Configuring OpenAI for 3CX AI Agents

Introduction

This guide explains how to integrate OpenAI with 3CX AI Agents for intelligent receptionist and call-handling scenarios.

This feature requires 3CX AI Edition.

Set up an OpenAI account

If you do not already have an OpenAI account, sign in or create one at the OpenAI login page.

Create a Project and set up Billing

  • Sign in to the OpenAI Login page.
  • Create a new Project and give it a descriptive name.
  • Go to "Settings → Billing" and complete the billing setup.
  • Ensure you have enough credit for your expected usage.

Note: You must have a paid OpenAI account for correct functionality; trial accounts are limited and can exhibit unpredictable issues/errors. OpenAI accounts who pay a minimum of $100 are typically elevated to Tier 3 directly.

Configure Model Access and Limits

  • Go to "Project → Limits".
  • Set a budget to control your spending.
  • Under Allow or block models, keep the list empty to allow all models
  • Under Rate limits, increase limits for the models above as needed (larger installations may require higher limits to avoid unpredictable behavior).

Note about Rate Limits: your ability to raise limits depends on your OpenAI API usage tier / account history.

Create a New API Key

  • Go to "Dashboard → API Keys".
  • Click Create a New Secret Key.
  • Enter a descriptive name and set permissions to All.
  • Copy the key and store it securely.

Configure OpenAI in 3CX

In the 3CX Admin Console, go to Admin > Integrations > AI. Click Realtime API and choose OpenAI in the AI Provider dropdown.

  • Configure the following settings:
  • API Key: paste the API key created in the OpenAI dashboard.
  • AI Realtime Model: select the OpenAI realtime model recommended by your 3CX version.
  • AI Text Model: select the OpenAI text model recommended by your 3CX version.
  • Fill in:
  • Company Name
  • Company Description; this is used by AI Agents to understand your organization’s context.
  • Click the Save button.

Setup AI Agents and Knowledge Sources

For detailed AI Agent setup, see the main 3CX AI Agents Configuration guide.

Technical notes

  • Audio codec: PCMU
  • If your OpenAI account restricts model access, allow gpt-realtime-whisper and the models selected for Realtime and Text in the Realtime API settings.
  • Ensure the 3CX Firewall Checker passes successfully.
  • Allow outbound traffic on:
  • TCP 443 – used for OpenAI Realtime API signaling and session setup.
  • UDP 3478 – used for the WebRTC media connection.
  • 3CX establishes the OpenAI Realtime connection in three stages:

AI models

OpenAI regularly updates models and may deprecate older versions. 3CX updates its recommended models as supported versions change. Ensure the OpenAI project can access the models required by your installed 3CX version.

See also

Last Updated
This document was last updated on 20 Aug 2026
https://www.3cx.com/docs/ai-agent-configuration-openai/