iii-sdk-reference

SDK Reference

Use this skill for language-specific SDK details. Use iii-core-primitives for the common model and
iii-error-handling for exception handling.

Install

# TypeScript / Node.js
npm install iii-sdk

# Browser apps
npm install iii-browser-sdk

# Python
pip install iii-sdk

# Rust
cargo add iii-sdk

Choose the SDK

SDK	Package	Best for	Important caveat
Node.js	iii-sdk	Server-side TypeScript/JavaScript workers	Supports custom headers, Logger, OpenTelemetry, HTTP-invoked functions
Browser	iii-browser-sdk	Web apps and interactive UI callbacks	Connect through an RBAC-protected listener; keep secrets server-side
Python	iii-sdk	Sync or async Python workers	Use trigger_async inside async handlers
Rust	iii-sdk	High-performance tokio workers	Handler error type should map into iii_sdk::Error

Logger/OpenTelemetry, HTTP request/response types, stream, queue, and worker-connection types live in
the helpers package — @iii-dev/helpers (Node, with submodules like /observability and /http) or
iii-helpers (Python iii_helpers.*, Rust iii_helpers::*) — installed alongside the SDK.

Common API Map

Capability	Node	Python	Rust
Connect worker	registerWorker(url, options?)	register_worker(address, options?)	register_worker(url, InitOptions)
Register local function	registerFunction(id, handler, options?)	register_function(id, handler, **options)	register_function(RegisterFunction::new(...))
Register trigger	registerTrigger({ type, function_id, config })	register_trigger({...})	register_trigger(RegisterTriggerInput { ... })
Invoke function	trigger({ function_id, payload })	trigger(request) / trigger_async(request)	trigger(TriggerRequest)
Durable enqueue	TriggerAction.Enqueue({ queue })	{"type": "enqueue", "queue": name}	TriggerAction::Enqueue { queue }
Channels	createChannel()	create_channel() / create_channel_async()	create_channel(None).await

Node.js

import { registerWorker } from "iii-sdk";
import { Logger } from "@iii-dev/helpers/observability";

const iii = registerWorker("ws://localhost:49134", {
  workerName: "node-worker",
  invocationTimeoutMs: 30000,
});

iii.registerFunction("users::lookup", async (input) => {
  new Logger().info("looking up user", { userId: input.userId });
  return { userId: input.userId, name: "Ada" };
});

Node supports custom WebSocket headers, Logger, OpenTelemetry options, HTTP-invoked function
registration, trigger metadata, channels, and custom trigger types.

Browser

import { registerWorker, TriggerAction } from "iii-browser-sdk";

const iii = registerWorker("wss://api.example.com/worker?token=session-token");

const result = await iii.trigger({
  function_id: "backend::get-user",
  payload: { userId: "123" },
});

await iii.trigger({
  function_id: "analytics::track",
  payload: { event: "page_view" },
  action: TriggerAction.Void(),
});

Do not expose the private engine worker port to untrusted browsers. Browser workers cannot send
custom WebSocket headers and must not hold backend secrets.

Python

from iii import InitOptions, register_worker
from iii_helpers.observability import Logger

iii = register_worker(
    address="ws://localhost:49134",
    options=InitOptions(worker_name="python-worker"),
)

def lookup_user(data):
    Logger().info("looking up user", {"userId": data["userId"]})
    return {"userId": data["userId"], "name": "Ada"}

iii.register_function("users::lookup", lookup_user)

Python handlers may be sync or async. Use await iii.trigger_async(request) inside async handlers,
and iii.trigger(request) in sync contexts. HttpResponse (from iii_helpers.http) uses camelCase statusCode.

Rust

use iii_sdk::{register_worker, InitOptions, RegisterFunction};
use serde_json::json;

let iii = register_worker("ws://127.0.0.1:49134", InitOptions::default());

iii.register_function(
    RegisterFunction::new("users::lookup", |input: serde_json::Value| {
        Ok(json!({ "userId": input["userId"], "name": "Ada" }))
    }).description("Look up a user"),
)?;

Rust supports typed handlers and schema extraction when input/output types derive
schemars::JsonSchema. Add the otel feature when using OpenTelemetry helpers.

Channels

• Use channels for binary data, large payloads, or streaming transfer between workers.
• Pass readerRef or writerRef through a function payload.
• Reconstruct readers/writers from refs in consumers when the SDK requires it.

When to Use

• Use this skill for package names, SDK exports, initialization options, browser security constraints,
  channel API details, and language-specific syntax.
• Use this when a task asks for Python or Rust examples and the issue is SDK syntax rather than iii
  architecture.

Boundaries

• For the common Function/Trigger/Worker model, built-in trigger schemas, custom triggers, and
  invocation mode decisions, use iii-core-primitives.
• For deployment config, queue adapter policy, worker manager, RBAC listeners, and ports, use
  iii-engine-config.
• For retryability and exception classes, use iii-error-handling.