diff --git a/src/pipecat/services/anthropic/llm.py b/src/pipecat/services/anthropic/llm.py
index 26e857122..916bc351c 100644
--- a/src/pipecat/services/anthropic/llm.py
+++ b/src/pipecat/services/anthropic/llm.py
@@ -39,7 +39,7 @@ from pipecat.processors.aggregators.llm_context import LLMContext
 from pipecat.processors.frame_processor import FrameDirection
 from pipecat.services.llm_service import FunctionCallFromLLM, LLMService
 from pipecat.services.settings import NOT_GIVEN as _NOT_GIVEN
-from pipecat.services.settings import LLMSettings, _NotGiven, is_given
+from pipecat.services.settings import LLMSettings, _NotGiven, assert_given, is_given
 from pipecat.utils.tracing.service_decorators import traced_llm
 
 try:
@@ -281,11 +281,13 @@ class AnthropicLLMService(LLMService):
         messages = []
         system = NOT_GIVEN
         tools = []
-        effective_instruction = system_instruction or self._settings.system_instruction
+        effective_instruction = system_instruction or assert_given(
+            self._settings.system_instruction
+        )
         adapter: AnthropicLLMAdapter = self.get_llm_adapter()
         invocation_params = adapter.get_llm_invocation_params(
             context,
-            enable_prompt_caching=self._settings.enable_prompt_caching,
+            enable_prompt_caching=assert_given(self._settings.enable_prompt_caching),
             system_instruction=effective_instruction,
         )
         messages = invocation_params["messages"]
@@ -305,8 +307,9 @@ class AnthropicLLMService(LLMService):
             "tools": tools,
             "betas": ["interleaved-thinking-2025-05-14"],
         }
-        if self._settings.thinking:
-            params["thinking"] = self._settings.thinking.model_dump(exclude_unset=True)
+        thinking = assert_given(self._settings.thinking)
+        if thinking:
+            params["thinking"] = thinking.model_dump(exclude_unset=True)
 
         params.update(self._settings.extra)
 
@@ -319,8 +322,8 @@ class AnthropicLLMService(LLMService):
         adapter: AnthropicLLMAdapter = self.get_llm_adapter()
         params: AnthropicLLMInvocationParams = adapter.get_llm_invocation_params(
             context,
-            enable_prompt_caching=self._settings.enable_prompt_caching,
-            system_instruction=self._settings.system_instruction,
+            enable_prompt_caching=assert_given(self._settings.enable_prompt_caching),
+            system_instruction=assert_given(self._settings.system_instruction),
         )
         return params
 
@@ -359,8 +362,9 @@ class AnthropicLLMService(LLMService):
             }
 
             # Add thinking parameter if set
-            if self._settings.thinking:
-                params["thinking"] = self._settings.thinking.model_dump(exclude_unset=True)
+            thinking = assert_given(self._settings.thinking)
+            if thinking:
+                params["thinking"] = thinking.model_dump(exclude_unset=True)
 
             # Messages, system, tools
             params.update(params_from_context)
diff --git a/src/pipecat/services/aws/llm.py b/src/pipecat/services/aws/llm.py
index e99ac6b3d..bf226d815 100644
--- a/src/pipecat/services/aws/llm.py
+++ b/src/pipecat/services/aws/llm.py
@@ -37,7 +37,7 @@ from pipecat.metrics.metrics import LLMTokenUsage
 from pipecat.processors.aggregators.llm_context import LLMContext
 from pipecat.processors.frame_processor import FrameDirection
 from pipecat.services.llm_service import LLMService
-from pipecat.services.settings import NOT_GIVEN, LLMSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, LLMSettings, _NotGiven, assert_given
 from pipecat.utils.tracing.service_decorators import traced_llm
 
 try:
@@ -279,7 +279,9 @@ class AWSBedrockLLMService(LLMService):
         """
         messages = []
         system = []
-        effective_instruction = system_instruction or self._settings.system_instruction
+        effective_instruction = system_instruction or assert_given(
+            self._settings.system_instruction
+        )
         adapter: AWSBedrockLLMAdapter = self.get_llm_adapter()
         params: AWSBedrockLLMInvocationParams = adapter.get_llm_invocation_params(
             context, system_instruction=effective_instruction
@@ -371,7 +373,7 @@ class AWSBedrockLLMService(LLMService):
     def _get_llm_invocation_params(self, context: LLMContext) -> AWSBedrockLLMInvocationParams:
         adapter: AWSBedrockLLMAdapter = self.get_llm_adapter()
         params: AWSBedrockLLMInvocationParams = adapter.get_llm_invocation_params(
-            context, system_instruction=self._settings.system_instruction
+            context, system_instruction=assert_given(self._settings.system_instruction)
         )
         return params
 
diff --git a/src/pipecat/services/aws/nova_sonic/llm.py b/src/pipecat/services/aws/nova_sonic/llm.py
index a99de2d8a..1d0ed7b8f 100644
--- a/src/pipecat/services/aws/nova_sonic/llm.py
+++ b/src/pipecat/services/aws/nova_sonic/llm.py
@@ -51,7 +51,7 @@ from pipecat.frames.frames import (
 from pipecat.processors.aggregators.llm_context import LLMContext
 from pipecat.processors.frame_processor import FrameDirection
 from pipecat.services.llm_service import LLMService
-from pipecat.services.settings import NOT_GIVEN, LLMSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, LLMSettings, _NotGiven, assert_given
 from pipecat.utils.time import time_now_iso8601
 
 try:
@@ -559,7 +559,9 @@ class AWSNovaSonicLLMService(LLMService):
 
             # Start the bidirectional stream
             self._stream = await self._client.invoke_model_with_bidirectional_stream(
-                InvokeModelWithBidirectionalStreamOperationInput(model_id=self._settings.model)
+                InvokeModelWithBidirectionalStreamOperationInput(
+                    model_id=assert_given(self._settings.model)
+                )
             )
 
             # Send session start event
@@ -598,7 +600,7 @@ class AWSNovaSonicLLMService(LLMService):
         # Read context
         adapter: AWSNovaSonicLLMAdapter = self.get_llm_adapter()
         llm_connection_params = adapter.get_llm_invocation_params(
-            self._context, system_instruction=self._settings.system_instruction
+            self._context, system_instruction=assert_given(self._settings.system_instruction)
         )
 
         # Send prompt start event, specifying tools.
diff --git a/src/pipecat/services/aws/stt.py b/src/pipecat/services/aws/stt.py
index 7ff72c9fd..aa1fdf9bf 100644
--- a/src/pipecat/services/aws/stt.py
+++ b/src/pipecat/services/aws/stt.py
@@ -30,7 +30,7 @@ from pipecat.frames.frames import (
     TranscriptionFrame,
 )
 from pipecat.services.aws.utils import build_event_message, decode_event, get_presigned_url
-from pipecat.services.settings import STTSettings
+from pipecat.services.settings import STTSettings, assert_given
 from pipecat.services.stt_latency import AWS_TRANSCRIBE_TTFS_P99
 from pipecat.services.stt_service import WebsocketSTTService
 from pipecat.transcriptions.language import Language, resolve_language
@@ -260,7 +260,7 @@ class AWSTranscribeSTTService(WebsocketSTTService):
 
             logger.debug("Connecting to AWS Transcribe WebSocket")
 
-            language_code = self._settings.language
+            language_code = assert_given(self._settings.language)
             if not language_code:
                 raise ValueError(f"Unsupported language: {language_code}")
 
@@ -534,20 +534,21 @@ class AWSTranscribeSTTService(WebsocketSTTService):
                             is_final = not result.get("IsPartial", True)
 
                             if transcript:
+                                language = assert_given(self._settings.language)
                                 if is_final:
                                     await self.push_frame(
                                         TranscriptionFrame(
                                             transcript,
                                             self._user_id,
                                             time_now_iso8601(),
-                                            self._settings.language,
+                                            language,
                                             result=result,
                                         )
                                     )
                                     await self._handle_transcription(
                                         transcript,
                                         is_final,
-                                        self._settings.language,
+                                        language,
                                     )
                                     await self.stop_processing_metrics()
                                 else:
@@ -556,7 +557,7 @@ class AWSTranscribeSTTService(WebsocketSTTService):
                                             transcript,
                                             self._user_id,
                                             time_now_iso8601(),
-                                            self._settings.language,
+                                            language,
                                             result=result,
                                         )
                                     )
diff --git a/src/pipecat/services/azure/stt.py b/src/pipecat/services/azure/stt.py
index 9740a1efe..72a8f76b0 100644
--- a/src/pipecat/services/azure/stt.py
+++ b/src/pipecat/services/azure/stt.py
@@ -27,7 +27,7 @@ from pipecat.frames.frames import (
     TranscriptionFrame,
 )
 from pipecat.services.azure.common import language_to_azure_language
-from pipecat.services.settings import STTSettings
+from pipecat.services.settings import STTSettings, assert_given
 from pipecat.services.stt_latency import AZURE_TTFS_P99
 from pipecat.services.stt_service import STTService
 from pipecat.transcriptions.language import Language
@@ -128,9 +128,9 @@ class AzureSTTService(STTService):
             **kwargs,
         )
 
-        recognition_language = default_settings.language or language_to_azure_language(
-            Language.EN_US
-        )
+        recognition_language = assert_given(
+            default_settings.language
+        ) or language_to_azure_language(Language.EN_US)
 
         if not region and not private_endpoint:
             raise ValueError("Either 'region' or 'private_endpoint' must be provided.")
@@ -280,7 +280,9 @@ class AzureSTTService(STTService):
 
     def _on_handle_recognized(self, event):
         if event.result.reason == ResultReason.RecognizedSpeech and len(event.result.text) > 0:
-            language = getattr(event.result, "language", None) or self._settings.language
+            language = getattr(event.result, "language", None) or assert_given(
+                self._settings.language
+            )
             frame = TranscriptionFrame(
                 event.result.text,
                 self._user_id,
@@ -295,7 +297,9 @@ class AzureSTTService(STTService):
 
     def _on_handle_recognizing(self, event):
         if event.result.reason == ResultReason.RecognizingSpeech and len(event.result.text) > 0:
-            language = getattr(event.result, "language", None) or self._settings.language
+            language = getattr(event.result, "language", None) or assert_given(
+                self._settings.language
+            )
             frame = InterimTranscriptionFrame(
                 event.result.text,
                 self._user_id,
diff --git a/src/pipecat/services/azure/tts.py b/src/pipecat/services/azure/tts.py
index dd54a1b41..46811a1a3 100644
--- a/src/pipecat/services/azure/tts.py
+++ b/src/pipecat/services/azure/tts.py
@@ -25,7 +25,7 @@ from pipecat.frames.frames import (
 )
 from pipecat.processors.frame_processor import FrameDirection
 from pipecat.services.azure.common import language_to_azure_language
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, assert_given
 from pipecat.services.tts_service import TextAggregationMode, TTSService
 from pipecat.transcriptions.language import Language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -428,7 +428,7 @@ class AzureTTSService(TTSService, AzureBaseTTSService):
         Returns:
             True if the language is CJK, False otherwise.
         """
-        language = (self._settings.language if self._settings.language else "").lower()
+        language = (assert_given(self._settings.language) or "").lower()
         # Check if language starts with CJK language codes
         return language.startswith(("zh", "ja", "ko", "cmn", "yue", "wuu"))
 
diff --git a/src/pipecat/services/camb/tts.py b/src/pipecat/services/camb/tts.py
index f2bc094b9..7b3aab768 100644
--- a/src/pipecat/services/camb/tts.py
+++ b/src/pipecat/services/camb/tts.py
@@ -31,7 +31,7 @@ from pipecat.frames.frames import (
     StartFrame,
     TTSAudioRawFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, assert_given
 from pipecat.services.tts_service import TTSService
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -270,8 +270,8 @@ class CambTTSService(TTSService):
             default_settings.apply_update(settings)
 
         # Warn if sample rate doesn't match model's supported rate
-        _model = default_settings.model
-        if sample_rate and sample_rate != MODEL_SAMPLE_RATES.get(_model):
+        _model = assert_given(default_settings.model)
+        if sample_rate and _model is not None and sample_rate != MODEL_SAMPLE_RATES.get(_model):
             logger.warning(
                 f"Camb.ai's {_model} model only supports {MODEL_SAMPLE_RATES.get(_model)}Hz "
                 f"sample rate. Current rate of {sample_rate}Hz may cause issues."
@@ -321,7 +321,8 @@ class CambTTSService(TTSService):
 
         # Use model-specific sample rate if not explicitly specified
         if not self._init_sample_rate:
-            self._sample_rate = MODEL_SAMPLE_RATES.get(self._settings.model, 22050)
+            model = assert_given(self._settings.model)
+            self._sample_rate = MODEL_SAMPLE_RATES.get(model, 22050) if model is not None else 22050
 
     @traced_tts
     async def run_tts(self, text: str, context_id: str) -> AsyncGenerator[Frame, None]:
diff --git a/src/pipecat/services/cartesia/tts.py b/src/pipecat/services/cartesia/tts.py
index 108ec33e6..320d5a913 100644
--- a/src/pipecat/services/cartesia/tts.py
+++ b/src/pipecat/services/cartesia/tts.py
@@ -26,7 +26,7 @@ from pipecat.frames.frames import (
     TTSAudioRawFrame,
     TTSStoppedFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, assert_given
 from pipecat.services.tts_service import TextAggregationMode, TTSService, WebsocketTTSService
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.text.skip_tags_aggregator import SkipTagsAggregator
@@ -427,7 +427,7 @@ class CartesiaTTSService(WebsocketTTSService):
         Returns:
             List of (word, start_time) tuples processed for the language.
         """
-        current_language = self._settings.language
+        current_language = assert_given(self._settings.language)
 
         # Check if this is a CJK language (if language is None, treat as non-CJK)
         if current_language and self._is_cjk_language(current_language):
@@ -472,10 +472,9 @@ class CartesiaTTSService(WebsocketTTSService):
         if self._settings.language:
             msg["language"] = self._settings.language
 
-        if self._settings.generation_config:
-            msg["generation_config"] = self._settings.generation_config.model_dump(
-                exclude_none=True
-            )
+        generation_config = assert_given(self._settings.generation_config)
+        if generation_config:
+            msg["generation_config"] = generation_config.model_dump(exclude_none=True)
 
         if self._settings.pronunciation_dict_id:
             msg["pronunciation_dict_id"] = self._settings.pronunciation_dict_id
@@ -904,10 +903,9 @@ class CartesiaHttpTTSService(TTSService):
             if self._settings.language:
                 payload["language"] = self._settings.language
 
-            if self._settings.generation_config:
-                payload["generation_config"] = self._settings.generation_config.model_dump(
-                    exclude_none=True
-                )
+            generation_config = assert_given(self._settings.generation_config)
+            if generation_config:
+                payload["generation_config"] = generation_config.model_dump(exclude_none=True)
 
             if self._settings.pronunciation_dict_id:
                 payload["pronunciation_dict_id"] = self._settings.pronunciation_dict_id
diff --git a/src/pipecat/services/deepgram/flux/base.py b/src/pipecat/services/deepgram/flux/base.py
index c54cdda38..1d8ad4794 100644
--- a/src/pipecat/services/deepgram/flux/base.py
+++ b/src/pipecat/services/deepgram/flux/base.py
@@ -25,7 +25,7 @@ from pipecat.frames.frames import (
     UserStartedSpeakingFrame,
     UserStoppedSpeakingFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven, assert_given
 from pipecat.services.stt_service import STTService
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.time import time_now_iso8601
@@ -647,7 +647,8 @@ class DeepgramFluxSTTBase(STTService):
         average_confidence = self._calculate_average_confidence(data)
         detected_language = self._primary_detected_language(data)
 
-        if not self._settings.min_confidence or average_confidence > self._settings.min_confidence:
+        min_confidence = assert_given(self._settings.min_confidence)
+        if not min_confidence or average_confidence > min_confidence:
             # EndOfTurn means Flux has determined the turn is complete,
             # so this TranscriptionFrame is always finalized
             await self.push_frame(
diff --git a/src/pipecat/services/elevenlabs/tts.py b/src/pipecat/services/elevenlabs/tts.py
index d0380f778..88254c0c3 100644
--- a/src/pipecat/services/elevenlabs/tts.py
+++ b/src/pipecat/services/elevenlabs/tts.py
@@ -39,7 +39,7 @@ from pipecat.frames.frames import (
     TTSStoppedFrame,
 )
 from pipecat.processors.frame_processor import FrameDirection
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, assert_given
 from pipecat.services.tts_service import (
     TextAggregationMode,
     TTSService,
@@ -1259,9 +1259,10 @@ class ElevenLabsHttpTTSService(TTSService):
         # Use the with-timestamps endpoint
         url = f"{self._base_url}/v1/text-to-speech/{self._settings.voice}/stream/with-timestamps"
 
+        model_id = assert_given(self._settings.model)
         payload: dict[str, str | dict[str, float | bool]] = {
             "text": text,
-            "model_id": self._settings.model,
+            "model_id": model_id,
         }
 
         # Include previous text as context if available
@@ -1276,11 +1277,12 @@ class ElevenLabsHttpTTSService(TTSService):
                 locator.model_dump() for locator in self._pronunciation_dictionary_locators
             ]
 
-        if self._settings.apply_text_normalization is not None:
-            payload["apply_text_normalization"] = self._settings.apply_text_normalization
+        apply_text_normalization = assert_given(self._settings.apply_text_normalization)
+        if apply_text_normalization is not None:
+            payload["apply_text_normalization"] = apply_text_normalization
 
-        language = self._settings.language
-        if self._settings.model in ELEVENLABS_MULTILINGUAL_MODELS and language:
+        language = assert_given(self._settings.language)
+        if model_id in ELEVENLABS_MULTILINGUAL_MODELS and language:
             payload["language_code"] = language
             logger.debug(f"Using language code: {language}")
         elif language:
@@ -1297,8 +1299,9 @@ class ElevenLabsHttpTTSService(TTSService):
         params = {
             "output_format": self._output_format,
         }
-        if self._settings.optimize_streaming_latency is not None:
-            params["optimize_streaming_latency"] = self._settings.optimize_streaming_latency
+        optimize_streaming_latency = assert_given(self._settings.optimize_streaming_latency)
+        if optimize_streaming_latency is not None:
+            params["optimize_streaming_latency"] = str(optimize_streaming_latency)
         if self._enable_logging is not None:
             params["enable_logging"] = str(self._enable_logging).lower()
 
diff --git a/src/pipecat/services/fish/tts.py b/src/pipecat/services/fish/tts.py
index 64639150f..83512da45 100644
--- a/src/pipecat/services/fish/tts.py
+++ b/src/pipecat/services/fish/tts.py
@@ -26,7 +26,7 @@ from pipecat.frames.frames import (
     TTSAudioRawFrame,
     TTSStoppedFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, assert_given
 from pipecat.services.tts_service import InterruptibleTTSService
 from pipecat.transcriptions.language import Language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -278,7 +278,9 @@ class FishAudioTTSService(InterruptibleTTSService):
 
             logger.debug("Connecting to Fish Audio")
             headers = {"Authorization": f"Bearer {self._api_key}"}
-            headers["model"] = self._settings.model
+            model = assert_given(self._settings.model)
+            if model is not None:
+                headers["model"] = model
             self._websocket = await websocket_connect(self._base_url, additional_headers=headers)
 
             # Send initial start message with ormsgpack
diff --git a/src/pipecat/services/gladia/stt.py b/src/pipecat/services/gladia/stt.py
index e0c6d69c7..ec3277943 100644
--- a/src/pipecat/services/gladia/stt.py
+++ b/src/pipecat/services/gladia/stt.py
@@ -39,7 +39,7 @@ from pipecat.services.gladia.config import (
     PreProcessingConfig,
     RealtimeProcessingConfig,
 )
-from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven, assert_given
 from pipecat.services.stt_latency import GLADIA_TTFS_P99
 from pipecat.services.stt_service import WebsocketSTTService
 from pipecat.transcriptions.language import Language, resolve_language
@@ -377,7 +377,7 @@ class GladiaSTTService(WebsocketSTTService):
         }
 
         # Add custom_metadata if provided
-        settings["custom_metadata"] = dict(s.custom_metadata or {})
+        settings["custom_metadata"] = dict(assert_given(s.custom_metadata) or {})
         settings["custom_metadata"]["pipecat"] = pipecat_version()
 
         # Add endpointing parameters if provided
@@ -389,20 +389,24 @@ class GladiaSTTService(WebsocketSTTService):
             )
 
         # Add language configuration
-        if s.language_config:
-            settings["language_config"] = s.language_config.model_dump(exclude_none=True)
+        language_config = assert_given(s.language_config)
+        if language_config:
+            settings["language_config"] = language_config.model_dump(exclude_none=True)
 
         # Add pre_processing configuration if provided
-        if s.pre_processing:
-            settings["pre_processing"] = s.pre_processing.model_dump(exclude_none=True)
+        pre_processing = assert_given(s.pre_processing)
+        if pre_processing:
+            settings["pre_processing"] = pre_processing.model_dump(exclude_none=True)
 
         # Add realtime_processing configuration if provided
-        if s.realtime_processing:
-            settings["realtime_processing"] = s.realtime_processing.model_dump(exclude_none=True)
+        realtime_processing = assert_given(s.realtime_processing)
+        if realtime_processing:
+            settings["realtime_processing"] = realtime_processing.model_dump(exclude_none=True)
 
         # Add messages_config if provided
-        if s.messages_config:
-            settings["messages_config"] = s.messages_config.model_dump(exclude_none=True)
+        messages_config = assert_given(s.messages_config)
+        if messages_config:
+            settings["messages_config"] = messages_config.model_dump(exclude_none=True)
 
         return settings
 
diff --git a/src/pipecat/services/google/gemini_live/llm.py b/src/pipecat/services/google/gemini_live/llm.py
index fdad6885b..b4ced161f 100644
--- a/src/pipecat/services/google/gemini_live/llm.py
+++ b/src/pipecat/services/google/gemini_live/llm.py
@@ -61,7 +61,7 @@ from pipecat.processors.frame_processor import FrameDirection
 from pipecat.services.google.frames import LLMSearchOrigin, LLMSearchResponseFrame, LLMSearchResult
 from pipecat.services.google.utils import update_google_client_http_options
 from pipecat.services.llm_service import FunctionCallFromLLM, LLMService
-from pipecat.services.settings import NOT_GIVEN, LLMSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, LLMSettings, _NotGiven, assert_given
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.string import match_endofsentence
 from pipecat.utils.time import time_now_iso8601
@@ -368,7 +368,7 @@ class GeminiLiveLLMService(LLMService):
     @property
     def _is_gemini_3(self) -> bool:
         """Check if the current model is a Gemini 3.x model."""
-        return "gemini-3" in (self._settings.model or "")
+        return "gemini-3" in (assert_given(self._settings.model) or "")
 
     def __init__(
         self,
@@ -482,9 +482,10 @@ class GeminiLiveLLMService(LLMService):
             default_settings.apply_update(settings)
 
         # Warn if user requested TEXT modality
-        if default_settings.modalities == GeminiModalities.TEXT:
+        default_modalities = assert_given(default_settings.modalities)
+        if default_modalities == GeminiModalities.TEXT:
             logger.warning(
-                f"Modality {default_settings.modalities.value!r} may not be supported by recent "
+                f"Modality {default_modalities.value!r} may not be supported by recent "
                 "Gemini Live models."
             )
 
@@ -524,13 +525,12 @@ class GeminiLiveLLMService(LLMService):
 
         self._sample_rate = 24000
 
-        self._language = self._settings.language
+        self._language = assert_given(self._settings.language)
         self._language_code = (
-            language_to_gemini_language(self._settings.language)
-            if self._settings.language
-            else "en-US"
+            language_to_gemini_language(self._language) if self._language else "en-US"
         )
-        self._vad_disabled = bool(self._settings.vad and self._settings.vad.disabled)
+        vad_settings = assert_given(self._settings.vad)
+        self._vad_disabled = bool(vad_settings and vad_settings.disabled)
 
         # Reconnection tracking
         self._consecutive_failures = 0
@@ -780,7 +780,7 @@ class GeminiLiveLLMService(LLMService):
             # chooses the init-provided value if there is one.
             adapter: GeminiLLMAdapter = self.get_llm_adapter()
             params = adapter.get_llm_invocation_params(
-                self._context, system_instruction=self._system_instruction_from_init
+                self._context, system_instruction=assert_given(self._system_instruction_from_init)
             )
             system_instruction = params["system_instruction"]
             tools = params["tools"]
@@ -812,7 +812,10 @@ class GeminiLiveLLMService(LLMService):
                         "No messages found in initial context; seeding with system instruction to trigger bot response."
                     )
                     self._context.add_message(
-                        {"role": "system", "content": self._system_instruction_from_init}
+                        {
+                            "role": "system",
+                            "content": assert_given(self._system_instruction_from_init),
+                        }
                     )
                 else:
                     logger.warning(
@@ -931,22 +934,25 @@ class GeminiLiveLLMService(LLMService):
             logger.info("Connecting to Gemini service")
         try:
             # Assemble basic configuration
+            modalities = assert_given(self._settings.modalities)
+            media_resolution = assert_given(self._settings.media_resolution)
+            language = assert_given(self._settings.language)
             config = LiveConnectConfig(
                 generation_config=GenerationConfig(
-                    frequency_penalty=self._settings.frequency_penalty,
-                    max_output_tokens=self._settings.max_tokens,
-                    presence_penalty=self._settings.presence_penalty,
-                    temperature=self._settings.temperature,
-                    top_k=self._settings.top_k,
-                    top_p=self._settings.top_p,
-                    response_modalities=[Modality(self._settings.modalities.value)],
+                    frequency_penalty=assert_given(self._settings.frequency_penalty),
+                    max_output_tokens=assert_given(self._settings.max_tokens),
+                    presence_penalty=assert_given(self._settings.presence_penalty),
+                    temperature=assert_given(self._settings.temperature),
+                    top_k=assert_given(self._settings.top_k),
+                    top_p=assert_given(self._settings.top_p),
+                    response_modalities=[Modality(modalities.value)],
                     speech_config=SpeechConfig(
                         voice_config=VoiceConfig(
-                            prebuilt_voice_config={"voice_name": self._settings.voice}
+                            prebuilt_voice_config={"voice_name": assert_given(self._settings.voice)}
                         ),
-                        language_code=self._settings.language,
+                        language_code=language,
                     ),
-                    media_resolution=MediaResolution(self._settings.media_resolution.value),
+                    media_resolution=MediaResolution(media_resolution.value),
                 ),
                 input_audio_transcription=AudioTranscriptionConfig(),
                 output_audio_transcription=AudioTranscriptionConfig(),
@@ -959,7 +965,7 @@ class GeminiLiveLLMService(LLMService):
                 config.history_config = history_config
 
             # Add context window compression to configuration, if enabled
-            cwc = self._settings.context_window_compression or {}
+            cwc = assert_given(self._settings.context_window_compression) or {}
             if cwc.get("enabled", False):
                 compression_config = ContextWindowCompressionConfig()
 
@@ -986,9 +992,9 @@ class GeminiLiveLLMService(LLMService):
                 config.proactivity = self._settings.proactivity
 
             # Add VAD configuration to configuration, if provided
-            if self._settings.vad:
+            vad_params = assert_given(self._settings.vad)
+            if vad_params:
                 vad_config = AutomaticActivityDetection()
-                vad_params = self._settings.vad
                 has_vad_settings = False
 
                 # Only add parameters that are explicitly set
@@ -1026,7 +1032,8 @@ class GeminiLiveLLMService(LLMService):
             tools = None
             if self._context:
                 params = adapter.get_llm_invocation_params(
-                    self._context, system_instruction=self._system_instruction_from_init
+                    self._context,
+                    system_instruction=assert_given(self._system_instruction_from_init),
                 )
                 system_instruction = params["system_instruction"]
                 tools = params["tools"]
@@ -1048,9 +1055,10 @@ class GeminiLiveLLMService(LLMService):
             await self.push_error(error_msg=f"Initialization error: {e}", exception=e)
 
     async def _connection_task_handler(self, config: LiveConnectConfig):
-        async with self._client.aio.live.connect(
-            model=self._settings.model, config=config
-        ) as session:
+        model = assert_given(self._settings.model)
+        if model is None:
+            raise ValueError("Gemini Live model must be specified")
+        async with self._client.aio.live.connect(model=model, config=config) as session:
             logger.info("Connected to Gemini service")
 
             # Mark connection start time
diff --git a/src/pipecat/services/google/image.py b/src/pipecat/services/google/image.py
index c8c33a68d..1ed8adc2c 100644
--- a/src/pipecat/services/google/image.py
+++ b/src/pipecat/services/google/image.py
@@ -27,7 +27,7 @@ from pydantic import BaseModel, Field
 from pipecat.frames.frames import ErrorFrame, Frame, URLImageRawFrame
 from pipecat.services.google.utils import update_google_client_http_options
 from pipecat.services.image_service import ImageGenService
-from pipecat.services.settings import NOT_GIVEN, ImageGenSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, ImageGenSettings, _NotGiven, assert_given
 
 try:
     from google import genai
@@ -157,8 +157,8 @@ class GoogleImageGenService(ImageGenService):
                 model=self._settings.model,
                 prompt=prompt,
                 config=types.GenerateImagesConfig(
-                    number_of_images=self._settings.number_of_images,
-                    negative_prompt=self._settings.negative_prompt,
+                    number_of_images=assert_given(self._settings.number_of_images),
+                    negative_prompt=assert_given(self._settings.negative_prompt),
                 ),
             )
             await self.stop_ttfb_metrics()
diff --git a/src/pipecat/services/google/llm.py b/src/pipecat/services/google/llm.py
index 556a4037a..e5e4fd5b6 100644
--- a/src/pipecat/services/google/llm.py
+++ b/src/pipecat/services/google/llm.py
@@ -43,6 +43,7 @@ from pipecat.services.settings import (
     NOT_GIVEN,
     LLMSettings,
     _NotGiven,
+    assert_given,
     is_given,
 )
 from pipecat.utils.tracing.service_decorators import traced_llm
@@ -356,10 +357,9 @@ class GoogleLLMService(LLMService):
         }
 
         # Add thinking parameters if configured
-        if self._settings.thinking:
-            generation_params["thinking_config"] = self._settings.thinking.model_dump(
-                exclude_unset=True
-            )
+        thinking = assert_given(self._settings.thinking)
+        if thinking:
+            generation_params["thinking_config"] = thinking.model_dump(exclude_unset=True)
 
         if self._settings.extra:
             generation_params.update(self._settings.extra)
@@ -368,8 +368,9 @@ class GoogleLLMService(LLMService):
 
     def _maybe_unset_thinking_budget(self, generation_params: dict[str, Any]):
         try:
+            model = assert_given(self._settings.model)
             # If we have an image model, we don't apply a thinking default.
-            if "image" in self._settings.model:
+            if model is None or "image" in model:
                 return
             # If thinking_config is already set, don't override it.
             if "thinking_config" in generation_params:
@@ -377,7 +378,6 @@ class GoogleLLMService(LLMService):
             # Apply model-aware low-latency thinking defaults.
             # Gemini 2.5 Flash: disable thinking via thinking_budget.
             # Gemini 3+ Flash: use minimal thinking via thinking_level.
-            model = self._settings.model
             if model.startswith("gemini-2.5-flash"):
                 generation_params["thinking_config"] = {"thinking_budget": 0}
             elif model.startswith("gemini-3") and "flash" in model:
@@ -388,7 +388,7 @@ class GoogleLLMService(LLMService):
     async def _stream_content(self, context: LLMContext) -> AsyncIterator[GenerateContentResponse]:
         adapter = self.get_llm_adapter()
         params: GeminiLLMInvocationParams = adapter.get_llm_invocation_params(
-            context, system_instruction=self._settings.system_instruction
+            context, system_instruction=assert_given(self._settings.system_instruction)
         )
 
         logger.debug(
diff --git a/src/pipecat/services/google/stt.py b/src/pipecat/services/google/stt.py
index 616627acc..b34056ee2 100644
--- a/src/pipecat/services/google/stt.py
+++ b/src/pipecat/services/google/stt.py
@@ -37,7 +37,7 @@ from pipecat.frames.frames import (
     StartFrame,
     TranscriptionFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven, assert_given
 from pipecat.services.stt_latency import GOOGLE_TTFS_P99
 from pipecat.services.stt_service import STTService
 from pipecat.transcriptions.language import Language, resolve_language
@@ -641,8 +641,9 @@ class GoogleSTTService(STTService):
         """
         if self._settings.languages:
             return [self.language_to_service_language(lang) for lang in self._settings.languages]
-        if self._settings.language_codes:
-            return list(self._settings.language_codes)
+        language_codes = assert_given(self._settings.language_codes)
+        if language_codes:
+            return list(language_codes)
         return ["en-US"]
 
     async def _reconnect_if_needed(self):
diff --git a/src/pipecat/services/google/tts.py b/src/pipecat/services/google/tts.py
index f9fe1a87d..b507fc26f 100644
--- a/src/pipecat/services/google/tts.py
+++ b/src/pipecat/services/google/tts.py
@@ -39,6 +39,7 @@ from pipecat.services.settings import (
     NOT_GIVEN,
     TTSSettings,
     _NotGiven,
+    assert_given,
     is_given,
 )
 from pipecat.services.tts_service import TTSService
@@ -815,8 +816,9 @@ class GoogleHttpTTSService(TTSService):
 
         try:
             # Check if the voice is a Chirp voice (including Chirp 3) or Journey voice
-            is_chirp_voice = "chirp" in self._settings.voice.lower()
-            is_journey_voice = "journey" in self._settings.voice.lower()
+            voice_name = assert_given(self._settings.voice)
+            is_chirp_voice = "chirp" in (voice_name or "").lower()
+            is_journey_voice = "journey" in (voice_name or "").lower()
 
             # Create synthesis input based on voice_id
             if is_chirp_voice or is_journey_voice:
@@ -1447,7 +1449,7 @@ class GeminiTTSService(GoogleBaseTTSService):
 
             # Use base class streaming logic with prompt support
             async for frame in self._stream_tts(
-                streaming_config, text, context_id, self._settings.prompt
+                streaming_config, text, context_id, assert_given(self._settings.prompt)
             ):
                 yield frame
 
diff --git a/src/pipecat/services/gradium/stt.py b/src/pipecat/services/gradium/stt.py
index 412f0a1b3..0b6a81cdd 100644
--- a/src/pipecat/services/gradium/stt.py
+++ b/src/pipecat/services/gradium/stt.py
@@ -31,7 +31,7 @@ from pipecat.frames.frames import (
     VADUserStoppedSpeakingFrame,
 )
 from pipecat.processors.frame_processor import FrameDirection
-from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven, assert_given
 from pipecat.services.stt_latency import GRADIUM_TTFS_P99
 from pipecat.services.stt_service import WebsocketSTTService
 from pipecat.transcriptions.language import Language, resolve_language
@@ -397,8 +397,9 @@ class GradiumSTTService(WebsocketSTTService):
             json_config = {}
             if self._json_config:
                 json_config = json.loads(self._json_config)
-            if self._settings.language:
-                gradium_language = language_to_gradium_language(self._settings.language)
+            language = assert_given(self._settings.language)
+            if language:
+                gradium_language = language_to_gradium_language(language)
                 if gradium_language:
                     json_config["language"] = gradium_language
             if self._settings.delay_in_frames:
@@ -482,7 +483,7 @@ class GradiumSTTService(WebsocketSTTService):
                 text=accumulated,
                 user_id=self._user_id,
                 timestamp=time_now_iso8601(),
-                language=self._settings.language,
+                language=assert_given(self._settings.language),
             )
         )
         await self.stop_processing_metrics()
@@ -514,12 +515,13 @@ class GradiumSTTService(WebsocketSTTService):
         text = " ".join(self._accumulated_text)
         self._accumulated_text.clear()
         logger.debug(f"Final transcription: [{text}]")
+        language = assert_given(self._settings.language)
         await self.push_frame(
             TranscriptionFrame(
                 text,
                 self._user_id,
                 time_now_iso8601(),
-                self._settings.language,
+                language,
             )
         )
-        await self._trace_transcription(text, is_final=True, language=self._settings.language)
+        await self._trace_transcription(text, is_final=True, language=language)
diff --git a/src/pipecat/services/groq/tts.py b/src/pipecat/services/groq/tts.py
index 49a4d7930..36e01ff8b 100644
--- a/src/pipecat/services/groq/tts.py
+++ b/src/pipecat/services/groq/tts.py
@@ -19,7 +19,7 @@ from pipecat.frames.frames import (
     Frame,
     TTSAudioRawFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, assert_given
 from pipecat.services.tts_service import TTSService
 from pipecat.transcriptions.language import Language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -173,13 +173,20 @@ class GroqTTSService(TTSService):
         logger.debug(f"{self}: Generating TTS [{text}]")
         measuring_ttfb = True
         try:
+            model = assert_given(self._settings.model)
+            voice = assert_given(self._settings.voice)
+            speed = assert_given(self._settings.speed)
+            if model is None:
+                raise ValueError("Groq TTS model must be specified")
+            if speed is None:
+                raise ValueError("Groq TTS speed must be specified")
             response = await self._client.audio.speech.create(
-                model=self._settings.model,
-                voice=self._settings.voice,
+                model=model,
+                voice=voice,
                 response_format=self._output_format,
                 # Note: as of 2026-02-25, only a speed of 1.0 is supported, but
                 # here we pass it for completeness and future-proofing
-                speed=self._settings.speed,
+                speed=speed,
                 input=text,
             )
 
diff --git a/src/pipecat/services/hume/tts.py b/src/pipecat/services/hume/tts.py
index ff82a9fc2..ac17efd48 100644
--- a/src/pipecat/services/hume/tts.py
+++ b/src/pipecat/services/hume/tts.py
@@ -26,7 +26,7 @@ from pipecat.frames.frames import (
     TTSStoppedFrame,
 )
 from pipecat.processors.frame_processor import FrameDirection
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, assert_given
 from pipecat.services.tts_service import TTSService
 from pipecat.utils.tracing.service_decorators import traced_tts
 
@@ -292,7 +292,7 @@ class HumeTTSService(TTSService):
         # Build the request payload
         utterance_kwargs: dict[str, Any] = {
             "text": text,
-            "voice": PostedUtteranceVoiceWithId(id=self._settings.voice),
+            "voice": PostedUtteranceVoiceWithId(id=assert_given(self._settings.voice)),
         }
         if self._settings.description is not None:
             utterance_kwargs["description"] = self._settings.description
diff --git a/src/pipecat/services/inworld/realtime/llm.py b/src/pipecat/services/inworld/realtime/llm.py
index 0c9ea623d..46b025006 100644
--- a/src/pipecat/services/inworld/realtime/llm.py
+++ b/src/pipecat/services/inworld/realtime/llm.py
@@ -55,6 +55,7 @@ from pipecat.services.settings import (
     NOT_GIVEN,
     LLMSettings,
     _NotGiven,
+    assert_given,
     is_given,
 )
 from pipecat.utils.time import time_now_iso8601
@@ -385,13 +386,14 @@ class InworldRealtimeLLMService(LLMService):
         Returns:
             Configured sample rate or None if not manually configured.
         """
-        if not self._settings.session_properties.audio:
+        session_properties = assert_given(self._settings.session_properties)
+        if not session_properties.audio:
             return None
 
         audio_config = (
-            self._settings.session_properties.audio.input
+            session_properties.audio.input
             if direction == "input"
-            else self._settings.session_properties.audio.output
+            else session_properties.audio.output
         )
 
         if audio_config and audio_config.format:
@@ -463,7 +465,7 @@ class InworldRealtimeLLMService(LLMService):
         """
         self._input_sample_rate = input_sample_rate
         self._output_sample_rate = output_sample_rate
-        props = self._settings.session_properties
+        props = assert_given(self._settings.session_properties)
         if not props.audio:
             props.audio = events.AudioConfiguration()
         if not props.audio.input:
@@ -661,12 +663,13 @@ class InworldRealtimeLLMService(LLMService):
 
     async def _send_session_update(self):
         """Update session settings on the server."""
-        settings = self._settings.session_properties
+        settings = assert_given(self._settings.session_properties)
         adapter: InworldRealtimeLLMAdapter = self.get_llm_adapter()
 
         if self._context:
             llm_invocation_params = adapter.get_llm_invocation_params(
-                self._context, system_instruction=self._settings.system_instruction
+                self._context,
+                system_instruction=assert_given(self._settings.system_instruction),
             )
 
             if llm_invocation_params["tools"]:
@@ -969,7 +972,8 @@ class InworldRealtimeLLMService(LLMService):
             )
 
             llm_invocation_params = adapter.get_llm_invocation_params(
-                self._context, system_instruction=self._settings.system_instruction
+                self._context,
+                system_instruction=assert_given(self._settings.system_instruction),
             )
             messages = llm_invocation_params["messages"]
 
@@ -986,7 +990,10 @@ class InworldRealtimeLLMService(LLMService):
         await self.start_processing_metrics()
         await self.start_ttfb_metrics()
 
-        modalities = self._settings.session_properties.output_modalities or ["text", "audio"]
+        modalities = assert_given(self._settings.session_properties).output_modalities or [
+            "text",
+            "audio",
+        ]
         await self.send_client_event(
             events.ResponseCreateEvent(response=events.ResponseProperties(modalities=modalities))
         )
diff --git a/src/pipecat/services/kokoro/tts.py b/src/pipecat/services/kokoro/tts.py
index 9e4dc1869..81c90487f 100644
--- a/src/pipecat/services/kokoro/tts.py
+++ b/src/pipecat/services/kokoro/tts.py
@@ -21,7 +21,7 @@ from pipecat.frames.frames import (
     Frame,
     TTSAudioRawFrame,
 )
-from pipecat.services.settings import TTSSettings
+from pipecat.services.settings import TTSSettings, assert_given
 from pipecat.services.tts_service import TTSService
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -215,9 +215,11 @@ class KokoroTTSService(TTSService):
         try:
             await self.start_tts_usage_metrics(text)
 
-            stream = self._kokoro.create_stream(
-                text, voice=self._settings.voice, lang=self._settings.language, speed=1.0
-            )
+            voice = assert_given(self._settings.voice)
+            lang = assert_given(self._settings.language)
+            if lang is None:
+                raise ValueError("Kokoro TTS language must be specified")
+            stream = self._kokoro.create_stream(text, voice=voice, lang=lang, speed=1.0)
 
             async for samples, sample_rate in stream:
                 await self.stop_ttfb_metrics()
diff --git a/src/pipecat/services/llm_service.py b/src/pipecat/services/llm_service.py
index 2a6e0668e..4ad17653c 100644
--- a/src/pipecat/services/llm_service.py
+++ b/src/pipecat/services/llm_service.py
@@ -53,7 +53,7 @@ from pipecat.processors.aggregators.llm_context import (
 )
 from pipecat.processors.frame_processor import FrameDirection
 from pipecat.services.ai_service import AIService
-from pipecat.services.settings import LLMSettings
+from pipecat.services.settings import LLMSettings, assert_given
 from pipecat.services.websocket_service import WebsocketService
 from pipecat.turns.user_turn_completion_mixin import UserTurnCompletionLLMServiceMixin
 from pipecat.utils.async_tool_cancellation import (
@@ -378,7 +378,9 @@ class LLMService(UserTurnCompletionLLMServiceMixin, AIService):
                 self._base_system_instruction = None
 
         if "user_turn_completion_config" in changed and self._filter_incomplete_user_turns:
-            self.set_user_turn_completion_config(self._settings.user_turn_completion_config)
+            self.set_user_turn_completion_config(
+                assert_given(self._settings.user_turn_completion_config)
+            )
             self._compose_system_instruction()
 
         if (
diff --git a/src/pipecat/services/mistral/stt.py b/src/pipecat/services/mistral/stt.py
index 9d8b965e5..85d218628 100644
--- a/src/pipecat/services/mistral/stt.py
+++ b/src/pipecat/services/mistral/stt.py
@@ -27,7 +27,7 @@ from pipecat.frames.frames import (
     VADUserStoppedSpeakingFrame,
 )
 from pipecat.processors.frame_processor import FrameDirection
-from pipecat.services.settings import STTSettings
+from pipecat.services.settings import STTSettings, assert_given
 from pipecat.services.stt_latency import MISTRAL_TTFS_P99
 from pipecat.services.stt_service import STTService
 from pipecat.utils.time import time_now_iso8601
@@ -214,8 +214,11 @@ class MistralSTTService(STTService):
                 sample_rate=self.sample_rate,
             )
 
+            model = assert_given(self._settings.model)
+            if model is None:
+                raise ValueError("Mistral STT model must be specified")
             self._connection = await self._client.audio.realtime.connect(
-                model=self._settings.model,
+                model=model,
                 audio_format=audio_format,
                 target_streaming_delay_ms=self._target_streaming_delay_ms,
             )
diff --git a/src/pipecat/services/mistral/tts.py b/src/pipecat/services/mistral/tts.py
index 6e660e6e2..8ece8facc 100644
--- a/src/pipecat/services/mistral/tts.py
+++ b/src/pipecat/services/mistral/tts.py
@@ -22,7 +22,7 @@ from pipecat.frames.frames import (
     Frame,
     TTSAudioRawFrame,
 )
-from pipecat.services.settings import TTSSettings
+from pipecat.services.settings import TTSSettings, assert_given
 from pipecat.services.tts_service import TTSService
 from pipecat.utils.tracing.service_decorators import traced_tts
 
@@ -137,8 +137,8 @@ class MistralTTSService(TTSService):
 
             async with await self._client.audio.speech.complete_async(
                 input=text,
-                model=self._settings.model,
-                voice_id=self._settings.voice,
+                model=assert_given(self._settings.model),
+                voice_id=assert_given(self._settings.voice),
                 response_format="pcm",
                 stream=True,
             ) as event_stream:
diff --git a/src/pipecat/services/moondream/vision.py b/src/pipecat/services/moondream/vision.py
index 70cbe89f5..01482df4b 100644
--- a/src/pipecat/services/moondream/vision.py
+++ b/src/pipecat/services/moondream/vision.py
@@ -25,7 +25,7 @@ from pipecat.frames.frames import (
     VisionFullResponseStartFrame,
     VisionTextFrame,
 )
-from pipecat.services.settings import VisionSettings
+from pipecat.services.settings import VisionSettings, assert_given
 from pipecat.services.vision_service import VisionService
 
 try:
@@ -127,8 +127,11 @@ class MoondreamService(VisionService):
 
         logger.debug("Loading Moondream model...")
 
+        model_path = assert_given(self._settings.model)
+        if model_path is None:
+            raise ValueError("Moondream model must be specified")
         self._model = AutoModelForCausalLM.from_pretrained(
-            self._settings.model,
+            model_path,
             trust_remote_code=True,
             revision=revision,
             device_map={"": device},
diff --git a/src/pipecat/services/nvidia/stt.py b/src/pipecat/services/nvidia/stt.py
index 0a281c8ef..49fb4573e 100644
--- a/src/pipecat/services/nvidia/stt.py
+++ b/src/pipecat/services/nvidia/stt.py
@@ -30,7 +30,7 @@ from pipecat.frames.frames import (
     StartFrame,
     TranscriptionFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven, assert_given
 from pipecat.services.stt_latency import NVIDIA_TTFS_P99
 from pipecat.services.stt_service import SegmentedSTTService, STTService
 from pipecat.transcriptions.language import Language, resolve_language
@@ -307,8 +307,11 @@ class NvidiaSTTService(STTService):
             interim_results=s.interim_results,
         )
 
-        if s.boosted_lm_words:
-            riva.client.add_word_boosting_to_config(config, s.boosted_lm_words, s.boosted_lm_score)
+        boosted_lm_words = assert_given(s.boosted_lm_words)
+        if boosted_lm_words:
+            riva.client.add_word_boosting_to_config(
+                config, boosted_lm_words, assert_given(s.boosted_lm_score)
+            )
 
         riva.client.add_endpoint_parameters_to_config(
             config,
@@ -323,9 +326,10 @@ class NvidiaSTTService(STTService):
         if self._custom_configuration:
             riva.client.add_custom_configuration_to_config(config, self._custom_configuration)
 
-        if s.speaker_diarization:
+        speaker_diarization = assert_given(s.speaker_diarization)
+        if speaker_diarization:
             riva.client.add_speaker_diarization_to_config(
-                config, s.speaker_diarization, s.diarization_max_speakers
+                config, speaker_diarization, assert_given(s.diarization_max_speakers)
             )
 
         return config
@@ -468,6 +472,7 @@ class NvidiaSTTService(STTService):
 
             transcript = result.alternatives[0].transcript
             if transcript and len(transcript) > 0:
+                language = assert_given(self._settings.language)
                 if result.is_final:
                     await self.stop_processing_metrics()
                     logger.debug(f"Transcription: [{transcript}]")
@@ -476,7 +481,7 @@ class NvidiaSTTService(STTService):
                             transcript,
                             self._user_id,
                             time_now_iso8601(),
-                            self._settings.language,
+                            language,
                             result=result,
                             finalized=True,
                         )
@@ -484,7 +489,7 @@ class NvidiaSTTService(STTService):
                     await self._handle_transcription(
                         transcript=transcript,
                         is_final=result.is_final,
-                        language=self._settings.language,
+                        language=language,
                     )
                 else:
                     await self.push_frame(
@@ -492,7 +497,7 @@ class NvidiaSTTService(STTService):
                             transcript,
                             self._user_id,
                             time_now_iso8601(),
-                            self._settings.language,
+                            language,
                             result=result,
                         )
                     )
@@ -689,7 +694,7 @@ class NvidiaSegmentedSTTService(SegmentedSTTService):
 
     def _get_language_code(self) -> str:
         """Get the current NVIDIA Nemotron Speech language code string."""
-        return self._settings.language or "en-US"
+        return assert_given(self._settings.language) or "en-US"
 
     def _create_recognition_config(self):
         """Create the NVIDIA Nemotron Speech ASR recognition configuration."""
@@ -705,8 +710,11 @@ class NvidiaSegmentedSTTService(SegmentedSTTService):
         )
 
         # Add word boosting if specified
-        if s.boosted_lm_words:
-            riva.client.add_word_boosting_to_config(config, s.boosted_lm_words, s.boosted_lm_score)
+        boosted_lm_words = assert_given(s.boosted_lm_words)
+        if boosted_lm_words:
+            riva.client.add_word_boosting_to_config(
+                config, boosted_lm_words, assert_given(s.boosted_lm_score)
+            )
 
         # Add any custom configuration
         if self._custom_configuration:
@@ -796,15 +804,16 @@ class NvidiaSegmentedSTTService(SegmentedSTTService):
                     text = alternatives[0].transcript.strip()
                     if text:
                         logger.debug(f"Transcription: [{text}]")
+                        language = assert_given(self._settings.language)
                         yield TranscriptionFrame(
                             text,
                             self._user_id,
                             time_now_iso8601(),
-                            self._settings.language,
+                            language,
                         )
                         transcription_found = True
 
-                        await self._handle_transcription(text, True, self._settings.language)
+                        await self._handle_transcription(text, True, language)
 
             if not transcription_found:
                 logger.debug(
diff --git a/src/pipecat/services/openai/image.py b/src/pipecat/services/openai/image.py
index eb3cd429d..45f21a7cb 100644
--- a/src/pipecat/services/openai/image.py
+++ b/src/pipecat/services/openai/image.py
@@ -26,7 +26,7 @@ from pipecat.frames.frames import (
     URLImageRawFrame,
 )
 from pipecat.services.image_service import ImageGenService
-from pipecat.services.settings import NOT_GIVEN, ImageGenSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, ImageGenSettings, _NotGiven, assert_given
 
 
 @dataclass
@@ -117,7 +117,10 @@ class OpenAIImageGenService(ImageGenService):
         logger.debug(f"Generating image from prompt: {prompt}")
 
         image = await self._client.images.generate(
-            prompt=prompt, model=self._settings.model, n=1, size=self._settings.image_size
+            prompt=prompt,
+            model=assert_given(self._settings.model),
+            n=1,
+            size=assert_given(self._settings.image_size),
         )
 
         image_url = image.data[0].url
diff --git a/src/pipecat/services/openai/realtime/llm.py b/src/pipecat/services/openai/realtime/llm.py
index c34345ae3..cf4f8943e 100644
--- a/src/pipecat/services/openai/realtime/llm.py
+++ b/src/pipecat/services/openai/realtime/llm.py
@@ -55,6 +55,7 @@ from pipecat.services.settings import (
     NOT_GIVEN,
     LLMSettings,
     _NotGiven,
+    assert_given,
     is_given,
 )
 from pipecat.transcriptions.language import Language
@@ -359,12 +360,18 @@ class OpenAIRealtimeLLMService(LLMService):
 
     def _is_modality_enabled(self, modality: str) -> bool:
         """Check if a specific modality is enabled, "text" or "audio"."""
-        modalities = self._settings.session_properties.output_modalities or ["audio", "text"]
+        modalities = assert_given(self._settings.session_properties).output_modalities or [
+            "audio",
+            "text",
+        ]
         return modality in modalities
 
     def _get_enabled_modalities(self) -> list[str]:
         """Get the list of enabled modalities."""
-        modalities = self._settings.session_properties.output_modalities or ["audio", "text"]
+        modalities = assert_given(self._settings.session_properties).output_modalities or [
+            "audio",
+            "text",
+        ]
         # API only supports single modality responses: either ["text"] or ["audio"]
         if "audio" in modalities:
             return ["audio"]
@@ -436,10 +443,11 @@ class OpenAIRealtimeLLMService(LLMService):
     async def _handle_interruption(self):
         # None and False are different. Check for False. None means we're using OpenAI's
         # built-in turn detection defaults.
+        session_properties = assert_given(self._settings.session_properties)
         turn_detection_disabled = (
-            self._settings.session_properties.audio
-            and self._settings.session_properties.audio.input
-            and self._settings.session_properties.audio.input.turn_detection is False
+            session_properties.audio
+            and session_properties.audio.input
+            and session_properties.audio.input.turn_detection is False
         )
         if turn_detection_disabled:
             await self.send_client_event(events.InputAudioBufferClearEvent())
@@ -458,10 +466,11 @@ class OpenAIRealtimeLLMService(LLMService):
     async def _handle_user_stopped_speaking(self, frame):
         # None and False are different. Check for False. None means we're using OpenAI's
         # built-in turn detection defaults.
+        session_properties = assert_given(self._settings.session_properties)
         turn_detection_disabled = (
-            self._settings.session_properties.audio
-            and self._settings.session_properties.audio.input
-            and self._settings.session_properties.audio.input.turn_detection is False
+            session_properties.audio
+            and session_properties.audio.input
+            and session_properties.audio.input.turn_detection is False
         )
         if turn_detection_disabled:
             await self.send_client_event(events.InputAudioBufferCommitEvent())
@@ -647,12 +656,13 @@ class OpenAIRealtimeLLMService(LLMService):
         return changed
 
     async def _send_session_update(self):
-        settings = self._settings.session_properties
+        settings = assert_given(self._settings.session_properties)
         adapter: OpenAIRealtimeLLMAdapter = self.get_llm_adapter()
 
         if self._context:
             llm_invocation_params = adapter.get_llm_invocation_params(
-                self._context, system_instruction=self._settings.system_instruction
+                self._context,
+                system_instruction=assert_given(self._settings.system_instruction),
             )
 
             # tools given in the context override the tools in the session properties
diff --git a/src/pipecat/services/openai/responses/llm.py b/src/pipecat/services/openai/responses/llm.py
index c7959f05a..adfdebd22 100644
--- a/src/pipecat/services/openai/responses/llm.py
+++ b/src/pipecat/services/openai/responses/llm.py
@@ -49,7 +49,7 @@ from pipecat.services.llm_service import (
     WebsocketReconnectedError,
 )
 from pipecat.services.settings import NOT_GIVEN as _NOT_GIVEN
-from pipecat.services.settings import LLMSettings, _NotGiven
+from pipecat.services.settings import LLMSettings, _NotGiven, assert_given
 from pipecat.utils.tracing.service_decorators import traced_llm
 
 try:
@@ -285,7 +285,9 @@ class _BaseOpenAIResponsesLLMService(LLMService):
             The LLM's response as a string, or None if no response is generated.
         """
         adapter: OpenAIResponsesLLMAdapter = self.get_llm_adapter()
-        effective_instruction = system_instruction or self._settings.system_instruction
+        effective_instruction = system_instruction or assert_given(
+            self._settings.system_instruction
+        )
         invocation_params = adapter.get_llm_invocation_params(
             context, system_instruction=effective_instruction
         )
@@ -742,7 +744,7 @@ class OpenAIResponsesLLMService(_BaseOpenAIResponsesLLMService, WebsocketLLMServ
         )
 
         invocation_params = adapter.get_llm_invocation_params(
-            context, system_instruction=self._settings.system_instruction
+            context, system_instruction=assert_given(self._settings.system_instruction)
         )
 
         full_input = invocation_params["input"]
@@ -982,7 +984,7 @@ class OpenAIResponsesHttpLLMService(_BaseOpenAIResponsesLLMService):
         )
 
         invocation_params = adapter.get_llm_invocation_params(
-            context, system_instruction=self._settings.system_instruction
+            context, system_instruction=assert_given(self._settings.system_instruction)
         )
 
         params = self._build_response_params(invocation_params)
diff --git a/src/pipecat/services/openai/stt.py b/src/pipecat/services/openai/stt.py
index f550d4395..b7dddf441 100644
--- a/src/pipecat/services/openai/stt.py
+++ b/src/pipecat/services/openai/stt.py
@@ -36,7 +36,7 @@ from pipecat.frames.frames import (
     VADUserStoppedSpeakingFrame,
 )
 from pipecat.processors.frame_processor import FrameDirection
-from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven, assert_given
 from pipecat.services.stt_latency import OPENAI_REALTIME_TTFS_P99, OPENAI_TTFS_P99
 from pipecat.services.stt_service import WebsocketSTTService
 from pipecat.services.whisper.base_stt import (
@@ -534,9 +534,8 @@ class OpenAIRealtimeSTTService(WebsocketSTTService):
         """Send ``session.update`` to configure the transcription session."""
         transcription: dict = {"model": self._settings.model}
 
-        language_code = (
-            self._language_to_code(self._settings.language) if self._settings.language else None
-        )
+        language = assert_given(self._settings.language)
+        language_code = self._language_to_code(language) if language else None
         if language_code:
             transcription["language"] = language_code
 
diff --git a/src/pipecat/services/openai/tts.py b/src/pipecat/services/openai/tts.py
index 6825d6968..66f027c8d 100644
--- a/src/pipecat/services/openai/tts.py
+++ b/src/pipecat/services/openai/tts.py
@@ -24,7 +24,7 @@ from pipecat.frames.frames import (
     StartFrame,
     TTSAudioRawFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, assert_given
 from pipecat.services.tts_service import TTSService
 from pipecat.utils.tracing.service_decorators import traced_tts
 
@@ -240,7 +240,7 @@ class OpenAITTSService(TTSService):
             create_params = {
                 "input": text,
                 "model": self._settings.model,
-                "voice": VALID_VOICES[self._settings.voice],
+                "voice": VALID_VOICES[assert_given(self._settings.voice)],
                 "response_format": "pcm",
             }
 
diff --git a/src/pipecat/services/openrouter/llm.py b/src/pipecat/services/openrouter/llm.py
index d257e4cc9..624dd3141 100644
--- a/src/pipecat/services/openrouter/llm.py
+++ b/src/pipecat/services/openrouter/llm.py
@@ -17,6 +17,7 @@ from loguru import logger
 
 from pipecat.services.openai.base_llm import BaseOpenAILLMService
 from pipecat.services.openai.llm import OpenAILLMService
+from pipecat.services.settings import assert_given
 
 
 @dataclass
@@ -105,7 +106,8 @@ class OpenRouterLLMService(OpenAILLMService):
             Transformed parameters ready for the API call.
         """
         params = super().build_chat_completion_params(params_from_context)
-        if "gemini" in self._settings.model.lower():
+        model = assert_given(self._settings.model)
+        if model is not None and "gemini" in model.lower():
             messages = params.get("messages", [])
             if not messages:
                 return params
diff --git a/src/pipecat/services/piper/tts.py b/src/pipecat/services/piper/tts.py
index ab055c76d..5cc725c2c 100644
--- a/src/pipecat/services/piper/tts.py
+++ b/src/pipecat/services/piper/tts.py
@@ -20,7 +20,7 @@ from pipecat.frames.frames import (
     Frame,
     TTSStoppedFrame,
 )
-from pipecat.services.settings import TTSSettings
+from pipecat.services.settings import TTSSettings, assert_given
 from pipecat.services.tts_service import TTSService
 from pipecat.utils.tracing.service_decorators import traced_tts
 
@@ -100,7 +100,7 @@ class PiperTTSService(TTSService):
 
         download_dir = download_dir or Path.cwd()
 
-        _voice = self._settings.voice
+        _voice = assert_given(self._settings.voice)
         model_file = f"{_voice}.onnx"
         model_path_resolved = Path(download_dir) / model_file
 
diff --git a/src/pipecat/services/sarvam/stt.py b/src/pipecat/services/sarvam/stt.py
index f41ec0faf..99b6a0bb3 100644
--- a/src/pipecat/services/sarvam/stt.py
+++ b/src/pipecat/services/sarvam/stt.py
@@ -37,6 +37,7 @@ from pipecat.services.settings import (
     NOT_GIVEN,
     STTSettings,
     _NotGiven,
+    assert_given,
     is_given,
 )
 from pipecat.services.stt_latency import SARVAM_TTFS_P99
@@ -319,8 +320,8 @@ class SarvamSTTService(STTService):
             default_settings.apply_update(settings)
 
         # Resolve model config and validate (after all overrides)
-        resolved_model = default_settings.model
-        if resolved_model not in MODEL_CONFIGS:
+        resolved_model = assert_given(default_settings.model)
+        if resolved_model is None or resolved_model not in MODEL_CONFIGS:
             allowed = ", ".join(sorted(MODEL_CONFIGS.keys()))
             raise ValueError(f"Unsupported model '{resolved_model}'. Allowed values: {allowed}.")
 
@@ -407,8 +408,9 @@ class SarvamSTTService(STTService):
 
     def _get_language_string(self) -> str | None:
         """Resolve the current language setting to a Sarvam language code string."""
-        if self._settings.language:
-            return language_to_sarvam_language(self._settings.language)
+        language = assert_given(self._settings.language)
+        if language:
+            return language_to_sarvam_language(language)
         return self._config.default_language
 
     def can_generate_metrics(self) -> bool:
diff --git a/src/pipecat/services/sarvam/tts.py b/src/pipecat/services/sarvam/tts.py
index fd40dbcee..1ab69ef15 100644
--- a/src/pipecat/services/sarvam/tts.py
+++ b/src/pipecat/services/sarvam/tts.py
@@ -59,7 +59,7 @@ from pipecat.frames.frames import (
     TTSStoppedFrame,
 )
 from pipecat.services.sarvam._sdk import sdk_headers
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, is_given
+from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, assert_given, is_given
 from pipecat.services.tts_service import InterruptibleTTSService, TextAggregationMode, TTSService
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -489,8 +489,8 @@ class SarvamHttpTTSService(TTSService):
             default_settings.apply_update(settings)
 
         # Get model configuration (validates model exists)
-        resolved_model = default_settings.model
-        if resolved_model not in TTS_MODEL_CONFIGS:
+        resolved_model = assert_given(default_settings.model)
+        if resolved_model is None or resolved_model not in TTS_MODEL_CONFIGS:
             allowed = ", ".join(sorted(TTS_MODEL_CONFIGS.keys()))
             raise ValueError(f"Unsupported model '{resolved_model}'. Allowed values: {allowed}.")
 
@@ -505,7 +505,7 @@ class SarvamHttpTTSService(TTSService):
             default_settings.voice = self._config.default_speaker
 
         # Validate and clamp pace to model's valid range
-        pace = default_settings.pace
+        pace = assert_given(default_settings.pace)
         pace_min, pace_max = self._config.pace_range
         if pace is not None and (pace < pace_min or pace > pace_max):
             logger.warning(f"Pace {pace} is outside model range ({pace_min}-{pace_max}). Clamping.")
@@ -907,8 +907,8 @@ class SarvamTTSService(InterruptibleTTSService):
             default_settings.apply_update(settings)
 
         # Get model configuration (validates model exists)
-        resolved_model = default_settings.model
-        if resolved_model not in TTS_MODEL_CONFIGS:
+        resolved_model = assert_given(default_settings.model)
+        if resolved_model is None or resolved_model not in TTS_MODEL_CONFIGS:
             allowed = ", ".join(sorted(TTS_MODEL_CONFIGS.keys()))
             raise ValueError(f"Unsupported model '{resolved_model}'. Allowed values: {allowed}.")
 
@@ -923,7 +923,7 @@ class SarvamTTSService(InterruptibleTTSService):
             default_settings.voice = self._config.default_speaker
 
         # Validate and clamp pace to model's valid range
-        pace = default_settings.pace
+        pace = assert_given(default_settings.pace)
         pace_min, pace_max = self._config.pace_range
         if pace is not None and (pace < pace_min or pace > pace_max):
             logger.warning(f"Pace {pace} is outside model range ({pace_min}-{pace_max}). Clamping.")
diff --git a/src/pipecat/services/soniox/stt.py b/src/pipecat/services/soniox/stt.py
index 95418011c..1732b3f91 100644
--- a/src/pipecat/services/soniox/stt.py
+++ b/src/pipecat/services/soniox/stt.py
@@ -25,7 +25,7 @@ from pipecat.frames.frames import (
     VADUserStoppedSpeakingFrame,
 )
 from pipecat.processors.frame_processor import FrameDirection
-from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven, assert_given
 from pipecat.services.stt_latency import SONIOX_TTFS_P99
 from pipecat.services.stt_service import WebsocketSTTService
 from pipecat.transcriptions.language import Language, resolve_language
@@ -504,7 +504,7 @@ class SonioxSTTService(WebsocketSTTService):
                 "num_channels": self._num_channels,
                 "enable_endpoint_detection": enable_endpoint_detection,
                 "sample_rate": self.sample_rate,
-                "language_hints": _prepare_language_hints(s.language_hints),
+                "language_hints": _prepare_language_hints(assert_given(s.language_hints)),
                 "language_hints_strict": s.language_hints_strict,
                 "context": context,
                 "enable_speaker_diarization": s.enable_speaker_diarization,
diff --git a/src/pipecat/services/speechmatics/stt.py b/src/pipecat/services/speechmatics/stt.py
index 1126fef37..2597724bb 100644
--- a/src/pipecat/services/speechmatics/stt.py
+++ b/src/pipecat/services/speechmatics/stt.py
@@ -34,7 +34,7 @@ from pipecat.frames.frames import (
     VADUserStoppedSpeakingFrame,
 )
 from pipecat.processors.frame_processor import FrameDirection
-from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven, assert_given
 from pipecat.services.stt_latency import SPEECHMATICS_TTFS_P99
 from pipecat.services.stt_service import STTService
 from pipecat.transcriptions.language import Language, resolve_language
@@ -719,22 +719,26 @@ class SpeechmaticsSTTService(STTService):
         s = settings
 
         # Preset from turn detection mode
-        config = VoiceAgentConfigPreset.load(s.turn_detection_mode.value)
+        turn_detection_mode = assert_given(s.turn_detection_mode)
+        config = VoiceAgentConfigPreset.load(turn_detection_mode.value)
 
         # Audio encoding (init-only, stored as instance attribute)
         config.audio_encoding = self._audio_encoding
 
         # Language + domain
-        language = s.language
+        language = assert_given(s.language)
         config.language = self._language_to_speechmatics_language(language)
         config.domain = s.domain if s.domain is not None else None
         config.output_locale = self._locale_to_speechmatics_locale(config.language, language)
 
         # Speaker config
+        focus_speakers = assert_given(s.focus_speakers)
+        ignore_speakers = assert_given(s.ignore_speakers)
+        focus_mode = assert_given(s.focus_mode)
         config.speaker_config = SpeakerFocusConfig(
-            focus_speakers=s.focus_speakers if s.focus_speakers is not None else [],
-            ignore_speakers=s.ignore_speakers if s.ignore_speakers is not None else [],
-            focus_mode=s.focus_mode if s.focus_mode is not None else SpeakerFocusMode.RETAIN,
+            focus_speakers=focus_speakers if focus_speakers is not None else [],
+            ignore_speakers=ignore_speakers if ignore_speakers is not None else [],
+            focus_mode=focus_mode if focus_mode is not None else SpeakerFocusMode.RETAIN,
         )
         config.known_speakers = s.known_speakers if s.known_speakers is not None else []
 
@@ -766,7 +770,8 @@ class SpeechmaticsSTTService(STTService):
                     setattr(config, key, value)
 
         # Enable sentences
-        split = s.split_sentences if s.split_sentences is not None else False
+        split_sentences = assert_given(s.split_sentences)
+        split = split_sentences if split_sentences is not None else False
         config.speech_segment_config = SpeechSegmentConfig(emit_sentences=split or False)
 
         return config
@@ -962,11 +967,9 @@ class SpeechmaticsSTTService(STTService):
         # Create frame from segment
         def attr_from_segment(segment: dict[str, Any]) -> dict[str, Any]:
             # Formats the output text based on the speaker and defined formats from the config.
-            text = (
-                self._settings.speaker_active_format
-                if segment.get("is_active", True)
-                else self._settings.speaker_passive_format
-            ).format(
+            active_format = assert_given(self._settings.speaker_active_format)
+            passive_format = assert_given(self._settings.speaker_passive_format)
+            text = (active_format if segment.get("is_active", True) else passive_format).format(
                 **{
                     "speaker_id": segment.get("speaker_id", "UU"),
                     "text": segment.get("text", ""),
diff --git a/src/pipecat/services/speechmatics/tts.py b/src/pipecat/services/speechmatics/tts.py
index 69db9e2c3..a4f99d03f 100644
--- a/src/pipecat/services/speechmatics/tts.py
+++ b/src/pipecat/services/speechmatics/tts.py
@@ -20,7 +20,7 @@ from pipecat.frames.frames import (
     Frame,
     TTSAudioRawFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, assert_given
 from pipecat.services.tts_service import TTSService
 from pipecat.utils.network import exponential_backoff_time
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -183,7 +183,9 @@ class SpeechmaticsTTSService(TTSService):
         }
 
         # Complete HTTP URL
-        url = _get_endpoint_url(self._base_url, self._settings.voice, self.sample_rate)
+        url = _get_endpoint_url(
+            self._base_url, assert_given(self._settings.voice), self.sample_rate
+        )
 
         try:
             # Track attempt
@@ -208,7 +210,8 @@ class SpeechmaticsTTSService(TTSService):
                             attempt += 1
 
                             # Check if we've exceeded the maximum number of attempts
-                            if attempt >= self._settings.max_retries:
+                            max_retries = assert_given(self._settings.max_retries)
+                            if max_retries is not None and attempt >= max_retries:
                                 raise ValueError()
 
                             # Report error frame
diff --git a/src/pipecat/services/ultravox/llm.py b/src/pipecat/services/ultravox/llm.py
index 935562dc1..c1cd8d750 100644
--- a/src/pipecat/services/ultravox/llm.py
+++ b/src/pipecat/services/ultravox/llm.py
@@ -48,7 +48,7 @@ from pipecat.frames.frames import (
 from pipecat.processors.aggregators.llm_context import LLMContext
 from pipecat.processors.frame_processor import FrameDirection
 from pipecat.services.llm_service import FunctionCallFromLLM, LLMService
-from pipecat.services.settings import NOT_GIVEN, LLMSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, LLMSettings, _NotGiven, assert_given
 from pipecat.utils.time import time_now_iso8601
 
 try:
@@ -377,7 +377,7 @@ class UltravoxRealtimeLLMService(LLMService):
     async def _update_settings(self, delta: Settings):
         changed = await super()._update_settings(delta)
         if "output_medium" in changed:
-            await self._update_output_medium(self._settings.output_medium)
+            await self._update_output_medium(assert_given(self._settings.output_medium))
         self._warn_unhandled_updated_settings(changed.keys() - {"output_medium"})
         return changed
 
diff --git a/src/pipecat/services/whisper/stt.py b/src/pipecat/services/whisper/stt.py
index 7d92009d1..47f896056 100644
--- a/src/pipecat/services/whisper/stt.py
+++ b/src/pipecat/services/whisper/stt.py
@@ -21,7 +21,7 @@ from loguru import logger
 from typing_extensions import override
 
 from pipecat.frames.frames import ErrorFrame, Frame, TranscriptionFrame
-from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven
+from pipecat.services.settings import NOT_GIVEN, STTSettings, _NotGiven, assert_given
 from pipecat.services.stt_service import SegmentedSTTService
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.time import time_now_iso8601
@@ -315,8 +315,11 @@ class WhisperSTTService(SegmentedSTTService):
             from faster_whisper import WhisperModel
 
             logger.debug("Loading Whisper model...")
+            model_name = assert_given(self._settings.model)
+            if model_name is None:
+                raise ValueError("Whisper model must be specified")
             self._model = WhisperModel(
-                self._settings.model, device=self._device, compute_type=self._compute_type
+                model_name, device=self._device, compute_type=self._compute_type
             )
             logger.debug("Loaded Whisper model")
         except ModuleNotFoundError as e:
@@ -354,24 +357,29 @@ class WhisperSTTService(SegmentedSTTService):
         # Divide by 32768 because we have signed 16-bit data.
         audio_float = np.frombuffer(audio, dtype=np.int16).astype(np.float32) / 32768.0
 
+        language = assert_given(self._settings.language)
         segments, _ = await asyncio.to_thread(
-            self._model.transcribe, audio_float, language=self._settings.language
+            self._model.transcribe, audio_float, language=language
         )
         text: str = ""
+        no_speech_prob_threshold = assert_given(self._settings.no_speech_prob)
         for segment in segments:
-            if segment.no_speech_prob < self._settings.no_speech_prob:
+            if (
+                no_speech_prob_threshold is not None
+                and segment.no_speech_prob < no_speech_prob_threshold
+            ):
                 text += f"{segment.text} "
 
         await self.stop_processing_metrics()
 
         if text:
-            await self._handle_transcription(text, True, self._settings.language)
+            await self._handle_transcription(text, True, language)
             logger.debug(f"Transcription: [{text}]")
             yield TranscriptionFrame(
                 text,
                 self._user_id,
                 time_now_iso8601(),
-                self._settings.language,
+                language,
             )
 
 
@@ -494,20 +502,29 @@ class WhisperSTTServiceMLX(WhisperSTTService):
             # Divide by 32768 because we have signed 16-bit data.
             audio_float = np.frombuffer(audio, dtype=np.int16).astype(np.float32) / 32768.0
 
+            model_path = assert_given(self._settings.model)
+            if model_path is None:
+                raise ValueError("Whisper model must be specified")
+            temperature = assert_given(self._settings.temperature)
+            language = assert_given(self._settings.language)
             chunk = await asyncio.to_thread(
                 mlx_whisper.transcribe,
                 audio_float,
-                path_or_hf_repo=self._settings.model,
-                temperature=self._settings.temperature,
-                language=self._settings.language,
+                path_or_hf_repo=model_path,
+                temperature=temperature,
+                language=language,
             )
             text: str = ""
+            no_speech_prob_threshold = assert_given(self._settings.no_speech_prob)
             for segment in chunk.get("segments", []):
                 # Drop likely hallucinations
                 if segment.get("compression_ratio", None) == 0.5555555555555556:
                     continue
 
-                if segment.get("no_speech_prob", 0.0) < self._settings.no_speech_prob:
+                if (
+                    no_speech_prob_threshold is not None
+                    and segment.get("no_speech_prob", 0.0) < no_speech_prob_threshold
+                ):
                     text += f"{segment.get('text', '')} "
 
             if len(text.strip()) == 0:
@@ -516,13 +533,13 @@ class WhisperSTTServiceMLX(WhisperSTTService):
             await self.stop_processing_metrics()
 
             if text:
-                await self._handle_transcription(text, True, self._settings.language)
+                await self._handle_transcription(text, True, language)
                 logger.debug(f"Transcription: [{text}]")
                 yield TranscriptionFrame(
                     text,
                     self._user_id,
                     time_now_iso8601(),
-                    self._settings.language,
+                    language,
                 )
 
         except Exception as e:
diff --git a/src/pipecat/services/xai/realtime/llm.py b/src/pipecat/services/xai/realtime/llm.py
index 3b2620a1f..448b5e339 100644
--- a/src/pipecat/services/xai/realtime/llm.py
+++ b/src/pipecat/services/xai/realtime/llm.py
@@ -53,6 +53,7 @@ from pipecat.services.settings import (
     NOT_GIVEN,
     LLMSettings,
     _NotGiven,
+    assert_given,
     is_given,
 )
 from pipecat.utils.time import time_now_iso8601
@@ -319,13 +320,14 @@ class GrokRealtimeLLMService(LLMService):
             Configured sample rate or None if not manually configured.
             For PCMU/PCMA formats, returns 8000 Hz (G.711 standard).
         """
-        if not self._settings.session_properties.audio:
+        session_properties = assert_given(self._settings.session_properties)
+        if not session_properties.audio:
             return None
 
         audio_config = (
-            self._settings.session_properties.audio.input
+            session_properties.audio.input
             if direction == "input"
-            else self._settings.session_properties.audio.output
+            else session_properties.audio.output
         )
 
         if audio_config and audio_config.format:
@@ -355,8 +357,9 @@ class GrokRealtimeLLMService(LLMService):
 
     def _is_turn_detection_enabled(self) -> bool:
         """Check if server-side VAD is enabled."""
-        if self._settings.session_properties.turn_detection:
-            return self._settings.session_properties.turn_detection.type == "server_vad"
+        session_properties = assert_given(self._settings.session_properties)
+        if session_properties.turn_detection:
+            return session_properties.turn_detection.type == "server_vad"
         return False
 
     async def _handle_interruption(self):
@@ -423,7 +426,7 @@ class GrokRealtimeLLMService(LLMService):
             input_sample_rate: Sample rate for audio input (Hz).
             output_sample_rate: Sample rate for audio output (Hz).
         """
-        props = self._settings.session_properties
+        props = assert_given(self._settings.session_properties)
         if not props.audio:
             props.audio = events.AudioConfiguration()
         if not props.audio.input:
@@ -592,12 +595,13 @@ class GrokRealtimeLLMService(LLMService):
 
     async def _send_session_update(self):
         """Update session settings on the server."""
-        settings = self._settings.session_properties
+        settings = assert_given(self._settings.session_properties)
         adapter: GrokRealtimeLLMAdapter = self.get_llm_adapter()
 
         if self._context:
             llm_invocation_params = adapter.get_llm_invocation_params(
-                self._context, system_instruction=self._settings.system_instruction
+                self._context,
+                system_instruction=assert_given(self._settings.system_instruction),
             )
 
             if llm_invocation_params["tools"]:
diff --git a/src/pipecat/services/xtts/tts.py b/src/pipecat/services/xtts/tts.py
index c39d79b0b..f9caa3819 100644
--- a/src/pipecat/services/xtts/tts.py
+++ b/src/pipecat/services/xtts/tts.py
@@ -24,7 +24,7 @@ from pipecat.frames.frames import (
     StartFrame,
     TTSAudioRawFrame,
 )
-from pipecat.services.settings import TTSSettings
+from pipecat.services.settings import TTSSettings, assert_given
 from pipecat.services.tts_service import TTSService
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -211,7 +211,7 @@ class XTTSService(TTSService):
             logger.error(f"{self} no studio speakers available")
             return
 
-        embeddings = self._studio_speakers[self._settings.voice]
+        embeddings = self._studio_speakers[assert_given(self._settings.voice)]
 
         url = self._base_url + "/tts_stream"