Fallback Iframe (Interpreter)

The heart of fallback data interpretation. Iframes are HTML elements that can embed external html content in an isolated sandbox.
The fallback iframe is used by the embedding application which is not capable of interpreting a foreign packet. The fallback iframe communicates with the embedding application in a standardized manner, to pass the packet to the iframe and enable further interaction.

There are two types of fallback iframes: Presenter Iframes and Translator Iframes

Presenter Iframes render a HTML presentation of the packet passed to it and may allow user interaction with the iframe.

Translator Iframes function in the same way, however, they do not render a presentation but return the given packet data in a different format back to the embedding application, hence “translate” the packet. For example, a client received a packet of type text/markdown. The packet has translator iframes referenced to convert text/markdown to image/jpeg and text/html. Since the application doesn’t know how to interpret markdown, it uses the translator to convert it to a HTML document, sanitizes the HTML, and shows it to the user.

Embedding Application

An embedding application is an application that wants to display content that it cannot interpret itself but that has iconet metadata attached. It therefore passes the content (a packet) to a fallback iframe which renders a presentation.

Foreign Protocol

A protocol that is not (natively) supported by a given embedding application.

Foreign Packet

A packet that is in the format of a foreign protocol.

Interpreter Manifest

A JSON-LD object that provides information on fallback iframes, their supported input packet types, their location, and their security-relevant permission requirements.


A collection of data used to communicate from one application to another.


Some sections begin with a WIP-Level: indicator. The Work-In-Progress-Levels is a guide as to how much mature the given section is. Where WIP-Level 5 means “absolutely just some notes or thoughts” and WIP-Level 0 means “we elaborated extensively and came up with something we feel confident enough to put in our prototype implementation”.


TODO: Somethink like a value of implemented, idea, in discussion.