diff --git a/tests/test_models.py b/tests/test_models.py
new file mode 100644
index 0000000..790437d
--- /dev/null
+++ b/tests/test_models.py
@@ -0,0 +1,47 @@
+import pytest
+from pydantic import ValidationError
+
+
+def test_search_request_defaults():
+    from axon.models import SearchRequest
+    req = SearchRequest(query="test")
+    assert req.max_results == 10
+    assert req.search_depth == "basic"
+    assert req.include_answer is False
+    assert req.include_raw_content is False
+    assert req.domains_whitelist == []
+    assert req.domains_blacklist == []
+    assert req.topic == "general"
+    assert req.time_range is None
+
+
+def test_search_request_max_results_capped():
+    from axon.models import SearchRequest
+    with pytest.raises(ValidationError):
+        SearchRequest(query="test", max_results=21)
+
+
+def test_search_request_max_results_minimum():
+    from axon.models import SearchRequest
+    with pytest.raises(ValidationError):
+        SearchRequest(query="test", max_results=0)
+
+
+def test_search_result_fields():
+    from axon.models import SearchResult
+    r = SearchResult(title="T", url="https://x.com", content="C", score=0.9)
+    assert r.published_date is None
+    assert r.favicon is None
+
+
+def test_extract_request():
+    from axon.models import ExtractRequest
+    req = ExtractRequest(urls=["https://a.com", "https://b.com"])
+    assert req.include_images is False
+
+
+def test_research_request_defaults():
+    from axon.models import ResearchRequest
+    req = ResearchRequest(query="topic")
+    assert req.depth == "basic"
+    assert req.output_format == "markdown"