diff --git a/asknews_sdk/api/chat.py b/asknews_sdk/api/chat.py
index c285817..b1d8561 100644
--- a/asknews_sdk/api/chat.py
+++ b/asknews_sdk/api/chat.py
@@ -50,6 +50,7 @@
 ]
 DeepNewsModel = Literal[
     "gpt-5",
+    "gpt-6-astra",
     "claude-3-7-sonnet-latest",
     "deepseek",
     "deepseek-basic",
diff --git a/tests/api/test_chat_model_types.py b/tests/api/test_chat_model_types.py
new file mode 100644
index 0000000..37016b7
--- /dev/null
+++ b/tests/api/test_chat_model_types.py
@@ -0,0 +1,40 @@
+import json
+from inspect import getmembers, isclass
+from typing import get_args, get_type_hints
+
+import pytest
+from pydantic import BaseModel
+
+from asknews_sdk.api.chat import AsyncChatAPI, ChatAPI, ChatModel, DeepNewsModel
+from asknews_sdk.dto import alert as alert_dto
+
+
+GPT_6_ASTRA = "gpt-6-astra"
+
+
+def test_gpt_6_astra_is_a_direct_deepnews_model_only():
+    assert GPT_6_ASTRA in get_args(DeepNewsModel)
+    assert GPT_6_ASTRA not in get_args(ChatModel)
+
+
+@pytest.mark.parametrize("api_type", [ChatAPI, AsyncChatAPI])
+def test_gpt_6_astra_is_scoped_to_get_deep_news(api_type):
+    deepnews_model = get_type_hints(api_type.get_deep_news)["model"]
+    forecast_model = get_type_hints(api_type.get_forecast)["model"]
+
+    assert GPT_6_ASTRA in get_args(deepnews_model)
+    assert GPT_6_ASTRA not in get_args(forecast_model)
+
+
+def test_gpt_6_astra_is_absent_from_alert_model_contracts():
+    alert_model_types = (
+        alert_dto.DeepNewsModel,
+        alert_dto.CheckAlertModel,
+        alert_dto.AlertReportModel,
+    )
+    for model_type in alert_model_types:
+        assert GPT_6_ASTRA not in get_args(model_type)
+
+    for name, model in getmembers(alert_dto, isclass):
+        if model.__module__ == alert_dto.__name__ and issubclass(model, BaseModel):
+            assert GPT_6_ASTRA not in json.dumps(model.model_json_schema()), name