Voice Agents

Overview

Voice Agents add a conversational AI assistant to your LinkTime account. The assistant can:

• Answer inbound phone calls and greet callers by name
• List your available meeting types
• Check real-time availability on your calendar
• Book meetings, create contacts, and send confirmations
• Make outbound calls for reminders, follow-ups, and confirmations (via Workflows)
• Work via a browser-based web widget (free tier) or a dedicated phone number in 14 countries (Pro+)

Multi-Agent

As of v2.31.0, you can create multiple voice agents, each with its own personality, phone number, and configuration. This is ideal for businesses that need separate agents for different locations, departments, or languages.

Agent limits by plan

Active Hours

Set business hours for each agent so it only answers calls during the times you choose. Outside of active hours, callers hear an after-hours response instead.

How it works

• 7-day schedule: Configure start and end times for each day of the week (e.g., Mon-Fri 9 AM - 6 PM, Sat 10 AM - 2 PM, Sun off).
• Timezone-aware: Active hours are evaluated in the agent's configured timezone, so your schedule works correctly regardless of the caller's location.
• After-hours behavior: Choose what happens outside active hours: play a voicemail greeting, deliver a custom message, or redirect the caller to your online booking page.

Linked Event Types

Control which of your event types each agent is allowed to book. This gives you fine-grained control over what each agent offers to callers.

• Default: all event types. When no specific event types are linked, the agent can book any of your active, non-secret event types.
• Restricted: link specific event types to limit what the agent offers. For example, a "Sales" agent might only book "Discovery Call" and "Demo", while a "Support" agent only books "Technical Consultation".

Use Cases

Here are three common patterns for multi-agent setups.

Architecture

LinkTime uses ElevenLabs Conversational AI for speech-to-text, LLM reasoning, and text-to-speech. Twilio provides phone number provisioning and telephony. ElevenLabs natively bridges the two — no custom TwiML or WebSocket code needed.

Inbound Call Flow

Outbound Call Flow

Web Widget Flow (free tier)

Plan Limits

Setup Guide

1. 1

   Navigate to Voice Agents

   Go to Dashboard → Voice Agents in your LinkTime dashboard.

2. 2

   Choose a template

   This triggers a multi-step provisioning process: (1) creates an ElevenLabs conversational agent with your booking tools, (2) purchases a phone number from Twilio in your selected country (Pro+ only), (3) imports the number into ElevenLabs so it auto-answers calls. Takes about 5 seconds.

3. 3

   Your agent is live

   You'll see your agent status (Active), phone number, and usage bar. Callers can now call the number and the AI will answer, check your calendar, and book meetings.

4. 4

   Customize (optional)

   Go to Voice Agents → Settings to change the agent name, custom greeting, voice, business context, and language.

Agent API (CRUD)

Manage your voice agents programmatically. All endpoints require Clerk session authentication.

{
  "agents": [
    {
      "id": "cm_abc...",
      "agentName": "Sales Assistant",
      "voiceId": "21m00Tcm4TlvDq8ikWAM",
      "greeting": null,
      "businessContext": "We sell enterprise SaaS.",
      "language": "en",
      "phoneNumber": "+19143593794",
      "isActive": true,
      "elevenlabsAgentId": "abc123...",
      "createdAt": "2026-02-08T15:00:00.000Z"
    },
    {
      "id": "cm_def...",
      "agentName": "Soporte Tecnico",
      "language": "es",
      "phoneNumber": "+19143593800",
      "isActive": true,
      "elevenlabsAgentId": "def456...",
      "createdAt": "2026-02-10T10:00:00.000Z"
    }
  ],
  "usage": {
    "minutesUsed": 12,
    "minuteLimit": 60,
    "remaining": 48
  },
  "plan": {
    "name": "PRO",
    "hasPhoneNumber": true,
    "maxMinutes": 60,
    "maxAgents": 2
  }
}

curl -X POST https://linktime.io/api/voice/agents \
  -H "Content-Type: application/json" \
  -H "Cookie: __session=<clerk_session>" \
  -d '{
    "agentName": "Sarah",
    "greeting": "Hi! I'm Sarah, Emmanuel's scheduling assistant.",
    "businessContext": "I run a design consultancy specializing in UX.",
    "language": "en"
  }'

const response = await fetch("/api/voice/agents", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    agentName: "Sarah",
    greeting: "Hi! I'm Sarah, Emmanuel's scheduling assistant.",
    businessContext: "I run a design consultancy specializing in UX.",
    language: "en",
  }),
});
const { agent } = await response.json();
console.log(agent.phoneNumber); // "+19143593794"

curl -X PATCH https://linktime.io/api/voice/agents/cm_abc... \
  -H "Content-Type: application/json" \
  -H "Cookie: __session=<clerk_session>" \
  -d '{
    "agentName": "Alex",
    "businessContext": "We are a law firm specializing in IP law."
  }'

{
  "eventTypeIds": ["cm_evt1...", "cm_evt2..."]
}

{
  "enabled": true,
  "timezone": "America/New_York",
  "afterHoursBehavior": "voicemail",
  "schedule": [
    { "day": "monday",    "start": "09:00", "end": "18:00" },
    { "day": "tuesday",   "start": "09:00", "end": "18:00" },
    { "day": "wednesday", "start": "09:00", "end": "18:00" },
    { "day": "thursday",  "start": "09:00", "end": "18:00" },
    { "day": "friday",    "start": "09:00", "end": "17:00" },
    { "day": "saturday",  "start": "10:00", "end": "14:00" }
  ]
}

Usage API

{
  "minutesUsed": 12,
  "minuteLimit": 60,
  "remaining": 48,
  "callsThisMonth": 8,
  "avgDurationSeconds": 90,
  "topOutcomes": [
    { "outcome": "booking_created", "count": 5 },
    { "outcome": "info_provided", "count": 2 },
    { "outcome": "no_action", "count": 1 }
  ]
}

Tool Webhooks (mid-call)

These endpoints are called by the ElevenLabs agent during a live conversation to access your calendar and booking system. They are authenticated with a shared secret in the X-Voice-Secret header.

{
  "user_id": "usr_abc123"
}

{
  "event_types": [
    {
      "slug": "30-min",
      "name": "30 Minute Meeting",
      "duration_minutes": 30,
      "description": "Quick chat"
    },
    {
      "slug": "consultation",
      "name": "Consultation",
      "duration_minutes": 60,
      "description": "In-depth session"
    }
  ]
}

{
  "user_id": "usr_abc123",
  "event_type_slug": "30-min",
  "date": "2026-02-10",
  "timezone": "America/New_York"
}

{
  "slots": [
    {
      "time": "9:00 AM",
      "start_time": "2026-02-10T14:00:00Z"
    },
    {
      "time": "10:30 AM",
      "start_time": "2026-02-10T15:30:00Z"
    },
    {
      "time": "2:00 PM",
      "start_time": "2026-02-10T19:00:00Z"
    }
  ],
  "date": "2026-02-10"
}

{
  "user_id": "usr_abc123",
  "event_type_slug": "30-min",
  "invitee_name": "John Doe",
  "invitee_email": "[email protected]",
  "start_time": "2026-02-10T14:00:00Z",
  "timezone": "America/New_York",
  "notes": "Wants to discuss Q3 plan",
  "invitee_phone": "+14155551234"
}

{
  "success": true,
  "booking": {
    "id": "cm...",
    "event_name": "30 Minute Meeting",
    "date": "Monday, February 10, 2026",
    "time": "9:00 AM EST",
    "confirmation_message": "Your 30 Minute Meeting with Emmanuel is booked for Monday, February 10 at 9:00 AM EST. A confirmation email is on its way to [email protected]."
  }
}

{
  "booking_id": "cm..."
}

{
  "booking": {
    "id": "cm...",
    "event_name": "30 Minute Meeting",
    "invitee_name": "John Doe",
    "invitee_email": "[email protected]",
    "date": "Monday, February 10, 2026",
    "time": "9:00 AM EST",
    "status": "CONFIRMED",
    "meeting_link": "https://meet.google.com/...",
    "notes": "Wants to discuss Q3 plan"
  }
}

{
  "error": true,
  "message": "I'm having trouble accessing the calendar right now. Can I take your number and have someone call you back?"
}

Lifecycle Webhooks

These endpoints handle the start and end of each call. They are called by ElevenLabs automatically.

{
  "from": "+14155551234",
  "to": "+19143593794",
  "conversation_id": "conv_abc...",
  "call_sid": "CA..."
}

{
  "type": "conversation_initiation_client_data",
  "dynamic_variables": {
    "host_name": "Emmanuel",
    "business_context": "I run a design consultancy",
    "booking_url": "https://linktime.io/emmanuel",
    "host_email": "[email protected]",
    "host_timezone": "America/New_York",
    "agent_name": "Scheduling Assistant"
  },
  "conversation_config_override": {
    "agent": {
      "first_message": "Hi! I'm Emmanuel's scheduling assistant. How can I help you today?"
    }
  }
}

{
  "type": "conversation_initiation_client_data",
  "conversation_config_override": {
    "agent": {
      "first_message": "I'm sorry, Emmanuel's scheduling assistant is currently unavailable. Please visit linktime.io/emmanuel to book a meeting online.",
      "prompt": {
        "prompt": "Apologize that you're unavailable and direct the caller to the booking URL. End the call politely."
      }
    }
  }
}

{
  "conversation_id": "conv_abc...",
  "status": "completed",
  "transcript": "Agent: Hi! I'm Emmanuel's assistant...\nCaller: I'd like to book a meeting...",
  "duration_secs": 142,
  "tool_calls": [
    { "name": "list_event_types", "result": "..." },
    { "name": "get_available_slots", "result": "..." },
    { "name": "create_booking", "result": "..." }
  ]
}

Web Widget (free tier)

Free-tier users (and all users) get a browser-based voice widget on their public booking page. It uses @elevenlabs/react with WebRTC — no phone number or Twilio needed.

How it works

1. 1.When your voice agent is active, a "Talk to AI Assistant" button appears on your booking page (linktime.io/your-username).
2. 2.The visitor clicks the button → browser requests microphone permission.
3. 3.A WebRTC connection is established directly with ElevenLabs. The AI agent greets the visitor and can check availability, book meetings, etc.
4. 4.The visitor clicks "End Call" when done. A CallLog is created via the post-call webhook.

Embedding on external sites

The widget is built into your LinkTime booking page automatically. To add voice to an external site, use the Embed Widget which includes the voice button when your agent is active.

<!-- Embed your LinkTime booking page with voice widget -->
<iframe
  src="https://linktime.io/your-username?embed=true"
  width="100%"
  height="700"
  frameborder="0"
  style="border: none; border-radius: 12px;"
></iframe>

Workflow Integration (outbound calls)

The AI_CALL workflow action lets you trigger outbound voice agent calls based on booking events. This requires an active voice agent with a phone number (Pro+ plan).

Setting up a workflow

1. 1.Go to Dashboard → Workflows and create a new workflow.
2. 2.Choose a trigger (e.g., "Before Meeting" → 1 hour).
3. 3.Add a "Voice Call" action.
4. 4.Configure: who to call (invitee, host, or custom number) and call type (reminder, confirmation, follow-up, or custom).

Call types

AI_CALL action configuration

// Workflow action configuration (internal)
{
  "type": "AI_CALL",
  "config": {
    "to": "invitee",          // "invitee" | "host" | "custom"
    "customPhone": null,       // Required when to = "custom"
    "callType": "reminder",    // "reminder" | "follow_up" | "confirmation" | "custom"
    "customMessage": null      // Optional message for the agent
  }
}

Security

Troubleshooting

Environment Variables