Agent behaviour
Write the persona, tone, and rules your agent follows on every reply.
Where to write it
The Behavior field lives on the Sandbox page (while you build) and on Publish → Model (after launch). Both surfaces edit the same prompt, so a change in one shows up in the other.
What it controls
Whatever you write here is the agent's source of truth for tone, voice, length, and persona. Every reply is shaped by it, and there are no hidden defaults working against you.
- "Speak like a pirate, long paragraphs, philosophical" → the agent replies in pirate English in long paragraphs, every turn.
- "Always include 2–4 emojis" → emojis on every reply.
- "Talk in Japanese" → replies in Japanese even if the visitor types in English.
Keep it as long or as short as you like, then iterate. Swap the model below the field to see how different LLMs answer the same question.
First-person voice
Start from a preset
The dropdown above the field offers ready-made examples you can edit freely:
- General AI agent, a simple, friendly assistant.
- Customer support, resolves issues quickly and empathetically.
- Sales assistant, understands needs and guides visitors to the right plan.
- Product expert, explains features and use cases in plain language.
- Lead qualification, engages visitors and collects contact details for follow-up.
Pick Custom behavior to start from a blank field and write your own from scratch. The role presets reference your company name, which is filled in for you from your workspace.
Pick a vibe
When a preset still has a highlighted placeholder in it (for example [friendly]), a vibe picker appears above the field. Click one to set the tone instantly, then tweak the wording:
- 🤝 Friendly, warm and approachable.
- ✨ Emoji-heavy, sprinkles emojis through every reply.
- 🎩 Formal, polished and professional.
- 😄 Funny, cracks jokes and keeps things light.
- 😎 Casual, chill and easygoing.
- 🤓 Geeky, leans into technical depth.
- 🧠 Sarcastic, dry wit with a raised eyebrow.
Refine instructions Starter
The Refine instructions button rewrites a rough description into a polished agent prompt for you. Available on Starter and above. Each plan includes a set number of refines per month, and higher plans get more. On the Free plan the button opens an upgrade prompt instead.
Save your own
Built a prompt you want to reuse? Choose Add custom behavior in the dropdown to name and save it. Saved behaviours appear under the Custom heading, where you can rename or delete them, and they stay in sync across the Sandbox, Publish, and side-by-side compare views.
Reset and full-screen
Use the reset icon next to the Behavior heading to return to the saved version, or the expand icon in the corner of the field to edit in a larger full-screen editor.
Still stuck? We'll help.
Every plan, including Free, comes with human support. If something isn't behaving the way you expect after following the steps above, send us a note and we'll get back to you within one business day.