HTTP -- get HTTP headers

• Called with the name of an HTTP request header field, returns its value. Capitalization and the use of hyphens versus underscores are not significant.
• Request headers are sent by the browser to the server. It is not possible to access the Response headers returned to the browser.
• Only returns headers permitted by site configuration. Returns '' if the header is not allowed.
• When called without a parameter, nothing is returned. See VarHTTPS for other options.

The HTTP and HTTPS macros are deprecated as of Foswiki release 2.1. and will be removed in a future release.

Parameters

Examples

Write	Returns	Notes
%HTTP{"Accept-language"}%
%HTTP{"User-Agent"}%	Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
%HTTP%		Always returns ''
%HTTP{"Cookie"}%		Not allowed by default.

You can see the HTTP headers your browser sends to the server on a number of sites e.g. http://www.ericgiguere.com/tools/http-header-viewer.html

Related