MenuFrame {
   };
 }
 
-/** Build the per-provider model sub-menu. */
-export function modelSubMenu(_state: AppStateRest, provider: string): MenuFrame | null {
-  // Candidate models for this provider. In a fuller build these come from a
-  // catalog / API; here we present a sensible, sortable list.
-  const known = [
-    "claude-opus-5",
-    "claude-sonnet-5",
-    "claude-haiku-4-5",
-    "deepseek-v4-flash-free",
-    "gpt-5",
-  ];
+/** Build the per-provider model sub-menu, preferring models fetched live. */
+export function modelSubMenu(state: AppStateRest, provider: string): MenuFrame | null {
+  const live = state.misc.availableModels;
+  const current = String(state.settings.model ?? "");
+  if (live.length > 0) {
+    return {
+      id: `model:${provider}`,
+      title: `Models — ${provider} (${live.length})`,
+      items: [...live],
+      details: live.map((m) => (m === current ? "  (current)" : (m === state.settings.model ? "  (current)" : ""))),
+      hint: "Enter applies · Esc back to providers",
+      selected: Math.max(0, live.indexOf(current)),
+    };
+  }
+  // No /models endpoint (or it's still fetching) — degrade to a small static
+  // catalog so the picker never blocks.
+  const known = ["claude-opus-5", "claude-sonnet-5", "claude-haiku-4-5", "deepseek-v4-flash-free", "gpt-5"];
   return {
     id: `model:${provider}`,
     title: `Models — ${provider}`,
     items: known,
-    details: known.map((m) => (m === _state.settings.model ? "  (current)" : "")),
-    hint: "Enter applies · Esc back to providers",
-    selected: Math.max(0, known.indexOf(String(_state.settings.model ?? ""))),
+    details: known.map((m) => (m === current ? "  (current)" : "")),
+    hint: "live /models unavailable — fallback list · Enter applies",
+    selected: Math.max(0, known.indexOf(current)),
   };
 }
 

src/interfaces/tui/run.ts

@@ -165,5 +165,16 @@ export async function runTui(): Promise<void> {
     sessionId: state.sessionId,
   } as Record<string, unknown>;
 
+  // Prime the /models list in the background so /model shows live models
+  // instead of a hardcoded catalog; the menu falls back until it lands.
+  if (runtime.listModels) {
+    void runtime.listModels().then((models) => {
+      if (models.length > 0) {
+        state.misc.availableModels = models;
+        state.dirty = true;
+      }
+    });
+  }
+
   await bootTui(state);
 }

src/interfaces/tui/state.ts

@@ -384,6 +384,8 @@ export class MiscState {
   activity: ActivityEntry[] = [];
   /** Stack of interactive menu frames (top = currently shown). */
   menuStack: MenuFrame[] = [];
+  /** Model ids fetched live from the provider's /models endpoint. */
+  availableModels: string[] = [];
 
   pushToast(toast: { kind: string; message: string; createdMs: number; ttlMs: number }): void {
     this.toasts.push(toast);

src/interfaces/tui/tui.test.ts

@@ -8,6 +8,7 @@ import { createTuiState, pushTranscript, makeChatMessage, reconcileStream, type
 import { applyAction } from "./action.ts";
 import { handleKey, decodeKey } from "./controller.ts";
 import { toControllerKey } from "./ui.tsx";
+import { modelProviderMenu, modelSubMenu, resolveMenu } from "./menu.ts";
 import { Roles } from "@zesdex/domain";
 
 function freshState() {
@@ -359,3 +360,51 @@ describe("reconcileStream (9router sliding-window vs incremental)", () => {
   });
 });
 
+
+describe("menu model lists (live vs fallback)", () => {
+  test("provider menu lists configured providers", () => {
+    const s = freshState();
+    s.appConfig = { providers: { zen: {}, router: {}, claude: {} } };
+    s.settings = { provider: "router" };
+    const frame = modelProviderMenu(s);
+    expect(frame.id).toBe("model:provider");
+    expect(frame.items).toEqual(["zen", "router", "claude"].map(() => expect.anything()).map((_, i) => ["zen","router","claude"][i]!));
+    expect(frame.selected).toBe(1); // router active
+  });
+
+  test("model sub-menu uses live /models list when available", () => {
+    const s = freshState();
+    s.misc.availableModels = ["gpt-5", "claude-sonnet-5", "deepseek-v3"];
+    s.settings = { provider: "zen", model: "claude-sonnet-5" };
+    const frame = modelSubMenu(s, "zen")!;
+    expect(frame.items).toEqual(["gpt-5", "claude-sonnet-5", "deepseek-v3"]);
+    expect(frame.selected).toBe(1); // current model highlighted
+    expect(frame.title).toContain("(3)");
+  });
+
+  test("model sub-menu falls back to a static catalog without a live list", () => {
+    const s = freshState();
+    s.misc.availableModels = [];
+    s.settings = { provider: "zen", model: "" };
+    const frame = modelSubMenu(s, "zen")!;
+    expect(frame.items.length).toBeGreaterThan(0);
+    expect(frame.hint).toContain("fallback");
+  });
+
+  test("resolving a live model row applies it and pops the stack", () => {
+    const s = freshState();
+    s.misc.availableModels = ["gpt-5", "claude-sonnet-5"];
+    s.appConfig = { providers: { zen: {} } };
+    s.settings = { provider: "zen", model: "claude-sonnet-5" };
+    applyAction(s, { tag: "OpenMenu", frame: modelProviderMenu(s) });
+    applyAction(s, { tag: "OpenMenu", frame: modelSubMenu(s, "zen")! });
+    // The sub-menu pre-selects the CURRENT model (claude-sonnet-5, index 1).
+    expect(s.misc.menuStack.at(-1)?.selected).toBe(1);
+    // Move to index 0 (gpt-5), then resolve Enter for the model row.
+    applyAction(s, { tag: "MenuHome" });
+    const acts = resolveMenu(s, "model:zen");
+    expect(acts).toEqual([{ tag: "MenuBackAll" }]);
+    expect(s.settings.provider).toBe("zen");
+    expect(s.settings.model).toBe("gpt-5");
+  });
+});