feat: Add OpenAI API type configuration and update provider settings

tests/agent/test_runner_fallback.py

@@ -241,7 +241,7 @@ def test_inline_fallback_reasoning_effort_does_not_inherit_primary() -> None:
     signature = provider_signature(config)
     fallback_signatures = signature[-1]
 
-    assert fallback_signatures[0][11] is None
+    assert fallback_signatures[0][12] is None
 
 
 # -- FallbackProvider tests --

tests/config/test_model_presets.py

@@ -1,3 +1,5 @@
+import pytest
+
 from nanobot.config.schema import Config
 
 
@@ -12,6 +14,28 @@ def test_resolve_preset_returns_defaults_when_no_preset() -> None:
     assert resolved.reasoning_effort == config.agents.defaults.reasoning_effort
 
 
+def test_provider_api_type_accepts_exact_values_only() -> None:
+    config = Config.model_validate({
+        "providers": {
+            "openai": {
+                "apiKey": "sk-test",
+                "apiType": "responses",
+            }
+        }
+    })
+    assert config.providers.openai.api_type == "responses"
+
+    with pytest.raises(ValueError):
+        Config.model_validate({
+            "providers": {
+                "openai": {
+                    "apiKey": "sk-test",
+                    "apiType": "response",
+                }
+            }
+        })
+
+
 def test_legacy_defaults_config_without_presets_still_resolves() -> None:
     config = Config.model_validate({
         "agents": {

tests/providers/test_github_copilot_routing.py

@@ -20,6 +20,7 @@ def _make_copilot_provider() -> OpenAICompatProvider:
     p.default_model = "github_copilot/gpt-5.4-mini"
     p._spec = find_by_name("github_copilot")
     p._effective_base = "https://api.githubcopilot.com"
+    p._api_type = "auto"
     p._responses_failures = {}
     p._responses_tripped_at = {}
     return p

tests/providers/test_responses_circuit_breaker.py

@@ -18,6 +18,7 @@ def provider():
     p.default_model = "gpt-5"
     p._spec = type("Spec", (), {"name": "openai"})()
     p._effective_base = "https://api.openai.com/v1"
+    p._api_type = "auto"
     p._responses_failures = {}
     p._responses_tripped_at = {}
     return p
@@ -27,6 +28,17 @@ def test_responses_api_available_by_default(provider):
     assert provider._should_use_responses_api("gpt-5", None) is True
 
 
+def test_api_type_chat_completions_disables_responses(provider):
+    provider._api_type = "chat_completions"
+    assert provider._should_use_responses_api("gpt-5", None) is False
+
+
+def test_api_type_responses_forces_responses_for_openai(provider):
+    provider.default_model = "gpt-4o"
+    provider._api_type = "responses"
+    assert provider._should_use_responses_api("gpt-4o", None) is True
+
+
 def test_circuit_opens_after_threshold(provider):
     for _ in range(_RESPONSES_FAILURE_THRESHOLD):
         provider._record_responses_failure("gpt-5", None)