diff --git a/frontend/src/shell/SettingsDialog.test.tsx b/frontend/src/shell/SettingsDialog.test.tsx
new file mode 100644
index 00000000..86ea5b27
--- /dev/null
+++ b/frontend/src/shell/SettingsDialog.test.tsx
@@ -0,0 +1,93 @@
+import { render, screen, waitFor } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import { http, HttpResponse } from "msw";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { server } from "../test/msw";
+import { SettingsDialog } from "./SettingsDialog";
+
+function renderDialog() {
+  const client = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+  render(
+    <QueryClientProvider client={client}>
+      <SettingsDialog />
+    </QueryClientProvider>,
+  );
+}
+
+beforeEach(() => {
+  server.use(
+    http.get("http://localhost:8787/workspaces", () =>
+      HttpResponse.json([
+        { name: "psd", file: "psd.yaml" },
+        { name: "tht-test", file: "tht-test.yaml" },
+      ]),
+    ),
+    http.get("http://localhost:8787/models", () =>
+      HttpResponse.json({
+        models: [
+          { provider: "zai", id: "glm-5.2", name: "GLM 5.2", reasoning: true },
+          { provider: "anthropic", id: "claude-opus-4-8", name: "Claude Opus 4.8", reasoning: true },
+        ],
+      }),
+    ),
+    http.get("http://localhost:8787/settings", () =>
+      HttpResponse.json({ workspace: "psd", provider: "zai", model: "glm-5.2", thinking: "medium" }),
+    ),
+  );
+});
+
+test("opens and pre-selects current settings", async () => {
+  renderDialog();
+  await userEvent.click(screen.getByRole("button", { name: /settings/i }));
+
+  const workspace = (await screen.findByLabelText(/workspace/i)) as HTMLSelectElement;
+  expect(workspace.value).toBe("psd");
+  const thinking = screen.getByLabelText(/thinking/i) as HTMLSelectElement;
+  expect(thinking.value).toBe("medium");
+  // thinking options are exactly low/medium/high
+  expect(Array.from(thinking.options).map((o) => o.value)).toEqual(["low", "medium", "high"]);
+});
+
+test("provider change filters the model list", async () => {
+  renderDialog();
+  await userEvent.click(screen.getByRole("button", { name: /settings/i }));
+
+  const provider = (await screen.findByLabelText(/provider/i)) as HTMLSelectElement;
+  await userEvent.selectOptions(provider, "anthropic");
+  const model = screen.getByLabelText(/modello/i) as HTMLSelectElement;
+  const optionValues = Array.from(model.options).map((o) => o.value);
+  expect(optionValues).toContain("claude-opus-4-8");
+  expect(optionValues).not.toContain("glm-5.2");
+});
+
+test("Salva PUTs the selected settings", async () => {
+  let body: unknown = null;
+  server.use(
+    http.put("http://localhost:8787/settings", async ({ request }) => {
+      body = await request.json();
+      return HttpResponse.json(await request.json());
+    }),
+  );
+  renderDialog();
+  await userEvent.click(screen.getByRole("button", { name: /settings/i }));
+  await screen.findByLabelText(/workspace/i);
+  await userEvent.selectOptions(screen.getByLabelText(/thinking/i), "high");
+  await userEvent.click(screen.getByRole("button", { name: /salva/i }));
+
+  await waitFor(() =>
+    expect(body).toEqual({ workspace: "psd", provider: "zai", model: "glm-5.2", thinking: "high" }),
+  );
+});
+
+test("degrades to free-text provider/model when models list is empty", async () => {
+  server.use(
+    http.get("http://localhost:8787/models", () => HttpResponse.json({ models: [] })),
+    http.get("http://localhost:8787/settings", () =>
+      HttpResponse.json({ workspace: "psd", provider: "", model: "", thinking: "low" }),
+    ),
+  );
+  renderDialog();
+  await userEvent.click(screen.getByRole("button", { name: /settings/i }));
+  expect(await screen.findByTestId("provider-freetext")).toHaveProperty("tagName", "INPUT");
+  expect(screen.getByTestId("model-freetext")).toHaveProperty("tagName", "INPUT");
+});
diff --git a/frontend/src/shell/SettingsDialog.tsx b/frontend/src/shell/SettingsDialog.tsx
new file mode 100644
index 00000000..24211148
--- /dev/null
+++ b/frontend/src/shell/SettingsDialog.tsx
@@ -0,0 +1,228 @@
+// frontend/src/shell/SettingsDialog.tsx
+import { useEffect, useMemo, useState } from "react";
+import { useQuery, useQueryClient } from "@tanstack/react-query";
+import {
+  Dialog,
+  DialogContent,
+  DialogHeader,
+  DialogTitle,
+} from "../components/ui/dialog";
+import { Button } from "../components/ui/button";
+import { listWorkspaces } from "../api/workspaces";
+import { listModels } from "../api/models";
+import { getSettings, putSettings } from "../api/settings";
+
+const THINKING_LEVELS = ["low", "medium", "high"] as const;
+
+export function SettingsDialog() {
+  const [open, setOpen] = useState(false);
+  const [workspace, setWorkspace] = useState("");
+  const [provider, setProvider] = useState("");
+  const [model, setModel] = useState("");
+  const [thinking, setThinking] = useState("medium");
+  const [error, setError] = useState<string | null>(null);
+  const [busy, setBusy] = useState(false);
+  const queryClient = useQueryClient();
+
+  const { data: workspaces = [] } = useQuery({
+    queryKey: ["workspaces"],
+    queryFn: listWorkspaces,
+    enabled: open,
+  });
+  const { data: modelsData } = useQuery({
+    queryKey: ["models"],
+    queryFn: listModels,
+    enabled: open,
+  });
+  const { data: current } = useQuery({
+    queryKey: ["settings"],
+    queryFn: getSettings,
+    enabled: open,
+  });
+
+  const models = useMemo(() => modelsData?.models ?? [], [modelsData]);
+  const hasModels = models.length > 0;
+  const providers = useMemo(
+    () => Array.from(new Set(models.map((m) => m.provider))),
+    [models],
+  );
+  const modelsForProvider = useMemo(
+    () => models.filter((m) => !provider || m.provider === provider),
+    [models, provider],
+  );
+
+  // Hydrate the form once the current settings arrive.
+  useEffect(() => {
+    if (!current) return;
+    setWorkspace(current.workspace ?? "");
+    setProvider(current.provider ?? "");
+    setModel(current.model ?? "");
+    setThinking(current.thinking && THINKING_LEVELS.includes(current.thinking as never)
+      ? current.thinking
+      : "medium");
+  }, [current]);
+
+  async function handleSave(e: React.FormEvent) {
+    e.preventDefault();
+    setError(null);
+    setBusy(true);
+    try {
+      await putSettings({
+        workspace: workspace || undefined,
+        provider: provider || undefined,
+        model: model || undefined,
+        thinking,
+      });
+      await queryClient.invalidateQueries({ queryKey: ["settings"] });
+      setOpen(false);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : "Errore nel salvataggio dei settings.");
+    } finally {
+      setBusy(false);
+    }
+  }
+
+  return (
+    <Dialog open={open} onOpenChange={setOpen}>
+      <Button
+        variant="outline"
+        size="sm"
+        className="w-full"
+        onClick={() => setOpen(true)}
+      >
+        Settings
+      </Button>
+      <DialogContent showCloseButton={false}>
+        <DialogHeader>
+          <DialogTitle>Settings</DialogTitle>
+        </DialogHeader>
+        <form onSubmit={handleSave} className="flex flex-col gap-3">
+          <div>
+            <label className="block text-xs font-medium mb-1" htmlFor="set-workspace">
+              Workspace
+            </label>
+            <select
+              id="set-workspace"
+              value={workspace}
+              onChange={(e) => setWorkspace(e.target.value)}
+              className="w-full border rounded px-2 py-1 text-sm"
+            >
+              {workspaces.length === 0 ? (
+                <option value="">—</option>
+              ) : (
+                workspaces.map((w) => (
+                  <option key={w.name} value={w.name}>
+                    {w.name}
+                  </option>
+                ))
+              )}
+            </select>
+          </div>
+
+          <div>
+            <label className="block text-xs font-medium mb-1" htmlFor="set-provider">
+              Provider
+            </label>
+            {hasModels ? (
+              <select
+                id="set-provider"
+                value={provider}
+                onChange={(e) => {
+                  setProvider(e.target.value);
+                  setModel(""); // reset model when provider changes
+                }}
+                className="w-full border rounded px-2 py-1 text-sm"
+              >
+                <option value="">— tutti —</option>
+                {providers.map((p) => (
+                  <option key={p} value={p}>
+                    {p}
+                  </option>
+                ))}
+              </select>
+            ) : (
+              <input
+                id="set-provider"
+                type="text"
+                value={provider}
+                onChange={(e) => setProvider(e.target.value)}
+                placeholder="es. anthropic"
+                className="w-full border rounded px-2 py-1 text-sm focus:outline-none focus:ring-1"
+                data-testid="provider-freetext"
+              />
+            )}
+          </div>
+
+          <div>
+            <label className="block text-xs font-medium mb-1" htmlFor="set-model">
+              Modello
+            </label>
+            {hasModels ? (
+              <select
+                id="set-model"
+                value={model}
+                onChange={(e) => setModel(e.target.value)}
+                className="w-full border rounded px-2 py-1 text-sm"
+              >
+                <option value="">— default —</option>
+                {modelsForProvider.map((m) => (
+                  <option key={`${m.provider}/${m.id}`} value={m.id}>
+                    {m.provider}/{m.name}
+                  </option>
+                ))}
+              </select>
+            ) : (
+              <input
+                id="set-model"
+                type="text"
+                value={model}
+                onChange={(e) => setModel(e.target.value)}
+                placeholder="es. glm-5.2"
+                className="w-full border rounded px-2 py-1 text-sm focus:outline-none focus:ring-1"
+                data-testid="model-freetext"
+              />
+            )}
+          </div>
+
+          <div>
+            <label className="block text-xs font-medium mb-1" htmlFor="set-thinking">
+              Thinking
+            </label>
+            <select
+              id="set-thinking"
+              value={thinking}
+              onChange={(e) => setThinking(e.target.value)}
+              className="w-full border rounded px-2 py-1 text-sm"
+            >
+              {THINKING_LEVELS.map((lvl) => (
+                <option key={lvl} value={lvl}>
+                  {lvl}
+                </option>
+              ))}
+            </select>
+          </div>
+
+          {!hasModels && (
+            <p className="text-xs text-muted-foreground">
+              Pi non ha restituito modelli (non in esecuzione o nessuna API key): inserimento libero.
+            </p>
+          )}
+          {error && (
+            <p className="text-xs text-destructive" role="alert">
+              {error}
+            </p>
+          )}
+
+          <div className="flex justify-end gap-2 pt-1">
+            <Button type="button" variant="outline" size="sm" onClick={() => setOpen(false)}>
+              Annulla
+            </Button>
+            <Button type="submit" size="sm" disabled={busy}>
+              {busy ? "Salvataggio…" : "Salva"}
+            </Button>
+          </div>
+        </form>
+      </DialogContent>
+    </Dialog>
+  );
+}