Description
The LinkedIn CAPI tag template does not read the li_fat_id cookie (LinkedIn First-party Ads Tracking UUID). This cookie is set by the LinkedIn Insight Tag and is one of the highest-signal match keys available for server-side conversion attribution.
Why this matters
LinkedIn's CAPI documentation lists LINKEDIN_FIRST_PARTY_ADS_TRACKING_UUID as a supported user identifier type in the userIds array. When present, it significantly improves match rates because it's a deterministic 1:1 identifier — unlike email hashing, which can fail due to normalization mismatches.
The Insight Tag already sets this cookie on the user's browser, so the value is available to GTM. The CAPI tag just needs to read it and include it in the conversion payload.
Proposed solution
Read the li_fat_id cookie via GTM's cookie variable API and include it in the userIds array with idType: "LINKEDIN_FIRST_PARTY_ADS_TRACKING_UUID". See PR #18 for an implementation.
Description
The LinkedIn CAPI tag template does not read the
li_fat_idcookie (LinkedIn First-party Ads Tracking UUID). This cookie is set by the LinkedIn Insight Tag and is one of the highest-signal match keys available for server-side conversion attribution.Why this matters
LinkedIn's CAPI documentation lists
LINKEDIN_FIRST_PARTY_ADS_TRACKING_UUIDas a supported user identifier type in theuserIdsarray. When present, it significantly improves match rates because it's a deterministic 1:1 identifier — unlike email hashing, which can fail due to normalization mismatches.The Insight Tag already sets this cookie on the user's browser, so the value is available to GTM. The CAPI tag just needs to read it and include it in the conversion payload.
Proposed solution
Read the
li_fat_idcookie via GTM's cookie variable API and include it in theuserIdsarray withidType: "LINKEDIN_FIRST_PARTY_ADS_TRACKING_UUID". See PR #18 for an implementation.