Integrating First-id with the Imagino CDP is a powerful way to stabilize user identity in a post-cookie landscape. Since First-id provides a deterministic, persistent first-party identifier, it allows Imagino to reconcile profiles with high precision across different domains and devices.
Here is a quick technical guide to setting up this integration.
How can I do that ?
1 – Pass the first-id to imagino
Option 1 – if you have the imagino sdk installed you can send the first-id value as a parameter :
Use the track or identify method to link the First-id to the current session.
imagino.track("identity_sync", {
"first_id": fId, // The value retrieved from the First-id first-party cookie
"source": "web_tracking"
});Option 2 – Via GTM
a – create a Variable: Create a “1st Party Cookie” variable in GTM (usually named firstid or similar, depending on your setup).
b – Event Tag: In your Imagino Event tag, map this variable to a custom attribute named first_id
1 – CDP Configuration (Imagino Side)
To make this data actionable, you must configure the ingestion rules within the Imagino interface:
| Action | Description |
| Schema Mapping | Add the first_id field to your “Person” or “Profile” data model. |
| Identity Keys | Set first_id as a Reconciliation Key. This allows Imagino to merge anonymous profiles across different domains. |
| Identity Stitching | Adjust the deduplication rules to prioritize First-id over standard session IDs for higher accuracy. |
don’t hesitate to contact us directly if you have any more specific questions.

