Fix: Cartesia's spelling feature adds whole word to context

CHANGELOG.md

@@ -66,6 +66,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Updated `daily-python` to 0.17.0 to fix an issue that was preventing to run on
   older platforms.
 
+- Fixed an issue where `CartesiaTTSService`'s spell feature would result in
+  the spelled word in the context appearing as "F,O,O,B,A,R" instead of
+  "FOOBAR".
+
 - Fixed an issue in the Azure TTS services where the language was being set
   incorrectly.
 

src/pipecat/services/cartesia/tts.py

@@ -166,6 +166,7 @@ class CartesiaTTSService(AudioContextWordTTSService):
             "output_format": self._settings["output_format"],
             "language": self._settings["language"],
             "add_timestamps": add_timestamps,
+            "use_original_timestamps": True,
         }
         return json.dumps(msg)