user guide

Creating A CodeMeta Instance File

A CodeMeta instance file describes the metadata associated with a software object using JSON’s linked data (JSON-LD) notation. A codemeta file can contain any of the properties described on the CodeMeta terms page.

When creating a CodeMeta document, note that they contain JSON name (“property” in linked-data), value pairs where the values can be simple values, arrays or JSON objects. A simple value is a number, string, or one the literal values false, null true, for example:

"name" : "R Interface to the DataONE REST API"

A JSON array is surrounded by the characters [ and ], and can contain multiple values:

"keywords": [ "data sharing", "data repository", "DataONE" ]

Some properties, such as author, can refer to other JSON objects surrounded by curly braces and can contain other JSON values or objects, for example:

"author": {
   "@id":"http://orcid.org/0000-0003-0077-4738",
   "@type":"Person",
   "email":"slaughter@nceas.ucsb.edu",
   "givenName":"Peter",
   "familyName: "Slaughter"
}

The JSON-LD “@type” keyword associates a JSON value or object with a well known type, for example, the statement "@type":"Person" associates the author object with http://schema.org/Person.
It is good practice to always provide the @type for any property which specifies a node (JSON object). The terms page indicates these node types.

The “author” JSON object illustrates the use of the JSON-LD keyword “@id”, which is used to associate an IRI with the JSON object. Any such node object can be assigned an @id, and we may use the @id to refer to this same object (the person, Peter), elsewhere in the document; e.g. we can indicate the same individual is also the maintainer by adding:

"maintainer": "http://orcid.org/0000-0003-0077-4738"

(Note: this should be added at the top level of the document, indicating that this individual is the maintainer of the software being described.) JSON-LD operations can later expand this reference and embed the full information at both locations.

The context

Every CodeMeta document must refer to the context file codemeta.jsonld, for example via a URL. This indicates that all terms in the document should be interpreted in the “context” of CodeMeta. Most terms are chosen to match the equivalent terms in http://schema.org, but CodeMeta provides a few additional terms not found in http://schema.org which may be helpful for software projects. CodeMeta also restricts the context to use only those https://schema.org terms that are explicitly listed on ther terms page. Users wanting to include additional terms must extend the context (see developer-guide).

The context file may be modified and updated in the future, if new JSON properties are added or existing ones modified. The CodeMeta github repository defines tags to allow specific versions of a file to be referenced, and assigns digital object identifiers, or DOIs, to each release tag. Please use the appropriate release of the CodeMeta schema in order to refer to the appropriate context file, e.g.

"@context": "https://doi.org/10.5063/SCHEMA/CODEMETA-1.0"

Release candidate versions may be referred to consistently using their git tag for the raw version, e.g. https://raw.githubusercontent.com/codemeta/codemeta/2.0-rc/codemeta.jsonld. Please do not refer to the raw GitHub URL for the master branch, as this is subject to change and will not guarantee a stable metadata file.

Testing An Instance file

[ TBD ]