ChatGPT Conversions API
The ChatGPT Conversions API sends conversion events directly to OpenAI from your server. Measurement is no longer entirely dependent on an event being sent successfully from a visitor's browser through the Pixel.
OpenAI describes the Conversions API as a more reliable measurement source than the Pixel alone and recommends using it where possible for more accurate conversion data. In practice, the strongest setup usually combines client-side and server-side tracking.
Why use the ChatGPT Conversions API?
Conversion tracking is only as useful as the events that actually reach the ad platform. If some purchases, registrations, or leads go unreported, both campaign reporting and the data available for optimization are incomplete.
The browser Pixel is an important part of ChatGPT Ads measurement, but browser restrictions, consent choices, and other interruptions can affect delivery. The Conversions API adds a server-side path for sending events such as a confirmed purchase or registration directly to OpenAI.
More reliable conversion data
Server-side tracking does not mean replacing every browser event. It complements the Pixel where a business outcome can also be identified and confirmed on the server.
A completed order or a registration saved in a backend system is often a verifiable event. Passing that event through the Conversions API means measurement does not depend solely on a successful browser-side request.
Better data for campaign optimization
The benefit goes beyond reporting. OpenAI connects received events to the conversion goals configured for campaigns, and eligible conversion data can also inform campaign optimization.
The closer an event is to a real business outcome, the more useful it is to the platform. The aim is not to send the largest possible number of events, but to deliver the right ones as reliably as possible.
Pixel and Conversions API work together
OpenAI recommends using the Pixel and Conversions API together where possible. The same conversion can then be sent from the browser and the server without automatically counting it twice.
A shared Event ID prevents duplicate conversions
When the same event is sent through the Pixel and Conversions API, both use one event identifier. The Pixel calls it event_id, while the server event uses the corresponding id.
OpenAI uses the Pixel ID, event name, and Event ID together to recognize a duplicate. It processes the first event received for that key and ignores later matching events.
Deduplication is essential to a hybrid setup. Sending the same conversion from two places without a shared identifier does not create a correctly functioning Pixel and CAPI integration.
The Conversions API is part of broader ChatGPT Ads conversion tracking. If client-side tracking or the conversion events themselves are not in place yet, it makes sense to set those up first.
What data can be sent through the ChatGPT Conversions API?
The Conversions API supports OpenAI's standard events as well as custom events when needed. Standard events include purchases, leads, registrations, appointments, checkout starts, and items added to a cart.
Where possible, choose an event that reflects the actual business outcome. This keeps server-side measurement aligned with the conversion goals used for campaign reporting and optimization.
Conversions and conversion value
For an online store, the Conversions API can send a completed purchase and its value. OpenAI supports monetary amount and currency fields, making it possible to evaluate campaigns by the value they generate as well as by conversion count.
For a lead-based business, the event might be lead_created, registration_completed, or appointment_scheduled. The event should represent a meaningful stage of the funnel rather than treating an ordinary page view as equivalent to a lead or registration.
Connecting an OpenAI ad click to a conversion
OpenAI uses a click reference called oppref to connect an ad click with a later conversion. It is appended to the landing-page URL after a ChatGPT Ads click, and the OpenAI Pixel can store it in a first-party cookie for later measurement.
When oppref is available, it can also be included with a Conversions API event. This helps OpenAI connect a server-sent conversion to the preceding ad click.
That is one practical reason a working CAPI integration involves more than sending a single purchase or lead event from a server.
Advanced matching
OpenAI also supports advanced matching signals to improve measurement quality when direct click information is incomplete. These can include eligible first-party customer details, normalized and hashed according to OpenAI's requirements before they are sent.
Whether to use those signals depends on the available data and what users have been told about measurement. OpenAI instructs advertisers to share conversion data only with the necessary rights and consents.
ChatGPT Conversions API setup
The ChatGPT Conversions API is not a switch in Ads Manager. Events must be sent to OpenAI from a server, so implementation requires server-side infrastructure that can deliver them securely. OpenAI requires CAPI calls to come from a server and the API key to stay in the server environment.
That infrastructure could be your own backend, a separate server-side tagging setup, or a managed service. An existing server-side GTM installation may be suitable, as may a provider such as Stape or Tracklution. If there is no server-side measurement environment yet, that infrastructure must be addressed before CAPI events can be sent.
Once the environment is in place, decide which events to send and what information is available for each. You need a Pixel ID for the relevant data source and a Conversions API key from the ChatGPT Ads account. The server then sends the events to OpenAI's Conversions API endpoint.
If the same conversion is also measured in the browser, the client-side and server-side events must be part of the same measurement setup. A shared Event ID handles deduplication; oppref and other relevant signals can accompany the server event when available.
After implementation, verify that OpenAI receives the events as expected. The recent-events endpoint can show whether a test event came through the browser Pixel or the server-to-server integration.
If you already use server-side tracking for other ad platforms, ChatGPT Ads can often join the same infrastructure. If you do not yet have a server-side environment, read more about server-side tracking.
Frequently asked questions about the ChatGPT Conversions API
Not necessarily. OpenAI recommends using the Pixel and Conversions API together where possible. The Pixel measures browser events, while CAPI adds a server-side delivery path.
The Conversions API can also be implemented without installing the browser Pixel. A server-only setup still uses a Pixel ID to identify its data source.
When an event is sent through both the Pixel and Conversions API, the two copies use the same Event ID and Pixel ID. OpenAI uses those identifiers to recognize and deduplicate the event.
You need a server-side environment that can send conversion events to OpenAI. Creating a Pixel ID and CAPI key in Ads Manager is not enough by itself.
That environment might be an existing backend, server-side GTM, or a managed tracking service. You also need the Pixel ID and Conversions API key from the OpenAI Ads account, plus a way to make the chosen conversion events and their data available on the server. The API key must stay server-side.
oppref is OpenAI's ad-click reference, appended to a landing-page URL after a ChatGPT Ads click. It helps connect a later conversion to the click that preceded it.
When available, it can also be included in a Conversions API event.
Often, yes. If you already have a working server-side measurement environment, ChatGPT Ads can often be added as another destination without rebuilding the entire setup.
The exact implementation depends on where conversions occur, what data the existing system can pass, and how Event IDs and attribution signals are handled.
OpenAI documentation
The technical information on this page is based on OpenAI's official Ads documentation.
- Conversions API
Server-to-server setup, authentication, and event delivery.
- Conversion measurement
Using the Pixel and Conversions API together,
oppref, and measurement quality. - Supported events
OpenAI's supported standard conversions and event parameters.
- Conversion setup
Event ID, deduplication, and technical requirements for a CAPI setup.
Need help setting up the ChatGPT Conversions API?
If ChatGPT Ads conversion tracking is already in place and you want to add server-side measurement, I can integrate the Conversions API into your existing tracking environment.
The setup can also ensure that browser and server events work together, duplicate conversions are handled correctly, and the signals OpenAI needs are passed when available.