Internet Assigned Numbers Authority

Hypertext Transfer Protocol (HTTP) Cache-Status

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Available Formats



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HTTP Cache-Status

Registration Procedure(s)
Expert Review
Mark Nottingham
Available Formats

Name Type Description Reference
hit Boolean When true, indicates that the request was satisfied by the cache; that is, it was not forwarded, and the response was obtained from the cache. [RFC9211]
fwd Token When present, indicates that the request went forward towards the origin; its value indicates why. [RFC9211]
fwd-status Integer Indicates which status code (see [RFC9110], Section 15) the next-hop server returned in response to the forwarded request. [RFC9211]
ttl Integer Indicates the response’s remaining freshness lifetime (see [RFC9111], Section 4.2.1) as calculated by the cache, as an integer number of seconds, measured as closely as possible to when the response header section is sent by the cache. [RFC9211]
stored Boolean Indicates whether the cache stored the response (see [RFC9111], Section 3); a true value indicates that it did. [RFC9211]
collapsed Boolean Indicates whether this request was collapsed together with one or more other forward requests (see [RFC9111], Section 4); If true, the response was successfully reused; if not, a new request had to be made. [RFC9211]
key String Conveys a representation of the cache key (see [RFC9111], Section 2) used for the response. [RFC9211]
detail String or Token Allows implementations to convey additional information not captured in other parameters, such as implementation-specific states or other caching-related metrics. [RFC9211]