usingvarclient=newGeminiClient(apiKey);try{// Gemini 3.1 Flash TTS supports 200+ audio tags for controlling vocal style,// pacing, and delivery. Tags are written inline as bracketed directives;// the GeminiAudioTags helper exposes constants for the commonly used ones.vartext=$"{GeminiAudioTags.Cheerful} Hello! "+$"{GeminiAudioTags.Excited} This is Gemini 3.1 Flash TTS. "+$"{GeminiAudioTags.Calm} It sounds great.";varresult=awaitclient.SpeakAsync(text:text,voiceName:GeminiVoices.Puck,modelId:"gemini-3.1-flash-tts-preview");}catch(ApiExceptionex)when(IsTransientAvailabilityIssue(ex)){AssertTransientAvailability(ex);}catch(ApiExceptionex)when(ex.StatusCodeisSystem.Net.HttpStatusCode.BadRequest&&ex.Message.Contains("only be used for TTS")){}