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The KV format

The KV format is a key-value text format that’s basically JSON without the JavaScript compatibility.

In the KV format a KV value can be

  • the keywords true, false or null,
  • a simple value like hello, or a quoted string like "hello" or 'world'.
  • a number.
  • an array, starting with [ and ending with ], with a series of comma-separated values (trailing comma allowed).
  • an object, starting with { and ending with }, with a series of key=value fields (key can be a quoted string). (For compatibility with javascript, key:value is also allowed).

A “simple key” is a key which does not need quoting, which means a non-empty key consisting of at most letters, numbers, periods, hyphens. A simple value can also include slashes.

Key-value data is a sequence of (simple key) key=value pairs, terminated by anything that doesn’t match the format.

a=b
c=d
GET ... # since GET doesn't end with an =, we know it's not part of the KV data.

This format is accepted at the top of any pardon .http template and allows us to specify values directly in-line with the request.

The main advantages of the KV format are

  • less syntax than JSON (quotes can often be elided)
  • trailing commas
  • using = inside objects so that object contents can be copied to the top level.

Interactive Parsing Demo