Updated: April 7, 2026
The Experience Cloud ID (ECID) is the primary identifier for users in Adobe Analytics. When deploying Adobe Analytics, ECID is commonly assigned to an eVar to enable cross-session and cross-device analysis.
The approach for setting ECID depends on whether you’re using client-side or server-side tracking.
Client-Side Tracking（Dynamic Variable）
When deploying client-side tracking, the recommended approach is to use dynamic variables to map ECID to an eVar.
Common Mistake
Some implementations directly use the Experience Cloud ID Service built-in data element as an eVar:
While this captures the ECID, it often leads to “Unspecified” values in reports.
Why this happens:
- “Unspecified” indicates that the variable is undefined or unavailable at the time the hit is sent.
- Using the built-in data element alone does not guarantee the ECID has been resolved before the eVar is set.
Correct Configuration
In client-side tracking, the ECID is available by default in the mid variable.
Map mid to your desired eVar using dynamic variables:
This ensures the eVar consistently receives the ECID, eliminating “Unspecified” values.
Server-Side Tracking (Processing Rules)
For server-side deployments, Some attempt to use the official getIdentity method to fetch ECID.
⚠️ For new users, hits may be sent before ECID is returned by the Identity Service, resulting in “Unspecified” values.
Recommended Approach：Use Processing Rules to set ECID on the server side, the ECID is available at a.x.identityMap.ecid.0.id，map this value to your eVar within the processing rules configuration
This ensures all server-side hits correctly capture ECID, eliminating “Unspecified” values in your reports.
Summary
| Deployment Type | Correct Method | Common Issue | Key Variable |
|---|---|---|---|
| Client-side | Dynamic Variables (mid) |
Using built-in data element → Unspecified | mid |
| Server-side | Processing Rules (a.x.identityMap.ecid.0.id) |
ECID not yet returned for new users → Unspecified | a.x.identityMap.ecid.0.id |
