AI Voice Agents – Fontumi
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Fontumi AI Voice iAgents:
✅ Real voices.
✅ Real accents.
✅ Real Business results. 🇨🇴🇺🇸🇲🇽

Welcome to the future of intelligent voice automation. This is today's technology that literally talks by itself 😉, pleased your customers and get things done on your behalf.

Create Virtual Voice Agents — real characters, with real accents — designed to handle real business tasks. Whether it’s booking appointments, closing sales, managing orders, or collecting payments, each iAgent acts like a specialized team member that speaks your customer’s language naturally, 24/7, without limits.
Elton Jhon Gómez
CEO

Fontumi.ai blends AI voice recognition with LLM-based replies to conduct live phone conversations. Below is a simplified flow:

  1. Caller or Lead is Dialed

    • Inbound: A customer dials your assigned phone number.
    • Outbound: Fontumi.ai’s system calls a list of phone numbers from your campaign.
  2. Speech Recognition
    The AI listens to what the person says and transcribes it into text in real time.

  3. LLM Decision
    Fontumi.ai uses a large language model (LLM) and your configured “system prompt” to craft a reply or decide the next action (like transferring the call).

  4. Voice Output
    The AI’s response is converted to natural-sounding speech via our voice engine (ElevenLabs voices).

  5. Result & Actions

    • For Inbound: The AI may answer questions, verify info, or take a message.
    • For Outbound: The AI can pitch a product, qualify leads, or transfer interested callers to a human agent.
  6. Data & Reporting
    You get transcripts, call recordings, call outcomes (like “no answer” or “success”), and the ability to automate follow-up actions.

Distinctions: Inbound vs. Outbound

  • Inbound

    • Caller dials a number you rented or integrated.
    • AI picks up, greets, and handles queries or routes the caller if needed.
  • Outbound

    • You upload or sync leads.
    • AI dials each number, follows your call script, possibly transfers if the lead is interested.

Next Steps

  • Learn about Key Terminology (like “AI Assistant,” “Campaign,” etc.).
  • Jump into Getting Started to set up your first AI assistant.

Understanding these terms will help you navigate Fontumi.ai more easily:

AI Assistant / Agent

A customizable bot you configure to handle inbound or outbound calls. Defines conversation style, voice, and behavior via a “system prompt.”

Campaign (Outbound)

A sequence or batch of calls to a list of contacts or leads. You can upload a CSV, connect Google Sheets, or integrate your CRM to launch these calls.

Inbound Number

A dedicated phone number that customers dial to reach your AI assistant. You can get one from the platform or integrate via SIP/PBX.

Outbound Caller ID

The number displayed on the customer’s phone when your AI calls them. You can rent one or verify an existing number to use as Caller ID.

No-Code Automation Platform

Fontumi.ai’s built-in workflow platform, similar to Zapier/Make. It lets you connect triggers (like “call ended”) to actions (like “send an email” or “update a Google Sheet”) without writing code. Learn more about automating your workflows.

Tools / Integrations

Refers to the specialized features your AI assistant can use, like transferring a call, ending a call, scheduling an appointment, or webhooks to external apps.

Tip: Keep these definitions in mind as you proceed through the docs. They’ll pop up in various setup steps or feature explanations.

 

Welcome to the fundamentals of Fontumi.ai. Here, we explore the essential building blocks that you need to understand before configuring your AI assistant and calls.

1. System Prompt & Initial Message

System Prompt

  • The “brain” of your AI assistant. You write a short (or long) set of instructions that guide the assistant’s behavior and tone of voice.
  • This includes any important business info, disclaimers, or how you want the AI to handle edge cases.
  • For example: “You are a helpful phone assistant for XYZ Company, you greet in a friendly manner, confirm the caller’s info, etc.”

Initial Message

  • The very first thing the AI says.
  • Typically short, like “Hello, thanks for calling XYZ Company!“

2. Voices

  • Fontumi.ai integrates with ElevenLabs voices for natural-sounding speech.
  • You can clone your own voice by providing audio samples or pick from built-in voices.
  • Each voice can have adjustable parameters like speech speed, filler usage, or accent (if available).

3. Putting It All Together

  • An AI Assistant is built by combining a system prompt, an initial message, and a chosen voice.
  • Optionally, you add tools (like “transfer call” or “end call”).
  • Once the assistant is set, you assign it to a phone number (for inbound) or a campaign (for outbound).

Next Steps

  • Learn how call minutes and billing work to plan your usage.
  • Or, jump to AI Assistants Overview to start building your first assistant.

Fontumi.ai operates on a usage-based model. You pay primarily for two things:

  1. The minutes your AI spends in calls.
  2. Any dedicated phone number rentals.

1. Included Minutes vs. Pay-as-You-Go

  • Included Minutes: Some plans may come with a set of monthly minutes. These are consumed first.
  • Pay-as-You-Go: If you exceed included minutes (or if you’re on a usage-based plan), you pay for each additional minute used.

2. How We Calculate Minutes

  • Per-Second Billing: Typically, Fontumi.ai bills by the second (converted to minutes). For example, a 90-second call is 1.5 minutes.
  • Rounding: Make sure you check your plan’s rounding rules. Some might round up to the nearest 30 seconds, while others do pure per-second.

3. Monthly Usage & Purchasing Extra

  • Monthly Reset: If your plan includes minutes, those reset monthly on your billing date.
  • Buying Add-Ons: You can purchase extra minute bundles if you expect a spike in call volume.

4. Additional Costs

  • Phone Number Rental: A monthly fee for each dedicated inbound/outbound number you rent (varies by region).
  • Possible Carrier Surcharges: Some countries may have unique taxes or surcharges—check the Costs & Pricing section for more details.

5. Monitoring Usage

  • Dashboard: The platform displays your current usage, how many minutes are left, and your estimated cost so far.
  • Notifications: You can set up alerts (e.g., “Email me when I hit 80% of monthly minutes”) using the no-code automation platform.

Next Steps

  • Check out our Costs & Pricing section for a deeper breakdown of number rentals, international rates, inbound vs. outbound cost differences, and more.
  • Or proceed to AI Assistants Overview to build your first agent.

An AI Assistant (sometimes called an agent) is your configurable bot that speaks with customers or leads over the phone—either when they call you (inbound) or when your system calls them (outbound).

Why Use an AI Assistant?

  • Automate Common Interactions: Answer FAQs, book appointments, or qualify leads 24/7.
  • Reduce Workload: Free your human team from repetitive tasks like verifying contact info or taking messages.
  • Scalable: One assistant can handle many calls in parallel, allowing you to grow without adding more agents.

Key Components

  1. System Prompt: The core instructions guiding how your assistant behaves.
  2. Initial Message: The very first phrase the AI says (especially critical for inbound calls).
  3. Voice Settings: Choose a built-in voice or clone your own.
  4. Tools (Optional): Transfer, end call, scheduling, and more.

Next Steps

  • Learn how to Create and Edit an AI Assistant.
  • Explore the various Tools & Functions you can add to your assistant.

The system prompt is the most crucial component of your AI assistant. It defines your assistant’s personality, behavior, knowledge, and capabilities. Think of it as the “brain” and “training manual” combined.

Quick Start with Templates

To get started quickly:

  1. Go to your assistant settings
  2. Find the system prompt field
  3. Click the “Templates” button nearby
  4. Choose a template that matches your use case
  5. Customize it for your needs

Language Support

Your system prompt can be written in any language, regardless of the spoken language setting:

  • Write the prompt in your preferred language
  • Set the spoken language separately in assistant settings
  • The AI will follow the prompt’s instructions while speaking in the selected language

For example:

  • System prompt in English, spoken language set to Spanish
  • System prompt in German, spoken language set to French
  • System prompt in Chinese, spoken language set to English

Why They Matter

Your system prompt:

  • Shapes how the AI thinks and responds
  • Defines conversation boundaries
  • Provides essential knowledge
  • Controls behavior and tone
  • Determines handling of edge cases

Key Components

A good system prompt should include:

1. Role & Identity

You are a professional sales 
representative for [Company]. You specialize in [Product/Service] and have extensive knowledge of our offerings.

2. Conversation Style

Maintain a friendly, professional tone. Use clear, concise language. Avoid technical jargon unless specifically asked.
 

3. Key Information

Our main products are:
- Product A ($X/month): [features]
- Product B ($Y/month): [features]
Current promotion: 20% off first 3 months

4. Behavioral Guidelines

- Always verify customer information before discussing account details
- Transfer to a human agent if the customer seems frustrated
- Don't make promises about delivery dates

5. Response Framework

When asked about pricing:
1. First understand their needs
2. Present relevant package options
3. Explain the value proposition
4. Share any applicable discounts

Best Practices

  1. Be Specific
    • Clear instructions get better results
    • Include examples of good responses
    • Define what NOT to do
  2. Structure Matters
    • Organize information logically
    • Use bullet points and sections
    • Keep related information together
  3. Test and Iterate
    • Start with a basic prompt
    • Test various scenarios
    • Refine based on call recordings
    • Add handling for edge cases

Common Mistakes

  • Too Vague: “Be helpful and professional” (Not specific enough)
  • Too Rigid: Scripting every possible response (Reduces natural flow)
  • Information Overload: Including unnecessary details
  • Missing Guidelines: Not specifying how to handle common situations

Example Structure

# Role and Purpose
[Define who the AI is and its main goals]
# Core Knowledge
[Essential information about products/services]
# Conversation Guidelines
[How to interact with customers]
# Response Patterns
[How to handle specific situations]
# Limitations and Boundaries
[What the AI should NOT do]

Testing Your Prompt

  1. Make test calls covering:
    • Common scenarios
    • Edge cases
    • Difficult situations
    • Various customer personalities
  2. Review and adjust:
    • Listen to call recordings
    • Check response accuracy
    • Verify tone consistency
    • Test knowledge retention

Optimization Tips

  • Start with Fast Engine for quick iterations
  • Use call recordings to identify gaps
  • Add examples of good/bad responses
  • Include handling for unexpected questions

Pro Tip: Your system prompt is a living document – regularly update it based on actual call experiences and customer interactions.

Ready to set up your first AI assistant? Follow these steps:

1. Go to “Assistants”

In your Fontumi.ai dashboard, find the Assistants page (sometimes labeled “AI Assistants” or similar).

2. Click “Create New Assistant”

  • Choose Inbound if you want it to answer incoming calls.
  • Choose Outbound if it’s for campaigns calling out to leads/customers.

3. Fill Out Basic Info

  • Assistant Name: Internal label, e.g. “Support Bot” or “Sales Bot.”
  • System Prompt: Outline the assistant’s role, tone, and key instructions.
  • Initial Message: The first line the AI will speak (inbound calls usually need a quick greeting).

4. Language & Voice

  • Select a Voice from the built-in library, or pick a cloned voice if you’ve created one.
  • (Optional) Configure speech speed, filler usage, or “voice activity detection” if you need specialized settings.

5. Tools & Functions

  • Add or remove items like transfer callend call, or appointment scheduling (more in Tools & Functions).

6. Save & Test

  • Click Save and your assistant is ready!
  • For inbound, you’ll need to assign a phone number.
  • For outbound, attach the assistant to a campaign or test with your own phone number.

Editing an Assistant

  • Return to Assistants in the dashboard.
  • Click on the assistant name.
  • Adjust prompts, voice, or add new tools—then Save.

Tip: Always test your changes by calling the assistant or running a small outbound campaign to confirm it behaves as expected.

 

The first few seconds of a call are crucial – they determine whether the customer stays on the line. You have two options for your assistant’s first greeting: text-based initial message or custom initial audio.

Initial Message

This is the first thing your AI assistant says when starting a call. The message is read exactly as written, so:

Best Practices

  1. Keep it Short

    • Aim for 5-10 seconds
    • Get to the point quickly
    • Avoid long company introductions
  2. Write Exactly as Needed

    • Include proper diacritics (é, ñ, ü, etc.)
    • Use punctuation for proper pausing
    • Write numbers as they should be spoken
  3. Example Formats

    Good:
    "Hi! This is Sarah from ABC Company. How can I help you today?"
    Better with pausing:
    "Hi! This is Sarah from ABC Company... How can I help you today?"
    With diacritics:
    "¡Hola! Soy María de ABC Company. ¿Cómo puedo ayudarte?"
    

Initial Audio

For the best first impression, you can use a pre-recorded audio file:

Benefits

  • Professional quality
  • Perfect pronunciation
  • Human warmth
  • Consistent delivery
  • Higher customer retention

Setup Process

  1. Record your greeting with a professional voice actor
  2. Upload the audio file in assistant settings
  3. Clone the same voice for the rest of the conversation
  4. Enable initial audio playback

Best Practices

  1. Recording Quality

    • Use professional equipment
    • Record in a quiet environment
    • Maintain consistent volume
    • Save in high quality format
  2. Voice Matching

    • Use the same voice actor for cloning
    • Maintain consistent tone and style
    • Match energy levels
  3. Content Guidelines

    • Keep under 10 seconds
    • Include company name
    • State purpose clearly
    • Sound welcoming

Example Script Structure

[Greeting] + [Company Name] + [Purpose/Question]
"Hello! This is ABC Company calling about your recent inquiry. How are you today?"

Combining Both Methods

You can set up both:

  • Initial audio as primary greeting
  • Initial message as backup
  • System will use audio when available

Testing

Before going live:

  1. Call your assistant
  2. Listen for:
    • Clear pronunciation
    • Natural pauses
    • Proper volume
    • Smooth transition to AI conversation

Language Considerations

  • Each language needs its own initial message/audio
  • Use native speakers for recordings
  • Consider regional accents
  • Test with target audience

Pro Tip: Record several versions of your initial audio and test which one gets better response rates.

 

Fontumi.ai offers built-in “tools” that your AI assistant can use during a call. These help you shape the conversation flow and automate actions like transferring calls or scheduling appointments.

1. End Call Tool

  • Purpose: Tells the AI to politely wrap up the conversation.
  • How It Works: You can specify in the system prompt or logic, for instance: “If the user says goodbye, end the call.”
  • Configuration: In the assistant’s settings, you can define any conditions that should trigger the end call.

2. Transfer Tool

  • Purpose: Moves the caller from the AI assistant to a human agent or external phone number.
  • Use Cases: Warm leads on a sales call, escalations on a support call, etc.
  • Settings: In the assistant’s config, add the phone number or department the call should go to, and optionally a short hold message.

3. Appointment Scheduler

  • Purpose: Lets the AI check your calendar availability (e.g. via Cal.com or Google Calendar) and book an appointment.
  • Typical Flow:
    1. AI offers scheduling.
    2. Caller selects date/time.
    3. AI confirms and sends a confirmation (using email or SMS if configured).

4. No-Code Automation Platform

  • Purpose: After or during calls, the AI can trigger actions in the automation platform (like updating a CRM, sending an email, or logging results in Google Sheets).
  • Setup: Link your assistant with the “Automation” tab, choose triggers (“Call Ended,” “Customer Agrees,” etc.), and pick the action (send a Slack notification or add a row in Sheets).

5. Custom Mid-Call Tools

  • Purpose: Create your own custom API integrations that the AI can use during calls.
  • Use Cases: Check inventory, verify customer data, fetch real-time information, or integrate with your own systems.
  • Setup: Define API endpoints, parameters, and when the AI should use them.
  • For detailed setup instructions and examples, see our Custom Mid-Call Tools Guide.

Note: Tools can be combined. For instance, the AI can use a custom tool to check availability, then schedule an appointment, and finally transfer to a human agent if needed.

Your AI assistant can speak with built-in voices or a custom cloned voice. Natural, realistic voices increase customer trust and engagement.

1. Built-In Voice Library

  • Powered by: ElevenLabs.
  • Selection: Choose male/female, accent, or language from our default list.
  • Customization: Adjust pitch, speed, or filler usage if desired.

2. Cloning Your Own Voice

  • Why Clone?: For brand consistency or a familiar voice to your audience.
  • Audio Sample Requirements: Provide a clear audio recording (usually 1–5 minutes).
  • Process:
    1. Record yourself reading a script (no background noise).
    2. Upload it in the “Clone Voice” section.
    3. Wait for training to complete (could be minutes or hours).
    4. Test the new voice with small sample texts.

3. Best Practices

  1. High-Quality Audio: The clearer your sample, the better the cloned result.
  2. Steady Delivery: Speak in a natural tone, avoid abrupt changes.
  3. Check for Legal: Ensure you have permission to clone any voice if it’s not yours.

Tip: After selecting or cloning a voice, always do a quick test call to confirm it sounds as expected.

Custom Mid-Call Tools let your AI assistant interact with external systems during calls. Whether checking inventory, verifying customer data, or fetching real-time information, these tools make your AI more powerful and connected.

Overview

Custom Mid-Call Tools enable your AI assistant to:

  • Make real-time API calls during conversations
  • Fetch or submit data to your systems
  • Make informed decisions based on live data
  • Provide accurate, up-to-date information to callers

Key Benefits

  • No coding required – just configure the API endpoint and parameters – AI automatically knows when and how to use the tools – Real-time data access during calls – Seamless integration with your existing systems

Setting Up Your Tool

1. Basic Configuration

 
Main Tool Configuration
 
1

Access Tool Creation

Navigate to Mid call tools and click Create Mid-Call Tool

2

Configure Main Settings

Fill in the essential details:

  • Name: Use lowercase and underscores (e.g., check_order_status)
  • Description: Explain when and how the AI should use this tool
  • Endpoint: Your API URL (e.g., https://api.yourcompany.com/orders)
  • Timeout: How long to wait for responses (in seconds)
  • Method: Choose GET, POST, PUT, PATCH, or DELETE
3

Add Headers

Common headers you might need:

Content-Type: application/json
Authorization: Bearer your_token

2. Variable Configuration

Variable Configuration
 
1

Define Parameters

These are the pieces of information your AI will collect during the call:

Name: order_number
Type: string
Description: "10-digit order number from the customer"
 
2

Set Validation Rules

Add format requirements in the description:

"Date in dd/mm/yyyy format"
"Phone number without spaces"
"Email address for confirmation"

Understanding Parameter Types

String

Text values like names, addresses, or reference numbers

Type: string
Examples: "John Doe", "123 Main St"

Number

Numeric values like amounts, quantities, or IDs

Type: number
Examples: 42, 99.99

true_false

Boolean values for yes/no situations

Type: true_false
Examples: true, false
 

Formatting Help

Add format instructions in descriptions

"Date in dd/mm/yyyy"
"Phone without spaces"

Dynamic Endpoints

When using variables in your endpoint URL, make sure to enclose them in curly braces and use the exact parameter name.

You can make your endpoints dynamic using variables:

Basic URL:
https://api.example.com/orders/status
With Variables:
https://api.example.com/orders/{order_id}/status

The AI will automatically replace {order_id} with the actual value collected during the conversation.

Testing Made Easy

Automatic Testing

Click “Test Tool” to run a test with dummy data:

  • String parameters: “test”
  • Number parameters: 1
  • Boolean parameters: true

You’ll see the response code and body, helping you verify everything works.

Power User Feature: Automation Platform Integration

Need more complex logic? Connect your tool to the automation platform for advanced workflows.

Here’s how to create powerful integrations:

  1. In the automation platform:

    • Create a new flow
    • Add a webhook trigger
    • Build your logic (API calls, data transformation, etc.)
    • End with “Return Response”
  2. In your custom tool:

    • Use the webhook URL as your endpoint
    • Add /sync at the end
    • Example: https://automation.fontumi.ai/webhook/abc123/sync

This lets you:

  • Transform data before/after API calls
  • Make multiple API calls in sequence
  • Apply complex business logic
  • Handle errors gracefully

Real-World Examples

 
 
 

Order Lookup System

 
 
 

Appointment Availability

 
 
 

Customer Verification

Configuring Your AI

 

The AI needs clear instructions in its system prompt to effectively use your custom tools.

Example prompt section:

When to use check_order tool:
1. Customer asks about order status
2. Mentions tracking or delivery
3. Wants to know where their package is
How to use it:
1. Ask for order number if not provided
2. Verify format (ORD-XXXXX)
3. Use tool to fetch status
4. Explain results in simple terms
 

Test your tools with various conversation flows to ensure the AI handles all scenarios smoothly. Start with simple test calls before going live.

 

Filler audio adds natural conversation sounds (like “hmm” or “one moment”) while your AI assistant processes responses. This creates a more human-like interaction by eliminating awkward silences.

How It Works

When enabled, your AI assistant will:

  • Use short audio fillers during processing time
  • Maintain engagement while formulating responses
  • Signal active listening to the caller

Benefits

  1. Improved Conversation Flow

    • Eliminates dead air
    • Keeps callers engaged
    • Reduces hang-ups
    • Creates natural dialogue rhythm
  2. Enhanced User Experience

    • More human-like interaction
    • Less awkward waiting
    • Better caller retention
    • Increased trust

Setup

  1. Go to your AI assistant settings
  2. Find the “Filler Audio” option
  3. Toggle it on
  4. Save your changes

Best Practices

Combine with Fast Engine

  • Use filler audio with the Fast Engine setting
  • Creates the most natural conversation flow
  • Minimizes perceived response time

Use Cases

  • Sales Calls: Keep prospects engaged
  • Customer Service: Show active listening
  • Lead Qualification: Maintain natural flow

Testing

After enabling filler audio:

  1. Make a test call
  2. Listen for natural transition sounds
  3. Verify timing and appropriateness
  4. Adjust if needed

Tip: Start with filler audio enabled – you can always disable it if it doesn’t suit your use case.

Enable your AI assistant to seamlessly schedule meetings and appointments using Cal.com integration. This powerful feature allows your AI to check availability and book meetings directly during calls.

Do not make any new fields required in your Cal.com event settings. The integration only supports default fields and the optional phone field. Adding required custom fields will cause the integration to fail.

Prerequisites

Before setting up Cal.com integration, you’ll need:

  • A Cal.com account (either hosted or self-hosted)
  • An event type configured in Cal.com
  • An API key from Cal.com

Setup Process

1. Cal.com Configuration

  1. Sign up or log in to your Cal.com account
  2. Create a new event type specifically for AI assistant bookings
    • Give it a clear name like “Meeting with AI Assistant”
    • Configure duration, availability, and other settings
  3. Once created, note down the event ID from the URL
  4. Generate an API key:
    • Go to Cal.com settings
    • Navigate to Developer Settings
    • Create a new API key
    • Copy and securely store the API key

2. Customer Contact Information

Email Configuration

To send calendar invites to customers:

  1. Define email in your assistant’s input variables
  2. Pass the customer’s email as the email variable when creating the lead
  3. The system will automatically use this email for calendar invitations

Phone Number in Calendar Events

To include the caller’s phone number in calendar events:

  1. Go to your event settings in Cal.com
  2. Click on “Add a question”
  3. Configure the field with these exact values:
    • Identifier: phone (this must be exact)
  4. Save your changes

3. Adding Cal.com to Your Assistant

  1. In your AI assistant settings, locate the Tools section
  2. Add the Cal.com integration
  3. Configure the tool with:
    • Your Cal.com API key
    • The event type ID

Best Practices

  • Create dedicated event types for AI bookings to track their usage
  • Set clear buffer times between meetings
  • Configure appropriate meeting durations
  • Use descriptive event names that make sense to your customers
  • Keep only default fields and the phone field optional
  • Always include customer email in lead creation for calendar invites

Testing

After setup, we recommend:

  1. Making a test call to your AI assistant
  2. Requesting to schedule a meeting
  3. Verifying the booking appears in your Cal.com dashboard
  4. Checking that the phone number appears in the calendar event
  5. Verifying the customer receives the calendar invitation email
  6. Checking the confirmation emails are received

Troubleshooting

If you encounter issues:

  • Verify your API key is active and has the correct permissions
  • Ensure the event type ID is correct
  • Check that your Cal.com availability is properly configured
  • Confirm no required custom fields are added
  • Verify the phone field identifier is exactly “phone”
  • Confirm the email variable is properly set in assistant settings
  • Check that customer email is being passed correctly in leads
  • Confirm your timezone settings are correct
 

There are two ways to test your AI assistant, depending on whether you want to test inbound or outbound functionality.

Testing Outbound Calls

The fastest way to test your assistant’s outbound capabilities:

  1. Go to your assistant’s settings
  2. Find the “Make test call” purple button
  3. Enter your phone number
  4. Click to initiate the test
  5. You’ll receive a call from your AI assistant immediately

Testing Inbound Calls

To test how your assistant handles incoming calls:

  1. Make sure you have a phone number assigned to your assistant
  2. Call that number from any phone
  3. Your AI assistant will answer and handle the call

Tip: Save your AI’s phone number in your contacts to easily make inbound test calls whenever needed.

 

Fontumi.ai lets you connect three different kinds of phone numbers to your AI assistant:

  1. Normal (Dedicated) Numbers

    • Rented directly from Fontumi.ai.
    • Can be used for both inbound and outbound calls.
    • Typically charged as a monthly rental, with the ability to handle multiple parallel calls on a single number.
  2. SIP Integration (VOIP/PBX)

    • Connect an existing VOIP or PBX number via SIP.
    • This setup allows you to keep your existing numbers while benefiting from Fontumi.ai’s AI.
    • Works for both inbound and outbound—see our SIP Integration Guide for setup instructions.
    • You can configure this directly in your dashboard under Phone Numbers.
  3. Caller ID (Outbound Only)

    • When you already have a phone number (e.g., your personal or business line) but don’t want to port it or integrate via SIP.
    • You verify ownership (via OTP or a short call) so that number can appear on people’s caller ID.
    • Inbound calls won’t be answered by the AI if you use Caller ID alone—it only masks the AI’s outbound calls.

Choosing the Right Option

  • If you need inbound and you don’t already have a VOIP solution, consider renting a dedicated number.
  • If you have an established PBX or VOIP provider, use SIP integration.
  • If you just want to do outbound calls showing your existing phone line, pick Caller ID.

Getting Started

  1. If you see a number you want in the platform, rent it instantly.
  2. If it’s not listed, contact us for custom provisioning. We’ll let you know which documents are required.
  3. Pricing may differ by country, we’ll provide final monthly cost once the number is ready.
  4. Any type of number (local, national, or toll-free) can be custom-provisioned if not visible in the platform.

Custom Provisioning

  • Our team handles the entire process with the carrier.
  • We’ll request any required documents based on the country’s regulations.
  • Typical processing time is 1-3 business days.

After Purchase

  • Assign the number to an AI assistant for inbound calls.
  • Use it as Caller ID for outbound campaigns if desired.
  • Monitor usage and costs in your dashboard.

Tip: Remember to assign the purchased number to an AI assistant.

 

Phone number rental fees vary based on country, number type, and local telecom rules. Below is a general guide:

1. Typical Monthly Costs

  • US/Canada: Around $3.99/month.
  • UK: Typically ~£3/month, but can vary.
  • EU Countries: €3–€5/month, or more for toll-free lines.
  • Others: Some countries can be $3 or more, depending on local taxes.

2. Advanced Documentation

  • Business Registration: Many countries (e.g., France, Germany, Italy) require a local address or company registration to rent a number.
  • ID Proof: Some carriers need a government-issued ID for individuals.

3. Additional Fees

  • Some toll-free lines or special region numbers have higher monthly costs or per-minute surcharges.
  • Calls to or from certain regions might also incur higher usage rates—see Costs & Pricing for full details.

4. Don’t See Your Region?

  • Contact us through the chat widget in the bottom right corner of the screen inside the app to request a number.
  • Provide the necessary documentation, and we’ll attempt to source a local number through our carrier partners.

Note: If you’re integrating SIP or using Caller ID verification, you do not pay a monthly rental, but usage costs may still apply.

Detailed SMS Documentation

This is an overview of SMS features. For detailed instructions on sending SMS through automation flows, check our Automation Platform Documentation.

Requirements

To send SMS messages, you need:

  • An SMS-capable phone number
  • Sufficient credits in your account
  • Proper automation flow setup

SMS Segments

SMS messages are split into segments:

  • Each segment is 160 characters for standard ASCII text
  • Or 70 characters for Unicode (special characters, emojis)
  • Longer messages are automatically split into multiple segments
  • You are charged per segment sent

For example:

  • “Hello! How are you?” (16 chars) = 1 segment
  • A message with 200 ASCII chars = 2 segments
  • A message with emojis and 100 chars = 2 segments

Costs

SMS pricing varies by:

  • Destination country
  • Number of segments
  • Type of content (standard/unicode)

Monitoring & History

Track your SMS activity in the dashboard:

  • Delivery status
  • Timestamp
  • Number of segments
  • Cost per message
  • Recipient details
  • Content preview

Best Practices

  1. Message Length

    • Keep messages concise
    • Monitor segment count
    • Use standard characters when possible
  2. Compliance

    • Include opt-out instructions
    • Follow local regulations
    • Respect quiet hours
  3. Testing

    • Verify number capabilities
    • Test delivery to different carriers
    • Monitor delivery rates

Want to start sending SMS? Check out our automation platform documentation to learn how to set up SMS workflows.

After you’ve acquired a number (or configured SIP or Caller ID), you’ll need to assign it to your AI assistant. The process is the same whether you’re using the number for inbound or outbound calls.

Assigning a Number

  1. Go to Assistants → (Your Assistant) → Settings
  2. Under Phone Numbers, select a number from your Fontumi.ai inventory
  3. Click Save to apply the changes

Number Usage

Once assigned, the number can be used for:

  • Inbound: Callers dialing this number will reach your AI assistant
  • Outbound: The number will appear as Caller ID for outbound campaigns
  • Both: The same number can handle both inbound and outbound calls

Number Verification

For numbers not rented from Fontumi.ai:

  • You’ll need to verify ownership via OTP code or a verification call
  • Once verified, the number can be used for both inbound and outbound
  • Verification status persists across different assistants

Testing

Before going live:

  1. Make an inbound test call to verify the assistant answers
  2. Run a test outbound call to check Caller ID display
  3. Verify any specific features (call transfers, voicemail, etc.)

Tip: Always test both inbound and outbound functionality after making any changes to number assignments.

When someone dials your dedicated (or SIP-integrated) number, Fontumi.ai can answer automatically through an AI Assistant. This section covers the big-picture flow of inbound calling:

  1. Caller Dials Your Number

    • A local, international, or toll-free line assigned to your AI assistant.
  2. AI Assistant Answers

    • Greets the caller using your configured voice and initial message.
    • Follows the system prompt to handle inquiries or gather information.
  3. Optional Actions

    • Transfer to a human operator (if configured).
    • Schedule appointments, check order statuses, or collect data for later use.
  4. Call Completion

    • AI ends the call politely or transfers to a queue/agent if needed.
    • You get transcripts and call analytics afterward.

Tip: Start by renting or provisioning a phone number and linking it to an inbound-type AI Assistant.

If you haven’t already, check out our Phone Numbers section to learn how to obtain or integrate a number. Once you have a number:

  1. Assign It to Your AI Assistant

    • Go to Assistants > (Your Inbound Assistant).
    • Under Phone Number, pick the number you want to use.
  2. Verify Functionality

    • Test by calling the number from an external phone.
    • The AI should answer with your configured greeting.
  3. Monitoring Inbound Lines

    • In the Phone Numbers page, you can see active lines, monthly cost, and usage.
    • Release lines you no longer need to avoid extra rental fees.

Handling Country-Specific Requirements

Some regions may require:

  • Local address or business registration
  • ID documents for toll-free or special lines

If so, you’ll be prompted to upload documents for custom provisioning before your number is activated.

An “Inbound Assistant” is simply an AI assistant set to inbound mode. Key steps:

  1. Prompt & Voice

    • Provide a clear system prompt. Example:
      “You are the Support Bot for Acme Inc. Greet politely, ask for the customer’s need, and attempt to answer basic FAQs.”
    • Choose a voice from the built-in library or a cloned voice.
  2. Initial Message

    • The first line of dialogue once the AI picks up.
    • Example: “Hi, thank you for calling Acme Inc. How may I help you?”
  3. Add Tools (Optional)

    • Transfer: If the caller needs a human agent.
    • End Call: Condition to end the call politely.
    • Appointment Scheduler: If you want them to book a slot on your calendar.
  4. Call Flow

    • In the system prompt, mention potential dialogues, e.g., “If they mention billing, ask for their invoice number.”
  5. Save & Test

    • Dial the inbound number from your cell phone.
    • Confirm the AI greets and responds according to your instructions.

Tip: Revisit your assistant’s settings regularly to improve the conversation flow—especially if you see frequent hang-ups or missed info.

After an inbound call, Fontumi.ai provides transcripts, analytics, and possible automation triggers.

1. Recording & Transcription

  • Recording: Typically saved in the call logs, so you can replay.
  • Transcription: The AI’s recognized text, which is used to generate its responses.

2. Post-Call Data (Summary & Extracted Variables)

  • The AI can store or forward call info (e.g., name, reason for calling) to a connected CRM or spreadsheet.
  • Summaries may include “intent” or “call outcome.”

3. Automation Triggers

  • Using the built-in no-code platform, you can do things like:
    1. Email or Slack the transcript to your team.
    2. Log the call outcome in Google Sheets.
    3. Notify a human agent if follow-up is needed.

4. Viewing Insights

  • In your Fontumi.ai dashboard, go to Calls or History.
    • Filter by inbound calls.
    • Click a specific call to see the transcript, recording, or final notes.

Note: For advanced analytics (like call sentiment or deeper classification), watch out for upcoming features or use the webhook/API to feed transcripts into external tools.

Fontumi.ai supports outbound call campaigns where the AI calls leads or customers automatically. Ideal for:

  • Sales/Marketing: Reaching out to potential clients, offering promotions.
  • Collections/Reminders: Checking overdue payments or reminding appointments.
  • Customer Follow-Ups: Post-purchase check-ins, feedback surveys, etc.

Key Elements

  1. Leads List
    Usually a list of phone numbers (with optional data like names or IDs).

  2. Campaign
    A structured way to manage who gets called, how many times, and in which time window.

  3. AI Assistant
    Handles the conversation, guided by your system prompt and call script.

  4. Caller ID
    The number shown on recipients’ phones. Could be a dedicated number or your verified existing line.

Tip: Each campaign references an AI assistant. If your script changes drastically, you might create a new assistant or edit the existing one.

An outbound “campaign” determines when, how, and to whom calls are made.

1. Setup a Campaign

  1. Go to Outbound / Campaigns in your dashboard.
  2. Click Create New Campaign:
    • Name: e.g. “January Promo,” “Payment Reminder,” etc.
    • Assistant: which AI assistant will handle these calls?
    • Window: choose the time window for the campaign

2. Importing Leads

  • CSV File: Upload phone numbers (plus any extra columns, like name or account number).
  • Google Sheets: Connect via the no-code platform or direct integration to pull leads.
  • CRM: Some CRMs (HubSpot, GHL, etc.) can send leads directly to Fontumi.ai via API or automation.

3. Call Retries & Scheduling

  • Max Retries: e.g., attempt each lead up to 2 times if they don’t answer.
  • Retry Interval: minutes/hours between retries.
  • Time Window: e.g., only call between 9 AM and 6 PM local time to avoid inconveniencing leads.

4. Monitoring & Pausing

  • Once the campaign is live, calls happen automatically during the allowed hours.
  • You can pause or stop the campaign anytime to revise your script or leads list.

5. Analyzing Results

  • Visit Campaign Reports to see:
    • How many calls were answered vs. no-answer.
    • Number of successful vs. failed calls.
    • Average call duration, etc.

Note: Large campaigns with thousands of leads can run concurrently, as AI can handle parallel calls. Watch your minute usage to avoid unexpected costs.

 

When you launch an outbound campaign, you can choose which number appears on recipients’ phones.

1. Dedicated Number

  • If you’ve rented a local or toll-free number, you can select it as the “Phone number” in the assistant settings.
  • Good for brand consistency or if you also accept inbound calls on the same line.
  • No OTP verification needed for numbers rented through Fontumi.ai.

2. Verified Existing Number (Caller ID Only)

  • If you want your personal or company phone line to appear, verify it with an OTP or short call.
  • This won’t handle inbound calls for the AI, but the lead sees that recognized number on caller ID.
  • Note: OTP verification is ONLY required when using your own existing number as Caller ID.

3. SIP Integration

  • If you use a PBX or VOIP platform, you might pass a custom caller ID from your existing system.
  • Make sure your trunk or provider is set to allow a specific outbound Caller ID.

4. Country-Specific Rules

  • Some regions prevent using numbers you don’t own as Caller ID.
  • Always ensure you have the right to present that number to avoid spam or legal issues.

Tip: Test by calling your own phone or a friendly colleague to confirm the correct caller ID is displayed before launching a big campaign.

 

When making outbound calls, the AI assistant can automatically detect if it has reached a voicemail or answering machine:

Voicemail Detection

  • The AI uses advanced detection to identify voicemail systems
  • When voicemail is detected, the call is automatically ended
  • This helps avoid wasting resources and ensures efficient call handling

Benefits of Auto-Drop

  • Saves time and call minutes
  • Prevents awkward or incomplete interactions
  • Allows for automatic retry scheduling
  • Maintains professional communication standards

Best Practices

  • Monitor call logs to track voicemail rates
  • Consider time zones when scheduling calls
  • Plan retries during different hours
  • Target business hours when people are more likely to answer

Reporting

You can track voicemail detection in your campaign analytics:

  • Number of detected voicemails
  • Time of day patterns
  • Success rates for different calling times

Tip: If you’re getting too many voicemails, try adjusting your campaign’s calling hours to when people are more likely to answer.

The power of outbound calling lies in having a clear, well-structured conversation flow. Here’s how to craft an effective script.

1. System Prompt Best Practices

  • Introduce Your Company“You are the Sales Bot for Ace Marketing…”
  • Purpose“…you offer a 20% discount if the user is interested, or schedule a callback if uncertain.”
  • Objection Handling“…if they say ‘no budget’, attempt to collect a reason or set a reminder for next month.”

2. Example (Sales Prompt)

"You are the Sales Bot for ACME Corp. Greet politely, mention the new product launch, and offer a 10% discount if the lead is interested. If they ask for more info, invite them to schedule a call with a human agent. If they refuse or express disinterest, politely end the call."

3. Example (Collections Prompt)

"You are the Collections Bot for ABC Finance. Greet the user, verify their name and last payment date. If they confirm a willingness to pay, gather payment details or schedule a callback. If they refuse, politely note the reason and end the call."

4. Handling Yes/No/Maybe

  • Yes: Provide details or transfer to a human for finalizing.
  • No: Respectfully close, mark lead as not interested.
  • Maybe: Offer to schedule a follow-up call or provide more info.

Tip: Keep your script short and direct. The AI can adapt, but a concise prompt helps keep calls focused and efficient.

 

One advantage of AI-driven outbound is that you can dial large batches of leads simultaneously without hiring more human agents.

1. Handling High-Volume Campaigns

  • Upload Thousands of Contacts:
    • If your plan or usage limit allows, you can import big lists from CSV or integrate with your CRM.
  • Parallel Calls:
    • A single phone number can handle multiple concurrent calls, but watch for compliance (some regions have rules against excessive cold calls).

2. Preventing Spam Flags

  • Reasonable Call Pace:
    • Don’t launch 10,000 calls instantly. Stagger them with short intervals to avoid spam detection or network blocks.
  • Caller ID Rotation (Optional):
    • Some advanced users rotate caller IDs, but ensure they’re all verified and within legal guidelines.

3. Real-Time Monitoring

  • Dashboard:
    • See how many calls are active, success/no-answer rates, average call durations, etc.
  • Campaign Pause:
    • If you spot unusual patterns (like high “no answer” or negative responses), pause the campaign to refine your script or lead quality.

Note: High-volume dialing may ramp up your minute usage quickly. Keep an eye on Costs & Pricing to avoid surprises.

Fontumi.ai uses a System Prompt to guide how your AI assistant interacts with callers. Crafting an effective prompt is key to smoother, more accurate phone conversations.

1. System Prompt vs. Initial Message

  • System Prompt: Overall instructions and context. Example:
    “You are the Support Bot for TechMasters Inc. Greet politely, ask for a name, handle basic troubleshooting, and transfer the call if the issue is complex.”

  • Initial Message: The first thing the AI says, especially for inbound. Example:
    “Thank you for calling TechMasters! How can I assist you today?“

2. Clarity & Structure

  • Be Specific: Outline the main purpose, tone, and steps you want the AI to follow.
  • Use Examples: Show sample dialogues. “If the user says they have a billing question, ask them for their invoice number.”

3. Handling “Unknown” Cases

  • If a user asks about something off-topic, decide whether the AI should:
    • Provide a default response: “I’m not sure, let me transfer you…”
    • Gather more details.

4. Keep It Short & Focused

  • A short prompt often works best; too-long instructions can make the AI slower or prone to “hallucination.”
  • If you have lengthy content, consider a knowledge-base or chunk your text with headings.

Tip: Periodically review your transcripts to see where the AI might need more or fewer instructions.

For more advanced usage, you may want the AI to reference detailed FAQs or documents. Below are current approaches:

1. Copy-Paste into Prompt

  • Pros: Quick to set up.
  • Cons: Large texts can slow down responses or risk partial “hallucination.”
  • Usage: Useful for short references, like top 10 FAQs.

2. Knowledge-Base Feature

  • Fontumi.ai plans to introduce a dedicated “Knowledge Base” or doc upload feature.
  • This would let you store PDFs or text docs that the AI can query on demand.
  • This feature is currently in development and will be available soon. However, you can contact our support team and send us your documents to manually embed them.

3. Best Practices

  • Keep info concise, use bullet points.
  • Separate topics with clear headings so the AI can parse more effectively.
  • Monitor call transcripts to confirm the AI references your data correctly.

Note: If you have an urgent need for large doc integration, contact our support about possible custom solutions or partial “manual” embeddings.

Phone conversations can be messy—callers may interrupt the AI or have background noise. Fontumi.ai provides voice activity detection and speech settings to handle these situations.

1. Voice Activity Detection (VAD)

  • What It Is: A setting that helps the AI wait for the user to finish talking before responding.
  • Configuration: In the assistant’s advanced settings, you can enable or disable VAD.
    • High Sensitivity: AI might interrupt less, but could lead to awkward pauses.
    • Low Sensitivity: AI might talk over the user if they pause mid-sentence.

2. Speech Speed & Filler Usage

  • Speech Speed: Some voices allow you to slow down or speed up how quickly the AI talks.
  • Filler Usage: Decide if the AI uses “umm,” “uhh,” or short “mhm” acknowledgments to sound more natural.

3. Interruptions

  • If a user starts speaking while the AI is talking, the AI can attempt to stop and listen. However, perfect interruption handling can’t be guaranteed due to phone audio overlap.
  • Encourage shorter AI responses in your prompt to reduce collision with the caller’s speech.

Tip: Conduct test calls to find the right balance of sensitivity and speed. Overly fast responses or overly long monologues can frustrate callers.

Fontumi.ai offers multiple languages and accents for your AI assistant. Choose from built-in sets or request new ones if needed.

1. Available Languages

  • English (various accents: US, UK, Australian, etc.)
  • Spanish (Latin American, Spain accent)
  • French, German, Italian
  • Others: +40 languages supported, play samples here

2. Requesting a New Language

  • If your language is missing, contact support. We may add it if feasible. Some might require a one-time fee for model training or verification.

3. Accent Tuning

  • Within a language, you can pick certain accents (like US English vs. British English).
  • Speed and pitch settings can further localize the sound.

4. Testing & Verification

  • Always run sample calls in your chosen language to ensure recognition is solid.
  • AI recognition quality can vary; watch transcripts for repeated errors and refine your prompt or speech speed.

Note: Additional fees or wait times might apply for lesser-known languages or custom accent requests.

Fontumi.ai uses a credit/minute system to track usage for both AI processing and carrier network fees. Here’s how it breaks down:

1. Main Components

  1. AI Cost

    • Billed in fractional increments by the second (e.g., 0.5 minute for a 30-sec call).
    • Rate depends on your plan (Starter, Pro, Agency, etc.).
  2. Carrier Cost

    • The telecom side of the call, generally rounded up to the next minute and converted to your plan’s minute rate.
    • Region-dependent: e.g., calling US vs. Europe vs. Asia has different carrier rates.
  3. Number Rental

    • If you rent a phone number, there’s a monthly fee (e.g., $3.99 for a standard US number).
    • If your region isn’t listed, we can custom-provision a number upon verifying documents.
    • Each number’s cost is billed monthly until released.
  4. Extra Fees (Optional)

    • SMS: If your number is SMS-capable, standard per-message fees apply.
    • Voicemail detection: Billed as 1 minute per call.
    • High-Volume: Potential bulk discounts if you exceed tens of thousands of minutes monthly.

2. Visual Example

Suppose you have 200 included minutes in your plan. A typical 1-minute call might consume ~1.5 minutes from your balance if carrier cost is half your plan’s rate. This means you’d have about 198.5 left. By the end of the billing cycle, any unused minutes do no rollover.

3. Checking Call Logs

  • Dashboard → Call History: See each call’s final cost breakdown.
    • AI usage (seconds → fraction of a minute).
    • Carrier usage (rounded up → fraction of a minute after conversion).
    • Summed total in “minutes” deducted from your included or purchased balance.

4. Monitoring & Alerts

  • Watch your real-time usage in the dashboard.

5. Putting It All Together

  1. Pick a Plan: Decide on Starter, Pro, or Agency—higher plans have cheaper AI rates.
  2. Acquire or Verify a Number: Rent from Fontumi.ai or add your own as caller ID for outbound.
  3. Start Making Calls: Inbound or outbound usage deducts from your minute balance.
  4. SMS & Extras: If relevant, each text or advanced feature also deducts from your balance or is billed separately.

That’s the overall cost structure. For a deeper look at the math behind minute conversion, check our Pricing Breakdown page.

Pricing Breakdown

Fontumi.ai uses a minutes-based system for billing. These minutes (or tokens/credits) get deducted from your balance each time you make or receive a call. The actual “per-minute cost” depends on your plan, and carrier costs are also converted into minutes. Below is how it works.

1. Inbound vs. Outbound Calls

  • Inbound: You spend minutes as soon as the AI assistant picks up and is engaged in a call.
  • Outbound: Minutes start deducting once the customer answers the call and stays connected. Dial time is not billed.

Note: A call is considered active until the AI or the user hangs up, or until voicemail detection ends the call if the user’s voicemail answers (for outbound).

2. How Minutes Are Used

a) AI Spoken Time

  • If your AI assistant is actively on the call for 1 minute, you consume 1 minute of AI time.
  • The cost is prorated by the second, so a 30-second call uses 0.5 minutes from your plan (for AI time).

b) Carrier Conversion

  • Carrier cost (the telecom network fee) is also deducted from your balance but is typically rounded up to the next minute.
  • We convert the carrier’s dollar amount to minutes at your plan’s rate.
    • Example: If your carrier charge is $0.05 for a 1-minute call, and your plan’s AI rate is $0.10/min, we convert that $0.05 to 0.5 minutes from your balance.

So a single 1-minute conversation might consume:

  • 1 AI minute (for the assistant)
  • + 0.5 “carrier minutes” (converted from the carrier’s $0.05 to half your AI cost).
  • = 1.5 minutes total deducted from your plan balance.

3. Per-Second Billing vs. Rounding

  1. AI Time

    • Measured per second, so 70 seconds is ~1.17 minutes of AI usage.
    • Deducted exactly from your plan’s minute balance.
  2. Carrier Time

    • Rounded to next full minute for the network fee.
    • Then converted into a fraction of your AI plan cost to decide how many “minutes” to deduct from your credit balance.

4. Included Minutes & Top-Ups

  • Each Plan: Usually includes a monthly allotment of minutes.
  • Using Up Minutes: Once you exceed included minutes, you can top up your wallet with additional minutes at your plan’s rate.
  • No Rollover: Unused minutes typically don’t roll over to the next month.

Example

You’re on the Starter Plan with 200 included minutes:

  • If you make enough calls that total 180 AI minutes + carrier conversions = 180 used, you have 20 left this month.
  • Next month, you reset to 200. If you need 210 minutes, you pay for 10 extra minutes at your plan’s rate.

5. Volume Discounts or Tiers

  • Plans vary (e.g., Starter at $0.20/min, Pro at $0.15/min, Agency at $0.09/min).
  • High-volume usage (like 50,000+ minutes/month) can often get bulk discounts by contacting sales.

6. Quick Usage Examples

Example A (Outbound Call, Starter Plan)

  • AI Rate: $0.20/min
  • Call Duration: 30 seconds → 0.5 AI minutes = $0.10 AI cost.
  • Carrier: $0.01/min, but 30 seconds → 1 minute rounded up → $0.01.
    • $0.01 at your plan’s $0.20 rate = 0.05 “plan minutes” used (Or if you do a simpler approach, $0.01 / $0.20 = 0.05 minutes)
  • Total: 0.5 (AI) + 0.05 (carrier) = 0.55 minutes from your plan. If you had 200 included, you’d have 199.45 left.

Example B (Inbound Call, Pro Plan)

  • AI Rate: $0.15/min
  • Call Duration: 90 seconds → 1.5 AI minutes = $0.225 AI cost.
  • Carrier: Suppose inbound is $0.015/min, rounding up to 2 minutes if the call was 1.5 min. That’s $0.03 total.
    • $0.03 / $0.15 = 0.2 minutes from your plan.
  • Total: 1.5 (AI) + 0.2 (carrier) = 1.7 minutes deducted.

FAQ

  • Do I pay double if user + AI talk simultaneously?
    No, it’s based on total call duration, not per speaker concurrency.
  • What if someone picks up then instantly hangs up?
    The AI might register a few seconds; cost is fractional for the AI, but carrier may round up to 1 minute.

Bottom Line
All calls burn AI time plus a converted carrier cost from your plan’s minute balance. Keep track of usage in your dashboard, top up if needed, and choose the plan that best suits your volume.

Fontumi.ai offers multiple ways to handle phone numbers for inbound or outbound calls. You can rent a dedicated number from us, use a SIP trunk (no monthly fee but carrier costs are on your own PBX), or verify an existing Caller ID (also no monthly fee, but region-based per-minute charges).

1. Renting a Dedicated Number

If you want a fully managed inbound/outbound line, you can rent it directly in the platform:

  • Monthly Fee: Typically $3.99/month for standard local numbers (US/CA/UK). Regions vary:
    • EU Countries: €3–€5/month
    • Latin America, Asia, Africa: $10+ in some cases, depending on availability or local taxes
  • Custom Provisioning: If you don’t see your desired country or region listed, our team can custom-provision a number after verifying local documents.

Per-Minute Rates

  • Outbound calls on a rented number: depends on the country you’re calling—could range from $0.05/min to $0.50/min if it’s an expensive destination.
  • Inbound calls: usually no extra charge unless it’s a special/toll scenario in that region.

2. SIP Integration (No Monthly Fee)

If you already have a VOIP/PBX solution, you can integrate via a SIP trunk with no monthly rental from Fontumi.ai. Instead, you pay:

  • SIP Per-Minute: $0.00045/min on our side for carrier bridging. Your VOIP provider may also have separate usage fees.
  • Your Existing Number: You’ll continue to use your own phone lines for inbound and outbound, but the carrier layer costs $0.00045/min with us whenever the AI is on the call.

This is ideal if you’re comfortable managing your own phone system or want to keep your existing numbers without renting from us. See our SIP Integration Guide for setup instructions.

3. Caller ID (No Monthly Fee)

You can verify an existing number for outbound calls only—no inbound routing.

  • Verification: We confirm ownership via a short OTP or call.
  • Per-Minute: For the telephony used behind the scenes, we charge region-based rates.
    • Example: In the US, Caller ID usage might be $0.01/min.
    • Other countries vary; contact support for specifics.

Note: Caller ID alone does not enable inbound AI; it only masks your outbound calls with your verified number.

4. International Rates & Regions

When making outbound calls:

  • Carrier Rates: Some countries cost $0.01/min, others $0.50/min due to local carriers.
  • Inbound: If you rent a number in a high-cost region or special type, inbound calls could have surcharges.

Regardless of whether you rent a number or use Caller ID/SIP, the carrier portion of the call cost depends on the destination/origin country and is typically added to your overall usage.

5. Putting It All Together

  1. Rent a Number
    • Pay a monthly fee (from $3.99), plus standard inbound/outbound carrier costs for calls on that line.
  2. Use SIP
    • No monthly from us, but a $0.00045/min AI bridging cost, plus your own PBX fees.
  3. Caller ID
    • No monthly from us, but region-based per-minute telephony charges (e.g., $0.01/min in the US). Outbound only.

Phone Number Availability

Fontumi.ai can provide phone numbers in any country. There are two ways to get a number:

1. Instant Provisioning

Numbers in these regions are available directly from your dashboard:

  • United States
  • Colombia
  • Mexico
  • Perú
  • And more…

Simply go to Phone Numbers in your dashboard and select from the dropdown.

2. Custom Provisioning

Need a number in a country not shown in the dropdown? No problem! We can help:

  1. Contact us via the live chat
  2. Let us know:
    • Which country you need
    • How many numbers
    • Your use case (inbound/outbound)
  3. We’ll handle the provisioning process for you

Documentation Requirements

  • Standard Countries (in dropdown): Usually just basic account verification
  • Other Countries: May need:
    • Business registration
    • Local address
    • Industry-specific licenses
    • Other compliance documents

We’ll guide you through exactly what’s needed for your specific case.

Timeframes

  • Dropdown Countries: Instant provisioning
  • Custom Provisioning: Usually 1-3 business days, depending on:
    • Country requirements
    • Document verification
    • Local regulations

Need a specific number? Just reach out via live chat, and we’ll help you get set up in any country you need!

After you meet any compliance requirements and purchase or provision your numbers:

  1. View All Numbers

    • In your dashboard → Numbers. You’ll see monthly costs, expiration/renewal dates, etc.
  2. Releasing or Renewing

    • Release a number if you no longer need it.
    • Renewals happen automatically each month unless you release it.
  3. Scaling Up

    • If you need multiple lines for different markets, repeat the provisioning steps.

This guide will help you understand and set up SIP integration. If you need clarification during setup, our support team is available to assist.

What is SIP Integration?

SIP (Session Initiation Protocol) integration allows you to connect your existing phone system to Fontumi.ai. Think of it as building a bridge between your current phone setup and our AI platform. This means you can:

  • Use your existing phone numbers with our AI assistants
  • Keep your current phone system and provider
  • Make and receive calls through your existing setup
  • Maintain full control of your numbers
  • Reduce carrier costs by using local VoIP providers with better rates

How It Works

When you integrate your phone system with Fontumi.ai:

  1. Inbound Calls: Calls to your numbers are routed through your phone system to our AI assistants
  2. Outbound Calls: Our AI assistants can make calls appearing from your numbers
  3. Management: You keep managing your numbers through your current provider
  4. Cost Efficiency: Leverage your VoIP provider’s competitive rates for call termination

Integration Options

You can connect your phone system to Fontumi.ai in two ways:

1. PBX Extension Integration

This is like giving our AI platform an “extension” on your phone system:

  • What it is: Connect a specific extension from your PBX/phone system
  • Perfect for:
    • Testing the integration
    • Routing specific extensions to AI
    • Simple setup with existing phone systems
  • You’ll need:
    • Your extension number (e.g., 1000)
    • Extension username and password
    • Your PBX server address (e.g., pbx.yourcompany.com)

Real-world example:

Your office uses extensions 1001-1010 for staff
You set up extension 1011 for the AI assistant
Calls to 1011 go to the AI
The AI can make calls appearing as extension 1011

2. Direct Number Integration

This connects specific phone numbers to our platform:

  • What it is: Route one or more of your phone numbers to our AI
  • Perfect for:
    • Dedicated AI phone lines
    • Customer service numbers
    • Sales or support lines
  • You’ll need:
    • Your phone number (e.g., +1 555 0123)
    • SIP credentials from your provider
    • Provider’s SIP server address

Real-world example:

You have a support number: +1 555 0123
You connect this number to our AI
All calls to +1 555 0123 are handled by the AI assistant
The AI makes outbound calls showing +1 555 0123

Authentication & Call Flow

Bidirectional Configuration

The SIP integration uses the same credentials for both inbound and outbound calls:

  • Inbound Calls (VoIP → Fontumi.ai):

    Your VoIP system authenticates using username/password
    
    Calls reach our platform
    
    AI assistant answers
    
  • Outbound Calls (Fontumi.ai → VoIP):

    AI initiates call
    
    Our platform authenticates to your VoIP using same username/password
    
    Call reaches destination
    

Credential Synchronization

For the integration to work properly:

  1. The credentials you set in Fontumi.ai dashboard must match exactly with your VoIP configuration
  2. The same username/password combination is used for both directions
  3. Any changes to credentials must be updated in both systems

If you change credentials in your VoIP system, remember to update them in Fontumi.ai dashboard (and vice versa) to maintain the connection.

Setting Up Your Integration

Step 1: Gather Your Information

For PBX Extension:

Extension number: e.g., 1000
Server address: e.g., pbx.company.com
Username: Your extension username
Password: Your extension password

For Direct Number:

Phone number: e.g., +1 555 0123
SIP server: e.g., sip.provider.com
Username: Provided by your phone company
Password: Provided by your phone company

Step 2: Configure in Dashboard

  1. Go to your Fontumi.ai dashboard
  2. Navigate to Phone Numbers
  3. Click “Integrate SIP trunk”
  4. Fill in your details based on your integration type

Step 3: Number Format Configuration

This tells our system how to format phone numbers when making calls. Choose based on your provider’s requirements:

  1. International with +

    Format: +[country][number]
    Example: +1 202 555 0123
    SIP Request: sip:+12025550123@your.pbx.com
    
  2. International without +

    Format: [country][number]
    Example: 1 202 555 0123
    SIP Request: sip:12025550123@your.pbx.com
    
  3. National format

    Format: [local number]
    Example: 0741926265
    SIP Request: sip:0741926265@your.pbx.com
    

Step 4: Verify Setup

After configuration:

  1. Make a test call to your number/extension
  2. Check that the AI assistant answers
  3. Use the test call feature to verify outbound calling

Security Requirements

Your SIP credentials need to be secure:

  • Username: Your extension number or provider-supplied username
  • Password must have:
    • 12 or more characters
    • Numbers
    • Upper and lowercase letters
    • Special characters recommended

Common Questions

Can I use multiple numbers?

Will I lose control of my numbers?

Can I still use my numbers for regular calls?

What if I need to change settings later?

How does this help with call costs?

Need help setting up? Our support team specializes in helping customers integrate their phone systems. We’ll guide you through the entire process, ensuring a smooth setup with your specific phone system configuration.

Read the full documentation

This is a brief overview of our automation capabilities. For in-depth documentation, tutorials, and advanced features, visit our dedicated Automation Platform Documentation.

Fontumi.ai includes an internal automation engine (similar to Zapier or Make) that lets you build flows—no coding required. For instance:

  1. Trigger: A call ends.
  2. Action: A Slack notification is sent with call outcome and transcript.

Key Concepts

  • Triggers: Events inside Fontumi.ai (e.g., “call ended,” “inbound call context injection”).
  • Actions: Steps that happen in response (e.g., “send email,” “update Google Sheets,” “webhook to CRM”).

Common Use Cases

  • Post-Call Data Handling: Log transcripts in a database or notify your team of new leads.
  • Lead Import: Automatically fetch new leads from a Google Sheet or CRM into an outbound campaign.
  • Appointment Scheduling: Once a caller confirms a time with the AI, you create or update a calendar event.

Setting Up a Workflow

  1. Go to Automations in your dashboard.
  2. Click Create Workflow.
  3. Pick a trigger (like “Call Ended”) and select the assistant.
  4. Add actions (like “Send Email to Team,” “Add Row in Sheets,” etc.).
  5. Test and monitor logs to ensure everything runs smoothly.

Tip: Keep your workflows simple at first. Complex logic is possible, but it’s best to start with a single trigger → single action until you get comfortable.

Want to learn more? Check out our detailed automation documentation for advanced features, tutorials, and best practices.

If you want deeper customization beyond no-code blocks, Fontumi.ai supports webhooks and a REST API.

1. Webhooks

  • When to Use: Trigger events in external systems the moment something happens in Fontumi.ai (e.g., “Call Ended,”).
  • Configuration: Set a webhook URL in your assistant/campaign settings or the automation platform.
  • Payload: Typically includes call ID, transcript, call outcome, or any user data collected.

2. REST API

  • Key Functions:

    1. Create/Update Leads
    2. Manage Campaigns
  • Auth & Rate Limits: Usually uses API tokens. Check API docs for details on endpoints and usage quotas.

3. Example Use Cases

  • Real-Time CRM Sync: For each new call, post data to your CRM’s endpoint.
  • Custom Dashboards: Pull call data into your own analytics dashboard.

Note: You’ll find the official API reference in a dedicated docs section or via your Fontumi.ai dashboard. Always secure your tokens and test endpoints in a dev environment.

 

For businesses with existing PBX or VOIP infrastructure, Fontumi.ai can integrate through SIP trunks or direct connections:

1. SIP Trunk

  • How It Works: You share your SIP credentials (server, username, password). Fontumi.ai configures a trunk internally.
  • Inbound/Outbound: AI can pick up inbound calls from your PBX or place outbound calls using your existing number ranges.

2. Caller ID Forwarding

  • If your PBX already handles call routing, pass the call to Fontumi.ai only when certain conditions are met (like after IVR selection).

3. Hybrid Model

  • Some advanced setups keep human agents on your PBX but leverage the AI for high-volume or after-hours calls.
  • Example: During business hours, normal agents handle calls. After hours, calls route to the AI assistant via SIP trunk.

4. Things to Note

  • SIP sometimes requires opening firewall ports or whitelisting IPs.
  • Carrier charges from your PBX provider still apply, plus any Fontumi.ai usage fees.

Tip: Contact support for guidance if you’re new to SIP or PBX integration. We can assist with the config steps.

If you’re experiencing issues with voice quality or response timing, you can adjust several settings to optimize performance.

Response Speed vs. Accuracy

Your AI assistant has adjustable engine settings:

  • Fast Engine: Quicker responses but might be less accurate
  • Standard Engine: Balanced speed and accuracy
  • Accurate Engine: Most accurate but slower responses

Adjust these in your assistant’s settings under “AI Engine Configuration”.

Filler Audio

To minimize silence during processing:

  • Enable “Filler Audio” in your assistant settings
  • The AI will use natural sounds (like “hmm” or “one moment”) while processing
  • Works best with the Fast Engine for near-instant perceived responses

Common Issues & Solutions

  1. Slow Responses

    • Switch to Fast Engine mode
    • Enable Filler Audio
    • Simplify your system prompt
  2. Inaccurate Responses

    • Use the Accurate Engine mode
    • Provide more context in your prompt
    • Add specific examples
  3. Voice Quality

    • Try different voice models
    • Adjust speech speed settings
    • Try cloning a voice

Optimization Tips

  • For sales calls: Use Fast Engine + Filler Audio for natural flow
  • For support: Consider Accurate Engine for better comprehension

Need help? Contact support if these adjustments don’t resolve your issues.

1. Unexpected Charges?

  • Large Outbound Campaign? Possibly your calls used more minutes than expected.
  • Did You Rent Multiple Numbers? Monthly fees stack if you keep multiple lines active.

2. Refund / Cancellation Policies

  • Check your plan’s terms. Usually usage-based minutes are non-refundable because resources are used in real-time.
  • If you have a monthly plan with included minutes, you can often cancel future renewals but not partial months.

3. Tracking Usage

  • Dashboard: Real-time usage counters show minutes consumed.
  • Notifications: Set alerts if you near a monthly threshold.

Tip: If usage spiked unexpectedly, see call logs or see if an employee triggered a large campaign by mistake.

 

Call quality can be affected by both technical factors and AI settings. Here’s how to optimize both:

AI Engine Impact

Your choice of AI engine affects perceived call quality:

Fast Engine + Filler Audio

  • Minimal latency
  • Quick back-and-forth
  • Natural conversation flow
  • Best for most calls

Standard/Accurate Engine

  • Longer processing time
  • More accurate responses
  • Better for complex conversations

Optimization Tips

  • Start with Fast Engine + Filler Audio
  • Switch to Standard/Accurate only if needed
  • Monitor call recordings for quality
  • Test different voice models

Quick Fixes

If experiencing issues:

  1. Try a test call
  2. Switch to a faster engine setting
  3. Enable filler audio
  4. Check network connection

Tip: The combination of Fast Engine and Filler Audio typically provides the best perceived call quality.

 

Your AI’s behavior can be fine-tuned through a combination of engine settings and prompt adjustments.

Engine Settings Impact

Different AI engine modes affect behavior:

Fast Engine

  • Quick, more conversational responses
  • May occasionally miss context
  • Best for: Simple interactions, sales calls
  • Works great with Filler Audio for natural flow

Standard Engine

  • Balanced understanding and speed
  • Good for most use cases
  • Default recommendation for new assistants

Accurate Engine

  • Deep context understanding
  • More thoughtful responses
  • Best for: Complex support, detailed information gathering
  • May have longer pauses between responses

Common Issues & Solutions

  1. AI Misunderstanding Context

    • Switch to Accurate Engine
    • Add more context to your prompt
    • Include example conversations
  2. Unnatural Conversation Flow

    • Enable Filler Audio for smoother transitions
    • Use Fast Engine for quicker back-and-forth
    • Add conversation examples in your prompt
  3. Repetitive Responses

    • Review and update your system prompt
    • Add variation examples
    • Consider switching to Standard/Accurate engine

Optimization Tips

  • Sales Calls: Fast Engine + Filler Audio for engagement
  • Customer Support: Accurate Engine for better problem solving
  • Lead Qualification: Standard Engine for balanced performance

Testing Changes

After adjusting settings:

  1. Use the test call feature
  2. Try different conversation scenarios
  3. Monitor call recordings for improvement

Tip: Start with Standard Engine and adjust based on your specific needs and feedback.

Automation Platform

The Fontumi Automation Platform helps you create powerful AI call automation workflows without coding. Build flows that enhance your AI calling system by processing variables before calls, handling post-call actions, and creating seamless integrations with your existing tools.

 

Flow Builder

Key Features

AI Call-Based Triggers

  1. Call Ended Trigger

    • Activates immediately when an AI call completes
    • Access full conversation transcript and AI responses
    • Use call duration, status, and detailed metadata
    • Perfect for post-call automation like CRM updates
    • Trigger follow-up actions based on call outcomes
  2. Inbound Call Variable Injection

    • Triggers before AI assistant picks up the call
    • Enriches AI context with real-time customer data
    • Customizes AI behavior based on caller information
    • Returns variables that get injected into AI prompts
    • Enables personalized conversation flows

Essential Actions

  1. Hubspot Integration

    • Update contact records with call outcomes
    • Create new contacts from inbound calls
    • Sync conversation insights to CRM
    • Track AI interaction history
    • Automate lead qualification
  2. Campaign Management

    • Add qualified leads to AI calling campaigns
    • Schedule AI follow-up calls
    • Manage call priorities based on outcomes
    • Track conversion rates per campaign
    • Automate campaign assignments
  3. External Systems

    • Send post-call summary emails
    • Update spreadsheets with call data
    • Trigger webhooks for custom integrations
    • Connect with your business tools
    • Automate multi-step workflows

How It Works

  1. Choose Your Call Trigger

    • “Call Ended” for post-conversation automation
    • “Inbound Call” for real-time AI context injection
  2. Configure Call Variables

    • Map AI conversation data and transcripts
    • Access caller details and history
    • Define AI routing logic
    • Set up custom conversation variables
  3. Add Smart Actions

    • Update CRM with call outcomes
    • Send automated notifications
    • Schedule follow-up activities
    • Return enriched context to AI

Example Use Cases

Intelligent CRM Update

Trigger: AI Call Ended

Process Conversation Insights

Update Hubspot Contact

Schedule Next AI Interaction

Smart Inbound Call Handling

Trigger: Inbound Call to AI

Lookup Customer in Hubspot

Return Enriched Context

AI Assistant Personalizes Conversation

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