iii

iii

iii is a language-agnostic runtime where services, agents, and tools are composed of the same things: workers, triggers, and functions. One engine process (default port 49134) holds a live registry of every connected worker, every function those workers expose, and every trigger bound to them. Workers are independent OS processes that open a WebSocket to the engine and register Functions (service::name handlers) and Triggers (the events that invoke those Functions). There is no direct worker-to-worker traffic — every call routes through the engine, which makes the language, runtime, and physical location of any worker invisible to its callers.

When to Use

Use this skill to discover live iii capabilities, call functions, author SDK workers, bind trigger types, or operate project workers through Compose.

You extend yourself by writing iii workers. A few lines get you on the bus:

import { registerWorker } from 'iii-sdk'

const iii = registerWorker(process.env.III_ENGINE_URL!, { workerName: 'demo' })

iii.registerFunction('demo::add', async (payload: { a: number; b: number }) => {
  return { c: payload.a + payload.b }
})

The instant the handshake completes, demo::add is callable from any worker (and the harness itself) via iii.trigger({ function_id: 'demo::add', payload: { a: 2, b: 3 } }). No restart, no registration with the harness — the engine routes it automatically.

The four primitives

Three consequences worth internalising:

1. No worker-to-worker traffic. Every call is worker → engine → worker. Workers never address each other directly. Location and language are invisible.
2. No restart coordination. Restarting a worker is invisible to callers as long as it re-registers the same function ids. Two workers registering the same function id = automatic load-balance.
3. No polling unless you opt in. Triggers are the engine's push channel. The engine fans events out to bound functions when the underlying source fires.

The function id is the only contract between any two workers.