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Data direction: This is a destination — Upstack sends event and conversion data out to this platform via server-side APIs.

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What it does

Microsoft Advertising’s Conversions API (CAPI) is the server-side counterpart to the Universal Event Tracking (UET) Tag. Upstack Signal forwards storefront events — page views, product views, add-to-carts, and purchases — directly to Microsoft’s servers, bypassing browser restrictions like ad blockers, ITP, and cookie limits. Server-side delivery gives Microsoft’s algorithm a fuller picture of the conversions your ads actually drove, which improves campaign optimization, audience modeling, and attribution accuracy. Match rates from server-side events are consistently higher than browser-only tracking because each event carries hashed customer data and the msclkid click identifier when available.
Microsoft’s Conversions API is currently in pilot program. Contact your Microsoft Advertising account manager to enroll before enabling server-side tracking in Upstack.

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How it works

Upstack runs as a dual-tracking layer alongside the Microsoft UET Tag. The Upstack Pixel captures events in the browser and forwards each event to Upstack’s edge infrastructure, where it is hashed, enriched with identity and click-ID data, and sent to the Microsoft Conversions API as a server-side event with a shared eventId. Microsoft deduplicates server events against matching browser UET Tag events using that eventId, so you do not double-count conversions as long as both sources use the same UET Tag ID. PII (email, phone) is hashed with SHA-256 before delivery, as required by the Conversions API.
Unlike Meta and Google, Microsoft does not support address-level enhanced matching. Only email and phone are accepted for identity matching.

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Setup guides

Onboarding guide

End-to-end walkthrough for connecting Microsoft Advertising to Upstack Data.

Configure destination

Configure the Microsoft Advertising destination inside Upstack Data.

Find UET Tag ID

Locate your UET Tag ID in Microsoft Advertising.

Create Event Goals

Create Event Goals to track specific conversion types.

Enable CAPI

Enroll in the CAPI pilot and generate your auth token.

Enable click ID tracking

Ensure msclkid is captured and stored for attribution.

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Event mapping

Upstack maps storefront events to Microsoft Advertising events automatically:
Upstack eventMicrosoft eventKey match data
PageViewpageLoadURL, referrer, user agent
ViewContentview_itemitemIds, value, currency
AddToCartadd_to_cartitemIds, value, currency
InitiateCheckoutbegin_checkoutvalue, currency
Purchasepurchasevalue, currency, transactionId, itemIds
Leadleademail, phone
SearchsearchsearchTerm
SignUpsign_upemail
Microsoft uses free-form event names rather than predefined standard events. Event matching is done via Event Goals configured in the Microsoft Advertising UI.
PII is hashed with SHA-256 before it leaves Upstack. Upstack includes every available match key on every event — hashed email, hashed phone, msclkid (Microsoft click ID), ip_address, and user_agent — to maximize match quality.

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FAQ

The UET Tag ID identifies your Microsoft Advertising tracking tag — it’s the same ID used for browser-side tracking via the UET Tag. The CAPI Auth Token is a Bearer token that authenticates server-side API requests. You need both: the Tag ID to identify your account, and the auth token to authorize server-side event submission.
Contact your Microsoft Advertising account manager or Microsoft Advertising support to request enrollment in the Conversions API pilot. Once enrolled, the auth token option becomes available in your UET Tag settings.
Open Microsoft Advertising → Tools → UET Tags → select your tag → Tag Status. Server-side events appear alongside browser events. Upstack also surfaces delivery status inside the destination settings and Event Debugger.
No — as long as the UET Tag ID in Upstack matches your browser UET Tag. Upstack sends a shared eventId on every server-side event, and Microsoft’s deduplication logic matches events by eventId and keeps only one.
Microsoft’s Conversions API rejects events older than 7 days. This is stricter than other platforms (Meta allows 7 days, Google allows 90 days). Ensure your event pipeline processes events promptly.
Microsoft’s match rate depends on how much identity data each event carries. Common causes of low match quality:
  • Missing msclkid — Microsoft ads should link directly to your storefront so the click ID lands in the URL and is captured by the Upstack Pixel.
  • Anonymous visitors — events from visitors without email have fewer keys to match against. Match rates improve as more identified customers convert.
  • Missing checkout fields — make sure your Shopify checkout collects email and phone; they’re the strongest server-side match keys.

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Troubleshooting

Check these in order:
  1. Verify UET Tag ID is correct in Upstack destination settings
  2. Verify CAPI auth token is valid (test in Event Debugger)
  3. Check event timestamp is within 7 days
  4. Ensure Event Goals are configured in Microsoft Advertising UI
Your CAPI auth token is invalid or expired. Generate a new token in Microsoft Advertising UET Tag settings and update your Upstack destination configuration.
Common validation issues:
  • eventType must be “pageLoad” or “custom”
  • eventTime must be UNIX seconds (not milliseconds) within 7 days
  • em and ph must be valid SHA-256 hex strings (64 characters)
  • eventSourceUrl is required for pageLoad events

Meta Conversions API

Server-side tracking for Meta (Facebook/Instagram) ads.

Google Ads

Send conversion events to Google Ads for campaign optimization.

TikTok Events API

Server-side event delivery to TikTok for attribution.

Pinterest Conversions API

Track conversions on Pinterest campaigns with server-side events.