X-Seen-By
The HTTP X-Seen-By unofficial response header is sent by Wix infrastructure to expose which internal nodes handled a request.
Usage
Wix runs its hosting platform on layered infrastructure: load balancers, application servers, and Caching systems. The X-Seen-By header records which nodes processed a given request as the request traveled through those layers.
Each node appends its identifier to the header before passing the request or response along. The result is a comma-separated list of Base64-encoded hashes, one per node. The hashes are opaque: internal identifiers meaningful only to Wix engineers diagnosing infrastructure issues.
The header appears on responses from Wix-hosted sites, typically
together with Wix's Server: Pepyaka signature. The header often
appears alongside GLB-X-Seen-By, which records
the same information from the global load balancer layer.
Values
Node identifier list
The header value is a comma-separated list of Base64-encoded strings. Each string identifies one infrastructure node in the request path. The order reflects the sequence in which the nodes handled the request.
Example
A simple response routed through two internal nodes shows two comma-separated Base64 hashes. The values have no meaning to external clients and are used for internal log correlation.
X-Seen-By: yvSunuo/8ld62ehjr5B7kA==,T7xPrjRFKDMHVv938PYVfx9slopJdhD+WySraMrpIY8=
Requests with more complex routing paths include additional entries. Each added hash corresponds to another layer in the Wix infrastructure stack.
X-Seen-By: yvSunuo/8ld62ehjr5B7kA==,T7xPrjRFKDMHVv938PYVfx9slopJdhD+WySraMrpIY8=,xIKq3IotbbLp4+7DTTMx8R9slopJdhD+WySraMrpIY8=
The header typically appears alongside X-Request-Id for end-to-end request tracing across Wix's systems.