test(ui): cover interactions MCP tool block serialization

Assert the playground interactions client forwards buildMcpToolBlocks
when servers are selected and omits tools otherwise

ui/litellm-dashboard/src/app/(dashboard)/playground/llm_calls/interactions_api.test.ts

@@ -0,0 +1,90 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { makeInteractionsRequest } from "./interactions_api";
+import type { MCPServer } from "@/components/mcp_tools/types";
+
+vi.mock("@/components/networking", () => ({
+  getGlobalLitellmHeaderName: vi.fn(() => "Authorization"),
+  getProxyBaseUrl: vi.fn(() => "https://example.com"),
+}));
+
+vi.mock("@/components/molecules/notifications_manager", () => ({
+  default: { fromBackend: vi.fn() },
+}));
+
+describe("makeInteractionsRequest", () => {
+  const mockUpdateUI = vi.fn();
+  let fetchMock: ReturnType<typeof vi.fn>;
+
+  beforeEach(() => {
+    fetchMock = vi.fn().mockResolvedValue({
+      ok: true,
+      body: {
+        getReader: () => ({
+          read: vi.fn().mockResolvedValue({ done: true, value: undefined }),
+        }),
+      },
+    });
+    vi.stubGlobal("fetch", fetchMock);
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+    vi.clearAllMocks();
+  });
+
+  it("forwards MCP tool blocks in the interactions request body", async () => {
+    const selectedMCPServers = ["server-1"];
+    const mcpServers = [
+      {
+        server_id: "server-1",
+        server_name: "deepwiki",
+        alias: "wiki",
+        url: "http://example.com",
+        created_at: "2024-01-01",
+        created_by: "test",
+        updated_at: "2024-01-01",
+        updated_by: "test",
+      },
+    ] as MCPServer[];
+
+    await makeInteractionsRequest(
+      "list tools",
+      mockUpdateUI,
+      "gpt-4o",
+      "test-token",
+      undefined,
+      undefined,
+      undefined,
+      undefined,
+      selectedMCPServers,
+      mcpServers,
+    );
+
+    expect(fetchMock).toHaveBeenCalledTimes(1);
+    const [, init] = fetchMock.mock.calls[0] as [string, RequestInit];
+    const body = JSON.parse(String(init.body)) as {
+      model: string;
+      input: string;
+      tools: Array<Record<string, unknown>>;
+    };
+
+    expect(body.model).toBe("gpt-4o");
+    expect(body.input).toBe("list tools");
+    expect(body.tools).toEqual([
+      {
+        type: "mcp",
+        server_label: "deepwiki",
+        server_url: "litellm_proxy/mcp/deepwiki",
+        require_approval: "never",
+      },
+    ]);
+  });
+
+  it("omits tools when no MCP servers are selected", async () => {
+    await makeInteractionsRequest("hello", mockUpdateUI, "gpt-4o", "test-token");
+
+    const [, init] = fetchMock.mock.calls[0] as [string, RequestInit];
+    const body = JSON.parse(String(init.body)) as Record<string, unknown>;
+    expect(body.tools).toBeUndefined();
+  });
+});