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Getting Started

Get up and running with Hot in minutes.

1. Install Hot

macOS / Linux

curl -fsSL https://get.hot.dev/install.sh | sh

Windows (PowerShell)

irm https://get.hot.dev/install.ps1 | iex

Homebrew

brew install hot-dev/hot/hot

Verify it works:

hot version

Already have Hot? Update to the latest version with hot update

2. Install VS Code Extension

For syntax highlighting and autocomplete:

  1. Open VS Code
  2. Go to Extensions (Cmd+Shift+X / Ctrl+Shift+X)
  3. Search for "Hot" and choose the Hot extension from hot-dev
  4. Click Install

3. Add AI Coding Support (Optional)

If you use an AI coding assistant, add Hot language support to help it understand your code:

hot ai add              # Add AGENTS.md + skills to project
hot ai add --global     # Install skills to ~/.skills/ (available in all projects)

This creates an AGENTS.md file and a .skills/hot-language/ directory that teach your AI assistant about Hot syntax and best practices. Works with Cursor, Claude Code, GitHub Copilot, Windsurf, and many other AI coding tools.

4. Initialize

From your existing project directory (or create a new one):

cd my-app
hot init my-app

This creates:

  • hot.hot — project configuration
  • hot/src/my-app/hi.hot — your first Hot file (it's a tutorial!)
  • .hot/ — local data (gitignored)

The project name (my-app) becomes your root namespace. All functions live under ::my-app::*.

5. Start Hot Dev

hot dev

This starts the development server with:

  • App at http://localhost:4680 — monitor runs, events, and streams
  • Scheduler — executes your scheduled functions
  • Worker — processes events

Open the app and watch things happen! The hi.hot file includes a scheduled function that runs every minute.

Tip: Use hot dev --open to automatically open the dashboard in your browser. You can also set hot.dev.open true in your hot.hot config to always open on start.

6. Run Some Code

Open another terminal and try:

# Call a function
hot eval '::my-app::hi/hello()'

# Call with arguments
hot eval '::my-app::hi/check-heat(42)'

# This one fails! (7 is divisible by 7)
hot eval '::my-app::hi/check-heat(7)'

# Trigger an event (hi.hot has a handler for this)
hot eval 'send("hot-take", {num: 42})'

Check the dashboard to see your runs and events.

7. Learn from hi.hot

Open hot/src/my-app/hi.hot in your editor—it's a complete tutorial covering:

  • Functions — basic definitions, arguments, and types
  • Flows — cond, parallel, and pipes (|>)
  • Result handling — using match on Result.Ok and Result.Err
  • Schedules — functions that run on a timer
  • Events — handlers that respond to events

Edit the file and Hot Dev reloads automatically. Experiment!

Deploy to Hot Cloud

When you're ready to go live, deploy to Hot Cloud with a single command.

Get a Hot API Key

  1. Go to hot.dev and sign in (or create an account)
  2. Navigate to Settings → API Keys
  3. Click Create API Key and copy the key
  4. Set your API key in your environment:
export HOT_API_KEY=your-api-key

Or store it in a .env file in your project root.

Deploy

hot deploy

This builds your project and deploys it to Hot Cloud. Your workflows, schedules, and event handlers will now run in production.

Next Steps

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