Outbound Calls

Make outbound calls with your UponAI agents using the API or dashboard.

Overview

This guide covers how to make outbound calls with your UponAI agents. Before proceeding, ensure you have:

• Created and configured an agent
• Purchased or imported phone numbers
• Set up your API credentials

Step 1: Bind Agents to Phone Numbers

Before making calls, assign agents to your phone numbers. This configuration determines how your number handles both inbound and outbound calls.

Setting	Purpose	Use Case
Inbound Agent	Handles incoming calls to this number	Customer support, callbacks
Outbound Agent	Used when making calls from this number	Sales outreach, notifications

Flexible agent assignment:

• Different agents — Use specialized agents for inbound vs outbound
• Outbound only — Leave inbound agent unset to prevent callbacks
• Inbound only — Configure only an inbound agent for receive-only numbers

After binding an inbound agent, your number is immediately ready to receive calls.

See A/B Testing to split outbound traffic across multiple agents.

Step 2: Make Outbound Calls

International Calling Restrictions

• UponAI-purchased numbers — Supports calling to 15 countries
• Imported numbers — International calling depends on your telephony provider’s settings

Call Parameters

When making outbound calls, these parameters are supported:

Parameter	Type	Description
from_number	string (E.164)	Your UponAI-managed or imported number
to_number	string (E.164)	Destination number
override_agent_id	string	Override the agent used for this call (optional)
override_agent_version	integer	Version of the override agent; defaults to latest if omitted
agent_override	object	Per-call partial overrides for agent behavior (optional)
metadata	object	Free-form metadata stored with the call
retell_llm_dynamic_variables	object	Key-value strings injected into prompts/tools (optional)
custom_sip_headers	object	Outbound SIP headers forwarded to your provider (optional)
ignore_e164_validation	boolean	Bypass E.164 validation for custom telephony only

Node

const registerCallResponse = await uponai.call.createPhoneCall({
  from_number: '[phone]', // replace with your number
  to_number: '[phone]',   // replace with the number to call
  // Optional: per-call agent selection and overrides
  override_agent_id: 'agent_abc123',
  override_agent_version: 0, // or omit to use latest
  agent_override: {
    agent: {
      voice_speed: 1.1,
      enable_backchannel: true,
    },
  },
  retell_llm_dynamic_variables: {
    name: 'John Doe',
    blood_group: 'B+',
  },
  custom_sip_headers: {
    'X-Custom-Header': 'Custom Value',
  },
});

console.log(registerCallResponse);

Step 3: Configure CPS (Calls Per Second)

CPS controls how many outbound calls you can initiate per second. This prevents system overload and ensures call quality.

Provider	Default CPS	Maximum CPS	Notes
Twilio	1	5	Changes take up to 10 minutes
Telnyx	1	16	Instant updates
Custom Telephony	1	Concurrency ÷ 20	Based on your concurrency limit

Exceeding CPS limits results in rejected calls. Start low and scale gradually based on actual needs.

Best practice — implement retry logic with exponential backoff:

const maxRetries = 3;
let retryDelay = 1000; // Start with 1 second

for (let i = 0; i < maxRetries; i++) {
  try {
    await makeCall();
    break;
  } catch (error) {
    if (error.code === 'rate_limited') {
      await sleep(retryDelay);
      retryDelay *= 2; // Exponential backoff
    }
  }
}

Step 4: Monitor Call Details

API Polling

Use the Get Call API to retrieve the full transcript, call recording, latency metrics, function call logs, and call duration/status.

Real-time Webhooks

Set up webhooks to receive instant notifications for: call started, call ended, call analyzed, and call failed events. Ideal for production systems.