fix(security): PKCE verifier leak, OAuth refresh Content-Type, tool_choice mcp_ prefix

gateway/session.py

@@ -944,7 +944,13 @@ def load_transcript(self, session_id: str) -> List[Dict[str, Any]]:
             for line in f:
                 line = line.strip()
                 if line:
-                    messages.append(json.loads(line))
+                    try:
+                        messages.append(json.loads(line))
+                    except json.JSONDecodeError:
+                        logger.warning(
+                            "Skipping corrupt line in transcript %s: %s",
+                            session_id, line[:120],
+                        )
 
         return messages
 

tests/gateway/test_session.py

@@ -336,6 +336,56 @@ def test_rewrite_with_empty_list(self, store):
         assert reloaded == []
 
 
+class TestLoadTranscriptCorruptLines:
+    """Regression: corrupt JSONL lines (e.g. from mid-write crash) must be
+    skipped instead of crashing the entire transcript load.  GH-1193."""
+
+    @pytest.fixture()
+    def store(self, tmp_path):
+        config = GatewayConfig()
+        with patch("gateway.session.SessionStore._ensure_loaded"):
+            s = SessionStore(sessions_dir=tmp_path, config=config)
+        s._db = None
+        s._loaded = True
+        return s
+
+    def test_corrupt_line_skipped(self, store, tmp_path):
+        session_id = "corrupt_test"
+        transcript_path = store.get_transcript_path(session_id)
+        transcript_path.parent.mkdir(parents=True, exist_ok=True)
+        with open(transcript_path, "w") as f:
+            f.write('{"role": "user", "content": "hello"}\n')
+            f.write('{"role": "assistant", "content": "hi th')  # truncated
+            f.write("\n")
+            f.write('{"role": "user", "content": "goodbye"}\n')
+
+        messages = store.load_transcript(session_id)
+        assert len(messages) == 2
+        assert messages[0]["content"] == "hello"
+        assert messages[1]["content"] == "goodbye"
+
+    def test_all_lines_corrupt_returns_empty(self, store, tmp_path):
+        session_id = "all_corrupt"
+        transcript_path = store.get_transcript_path(session_id)
+        transcript_path.parent.mkdir(parents=True, exist_ok=True)
+        with open(transcript_path, "w") as f:
+            f.write("not json at all\n")
+            f.write("{truncated\n")
+
+        messages = store.load_transcript(session_id)
+        assert messages == []
+
+    def test_valid_transcript_unaffected(self, store, tmp_path):
+        session_id = "valid_test"
+        store.append_to_transcript(session_id, {"role": "user", "content": "a"})
+        store.append_to_transcript(session_id, {"role": "assistant", "content": "b"})
+
+        messages = store.load_transcript(session_id)
+        assert len(messages) == 2
+        assert messages[0]["content"] == "a"
+        assert messages[1]["content"] == "b"
+
+
 class TestWhatsAppDMSessionKeyConsistency:
     """Regression: all session-key construction must go through build_session_key
     so DMs are isolated by chat_id across platforms."""

tests/tools/test_transcription.py

@@ -26,13 +26,14 @@ def test_local_when_available(self):
             from tools.transcription_tools import _get_provider
             assert _get_provider({"provider": "local"}) == "local"
 
-    def test_local_fallback_to_openai(self, monkeypatch):
+    def test_explicit_local_no_cloud_fallback(self, monkeypatch):
+        """Explicit local provider must not silently fall back to cloud."""
         monkeypatch.setenv("VOICE_TOOLS_OPENAI_KEY", "sk-test")
         monkeypatch.delenv("GROQ_API_KEY", raising=False)
         with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
              patch("tools.transcription_tools._HAS_OPENAI", True):
             from tools.transcription_tools import _get_provider
-            assert _get_provider({"provider": "local"}) == "openai"
+            assert _get_provider({"provider": "local"}) == "none"
 
     def test_local_nothing_available(self, monkeypatch):
         monkeypatch.delenv("VOICE_TOOLS_OPENAI_KEY", raising=False)
@@ -47,12 +48,13 @@ def test_openai_when_key_set(self, monkeypatch):
             from tools.transcription_tools import _get_provider
             assert _get_provider({"provider": "openai"}) == "openai"
 
-    def test_openai_fallback_to_local(self, monkeypatch):
+    def test_explicit_openai_no_key_returns_none(self, monkeypatch):
+        """Explicit openai without key returns none — no cross-provider fallback."""
         monkeypatch.delenv("VOICE_TOOLS_OPENAI_KEY", raising=False)
         with patch("tools.transcription_tools._HAS_FASTER_WHISPER", True), \
              patch("tools.transcription_tools._HAS_OPENAI", True):
             from tools.transcription_tools import _get_provider
-            assert _get_provider({"provider": "openai"}) == "local"
+            assert _get_provider({"provider": "openai"}) == "none"
 
     def test_default_provider_is_local(self):
         with patch("tools.transcription_tools._HAS_FASTER_WHISPER", True):

tests/tools/test_transcription_tools.py

@@ -66,19 +66,12 @@ def test_groq_when_key_set(self, monkeypatch):
             from tools.transcription_tools import _get_provider
             assert _get_provider({"provider": "groq"}) == "groq"
 
-    def test_groq_fallback_to_local(self, monkeypatch):
+    def test_groq_explicit_no_fallback(self, monkeypatch):
+        """Explicit groq with no key returns none — no cross-provider fallback."""
         monkeypatch.delenv("GROQ_API_KEY", raising=False)
         with patch("tools.transcription_tools._HAS_FASTER_WHISPER", True):
             from tools.transcription_tools import _get_provider
-            assert _get_provider({"provider": "groq"}) == "local"
-
-    def test_groq_fallback_to_openai(self, monkeypatch):
-        monkeypatch.delenv("GROQ_API_KEY", raising=False)
-        monkeypatch.setenv("VOICE_TOOLS_OPENAI_KEY", "sk-test")
-        with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
-             patch("tools.transcription_tools._HAS_OPENAI", True):
-            from tools.transcription_tools import _get_provider
-            assert _get_provider({"provider": "groq"}) == "openai"
+            assert _get_provider({"provider": "groq"}) == "none"
 
     def test_groq_nothing_available(self, monkeypatch):
         monkeypatch.delenv("GROQ_API_KEY", raising=False)
@@ -90,36 +83,25 @@ def test_groq_nothing_available(self, monkeypatch):
 
 
 class TestGetProviderFallbackPriority:
-    """Cross-provider fallback priority tests."""
-
-    def test_local_fallback_prefers_groq_over_openai(self, monkeypatch):
-        """When local unavailable, groq (free) is preferred over openai (paid)."""
-        monkeypatch.setenv("GROQ_API_KEY", "gsk-test")
-        monkeypatch.setenv("VOICE_TOOLS_OPENAI_KEY", "sk-test")
-        with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
-             patch("tools.transcription_tools._HAS_OPENAI", True):
-            from tools.transcription_tools import _get_provider
-            assert _get_provider({"provider": "local"}) == "groq"
+    """Auto-detect fallback priority and explicit provider behaviour."""
 
-    def test_local_fallback_to_groq_only(self, monkeypatch):
-        """When only groq key available, falls back to groq."""
-        monkeypatch.setenv("GROQ_API_KEY", "gsk-test")
-        with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
-             patch("tools.transcription_tools._HAS_OPENAI", True):
+    def test_auto_detect_prefers_local(self):
+        """Auto-detect prefers local over any cloud provider."""
+        with patch("tools.transcription_tools._HAS_FASTER_WHISPER", True):
             from tools.transcription_tools import _get_provider
-            assert _get_provider({"provider": "local"}) == "groq"
+            assert _get_provider({}) == "local"
 
-    def test_openai_fallback_to_groq(self, monkeypatch):
-        """When openai key missing but groq available, falls back to groq."""
-        monkeypatch.delenv("VOICE_TOOLS_OPENAI_KEY", raising=False)
+    def test_auto_detect_prefers_groq_over_openai(self, monkeypatch):
+        """Auto-detect: groq (free) is preferred over openai (paid)."""
         monkeypatch.setenv("GROQ_API_KEY", "gsk-test")
+        monkeypatch.setenv("VOICE_TOOLS_OPENAI_KEY", "sk-test")
         with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
              patch("tools.transcription_tools._HAS_OPENAI", True):
             from tools.transcription_tools import _get_provider
-            assert _get_provider({"provider": "openai"}) == "groq"
+            assert _get_provider({}) == "groq"
 
-    def test_openai_nothing_available(self, monkeypatch):
-        """When no openai key and no local, returns none."""
+    def test_explicit_openai_no_key_returns_none(self, monkeypatch):
+        """Explicit openai with no key returns none — no cross-provider fallback."""
         monkeypatch.delenv("VOICE_TOOLS_OPENAI_KEY", raising=False)
         monkeypatch.delenv("GROQ_API_KEY", raising=False)
         with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
@@ -136,18 +118,83 @@ def test_empty_config_defaults_to_local(self):
             from tools.transcription_tools import _get_provider
             assert _get_provider({}) == "local"
 
-    def test_openai_fallback_to_local_command(self, monkeypatch):
-        monkeypatch.delenv("VOICE_TOOLS_OPENAI_KEY", raising=False)
-        monkeypatch.delenv("OPENAI_API_KEY", raising=False)
+
+# ============================================================================
+# Explicit provider config respected  (GH-1774)
+# ============================================================================
+
+class TestExplicitProviderRespected:
+    """When stt.provider is explicitly set, that choice is authoritative.
+    No silent fallback to a different cloud provider."""
+
+    def test_explicit_local_no_fallback_to_openai(self, monkeypatch):
+        """GH-1774: provider=local must not silently fall back to openai
+        even when an OpenAI API key is set."""
+        monkeypatch.setenv("OPENAI_API_KEY", "sk-real-key-here")
         monkeypatch.delenv("GROQ_API_KEY", raising=False)
+        with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
+             patch("tools.transcription_tools._HAS_OPENAI", True):
+            from tools.transcription_tools import _get_provider
+            result = _get_provider({"provider": "local"})
+            assert result == "none", f"Expected 'none' but got {result!r}"
+
+    def test_explicit_local_no_fallback_to_groq(self, monkeypatch):
+        monkeypatch.setenv("GROQ_API_KEY", "gsk-test")
+        with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
+             patch("tools.transcription_tools._HAS_OPENAI", True):
+            from tools.transcription_tools import _get_provider
+            result = _get_provider({"provider": "local"})
+            assert result == "none"
+
+    def test_explicit_local_uses_local_command_fallback(self, monkeypatch):
+        """Local-to-local_command fallback is fine — both are local."""
         monkeypatch.setenv(
             "HERMES_LOCAL_STT_COMMAND",
             "whisper {input_path} --output_dir {output_dir} --language {language}",
         )
+        with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False):
+            from tools.transcription_tools import _get_provider
+            result = _get_provider({"provider": "local"})
+            assert result == "local_command"
+
+    def test_explicit_groq_no_fallback_to_openai(self, monkeypatch):
+        monkeypatch.delenv("GROQ_API_KEY", raising=False)
+        monkeypatch.setenv("OPENAI_API_KEY", "sk-real-key")
+        with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
+             patch("tools.transcription_tools._HAS_OPENAI", True):
+            from tools.transcription_tools import _get_provider
+            result = _get_provider({"provider": "groq"})
+            assert result == "none"
+
+    def test_explicit_openai_no_fallback_to_groq(self, monkeypatch):
+        monkeypatch.delenv("OPENAI_API_KEY", raising=False)
+        monkeypatch.delenv("VOICE_TOOLS_OPENAI_KEY", raising=False)
+        monkeypatch.setenv("GROQ_API_KEY", "gsk-test")
+        with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
+             patch("tools.transcription_tools._HAS_OPENAI", True):
+            from tools.transcription_tools import _get_provider
+            result = _get_provider({"provider": "openai"})
+            assert result == "none"
+
+    def test_auto_detect_still_falls_back_to_cloud(self, monkeypatch):
+        """When no provider is explicitly set, auto-detect cloud fallback works."""
+        monkeypatch.setenv("OPENAI_API_KEY", "sk-real-key")
+        monkeypatch.delenv("GROQ_API_KEY", raising=False)
+        with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
+             patch("tools.transcription_tools._HAS_OPENAI", True):
+            from tools.transcription_tools import _get_provider
+            # Empty dict = no explicit provider, uses DEFAULT_PROVIDER auto-detect
+            result = _get_provider({})
+            assert result == "openai"
+
+    def test_auto_detect_prefers_groq_over_openai(self, monkeypatch):
+        monkeypatch.setenv("GROQ_API_KEY", "gsk-test")
+        monkeypatch.setenv("OPENAI_API_KEY", "sk-real-key")
         with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
              patch("tools.transcription_tools._HAS_OPENAI", True):
             from tools.transcription_tools import _get_provider
-            assert _get_provider({"provider": "openai"}) == "local_command"
+            result = _get_provider({})
+            assert result == "groq"
 
 
 # ============================================================================
@@ -686,28 +733,19 @@ def test_no_provider_returns_error(self, sample_ogg):
         assert "faster-whisper" in result["error"]
         assert "GROQ_API_KEY" in result["error"]
 
-    def test_openai_provider_falls_back_to_local_command(self, monkeypatch, sample_ogg):
+    def test_explicit_openai_no_key_returns_error(self, monkeypatch, sample_ogg):
+        """Explicit provider=openai with no key returns an error, not a fallback."""
         monkeypatch.delenv("VOICE_TOOLS_OPENAI_KEY", raising=False)
         monkeypatch.delenv("OPENAI_API_KEY", raising=False)
-        monkeypatch.setenv(
-            "HERMES_LOCAL_STT_COMMAND",
-            "whisper {input_path} --model {model} --output_dir {output_dir} --language {language}",
-        )
 
         with patch("tools.transcription_tools._load_stt_config", return_value={"provider": "openai"}), \
              patch("tools.transcription_tools._HAS_FASTER_WHISPER", False), \
-             patch("tools.transcription_tools._HAS_OPENAI", True), \
-             patch("tools.transcription_tools._transcribe_local_command", return_value={
-                 "success": True,
-                 "transcript": "hello from fallback",
-                 "provider": "local_command",
-             }) as mock_local_command:
+             patch("tools.transcription_tools._HAS_OPENAI", True):
             from tools.transcription_tools import transcribe_audio
             result = transcribe_audio(sample_ogg)
 
-        assert result["success"] is True
-        assert result["transcript"] == "hello from fallback"
-        mock_local_command.assert_called_once_with(sample_ogg, "base")
+        assert result["success"] is False
+        assert "No STT provider" in result["error"]
 
     def test_invalid_file_short_circuits(self):
         from tools.transcription_tools import transcribe_audio