arin

The Rust API for Arin, an annotation layer any agent can draw on.

Installing Arin itself

This crate is not the application, and cargo install arin will not work. There is no binary here, by design. Arin is a menu bar app and a daemon that draws on your screen:

brew install anistark/tools/arin

That compiles from source, so it wants a Rust toolchain and a couple of minutes. Building locally is deliberate rather than lazy: an unsigned app that was downloaded is quarantined and refused by Gatekeeper, while one compiled on your own machine is not. A signed build shipping as a cask comes later, and the install line becomes brew install --cask anistark/tools/arin when it does.

Or build it directly:

git clone https://github.com/anistark/arin
cd arin
just bundle          # produces target/bundle/Arin.app

Either way, start it and grant Screen Recording when asked:

arin -d              # the daemon, in the foreground

macOS 14 or later. The daemon is macOS-only today; this crate builds anywhere.

What this crate is

The contract for talking to the daemon from Rust. Arin points at things, highlights regions, writes explanatory text boxes, and draws freehand paths. It never clicks, types, or scrolls. This is the type definitions for the messages that ask it to.

[dependencies]
arin = "0.2"

It is pure types plus validation. No IO, no async runtime, no platform code, and it builds anywhere.

use arin::{Anchor, DisplayId, LogicalRect};

let rect = LogicalRect::new(412.0, 88.0, 120.0, 32.0);
assert!(rect.is_valid());

let anchor = Anchor::new(rect, DisplayId(1));
assert_eq!(anchor.display_id, DisplayId(1));

The crate version is not the wire version. This crate is 0.2 while the protocol it describes is 0.1, and they move independently: a Rust API change bumps the crate, a wire format change bumps PROTOCOL_VERSION. Check compatibility against that constant rather than against the version in your Cargo.toml.

Two names for it

Everything here is arin-protocol re-exported. Depend on whichever name reads better where you are using it: arin if you are writing a client and think of it as talking to Arin, arin-protocol if you are implementing the wire format somewhere else and think of it as a specification. They do not drift, because this crate tracks the protocol within a compatible range.

Licence

MIT.