Installation

Install the iii engine using curl, Docker, or build from source

Installing iii

iii runs as a single binary that orchestrates your backend functions and triggers. Choose your preferred installation method below.

Quick Install (Recommended)

The fastest way to get started is with the installation script:

Default

curl -fsSL https://install.iii.dev/iii/main/install.sh | sh

The installation script automatically detects your platform (Linux, macOS, Windows) and architecture (x86_64, ARM64).

Verify Installation

After installation, verify that iii is available:

command -v iii && iii --version

Expected output:

/usr/local/bin/iii
iii v0.7.0

Docker Installation

iii is available as a Docker image for containerized deployments.

Pull the Image

docker pull iiidev/iii:latest

Run with Docker

1. Create a config file (optional)

   If you need custom module configuration, create a config.yaml file:

   config.yaml

   modules:
     - class: modules::rest_api::RestApiCoreModule
       config:
         host: 0.0.0.0
         port: 3111
     - class: modules::observability::OtelModule
       config:
         enabled: true
         level: info
   
2. Run the container

   docker run -p 3111:3111 -p 49134:49134 \
     -v ./config.yaml:/app/config.yaml:ro \
     iiidev/iii:latest
   

   If you don’t provide a config file, iii loads default modules: HTTP, Queue, Cron, Stream, and Observability.

3. Verify the engine is running

   The engine exposes several ports:

   Port	Service
   49134	WebSocket (worker connections)
   3111	HTTP API
   3112	Stream API
   9464	Prometheus metrics

Production Docker Deployment

For production environments, use a hardened configuration:

docker run --read-only --tmpfs /tmp \
  --cap-drop=ALL --cap-add=NET_BIND_SERVICE \
  --security-opt=no-new-privileges:true \
  -v ./config.yaml:/app/config.yaml:ro \
  -p 3111:3111 -p 49134:49134 -p 3112:3112 -p 9464:9464 \
  iiidev/iii:latest

Production images use distroless runtime (no shell, minimal attack surface) and run as non-root user.

Docker Compose

For a complete stack with Redis and RabbitMQ:

1. Create docker-compose.yml

   docker-compose.yml

   services:
     iii:
       image: iiidev/iii:latest
       ports:
         - "49134:49134"  # WebSocket
         - "3111:3111"    # REST API
         - "3112:3112"    # Stream API
         - "9464:9464"    # Metrics
       volumes:
         - ./config.yaml:/app/config.yaml:ro
       environment:
         - RUST_LOG=info
       depends_on:
         redis:
           condition: service_healthy
       restart: unless-stopped
   
     redis:
       image: redis:7-alpine
       ports:
         - "6379:6379"
       volumes:
         - redis_data:/data
       healthcheck:
         test: ["CMD", "redis-cli", "ping"]
         interval: 5s
         timeout: 3s
         retries: 5
       restart: unless-stopped
   
   volumes:
     redis_data:
   
2. Start the stack

   docker compose up -d
   
3. Check status

   docker compose ps
   docker compose logs iii
   

Queue and Stream modules require Redis at redis://localhost:6379 by default. Override with environment variables in your config.

Build from Source

For development or custom builds:

1. Install Rust toolchain

   curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
   
2. Clone the repository

   git clone https://github.com/iii-hq/iii.git
   cd iii
   
3. Build the binary

   cargo build --release
   

   The binary will be at target/release/iii.

4. Run the engine

   cargo run
   # Or with config:
   cargo run -- --config config.yaml
   

Development Commands

# Watch mode (requires cargo-watch)
make watch

# Lint and format
cargo fmt && cargo clippy -- -D warnings

# Run tests
cargo test

# Build Docker images locally
docker build -t iii:local .                        # production
docker build -f Dockerfile.debug -t iii:debug .    # debug

Environment Configuration

iii supports environment variable expansion in config files:

config.yaml

modules:
  - class: modules::queue::QueueModule
    config:
      adapter:
        class: modules::queue::RedisAdapter
        config:
          redis_url: ${REDIS_URL:redis://localhost:6379}

The syntax ${VAR:default} reads from environment or uses the default value.

Next Steps

Start the Engine

Learn how to start iii and connect your first worker

Install an SDK

Install the Node.js, Python, or Rust SDK to write functions

Configure Modules

Customize HTTP, Queue, Cron, Stream, and other modules

Production Setup

Hardening, monitoring, and scaling for production

Default Modules: Without a config file, iii loads HTTP, Queue, Cron, Stream, and Observability modules. Queue and Stream expect Redis at redis://localhost:6379.