> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pulsyai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Key Concepts

> Understand the core PulsyAI building blocks — assistants, call flows, knowledge bases, phone numbers, and sub-accounts — before building agents.

This page defines the core concepts and terms used throughout PulsyAI. Understanding these building blocks will make every other guide easier to follow — whether you are building agents or reselling the platform to your clients.

## Platform Basics

Whether you are building voice AI agents or reselling a white-label voice AI platform, these core concepts apply across PulsyAI.

<CardGroup cols={2}>
  <Card title="AI Assistant (Agent)" icon="bot">
    An AI assistant is a single AI configuration that handles phone calls or text messages. Each assistant has its own phone number, voice, call flow, and settings. An assistant can be Inbound, Outbound, or SMS.
  </Card>

  <Card title="Call Flow (Agent Script)" icon="git-branch">
    A call flow is the script that tells the AI how to behave during a call. It defines which questions to ask, what information to collect, and in what order. Use the prompt box to write the instructions your agent follows at each step of the conversation.
  </Card>

  <Card title="Knowledge Base" icon="book-open">
    A knowledge base is the content an AI assistant uses to answer questions accurately. Upload your website or PDF documents, and once the status shows **Ready**, the content becomes the agent's memory — when a caller asks a question, the AI fetches the answer directly from your source material and responds accordingly.

    <Note>
      This content can also be pasted directly into the Call Flow prompt box to reduce response latency. More on this in a dedicated guide.
    </Note>
  </Card>

  <Card title="Voice Selection" icon="mic">
    A voice is the synthetic speaking voice your AI assistant uses on calls. Go to **Global Settings → Voice** and click **Select Assistant Voice** to choose one. You can also adjust the **voice speed** and **voice volume** to fine-tune how the AI sounds.

    Once inside the voice selector, you'll see the full library — over 700 voices powered by Cartesia alone. Filter by **gender**, **language**, or **provider** to narrow down your options. Preview any voice before selecting it, and swap it out anytime.

    <Note>
      Filtering by **accent** is coming soon.
    </Note>
  </Card>
</CardGroup>

## The Three Agent Types

Every assistant in PulsyAI is one of three types, each built for a specific use case.

<CardGroup cols={3}>
  <Card title="Inbound" icon="phone-incoming">
    An inbound agent answers incoming calls. Used for customer service, appointment booking, lead qualification, and FAQ handling.
  </Card>

  <Card title="Outbound" icon="phone-outgoing">
    An outbound agent calls contacts from an uploaded list. Used for prospecting, reminders, confirmations, and database reactivation.
  </Card>

  <Card title="SMS" icon="message-square">
    An SMS agent handles text-message conversations. Used for campaigns, follow-ups, lead nurturing, and asynchronous support.
  </Card>
</CardGroup>

## Latency & Endpointing

Endpointing is how an assistant decides when a caller has finished speaking before it responds. PulsyAI offers two endpointing modes: Time Based and Semantic.

### Time Based

Time based mode waits a fixed delay before the assistant responds. You choose one of three latency levels:

<CardGroup cols={3}>
  <Card title="Low — 1.5s" icon="zap">
    Best for outbound cold calling. Fast responses keep prospects engaged and reduce hang-ups.
  </Card>

  <Card title="Medium — 2.5s" icon="gauge">
    Best for inbound customer service. Balances natural pacing with accurate information capture.
  </Card>

  <Card title="High — 3.5s" icon="target">
    Best for technical or legal calls. Maximum accuracy when precision matters more than speed.
  </Card>
</CardGroup>

When unsure, start with Medium and adjust based on call recordings and conversion rates.

### Semantic

<CardGroup cols={1}>
  <Card title="Semantic Endpointing" icon="sparkles">
    Semantic mode does not rely on a fixed delay. The assistant intelligently detects when a caller has finished their thought by understanding the meaning of what is being said. For example, if a caller pauses while giving a phone number, the assistant waits instead of interrupting — producing the most natural-feeling conversations.
  </Card>
</CardGroup>

## Actions

Actions are everything an AI assistant can do during a call beyond talking — transferring to a human, booking appointments, sending SMS, triggering notifications, and pushing data to your tools. Each action is connected to a specific step in the call flow.

<CardGroup cols={3}>
  <Card title="Call Transfer" icon="phone-forwarded">
    Transfer the live call to a human agent when needed.
  </Card>

  <Card title="Booking" icon="calendar">
    Book appointments during the call via Cal.com or a live API call to your own scheduling system.
  </Card>

  <Card title="Send SMS" icon="message-square">
    Send a text message to the caller during or after the call.
  </Card>

  <Card title="Notifications" icon="bell">
    Alert your team after a call with extracted lead data.
  </Card>

  <Card title="Webhooks & Integrations" icon="webhook">
    Push call data to a CRM, Zapier, Make, or any HTTPS endpoint.
  </Card>

  <Card title="Live API Call" icon="zap">
    Let the assistant call an external API in real time during the conversation.
  </Card>

  <Card title="Collect Keypad Input (DTMF)" icon="keyboard">
    Capture digits the caller types on their keypad — useful for inbound menus and verification.
  </Card>

  <Card title="Send DTMF Digits" icon="hash">
    Let the assistant send keypad tones during outbound calls — useful for navigating phone menus.
  </Card>

  <Card title="Call Back" icon="phone-missed">
    Automatically call back inbound callers who hung up before the AI could help them — a second chance to connect and boost conversions.
  </Card>

  <Card title="Stale Conversations" icon="message-circle">
    Automatically re-engage SMS conversations that have gone quiet, with configurable timing and retry limits.
  </Card>

  <Card title="End Call" icon="phone-off">
    Gracefully terminate the call when the conversation is complete.
  </Card>
</CardGroup>

## White-Label & Reselling Concepts

PulsyAI is built for partners who resell voice AI under their own brand. These concepts are central to how the platform works.

<CardGroup cols={2}>
  <Card title="Sub-Account" icon="users">
    An isolated workspace for one of your clients, with its own assistants, phone numbers, call logs, and billing — all managed from your main account.
  </Card>

  <Card title="Multi-Tenant Architecture" icon="layers">
    A single platform serving many isolated clients at once. Each client has separated data, telephony, and branding.
  </Card>

  <Card title="White-Label" icon="paintbrush">
    The platform appears under your brand, not PulsyAI's. Your clients see your domain, logo, and branding — never PulsyAI.
  </Card>

  <Card title="Rebilling" icon="credit-card">
    Set your own prices and charge clients directly through your own Stripe account. You decide the markup.
  </Card>

  <Card title="BYOC (Bring Your Own Carrier)" icon="radio-tower">
    BYOC lets you connect your own telephony carrier to PulsyAI through a SIP trunk, instead of using PulsyAI's managed telephony. Connect carriers like Twilio, Bandwidth, or Telnyx and keep your existing contracts and rates.
  </Card>

  <Card title="Dedicated Instance" icon="server">
    A fully isolated deployment with its own database and infrastructure, available to Enterprise partners for complete data isolation.
  </Card>

  <Card title="Developer API" icon="code">
    The PulsyAI API is a full REST API that lets partners build custom integrations, automate agent management, and connect PulsyAI to their own systems programmatically. Explore the full interactive API reference in our [Swagger documentation](https://backend.pulsyai.com/docs/).
  </Card>
</CardGroup>

## Support Terms

<CardGroup cols={2}>
  <Card title="Call SID" icon="hash">
    A unique identifier assigned to every call. When contacting support about a specific call, always provide the Call SID so the team can locate and debug it.
  </Card>

  <Card title="Connect Action" icon="link">
    A Connect Action links a configured integration to a call flow step. An integration must be connected as an action in the call flow to actually run.
  </Card>
</CardGroup>

## Next Steps

<CardGroup cols={2}>
  <Card title="Build a Script" icon="pencil" href="/platform/build-your-agent/build-a-script">
    Create your first call flow for an agent.
  </Card>

  <Card title="White-Label Setup" icon="building-2" href="/platform/white-label/custom-domain">
    Configure sub-accounts, branding, and Stripe rebilling.
  </Card>
</CardGroup>

## Next step

<CardGroup cols={1}>
  <Card title="Phone Numbers" icon="phone" href="/platform/phone-numbers">
    Set up the phone numbers your AI agents will use for inbound and outbound calls.
  </Card>
</CardGroup>