What is Conversions API and why it matters for CTWA ads

Learn how Conversions API (CAPI) in DoubleTick shares conversion events from your WhatsApp chats with Meta, so you can see which Click-to-WhatsApp ads bring qualified leads, bookings, and purchases.

Click-to-WhatsApp (CTWA) ads can bring in a lot of conversations, but a conversation is not the same as a qualified lead, a booked appointment, or a sale. DoubleTick's Conversions API (CAPI) add-on helps close that gap by sharing what happens after the chat starts with Meta. This article explains what CAPI is, how it works, and how to get started.

What's covered

• What is Conversions API (CAPI)

• How CAPI works

• Why CAPI helps

• What you can track

• Example: a real estate business

• More examples

• Is CAPI right for you

• How to get started

• Key takeaways

What is Conversions API (CAPI)

CAPI helps DoubleTick share conversion events from your WhatsApp conversations with Meta. When someone clicks your CTWA ad, they start a conversation with your business. That conversation may later turn into a qualified lead, a booked appointment, or a purchase. CAPI sends information about the customer actions you have configured back to Meta. This helps Meta connect eligible conversions to the ads that brought them in, and use these signals to improve how your campaigns are delivered. The traditional Meta Pixel only tracks activity on a website. CAPI tracks what customers do in your WhatsApp conversations. CAPI sends configured events only.

How CAPI works

• A customer clicks your ad: They start a WhatsApp conversation from your CTWA ad.

• The customer takes an action: For example, they qualify as a lead, book an appointment, or complete another action you have configured.

• DoubleTick sends the conversion event: The configured event, along with the supported matching information, is sent to Meta through CAPI.

• Meta receives the conversion signal: Meta can use matched events for conversion reporting and campaign optimisation.

Why CAPI helps

Without CAPI, you can see that your ads are bringing in WhatsApp conversations. But the number of conversations alone may not tell you which ads bring qualified leads or confirmed bookings. With CAPI, DoubleTick shares the events you have configured with Meta. This helps you connect eligible WhatsApp outcomes to your campaigns, and gives Meta more signals to work with. CAPI helps in two ways:

• Full funnel visibility: Eligible leads and purchases can be tied back to the campaign that brought them in. You can see which campaigns drive real results, which ones need changes or should be paused, and what your return on investment looks like.

• Smarter ad optimisation: Meta can use your CAPI signals to improve how your campaigns are delivered. This can help lower your cost per qualified lead and cost per purchase, and improve the return on your ads.

Here is a quick comparison of what you can see with and without CAPI:

Metric	With CAPI (configured events)	Without CAPI
Conversations started	✅ Yes	✅ Yes
Leads submitted	✅ Yes	❌ Not tracked
Cost per lead	✅ Yes	❌ Not tracked
Purchases	✅ Yes	❌ Not tracked
Cost per purchase	✅ Yes	❌ Not tracked
Return on ad spend (RoAS)	✅ Yes*	❌ Not tracked

*Only if the purchase value is passed correctly.

CAPI gives Meta additional information, but it does not promise a lower cost per lead or more sales. Your results depend on your campaign setup, how well events are matched, and the data Meta receives.

What you can track

You can set up events for actions such as:

• Leads submitted through WhatsApp flows.

• Consultations or appointments booked through chat.

• Purchases, when your setup supports them. If you want to see return on ad spend (RoAS), the purchase value needs to be passed correctly with each purchase event.

The customer action must be configured first, and Meta needs enough information to match the event to the original ad click. A purchase that happens later on an external website is not automatically tracked as a WhatsApp event.

Example: a real estate business

Imagine a real estate company that runs CTWA ads to get property enquiries.

• A prospect clicks the ad and starts a WhatsApp conversation.

• The DoubleTick flow asks qualifying questions, such as budget and preferred location.

• The prospect meets your criteria and is marked as a qualified lead through a configured action.

• DoubleTick sends the matching conversion event to Meta through CAPI.

• Meta can use the matched event for attribution and optimisation.

More examples

• E-commerce brand: Compare campaigns by purchases, not just conversations. For example, if Campaign A led to 15 purchases and Campaign B led to only 5, you can put more budget behind Campaign A.

• Real estate agency: Track site visits and appointments from WhatsApp leads. For example, if Campaign X led to 10 site visits from 50 conversations and Campaign Y led to only 1 visit from 70 conversations, you know where to invest.

• Event management company: Track event registrations from WhatsApp leads, and follow up with people who started a conversation but didn't book right away.

Is CAPI right for you

CAPI may be useful for your business if:

• You run Click-to-WhatsApp ads.

• You want to measure actions beyond the first conversation, such as qualified leads or bookings.

• Your team can identify these actions through configured DoubleTick flows or triggers.

• The required event and click-matching information is available.

Businesses such as e-commerce brands, service providers, retail stores, high-ticket industries (real estate, jewellery, travel), and marketing agencies often use CAPI. But your industry alone does not decide whether it suits you. What matters is how you run your ads and what you want to measure.

CAPI works only with Click-to-WhatsApp campaigns. It is not a general tracking tool for every ad type. Meta matches a conversion to the original ad click using the Click-to-WhatsApp click ID (clid). If this information is missing, Meta may not be able to match the event, and it can show a "Not a Click to WhatsApp customer" error.

How to get started

• Contact your DoubleTick Account Manager to enable the CAPI add-on.

• Decide which outcomes you want to measure, such as qualified leads, bookings, or purchases that your setup supports.

• DoubleTick helps you set up the relevant events and triggers in your WhatsApp flows.

• Once it is live, check that events are being sent correctly and review the results in Meta's reporting tools.

• Reach 100 purchase signals to unlock Purchase-Optimised campaigns for automated scaling.

Key takeaways

• CAPI shares the conversion events you configure from your WhatsApp conversations with Meta.

• It helps you measure outcomes beyond conversations and gives Meta more signals for optimisation.

• It works only with Click-to-WhatsApp campaigns, and it does not guarantee attribution or better campaign results.

Frequently asked questions

Does CAPI automatically track all my WhatsApp conversions?

No. CAPI sends configured conversion events. Your setup must identify the customer action you want to measure.

Does CAPI work with all Meta ads?

No. This integration is for Click-to-WhatsApp campaigns, not every Meta ad type.

Will CAPI guarantee more leads or lower advertising costs?

No. CAPI gives Meta additional conversion signals for measurement and optimisation, but campaign results can vary.

What happens if the click ID is missing?

Meta may not be able to match the conversion to the original CTWA click. The outcome depends on the matching information available and the requirements of the event.

What is the difference between CAPI and the Meta Pixel?

The Meta Pixel only tracks activity on a website. CAPI sends the customer actions from your WhatsApp conversations, such as leads, bookings, and purchases.

Can I see return on ad spend (RoAS) with CAPI?

Yes, as long as the purchase value is passed correctly with each purchase event.

How many purchase signals do I need to unlock Purchase-Optimised campaigns?

You need to reach 100 purchase signals. Once Meta receives them, you can create Purchase-Optimised campaigns for automated scaling.

Do I need technical expertise to set up CAPI?

No. Contact your DoubleTick Account Manager to confirm the add-on and setup requirements. The DoubleTick team can guide you through the supported setup.

Related articles

How to set up Conversions API to track CTWA conversionsGetting started with Click-to-WhatsApp (CTWA) ads