Connecting OpenAI to Your Phone Number
Click2Call has a built-in OpenAI connection profile: enter your Project ID and calls to your Australian number are routed to the OpenAI Realtime API. This guide covers both ends — what to set up in the OpenAI platform, and what to configure in Click2Call.
Last reviewed: September 2026
Before you start: this one needs code
OpenAI’s SIP integration is not a no-code setup. When a call arrives, OpenAI sends a realtime.call.incoming event to a webhook you host, and your code has to accept the call before any audio connects. If you want an agent you configure in a dashboard with no server of your own, ElevenLabs, Retell or Synthflow are the simpler choices — Click2Call supports those too.
Connecting OpenAI, Step by Step
Find your OpenAI Project ID
Sign in at platform.openai.com and open Settings → Project → General. The Project ID is shown there and begins with proj_.
Copy it — this is the one value Click2Call needs.
Set up a webhook that accepts calls
In the OpenAI platform, open Settings → Project → Webhooks and register an endpoint you control.
When someone rings your number, OpenAI sends that endpoint a realtime.call.incoming event containing a call_id. Your code accepts the call using that id, and that is also where you give the agent its instructions and context.
This is the step that catches people. Until your webhook accepts the call, the phone will ring and nothing will answer. OpenAI’s own Realtime API with SIP guide has the request format and sample code.
Create the profile in Click2Call
In the portal open Voice → Profiles, set Connection Type to OpenAI, and paste your Project ID into the OpenAI Project ID field.
That field is mandatory — the profile will not save without it. Click2Call then builds the SIP address for you and sets the number format to +E.164 automatically. There is no SIP URI to type.
Assign your number to the profile
Open Voice → Line Manager and set the Profile column for your number to the profile you just created.
The default profile applies to every line that has no profile assigned, and new numbers land on it automatically. A number left on Default will ignore everything you just configured.
Check the time zone, then test
While you are in the profile, confirm the Time Zone matches where the business operates — business hours, after-hours routing and queue schedules all read it.
Then ring the number from a mobile. Your webhook should receive the incoming-call event, and the agent answers once your code accepts it.
Troubleshooting
The provider replies 407 Proxy Authentication Required
The provider is challenging our INVITE for a username and password, which means our signalling address is not on their allowlist. Click2Call cannot answer that challenge on an outbound call, so the fix is always at the provider end — allowlist 103.212.52.19 rather than issuing credentials. While this is happening, callers hear “the number you have called is not available from this service”.
The profile will not save
The OpenAI Project ID field is empty or malformed. It is mandatory, and the value should begin with proj_. Copy it from Settings → Project → General rather than typing it.
The phone rings but nothing answers
Almost always the webhook. Either it is not registered in the OpenAI project, it is not reachable from the internet, or it is receiving the event but not accepting the call. Check your endpoint logs for a realtime.call.incoming event.
Calls go to Click2Call voicemail instead
The number is still on the Default profile rather than your OpenAI profile, so the call never leaves for OpenAI at all. Check the Profile column in Line Manager.
Calls connect but the agent has no context
Context is supplied by your code at the moment it accepts the call, not by Click2Call. Review the accept request in OpenAI’s SIP guide — that is where the session instructions belong.
Frequently Asked Questions
Do I need to write code?
Yes, for OpenAI specifically. The Click2Call side is configuration only, but OpenAI requires a webhook you host to accept each call. If you would rather not run a server, ElevenLabs, Retell and Synthflow are configured entirely in their own dashboards — see connecting an AI voice agent.
Where is my Project ID?
platform.openai.com → Settings → Project → General. It starts with proj_.
Are calls still recorded and transcribed?
Yes, provided Recording Enabled is ticked on the profile. Recording, transcription, summaries and sentiment all work as normal on the Click2Call side, stored in Australia and New Zealand. See AI voice tools.
Can I use my existing business number?
Yes — port it across first, then assign it to the profile. Most businesses test on a new number and move the main one once the agent behaves.
Related Guides
Still need help?
Our Australian support team is available to assist you.