Settings
The Settings tab is where you configure your agent's personality, voice, language, and basic behavior.
For technical settings like turn detection, DTMF keypress collection, and logging levels, see Advanced settings.
Agent Name
A descriptive name for internal use in Studio. Customers do not see this name.
Voice Selection
Stellar offers multiple voices, each with distinct characteristics. All voices support over 50 languages and can be tuned to speak in regional dialects or accents. Some voices are warm and expressive, others are more neutral and professional — choose the one that matches your brand's tone of voice.
Available voices: Alloy, Ash, Ballad, Coral, Echo, Sage, Shimmer, Verse, Marin, Cedar
Experiment with different voices in the Playground before committing to one. Voice characteristics can vary between languages.
Personality / System Prompt
The personality prompt is the most important setting for your agent. It defines how your agent behaves, what it should and shouldn't do, and how it responds to customers. It works together with state-level instructions in the Dialogue Builder — the personality applies globally, while each state can add context-specific behavior.
Example personality prompt
You are a friendly customer support agent for TechCo, a software company.
Your responsibilities:
- Answer questions about our products, pricing, and features
- Help customers troubleshoot common technical issues
- Guide customers through account setup and basic configuration
- Collect customer information for issues that require technical support
Guidelines:
- Be warm, patient, and professional at all times
- Listen carefully and ask clarifying questions when needed
- Keep responses concise—aim for 2-3 sentences unless more detail is requested
- Admit when you don't know something rather than guessing
- Offer to transfer to a human agent for complex technical issues
What you should NOT do:
- Make promises about features or timelines
- Offer discounts or change pricing without approval
- Attempt to troubleshoot advanced technical issues
- Share information about unreleased products
Avoid overly long prompts. Clear, specific bullet points are more effective than long paragraphs. Make sure instructions don't conflict with each other — conflicting instructions degrade performance.
Model-specific prompting
How you phrase your prompt matters as much as what it says, and the most effective techniques depend on the AI model your agent runs on. OpenAI publishes a realtime models prompting guide with detailed recommendations for structuring instructions, controlling tone and pacing, and guiding tool usage.
GPT Realtime 2 and GPT Realtime 1.5 respond to significantly different prompting styles. The guide contains separate instructions for each, so follow the section that matches the AI model selected for your agent, and review your prompts when switching between models.
Transcription Language
Select the primary language for transcriptions. This determines the speech-to-text accuracy for your agent's conversations.
Supported languages
Afrikaans, Arabic, Armenian, Azerbaijani, Belarusian, Bosnian, Bulgarian, Catalan, Chinese, Croatian, Czech, Danish, Dutch, English, Estonian, Finnish, French, Galician, German, Greek, Hebrew, Hindi, Hungarian, Icelandic, Indonesian, Italian, Japanese, Kannada, Kazakh, Korean, Latvian, Lithuanian, Macedonian, Malay, Marathi, Maori, Nepali, Norwegian, Persian, Polish, Portuguese, Romanian, Russian, Serbian, Slovak, Slovenian, Spanish, Swahili, Swedish, Tagalog, Tamil, Thai, Turkish, Ukrainian, Urdu, Vietnamese, and Welsh.
Allowed Languages for Language Switching
Control which languages your agent can switch to during a conversation. If left empty, all supported languages are available. If you specify languages, the agent can only switch to those.
Language switching is handled by the built-in set_language action. The agent calls it when a caller explicitly asks to switch languages — it does not switch automatically based on detected language. When the action runs, it validates the requested language against your allowed list, updates the transcription language for the rest of the conversation, and retranscribes the last user message in the new language to correct any misrecognition from the previous language setting.
If your allowed list contains five or fewer languages, the agent's prompt includes the specific language names. For larger lists, it uses ISO 639-1 language codes instead.
There are two separate layers at play: transcription (speech-to-text accuracy) depends on the configured language and is updated by set_language, while generation (the agent's spoken responses) can use any language regardless of the transcription setting. Until a caller explicitly requests a switch, transcription stays on the default language even if the agent is responding in another language.
Genesys language parameter
If the Genesys language parameter is active for a conversation, it takes precedence over the allowed languages setting. The agent can only use the language provided by Genesys, and set_language requests for other languages are declined.
Transcription Prompt
The transcription prompt helps the speech-to-text model accurately recognize terms specific to your business — product names, industry jargon, customer names, or technical acronyms that might otherwise be misheard.
Example
Common terms:
- TechCo (company name)
- CloudSync (product name)
- API (not "a P I")
- OAuth (not "O off")
Common customer locations:
- Schiphol (airport in Amsterdam)
- Den Haag (The Hague)
Saving changes
Click Save in the editor header after making changes. Changes take effect immediately for new conversations.
Next steps
- Add knowledge to help your agent answer specific questions
- Build dialogue flows to handle different conversation scenarios
- Set up actions to let your agent interact with external systems
- Configure guardrails to ensure safe, compliant conversations
- Set up evaluation rules to automatically assess conversation quality