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Setup

Stellar agents can handle text chat in addition to voice. Enable chat on an existing agent and it reuses the same dialogue, knowledge, actions, and guardrails. Chat has its own AI model and can optionally have its own personality prompt.

Once chat is enabled, you put it on a website using the Chat widget (paste a <script> tag) or build your own UI with the Text chat SDK.

Enable the chat channel​

Open your agent in Studio and scroll past General and Voice to the Chat section. If chat hasn't been enabled yet, click Enable chat to expand the section.

You can run an agent as voice-only, chat-only, or both at once. Disabling chat later preserves the configuration so you can re-enable it without redoing the setup.

AI model​

The chat AI model field is separate from the voice realtime model because chat doesn't use audio-capable models. We recommend GPT-5.4 for now.

Personality​

By default, chat reuses the personality prompt from the General section at the top of the editor; anything you've written there applies to chat too.

If you want chat to behave differently (shorter replies, a more formal tone, no small talk), click Customize for chat in the top-right corner of the personality field. The prompt splits into a Voice version and a Chat version that you can edit independently.

The dialogue, knowledge, actions, and guardrails stay shared across both channels; only the personality prompt and the AI model can differ.

See Settings for general guidance on writing personality prompts.

Reviewing chat conversations​

Chat conversations show up in Studio under Chat → Conversations. They use the same review tools as voice: transcripts, variables, action executions, evaluation results, and guardrail triggers. See Reviewing conversations for the full walkthrough.

If a conversation was handed over to a human operator, the transcript shows both AI and human messages in the same timeline, labelled by sender.

Disabling chat​

To stop serving chat conversations, click Disable chat in the Chat section. A confirmation tells you the channel will stop serving conversations but the configuration will be preserved. Re-enabling chat later brings the same settings back.

What's next​

  • Chat widget — configure, embed, and personalize the prebuilt widget on your website.
  • Text chat SDK — for custom integrations.