What Is the Microsoft Conversion API?
The Microsoft Conversion API (CAPI) lets you send conversion events from Cometly directly to Microsoft Ads as offline conversions. This gives Microsoft more complete data about how your ads are performing, even when browser-based tracking (like the UET tag) misses events due to ad blockers, cookie restrictions, or cross-device behavior.
With CAPI enabled, you map your Cometly events to Microsoft Conversion Goals, and Cometly automatically sends matching conversion data to Microsoft Ads in real time.
Before You Begin
Make sure you have the following in place before configuring CAPI:
A connected Microsoft profile. You need to sign in with Microsoft through Cometly's Integrations page so Cometly has permission to communicate with your Microsoft Ads account.
A Microsoft Ad account connected to your Space. The ad account you want to send conversions to must be linked to your current Space.
Offline Conversion Goals created in Microsoft Ads. CAPI sends data as offline conversions, so you need at least one Offline Conversion Goal set up in your Microsoft Ads account. Cometly will pull these goals in automatically during configuration.
Step 1: Connect Your Microsoft Profile
If you haven't already connected your Microsoft profile:
Go to Integrations
Find the Microsoft section
Click Sign in with Microsoft
Complete the OAuth flow in the popup window
Once connected, your Microsoft profile will appear on the Integrations page
Step 2: Connect Your Ad Account to Your Space
On the Integrations page, find your Microsoft profile
You'll see a list of ad accounts associated with that profile
Click Connect to Space next to the ad account you want to use
The account is now linked to your current Space and ready for CAPI configuration
Step 3: Enable the Microsoft Conversion API
Navigate to the Events Manager on the left app menu, and click Conversion API
Find the Microsoft section
Toggle the data sharing switch to Turn On
Once enabled, you'll see configuration options for mapping your events.
Step 4: Create Offline Conversion Goals in Microsoft Ads
For every offline conversion you want to measure, you need to create a new offline conversion goal type in Microsoft Ads.
You can create as many offline conversions as you need. Also, auto-tagging of Microsoft Click ID is automatically turned on when you create your first offline conversion goal and you can check your auto-tagging status of the click ID in the Account level options page.
From the navigation menu on the left, hover over Conversions and select Conversion goals.
Select Create conversion goal and select the Offline conversions type.
Enter a name for your goal in the Goal name box. When naming your goal, use a descriptive name that makes sense to you (for example, "Check-out page"). Note: You cannot use the same name for two different conversion goals.
Under Sharing, select if you want this goal to apply to all accounts or a specific account.
If you want to add a monetary value for each conversion, under Revenue value, select one of the following checkboxes:
Each time it happens, the conversion action has the same value. Then, enter the amount and select the currency, if available. This is a static revenue value that doesn't change.
The value of this conversion action may vary (for instance, by purchase price). Then, enter the default amount and select the default currency, if available, to be used when no value is received for a conversion.
You can also assign a Count to the conversion and enter a Conversion window to track up to 90 days in the past.
Select Save.
After you have created a conversion goal, you’ll be prompted to upload the conversions now or later.
According to Microsoft Ads documentation, after you create a new conversion goal, you must wait 2 hours before uploading conversions for that conversion goal.
Once you have finished creating an offline conversion goal, you’ll see a dash ( - ) for UET tag ID and Tracking status in the grid, as UET tags aren’t required.
Step 5: Map Your Events to Conversion Goals
This is the most important step. You're telling Cometly which of your events should be sent to Microsoft, and which Microsoft Conversion Goal each event maps to.
Select a Microsoft Ad Account from the dropdown
Cometly will automatically fetch the Offline Conversion Goals from that account
For each conversion goal you want to receive data, configure the following:
Microsoft Conversion Goal. Select the goal from the dropdown (these are pulled directly from your Microsoft Ads account).
Cometly Event. Select which Cometly event should trigger this conversion (e.g., Purchase, Lead, or any custom event you've created).
Send Rule. Choose one of the following:
Send all events. Every time this Cometly event fires, it will be sent to Microsoft regardless of which ad platform gets the attribution.
Only send attributed events. Only sends the event to Microsoft if Cometly attributed the conversion to a Microsoft ad. This is the more conservative option and avoids inflating your Microsoft conversion counts.
Click Save to save your mappings
You can map multiple conversion goals per account, and each goal can be mapped to a different Cometly event.
What Data Gets Sent to Microsoft
When a matching event fires and CAPI is enabled, Cometly sends the following data to Microsoft Ads:
Data | Description |
Conversion Goal Name | The name of the mapped Microsoft Conversion Goal |
Conversion Time | The timestamp of the event (UTC) |
Conversion Value | The monetary value of the event (if available) |
Currency Code | Your Space's currency setting |
Microsoft Click ID (msclkid) | The click identifier from the original ad click (if available) |
Hashed Email | SHA-256 hashed, normalized email address (if available) |
Hashed Phone Number | SHA-256 hashed, normalized phone number (if available) |
Cometly automatically normalizes and hashes personal data before sending. At least one identifier (msclkid, email, or phone) is required for Microsoft to accept the conversion.
Turning CAPI Off
To disable the Microsoft Conversion API:
Navigate to the Conversion API page
Find the Microsoft section
Toggle the data sharing switch to Turn Off
No events will be sent to Microsoft while CAPI is off. Your event mappings are preserved, so you can turn it back on at any time without reconfiguring.
Microsoft Ads Conversion API Troubleshooting
If conversions aren't appearing in Microsoft Ads, check the following:
Is CAPI turned on?
Verify the toggle is set to "on" on the Conversion API page.
Is the event mapped?
Make sure the Cometly event that's firing is actually mapped to a Microsoft Conversion Goal.
Are identifiers present?
Microsoft requires at least one of the following: msclkid, email, or phone number. If the event doesn't have any of these, it won't be sent.
Is the account active?
Make sure the Microsoft Ad account is still connected and active in your Space.
Are you using "Only send attributed"?
If this option is selected and Cometly didn't attribute the conversion to Microsoft, the event won't be sent. Try switching to "Send all events" to test.
Does the Conversion Goal exist in Microsoft Ads?
The Offline Conversion Goal must exist in your Microsoft Ads account. If it was deleted or renamed on the Microsoft side, the mapping will fail.
FAQ
Do I need a UET tag if I'm using CAPI?
CAPI works independently of the UET tag. However, Microsoft recommends using both together for the most complete tracking coverage.
Can I map the same Cometly event to multiple conversion goals?
Yes. You can create multiple mappings for the same event if you want it to trigger different conversion goals.
What's the difference between "Send all events" and "Only send attributed events"?
"Send all events" sends every occurrence of the mapped event to Microsoft, regardless of which ad platform Cometly attributed it to. "Only send attributed events" only sends the conversion if Cometly determined it came from a Microsoft ad. Use "Only send attributed" if you want to avoid double-counting across platforms.
How quickly do conversions appear in Microsoft Ads?
Conversions are sent in real time as events come in. However, Microsoft Ads may take some time to process and display offline conversions in their reporting. This is controlled by Microsoft, not Cometly. Expect up to a 24 hour delay for Microsoft conversion processing.
Is personal data shared with Microsoft?
Email addresses and phone numbers are normalized and hashed (SHA-256) before being sent. Cometly never sends raw personal data to Microsoft.