diff --git a/test/quality/test_api_extended.py b/test/quality/test_api_extended.py
new file mode 100644
index 000000000..ca8768a08
--- /dev/null
+++ b/test/quality/test_api_extended.py
@@ -0,0 +1,49 @@
+"""Extended API tests for quality tier. Increases coverage of API endpoints."""
+import pytest
+import requests
+
+
+@pytest.mark.parametrize("url", [
+    "sdapi/v1/progress",
+    "sdapi/v1/sd-vae",
+    "sdapi/v1/latent-upscale-modes",
+    "sdapi/v1/memory",
+    "sdapi/v1/scripts",
+    "sdapi/v1/script-info",
+    "sdapi/v1/extensions",
+])
+def test_get_api_endpoint(base_url, url):
+    """Verify extended API endpoints return 200."""
+    assert requests.get(f"{base_url}/{url}").status_code == 200
+
+
+def test_interrogate_deepbooru(base_url, img2img_basic_image_base64):
+    """Interrogate with deepbooru model."""
+    payload = {"image": img2img_basic_image_base64, "model": "deepbooru"}
+    assert requests.post(f"{base_url}/sdapi/v1/interrogate", json=payload).status_code == 200
+
+
+def test_png_info(base_url, img2img_basic_image_base64):
+    """PNG info endpoint."""
+    payload = {"image": img2img_basic_image_base64}
+    assert requests.post(f"{base_url}/sdapi/v1/png-info", json=payload).status_code == 200
+
+
+def test_extra_batch_images(base_url, img2img_basic_image_base64):
+    """Extra batch images API."""
+    batch_payload = {
+        "resize_mode": 0,
+        "show_extras_results": True,
+        "gfpgan_visibility": 0,
+        "codeformer_visibility": 0,
+        "codeformer_weight": 0,
+        "upscaling_resize": 2,
+        "upscaling_resize_w": 128,
+        "upscaling_resize_h": 128,
+        "upscaling_crop": True,
+        "upscaler_1": "Lanczos",
+        "upscaler_2": "None",
+        "extras_upscaler_2_visibility": 0,
+        "imageList": [{"data": img2img_basic_image_base64, "name": "test.png"}],
+    }
+    assert requests.post(f"{base_url}/sdapi/v1/extra-batch-images", json=batch_payload).status_code == 200