X-ContextId
Squarespace attaches an opaque identifier to every
response through the X-ContextId unofficial
response header, pairing the value with
Server: Squarespace on the platform's sites.
Usage
Squarespace routes requests from many sites through common infrastructure, and the X-ContextId header provides a short identifier associating a response with the context generating the response.
The value is an opaque alphanumeric string with a fixed shape: 17 characters with a slash after the eighth on every observed value. Squarespace publishes no documentation for the header, so the meaning of the two segments stays internal. External clients receive the header as part of the response, but the value serves platform diagnostics rather than consumption by browsers or API clients.
The header allows hosting platform engineers to correlate log entries with the specific account context when troubleshooting shared infrastructure issues. Its role is similar to X-Request-Id, though X-ContextId identifies the hosting context rather than a specific request.
Values
Opaque context identifier
The header value is a 17-character alphanumeric string, a slash invariably splitting an 8-character prefix from an 8-character suffix. The segmentation is consistent across every observation while the meaning stays undocumented.
Example
A Squarespace response includes the context identifier alongside the platform's server banner.
Server: Squarespace
X-ContextId: mLtZi0va/HaKz4Ve2
Different responses produce different identifiers. The format stays fixed while the values vary per request.
X-ContextId: jdlCbfFq/Jlddg2qM