Microsoft Advertising said on October 28 that its Conversions API (CAPI), a server-side way to send conversion data, is now generally available. In the same monthly update, the company made age and gender targeting generally available in Performance Max campaigns and opened a pilot that lets advertisers set rules for AI-written ad copy.

Server-side conversion tracking

Microsoft described CAPI as a server-to-server connection that sends conversion data from websites, apps, customer relationship management (CRM) systems and point-of-sale systems to Microsoft Advertising in real time. “Conversions API works alongside your Universal Event Tracking tag,” the company wrote, referring to the UET browser tag most advertisers already use, and said it captures activity that browser limitations may miss.

Advertisers can integrate directly, use Google Tag Manager or connect through technology partners. The announcement named 10: Adobe Real-Time CDP, Commanders Act, Freshpaint, Invoca, MetaRouter, Segment by Twilio, Stape.io, Switch Growth, Tealium and Zeotap.

The technical guide on Microsoft Learn sets out how it works. Microsoft recommends using CAPI with UET whenever possible. When the same conversion can be sent by both, advertisers should use a shared event ID “so Microsoft Advertising can avoid double-counting,” the guide says. Events must carry at least one identifier, such as Microsoft’s click ID, an anonymous visitor ID, or an email address or phone number hashed with SHA-256. Events can be sent one at a time or in batches of up to 1,000, and event timestamps must fall within the last seven days.

The guide also covers consent. By default, all events are processed with consent set to granted. Advertisers that need explicit consent signals can send a parameter marking ad storage consent as granted or denied, and events marked denied “will not be used for any advertising purposes, including conversion attribution and retargeting,” according to the documentation.

Performance Max controls and reporting

For Performance Max, Microsoft’s automated campaign type, the update lists several changes at different stages:

  • Age and gender targeting: generally available, with options to include or exclude groups.
  • Device targeting: “rolling out to all advertisers in the coming weeks.”
  • Audience exclusions: in open pilot, available through an account team or Microsoft Advertising Support.
  • Brand exclusions: being refined so they can apply to text ads only, while product ads still show on those brand searches; also in pilot.
  • Search term and auction insights reports: now available, with auction insights showing how advertisers compare with competitors.
  • Search term landing page reporting: “rolling out to advertisers starting mid-November.”

Rules for AI-written copy

A messaging guidelines feature is in open pilot for Performance Max campaigns and for Search campaigns with AI Max enabled. “Messaging guidelines let you provide up to 40 guidelines to help steer generated copy and protect your brand,” Microsoft wrote. Advertisers can set negative rules, with the example “Never imply that products are low cost,” as well as positive guidance on wording, themes and tone.

Microsoft also introduced AI-powered campaign creation for a first Performance Max campaign. Advertisers supply their website, marketing plans, brand guidelines and product images, and the tool builds an editable snapshot of the business, including products or services and ad tone. Users can launch directly or first adjust budget, bid strategy, copy and creative.

Why it matters

The general release gives merchants a way to send purchase and lead data from back-end systems, such as order platforms and CRMs, to Microsoft Advertising rather than relying only on a browser tag. Microsoft’s guide lists reducing “reliance on browser-only tracking solutions” among the reasons advertisers use CAPI, and notes that some browsers already block third-party cookies.

The setup details matter for accuracy. Advertisers running both UET and CAPI need consistent event IDs to avoid counting a sale twice, and those operating under consent rules need to pass consent signals, since the default treats events as granted. The Performance Max changes give retailers more control over who sees ads and more visibility into the search terms that trigger them, though several are still pilots.

What to watch

Device targeting is due to reach all advertisers in the coming weeks, and search term landing page reporting begins rolling out in mid-November. Microsoft did not say when the audience exclusion, brand exclusion or messaging guidelines pilots will become generally available.

The caveats

The announcement did not specify which markets each feature covers. Microsoft did not publish performance data for the new tools.