diff --git a/tests/unit/agent/refresh-interval.test.ts b/tests/unit/agent/refresh-interval.test.ts
new file mode 100644
index 0000000..efc9da8
--- /dev/null
+++ b/tests/unit/agent/refresh-interval.test.ts
@@ -0,0 +1,61 @@
+import { describe, expect, test, vi, beforeEach, afterEach } from "vitest";
+
+describe("Agent refresh interval", () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  test("setInterval is called with cache_ttl value", () => {
+    const setIntervalSpy = vi.spyOn(global, "setInterval");
+    const cache_ttl = 180000; // 3 minutes
+
+    // Simulate what the agent does when starting refresh
+    const refreshInterval = setInterval(() => {
+      // refresh logic
+    }, cache_ttl);
+
+    expect(setIntervalSpy).toHaveBeenCalledWith(expect.any(Function), cache_ttl);
+
+    clearInterval(refreshInterval);
+    setIntervalSpy.mockRestore();
+  });
+
+  test("interval triggers callback at expected times", () => {
+    const callback = vi.fn();
+    const cache_ttl = 60000; // 1 minute for test
+
+    const interval = setInterval(callback, cache_ttl);
+
+    expect(callback).not.toHaveBeenCalled();
+
+    vi.advanceTimersByTime(cache_ttl);
+    expect(callback).toHaveBeenCalledTimes(1);
+
+    vi.advanceTimersByTime(cache_ttl);
+    expect(callback).toHaveBeenCalledTimes(2);
+
+    vi.advanceTimersByTime(cache_ttl);
+    expect(callback).toHaveBeenCalledTimes(3);
+
+    clearInterval(interval);
+  });
+
+  test("clearInterval stops the refresh", () => {
+    const callback = vi.fn();
+    const cache_ttl = 60000;
+
+    const interval = setInterval(callback, cache_ttl);
+
+    vi.advanceTimersByTime(cache_ttl);
+    expect(callback).toHaveBeenCalledTimes(1);
+
+    clearInterval(interval);
+
+    vi.advanceTimersByTime(cache_ttl * 5);
+    expect(callback).toHaveBeenCalledTimes(1); // still 1, not called again
+  });
+});