RDF/POST

RDF/POST is a compact syntax for serialising an RDF graph inside a classic HTML application/x-www-form-urlencoded payload, so it works with any browser’s GET or POST mechanisms—no JavaScript required.

Why use it?

• Plain‑HTML forms – build RDF edit and create interfaces with ordinary <form> elements—no JavaScript required.
• Language‑agnostic – piggybacks on the ubiquitous application/x-www-form-urlencoded encoding that every web framework already understands.
• Streaming‑friendly – triples arrive in a simple key/value stream, so parsers can handle very large graphs with constant memory.

TL;DR syntax

Part	Key(s)	Meaning
rdf=	(first pair)	marks the start of an RDF/POST body
&v=	default namespace IRI
&n=…&v=	extra namespace prefix + IRI
Subject	&sb= blank ‖ &su= full IRI ‖ &sv= suffix ‖ &sn=…&sv= prefixed suffix
Predicate	&pv= suffix ‖ &pn=…&pv= prefixed suffix ‖ &pu= full IRI
Object	&ob= blank ‖ &ou= full IRI ‖ &ov= suffix ‖ &on=…&ov= prefixed suffix ‖ &ol= literal (plus optional &lt= datatype | &ll= lang)

(See the specification for the full EBNF grammar.)

Minimal example

<form action="/post" method="post">
  <!-- start -->
  <input type="hidden" name="rdf" value="">
  <!-- namespaces -->
  <input type="hidden" name="v" value="http://xmlns.com/foaf/0.1/">
  <input type="hidden" name="n" value="dc">
  <input type="hidden" name="v" value="http://purl.org/dc/elements/1.1/">
  <!-- triples -->
  <input type="hidden" name="sb" value="o">
  <input type="hidden" name="pv" value="givenName">
  <input type="text"   name="ol" value="Ora">
  …
</form>

When submitted, the browser sends a single line such as

rdf=&v=http://xmlns.com/foaf/0.1/&n=dc&v=http://purl.org/dc/elements/1.1/&sb=o&pv=givenName&ol=Ora …

which is equivalent to the Turtle below:

_:o foaf:givenName "Ora" ;
    dc:creator         _:b .

Media type & file extension

• Default: application/x-www-form-urlencoded
• RDF‑specific (proposed): application/rdf+x-www-form-urlencoded
• Recommended extension: .rpo

Implementations

• RDFPostReader – streaming parser for Apache Jena (AtomGraph Core)

Credits

Specification by Sergei Egorov, maintained by AtomGraph.