Overview#

JSON Resource Descriptor (JRD) is defined in RFC 6415 and provides a lightweight metadata document format for describing hosts (thus the name "host-meta"), intended for use by web-based protocols. This document also registers the well-known URI suffix "host-meta" in the Well-known URI Registry established by RFC 5785.

JSON Resource Descriptor, originally introduced in RFC 6415 and based on the Extensible Resource Descriptor (XRD) format, is a JSON Object that comprises the following name/value pairs:

• subject - is a name/value pair whose value is a string
• aliases - is an array of strings
• properties - is an object comprising name/value pairs whose values are strings
• links - is an array of objects that contain link relation information.

When processing a JSON Resource Descriptor, the client MUST ignore any unknown member and not treat the presence of an unknown member as an error.

The "links" array has any number of member objects, each of which represents a Link Relation Type. Each of these link objects can have the following members:

• rel
• type
• href
• titles
• properties

The "rel" and "href" members are strings representing the Link Relation Type and the target URI, respectively. The context of the link is the "subject".

The "type" member is a string indicating what the media type of the result of dereferencing the link ought to be.

The order of elements in the "links" array MAY be interpreted as indicating an order of preference. Thus, if there are two or more link relations having the same "rel" value, the first link relation would indicate the user's preferred link.

The "links" array is OPTIONAL in the JSON Resource Descriptor.

More Information#

There might be more information for this subject on one of the following:

• JRD
• RFC 6415
• WebFinger