Address review feedback

- Fall back to Language.EN in _primary_detected_language when model is
  flux-general-en, preserving prior behavior on the default model.
- Standardize example on DeepgramFluxSTTService.Settings and drop the
  now-redundant DeepgramFluxSTTSettings import.
- Narrow the changed-behavior changelog to reflect that flux-general-en
  frames still carry Language.EN.

changelog/4326.changed.md

@@ -1 +1 @@
-- `TranscriptionFrame.language` and `InterimTranscriptionFrame.language` emitted by `DeepgramFluxSTTService` now reflect the language Deepgram detected for each turn (read from the `languages` field on Flux's `TurnInfo` event) instead of a statically configured value. On `flux-general-multi` this means per-turn accuracy for downstream consumers (e.g. TTS voice selection). On `flux-general-en` the field is absent in Flux responses, so emitted frames now carry `language=None` instead of the previously hardcoded `Language.EN`.
+- `TranscriptionFrame.language` and `InterimTranscriptionFrame.language` emitted by `DeepgramFluxSTTService` now reflect the language Deepgram detected for each turn (read from the `languages` field on Flux's `TurnInfo` event). On `flux-general-multi` this gives per-turn accuracy for downstream consumers (e.g. TTS voice selection). `flux-general-en` continues to emit `Language.EN`.

examples/update-settings/stt/stt-deepgram-flux.py

@@ -23,7 +23,6 @@ from pipecat.processors.aggregators.llm_response_universal import (
 from pipecat.runner.types import RunnerArguments
 from pipecat.runner.utils import create_transport
 from pipecat.services.cartesia.tts import CartesiaTTSService
-from pipecat.services.deepgram.flux.base import DeepgramFluxSTTSettings
 from pipecat.services.deepgram.flux.stt import DeepgramFluxSTTService
 from pipecat.services.openai.llm import OpenAILLMService
 from pipecat.transcriptions.language import Language
@@ -118,7 +117,7 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
         logger.info("Updating Deepgram Flux STT settings: eot_threshold, keyterm")
         await task.queue_frame(
             STTUpdateSettingsFrame(
-                delta=DeepgramFluxSTTSettings(
+                delta=DeepgramFluxSTTService.Settings(
                     eot_threshold=0.8,
                     keyterm=["Pipecat", "Deepgram"],
                 )
@@ -130,7 +129,9 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
         await asyncio.sleep(10)
         logger.info("Updating Deepgram Flux STT settings: language_hints=[es]")
         await task.queue_frame(
-            STTUpdateSettingsFrame(delta=DeepgramFluxSTTSettings(language_hints=[Language.ES]))
+            STTUpdateSettingsFrame(
+                delta=DeepgramFluxSTTService.Settings(language_hints=[Language.ES])
+            )
         )
 
     @transport.event_handler("on_client_disconnected")

src/pipecat/services/deepgram/flux/base.py

@@ -611,12 +611,16 @@ class DeepgramFluxSTTBase(STTService):
     def _primary_detected_language(self, data: dict[str, Any]) -> Language | None:
         """Extract the primary detected language from a TurnInfo payload.
 
-        Only populated by ``flux-general-multi``; returns ``None`` otherwise.
+        On ``flux-general-multi`` the language is read from TurnInfo's
+        ``languages`` field. On ``flux-general-en`` the field is absent, so we
+        fall back to ``Language.EN`` to match the model's fixed language.
         """
         codes = data.get("languages") or []
-        if not codes:
-            return None
-        return _code_to_pipecat_language(codes[0])
+        if codes:
+            return _code_to_pipecat_language(codes[0])
+        if self._settings.model == "flux-general-en":
+            return Language.EN
+        return None
 
     async def _handle_end_of_turn(self, transcript: str, data: dict[str, Any]):
         """Handle EndOfTurn events from Deepgram Flux.