iii-getting-started

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 | sh

Verify it installed:

iii --version

Step 2: Create a Project

iii create

Follow the interactive prompts to select a template and language. The default quickstart template includes TypeScript, Python, and Rust workers.

Then change into the project directory you chose at the prompt:

cd <your-projec

Step 3: Start the Project

The file's engine: section starts the engine; containers: starts project workers. The engine commonly listens on ws://localhost:49134. Keep this foreground supervisor running.

Step 4: Install the SDK

Pick your language:

Step 5: Write Your First Worker

TypeScript

Python

Rust

Step 6: Test It

Expected response:

Add Existing Workers

To add a capability that already exists, browse https://workers.iii.dev/ and add it through the running Compose daemon:

compose::add resolves dependencies, writes exact versions to worker-compose.yaml, and restarts the affected project. A local worker can be declared as a path:// container or added by path.

Install Agent Skills

Get all iii skills for your AI coding agent:

Skills teach your agent the top-level iii model: functions, triggers, workers, registry access, SDKs, engine configuration, architecture patterns, and error handling. Worker-backed capabilities live with the worker docs and registry entries.

Adapting This Pattern

• Add more functions to the same worker — each gets its own registerFunction + registerTrigger calls
• 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::set to persist data across function calls
• Use iii trigger -n <daemon> compose::add worker=<name> when the capability already exists in the worker registry

Recommended Next Steps

After getting your first worker running:

1. Register functions, triggers, and workers — See iii-core-primitives
2. Choose the right SDK APIs — See iii-sdk-reference
3. Configure the engine — See iii-engine-config
4. Explore backend patterns — See iii-architecture-patterns
5. Handle failures well — See iii-error-handling

Key Resources

• Quickstart Guide
• SDK Reference — Node.js
• SDK Reference — Python
• SDK Reference — Rust
• Engine Configuration
• Console

Pattern Boundaries

• For function and trigger registration patterns, worker creation, worker registry access, trigger payload schemas, invocation modes, channels, custom triggers, and HTTP-invoked functions, prefer iii-core-primitives
• For language-specific SDK APIs, prefer iii-sdk-reference
• For engine configuration, prefer iii-engine-config
• For worker-backed HTTP, cron, queue, pubsub, state, stream, and observability behavior, use the matching worker docs under engine/src/workers/**/skills
• Stay with iii-getting-started for 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.