Getting Started with iii
iii replaces your API framework, task queue, cron scheduler, pub/sub, state store, and observability pipeline with a single engine and three primitives: Function, Trigger, Worker.
Step 1: Install the Engine
curl -fsSL https://install.iii.dev/iii/main/install.sh | shVerify it installed:
iii --versionStep 2: Create a Project
curl -LO https://github.com/iii-hq/cli-tooling/releases/latest/download/quickstart.zip
unzip quickstart.zip
cd quickstartThe quickstart includes TypeScript, Python, and Rust workers. If you don't have all runtimes, the README includes Docker Compose instructions.
Step 3: Start the Engine
iii --config iii-config.yamlThe engine starts and listens for worker connections on ws://localhost:49134. The REST API is available at http://localhost:3111. The console is available at http://localhost:3113.
Step 4: Install the SDK
Pick your language:
# TypeScript / Node.js
npm install iii-sdk
# Python
pip install iii-sdk
# Rust — add to Cargo.toml
# [dependencies]
# iii-sdk = "*"Step 5: Write Your First Worker
TypeScript
import { registerWorker, Logger, TriggerAction } from 'iii-sdk'
const iii = registerWorker(process.env.III_URL ?? 'ws://localhost:49134')
iii.registerFunction(
'hello::greet',
async (input) => {
const logger = new Logger()
const name = input?.name ?? 'world'
logger.info('Greeting user', { name })
return { message: `Hello, ${name}!` }
},
{ description: 'Greet a user by name' },
)
iii.registerTrigger({
type: 'http',
function_id: 'hello::greet',
config: { api_path: '/hello', http_method: 'POST' },
})Python
from iii import register_worker, InitOptions, Logger
iii = register_worker(address="ws://localhost:49134", options=InitOptions(worker_name="hello-worker"))
def greet(data):
logger = Logger()
name = data.get("name", "world") if isinstance(data, dict) else "world"
logger.info("Greeting user", {"name": name})
return {"message": f"Hello, {name}!"}
iii.register_function({"id": "hello::greet", "description": "Greet a user by name"}, greet)
iii.register_trigger({"type": "http", "function_id": "hello::greet", "config": {"api_path": "/hello", "http_method": "POST"}})Rust
use iii_sdk::{register_worker, InitOptions, Logger, RegisterFunctionMessage, RegisterTriggerInput};
use serde_json::json;
let iii = register_worker("ws://127.0.0.1:49134", InitOptions::default());
iii.register_function(
RegisterFunctionMessage::with_id("hello::greet".into()),
|input: serde_json::Value| async move {
let logger = Logger::new();
let name = input["name"].as_str().unwrap_or("world");
logger.info("Greeting user", Some(&json!({ "name": name })));
Ok(json!({ "message": format!("Hello, {}!", name) }))
},
);
iii.register_trigger(RegisterTriggerInput {
trigger_type: "http".into(),
function_id: "hello::greet".into(),
config: json!({ "api_path": "/hello", "http_method": "POST" }),
})?;Step 6: Test It
curl -X POST http://localhost:3111/hello \
-H "Content-Type: application/json" \
-d '{"name": "iii"}'Expected response:
{"message": "Hello, iii!"}Install Agent Skills
Get all iii skills for your AI coding agent:
npx skillkit add iii-hq/iii/skillsSkills teach your agent how to use every iii primitive — HTTP endpoints, cron scheduling, queues, state management, streams, channels, and more. Available for Claude Code, Cursor, Codex, Gemini CLI, and 30+ other agents.
Adapting This Pattern
- Add more functions to the same worker — each gets its own
registerFunction+registerTriggercalls - Use
::separator for function IDs to namespace them:orders::create,orders::validate - Add cron triggers with
{type: 'cron', config: {expression: '0 0 9 * * * *'}}(7-field: sec min hour day month weekday year) - Add queue triggers with
{type: 'durable:subscriber', config: {topic: 'my-queue'}} - Use
iii.trigger()to invoke other functions from within a function - Use
state::get/state::setto persist data across function calls
Recommended Next Steps
After getting your first worker running:
- Add state — Use
iii-state-managementskill to persist data - Add a queue — Use
iii-queue-processingskill for async job processing - Add a cron job — Use
iii-cron-schedulingskill for scheduled tasks - Build an API — Use
iii-http-endpointsskill for REST endpoints with CRUD - Add observability — Use
iii-observabilityskill for tracing and metrics - Explore architecture patterns — See
iii-agentic-backend,iii-reactive-backend,iii-workflow-orchestration
Key Resources
- Quickstart Guide
- SDK Reference — Node.js
- SDK Reference — Python
- SDK Reference — Rust
- Engine Configuration
- Console Dashboard
Pattern Boundaries
- For HTTP endpoint patterns (CRUD, parameterized routes), prefer
iii-http-endpoints - For cron/scheduling patterns, prefer
iii-cron-scheduling - For queue/async job patterns, prefer
iii-queue-processing - For state persistence patterns, prefer
iii-state-management - For engine configuration, prefer
iii-engine-config - Stay with
iii-getting-startedfor installation, initial setup, and first-worker guidance
When to Use
- Use this skill when the task is about installing iii, creating a new project, or writing a first worker.
- Triggers when the request asks for setup help, quickstart guidance, or getting started with iii.
Boundaries
- Never use this skill as a generic fallback for unrelated tasks.
- You must not apply this skill when a more specific iii skill is a better fit.
- Always verify environment and safety constraints before applying examples from this skill.