diff --git a/tests/test_ai_client_result.py b/tests/test_ai_client_result.py
new file mode 100644
index 00000000..6a863300
--- /dev/null
+++ b/tests/test_ai_client_result.py
@@ -0,0 +1,59 @@
+from unittest.mock import MagicMock, patch
+import pytest
+from src import ai_client
+from src.result_types import Result, ErrorInfo, ErrorKind
+
+
+def test_send_result_public_api_returns_result() -> None:
+ with patch.object(ai_client, "set_provider"):
+  with patch.object(ai_client, "_send_anthropic_result", return_value=Result(data="hello")) as mock_send:
+   r = ai_client.send_result("system", "user")
+   assert isinstance(r, Result)
+   assert r.ok
+   assert r.data == "hello"
+
+
+def test_send_deprecated_emits_warning() -> None:
+ import warnings
+ with warnings.catch_warnings(record=True) as w:
+  warnings.simplefilter("always")
+  with patch.object(ai_client, "set_provider"):
+   with patch.object(ai_client, "_send_anthropic_result", return_value=Result(data="hi")):
+    result = ai_client.send("system", "user")
+    assert result == "hi"
+    assert any(issubclass(x.category, DeprecationWarning) for x in w)
+
+
+def test_send_result_preserves_errors() -> None:
+ err = ErrorInfo(kind=ErrorKind.RATE_LIMIT, message="slow down", source="test")
+ with patch.object(ai_client, "set_provider"):
+  with patch.object(ai_client, "_send_anthropic_result", return_value=Result(data="", errors=[err])):
+   r = ai_client.send_result("system", "user")
+   assert not r.ok
+   assert r.errors == [err]
+
+
+def test_send_extracts_data_from_result() -> None:
+ with patch.object(ai_client, "set_provider"):
+  with patch.object(ai_client, "_send_anthropic_result", return_value=Result(data="result text")):
+   result = ai_client.send("system", "user")
+   assert result == "result text"
+
+
+def test_send_returns_empty_string_on_error_result() -> None:
+ err = ErrorInfo(kind=ErrorKind.AUTH, message="bad key", source="test")
+ with patch.object(ai_client, "set_provider"):
+  with patch.object(ai_client, "_send_anthropic_result", return_value=Result(data="", errors=[err])):
+   result = ai_client.send("system", "user")
+   assert result == ""
+
+
+def test_classify_gemini_error_returns_error_info() -> None:
+ from src.ai_client import _classify_gemini_error
+ class FakeRateLimitError(Exception): pass
+ e = FakeRateLimitError("rate limited")
+ info = _classify_gemini_error(e, source="test.gemini")
+ assert isinstance(info, ErrorInfo)
+ assert info.kind == ErrorKind.RATE_LIMIT
+ assert info.source == "test.gemini"
+ assert info.original is e
diff --git a/tests/test_deprecation_warnings.py b/tests/test_deprecation_warnings.py
new file mode 100644
index 00000000..7a7a1638
--- /dev/null
+++ b/tests/test_deprecation_warnings.py
@@ -0,0 +1,25 @@
+import warnings
+from unittest.mock import patch
+from src import ai_client
+from src.result_types import Result
+
+
+def test_send_deprecated_warning_emitted_once_per_site() -> None:
+ with patch.object(ai_client, "set_provider"):
+  with patch.object(ai_client, "_send_anthropic_result", return_value=Result(data="x")):
+   with warnings.catch_warnings(record=True) as w:
+    warnings.simplefilter("always")
+    ai_client.send("s", "u")
+    ai_client.send("s", "u")
+   deprecation_warnings = [x for x in w if issubclass(x.category, DeprecationWarning)]
+   assert len(deprecation_warnings) >= 1
+
+
+def test_send_result_does_not_emit_deprecation() -> None:
+ with patch.object(ai_client, "set_provider"):
+  with patch.object(ai_client, "_send_anthropic_result", return_value=Result(data="x")):
+   with warnings.catch_warnings(record=True) as w:
+    warnings.simplefilter("always")
+    ai_client.send_result("s", "u")
+   deprecation_warnings = [x for x in w if issubclass(x.category, DeprecationWarning)]
+   assert len(deprecation_warnings) == 0