Your First Voice Agent in ElevenLabs: An After-Hours Receptionist

Updated October 10, 2026. Built against the tool’s current screens and checked step by step. How we check this lesson

When the office closes, calls go to voicemail, and a leaking pipe does not wait until morning. In this free ElevenLabs voice agent tutorial you build an after-hours receptionist for a small plumbing company: you write its system prompt, give it a greeting that tells callers they are talking to AI, pick a calm voice and a fast model, publish it, then call it from your browser as a customer with a leak and read the whole call afterwards.

In the course: Part 11 · AI Voice Agents (Module 51 of the full course)

Part of: AI Agents 101 (step 3 of 3)

What you will build

A voice agent is an AI that answers a call and talks with the caller in a natural voice. It listens, turns speech into text, works out what to say with a language model (the LLM) and speaks the answer back, fast enough to feel like a normal conversation.

You build one called Cedar Creek After-Hours for Cedar Creek Plumbing, a small family plumbing company. The agent introduces itself as Riley, spots emergencies like an active leak, gives one safety tip, takes the caller's name, number and address, reads the number back, and answers questions about office hours. It never guesses a price or promises an arrival time.

Who this is for

This module is for owners and office managers of small service businesses such as plumbing, HVAC, electrical, cleaning or landscaping companies that miss calls after hours or while everyone is on a job. No coding is needed.

What the system prompt does

The system prompt is the agent's job description. It is read before every call and decides who the agent is, what it is allowed to do and how it should sound. Write it the way you would brief a new receptionist: the company, the job, the steps, the facts (like hours) and the rules, including what not to do, such as quoting prices.

Why the first message matters

The first message is the first thing every caller hears. It tells them they reached the right company, sets a calm tone and gives the disclosures up front. Callers should always be told they are talking to AI, and ElevenLabs' own disclosure requirements (linked right above the First message box) ask you to say so and to tell people the conversation is recorded. That is why the greeting in this module says "I'm Riley, the after-hours AI assistant, and this call may be recorded." Call-recording and consent rules also vary by state, so check the rules where you and your callers are. This is not legal advice.

What it costs

ElevenAgents is billed by call minutes. On ElevenLabs' pricing page the Free plan includes 15 minutes of calls a month, Starter is $6 a month with 75 minutes, and Creator is $22 a month with 275 minutes. Extra minutes are $0.08 each. The LLM is charged on top at cost and depends on the model you pick, which is one more reason to start with a fast, small model. When you connect a phone number, your phone provider (for example Twilio) bills you for its side of the call. Prices change, so check the pricing page before you rely on these numbers.

Before you put it on a real phone line

At the end of this module the agent can talk and take down details, but it cannot send them anywhere yet, so someone would have to read Conversations to find the message. The next modules fix that: you give it your price list and FAQ in the knowledge base, connect a phone number and read call analysis, then add tools so it can book a job, take a message and transfer to a person.

How the interactive lesson works

Every step is shown first in the Watch panel with a short voice-over, then you do it yourself in Your turn on a practice copy of the dashboard, which follows the current ElevenAgents screens. During the test call you click Say it instead of talking. Nothing is created in a real ElevenLabs account and no call is made.

Step by step: Your First Voice Agent in ElevenLabs: An After-Hours Receptionist

All 29 steps of the interactive module, in order. In the module you watch each one, then do it yourself in a practice copy that checks your work.

1. Create the agent

1. Open Agents. You are in the ElevenAgents dashboard. In the left menu, click Agents.

   A voice agent is an AI that answers the phone and talks with callers in a natural voice. You're setting one up for Cedar Creek Plumbing, to pick up calls after the office closes. In the left menu, click Agents.

2. Start a new agent. There are no agents yet. In the left menu, click the + next to Agents.

   There are no agents here yet. In the left menu, click the plus button next to Agents.

3. Choose Blank Agent. ElevenLabs asks what type of agent you want. Click Blank Agent.

   You can start from a template, and Browse Templates even has receptionist agents. For your first one, start blank, so you see what every setting does.

4. Name the agent. Type the agent name: Cedar Creek After-Hours

   Give it a name you will recognize later.

5. Create it. Click Create agent.

2. Tell it who it is

6. Open the system prompt. Your agent opens on the Agent page. Click inside the System prompt box.

   Your agent opens on the Agent page. The system prompt is the agent's job description: who it is, what it does, and the rules it has to follow on every call. Right now it just says, you are a helpful assistant.

7. Write the system prompt. Paste in the prompt to replace it with Riley’s job: the emergencies to spot, what to collect, the office hours and the rules.

   Replace it with the real job. It tells Riley what counts as an emergency, to collect a name, number and address, the office hours, and to keep answers short, because this is a phone call.

   You are Riley, the after-hours phone receptionist for Cedar Creek Plumbing, a small family plumbing company. You are an AI assistant, and you say so if anyone asks.
   
   Your job:
   - Find out what the problem is and whether it is an emergency (active leak, burst pipe, no water, sewage backup).
   - For an active leak, tell the caller to turn off the valve under the fixture, or the main water shut-off, if they can do it safely.
   - If they smell gas, tell them to leave the house and call the gas company or 911 first.
   - Take the caller's name, phone number and address, and read the number back.
   - Tell them the on-call plumber will call back within 15 minutes for emergencies. For anything else, the office will call the next business morning.
   
   Office hours: Monday to Friday 7 AM to 6 PM, Saturday 8 AM to noon.
   
   Rules:
   - Keep answers short: one or two sentences, like a real phone call.
   - Never guess a price or promise an arrival time. Say the plumber will go over that on the callback.
   - Be calm and kind. People calling at night are often stressed.

8. Open the first message. Below it, click inside the First message box.

   Next, the first message. It's the very first thing callers hear, so it sets the tone and tells them they reached the right place.

9. Write the greeting. Paste in the message. It names the company, says Riley is an AI assistant and that the call may be recorded.

   Callers should always be told they're talking to AI, and ElevenLabs requires it too. That's the Disclosure Requirements link up here. So this greeting names the company, says Riley is an AI assistant, and that the call may be recorded. Recording and consent rules vary by state, so check yours.

   Hi, thanks for calling Cedar Creek Plumbing. I'm Riley, the after-hours AI assistant, and this call may be recorded. How can I help you tonight?

3. Pick a voice and a model

10. Open the voice. On the right, under Voices, click the Primary voice.

    Now the voice. On the right, under Voices, click the one marked Primary.

11. Change the voice. The Agent voice panel opens. Click the Voice row to pick a different one.

    The Agent voice panel opens. The sliders fine-tune how it speaks, but the defaults are fine.

12. Search the library. In Select a voice, type calm in the search box.

    For a late-night plumbing emergency, you want someone calm. Search the library for calm.

13. Listen first. Click the play button next to Dana - Calm and Clear to hear a sample.

    Always listen before you choose.

14. Use Dana. Clear and unhurried. Next to Dana - Calm and Clear, click Use.

    Clear and unhurried. Next to Dana, click Use.

15. Close the panel. Dana is now the voice. Close the panel with the X.

    Dana is now the agent's voice. Close the panel.

16. Open the LLM. Under LLM, click the model.

    The LLM is the brain that decides what Riley says. Under LLM, click the model.

17. Open the model list. The LLM panel opens. Click the model marked Primary to see the choices.

    The LLM panel opens.

18. Pick a fast model. Click Gemini 3.5 Flash.

    On a phone call, speed matters most. A big model thinks longer, and the caller hears the pause. LLM use is also charged on top of your call minutes. Stick with a fast Flash model. 5 Flash.

4. Publish and test-call it

19. Publish your changes. The Draft chip means you have unpublished changes. Click Publish.

    See the Draft label at the top? Your changes aren't live yet.

20. Confirm. Check the changes, then click Publish.

    It shows what changed since the last version. You can add a short description, so you know later what you changed.

21. Open Preview. Click Preview to talk to your agent in the browser.

    Time to hear it. You can talk to your agent right in the browser, no phone number needed.

22. Start the test call. Click the round phone button under the orb.

    On the real site, your browser asks to use your microphone the first time. Allow it.

23. Describe the emergency. Riley answers with the greeting. Click Say it to tell Riley about the leak.

    Riley answers with your greeting, AI disclosure and all. Now play the caller. In the real test you just talk. Here, click Say it.

24. Give your details. Riley tells you to shut off the valve and asks for your details. Click Say it.

    It gives the safety tip first, then asks for your details, just like the prompt said.

25. Ask about hours. Riley reads your number back. Click Say it to ask about office hours.

    It reads the number back so there are no mistakes. Now ask about the regular hours.

26. Hang up. Riley gives the hours from the prompt. Click the red button to end the call.

    Right hours, short answers, no made-up prices.

5. Read the transcript

27. Open Conversations. In the left menu, under Monitor, click Conversations.

    Every call is saved, including tests. In the left menu, under Monitor, click Conversations.

28. Open the call. Click the call at the top of the list.

    Your test call is at the top.

29. Read the transcript. The Overview shows a summary. Click the Transcription tab.

    The Overview gives a short summary with the caller's details. Right now this is where the plumber would find the message, so don't put it on a real line until you've connected a phone number and an alert.

Screenshots

Frequently asked questions

How do I create a voice agent in ElevenLabs?

Open ElevenAgents and click the + next to Agents in the left menu. Choose Blank Agent (or a template), give it a name and create it. On the Agent page, write the system prompt and first message, choose a voice and an LLM, publish, and click Preview to test it in your browser.

How much does an ElevenLabs voice agent cost?

The Free plan includes 15 minutes of calls a month. Paid plans start at $6 a month for 75 minutes, extra minutes are $0.08, and the LLM is billed on top depending on the model. A phone provider such as Twilio bills separately for phone calls.

Is this course really free?

Yes. Stepthrough is completely free, and the practice copy needs no accounts. To do it for real you need your own ElevenLabs account. The free plan is enough to build and test a first agent.

Do I have to tell callers they are talking to AI?

Yes. Tell callers they are talking to an AI assistant, ideally in the first message, and that the call may be recorded. ElevenLabs' disclosure requirements ask for this, and recording and consent laws vary by state.

Start this module free

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