Urbit for Developers: Glossary

Mars (Urbit) is hermetically sealed from Earth except for system calls.

Hoon structures all programs as binary trees of Nock.

The %clay vane acts as a file system for Urbit.

All types in Urbit are unsigned integers @ud.

Molds provide a structured type system for Hoon.

All data in Hoon are binary trees; thus, common patterns arise again and again.

Generators are Dojo’s way of importing simple standalone programs.

The subject consists of the context and arguments to a program.

Libraries are code which can be built and included in the subject of downstream code.

Doors generalize the notion of a gate to a gate-factory.

Units, sets, maps, jars, and jugs provide a principled way to access and operate on data.

Arvo is an event processor or state machine.

Events are well-defined single operations on the system state.

The binary executable is separated into king and serf, the system state, an event log and runtime support.

Vanes communicate by means of events.

%ames provides network communications including peer-to-peer events.

%clay instruments a typed version-controlled filesystem.

%eyre and %iris together offer client and server operations.

%khan is the external control plane.

The main data operations in Urbit are: pokes, scries, and subscriptions.

A poke is like an HTTP PUT request for data.

A scry is like an HTTP GET retrievel of data.

A subscription is a reactive request for data updates.

A %gall app expects certain arms to be present to handle and emit events.

A %gall app can be outfitted with a helper core to provide necessary operations.

A %gall app can talk to a user interface client.

A %gall app can be readily produced to a standard of operability.

The Urbit software distribution service affords a straightforward way to deploy, update, and remove %gall apps.

The Urbit software distribution service affords a straightforward way to deploy, update, and remove %gall apps.