Skip to main content

​
What are Functions?

Functions give your AI agent the ability to perform actions during calls. They enable real-time capabilities like transferring calls, ending conversations, booking appointments, and executing custom logic. Two Categories:
  • Built-in Functions - Pre-configured actions (transfer, end call, scheduling)
  • Custom Functions - Your own logic (API calls, custom code)

​
Built-in Functions

Ready-to-use functions for common call management and scheduling tasks.

​
Call Management

Control call flow and routing.

Transfer Call

Transfer calls to phone numbers with warm transfer support

End Call

Gracefully end conversations when appropriate

​
Scheduling (Cal.com)

Book appointments and check availability using Cal.com integration.

Check Availability

Query available time slots from Cal.com

Book a Meeting

Schedule appointments directly in Cal.com

​
Custom Functions

Create your own functions with API integrations or custom code.

​
Three Types

Pre-Call

Modify system prompt and metadata before calls start

In-Call

Execute actions during active calls with AI triggers

Post-Call

Process call data and execute logic after calls end

​
Modes

Basic Mode - API integration without code
  • Configure API endpoints
  • Map variables to parameters
  • Perfect for existing APIs
Advanced Mode - Write custom code
  • Python (pre-call, in-call)
  • JavaScript (post-call)
  • AI-powered code generation

Custom Functions Guide

Complete guide to creating custom functions

​
How Functions Work

​
Built-in Functions

  1. Add Function - Configure in agent settings
  2. Set Parameters - Phone numbers, descriptions, Cal.com details
  3. AI Triggers - AI decides when to call based on description
  4. Action Executes - Function runs automatically

​
Custom Functions

Pre-Call: 
[Pre-Call Function] → [System Prompt Updated] → [Call Starts]
In-Call: 
[AI Detects Trigger] → [Function Executes] → [AI Uses Result]
Post-Call: 
[Call Ends] → [Conditions Check] → [Function Executes]

​
Common Use Cases

​
Built-in Functions

  • Transfer: Route to human agents, specialists, departments
  • End Call: Complete resolved conversations gracefully
  • Scheduling: Book appointments, check calendars

​
Custom Functions

Pre-Call:
  • Fetch user preferences from database
  • Customize greeting based on region
  • Load context from CRM
In-Call:
  • Check product availability
  • Validate customer data
  • Query databases
  • Call external APIs
Post-Call:
  • Calculate next date of action (NDOA)
  • Update CRM with call results
  • Send follow-up emails
  • Generate reports

​
Quick Start

1

Choose Function Type

Built-in for common tasks, custom for specific needs
2

Configure Function

Set parameters (built-in) or create logic (custom)
3

Add Description

Tell AI when to trigger the function
4

Test

Make test calls to verify function behavior

​
Best Practices

  • Clear descriptions - Be specific about when AI should call functions
  • Test thoroughly - Verify functions work in different scenarios
  • Error handling - Handle failures gracefully in custom functions
  • Keep focused - One function, one purpose
  • Monitor usage - Review function calls in analytics
Start with built-in functions for standard tasks, then add custom functions as your needs grow.

​
Next Steps

Choose a function category to get started:

Built-in Functions

Explore pre-built call management and scheduling

Custom Functions

Create your own functions with code or APIs