Instructions and opening line
Write the system prompt and opening line that decide how your agent behaves, with guidance for spoken conversations.
What you will achieve
You will write the opening line the agent says first and the instructions that shape everything after it.
Where to find them
Open the agent, stay on the Assistant tab, and scroll to Opening line and System prompt.
Opening line
Opening line is what the agent says first, before the caller has said anything. The default is "Hello! How can I help you today?". Make it short and say who is calling or answering, for example: "Thank you for calling Acme Dental. How can I help?"
If you choose a language other than English when you create the agent, Phynxa fills in an opening line in that language.
System prompt
System prompt tells the model who it is and what to do. The field notes that replies are spoken, so ask for short sentences and no formatting. A good prompt covers:
- Role. "You are the receptionist for Acme Dental in Dubai."
- Goal. "Book appointments and answer questions about opening hours and prices."
- What it knows and does not know. "Use only the information in your knowledge. If you do not know, offer to take a message."
- Style. "Speak in short sentences. Ask one question at a time. Never read out a list."
- When to use tools. "When the caller wants to book, use the booking tool. Confirm the day and time back before you finish."
- When to hand over. "If the caller asks for a person, or is upset, offer to transfer them."
Tip. Callers hear every word. Avoid symbols, bullet points and markdown. A reply of one or two sentences sounds natural; longer replies feel like a recording.
Description
Description (below the prompt) is only for you. Callers never hear it, and the agent does not read it. It is also what other agents see when one agent can hand a call to another, so write a clear one if you use transfers between agents.
Testing
Choose Talk or Chat, try the situations you wrote about, and refine the prompt. Press Save after each change; tests use what is on screen either way.
Expected result
The agent opens with your line, keeps to the role you gave it, and replies in short spoken sentences.
Troubleshooting
- It talks too long. Add "Keep every reply under two sentences" to the prompt.
- It makes things up. Say what to do when it does not know, and attach a knowledge base.
- It ignores a rule. Put important rules near the start of the prompt, and state each one once, plainly.
Related guides
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