This request header contains the current Unpoly version to mark this request as a fragment update.
Server-side code may check for the presence of an
X-Up-Version header to
distinguish fragment updates from full page loads.
X-Up-Version header is guaranteed to be set for all requests made through Unpoly.
The user updates a fragment. Unpoly automatically includes the following request header:
The server chooses to render different HTML to Unpoly requests, e.g. by excluding the document
and only rendering the
<body>. The server responds with the folowing HTTP:
Vary: X-Up-Version <body> ... </body>
Request headers that influenced a response should be listed in a
Varyresponse header. This tells Unpoly to partition its cache for that URL so that each request header value gets a separate cache entries.