Backend Workflows for the AI Age

Because observability is hot!

How It Works

Install Hot

One command install

terminal

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

PowerShell

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

Also available via Homebrew, installers, and more

Initialize a new Hot project

Add to any existing codebase

terminal

cd dev/so-fire-backend/
hot init so-fire

Creates a .hot data directory, hot/src source directory, and hot.hot configuration file

Write some Hot code

in hot/src

hot/src/so-fire/user.hot

::so-fire::user ns

send-welcome-email
meta {
  on-event: "user:created",
  doc: "Send a welcome email when user is created"
}
fn (event) {
  ::resend::emails/send-email(
    POSTEmailsRequest({
      from: "hello@so-fire.app",
      to: [event.data.user.email],
      subject: "Welcome to SoFire!",
      html: "<p>Welcome to SoFire!</p>"
    })
  )
}

Run the dev servers

App, API, Scheduler, Worker — all in one command

terminal

hot dev

Watch your workflow running

Real-time observability at localhost:4680

Runs

Every execution captured. Status, timing, input, output, full trace.

Events

See every event, its payload, and which handlers processed it.

Execution Trace

Each expression, intermediate values, return values, timing.

Errors

Failures, cancellations, stack traces. Debug fast.

Deploy to Hot Cloud

Optional — when you're ready to go live

terminal

hot deploy

The Hot Language

Purpose-built for backend workflows

Familiar Data Literals

If you know JSON, you know Hot's data syntax. Maps, vectors, strings, numbers — all familiar.

Types Are Optional

Add types where they help, skip them where they don't. Autocomplete and error checking when you want it.

Flows Control Execution

Parallel, conditional, and pipe patterns built into the language. Clean workflow logic.

Event Handlers

Declare handlers with meta {on-event: "..."}. Hot routes events automatically.

Built-in Schedules

Schedule functions with meta {schedule: "every 5 minutes"}. Cron syntax supported.

Event-Driven Workflows

Send events to trigger other runs. Build complex flows from simple, composable handlers.

Run Control

Fail fast, cancel gracefully. Built-in primitives for controlling workflow execution.

Standard Library

Rich built-in functions for collections, strings, math, HTTP, and more. Ready to use.

Learn the Hot Language

The Hot App

Real-time observability for your workflows

Dashboard

Stream Graph

Execution Trace

Learn about the Hot App

The Platform

Everything you need from local dev to production

Hot Packages

Pre-built integrations for AI and SaaS services

HTTP API

OpenAPI-compatible REST endpoints

MCP Tools

Turn any Hot function into an MCP Tool for AI agents

Webhooks

Turn any Hot function into a Webhook endpoint

VS Code & LSP

Syntax highlighting, autocomplete, diagnostics

Hot Cloud

Deploy with one command, scale automatically

Ready to ship?

Free local development.
Simple, transparent cloud pricing when you're ready.

Things people say

"Hot Dev? Is that a dating site for developers?"

— Everyone, at first

"Print statements aren't observability!"

— Us, constantly

"Wait, I can actually see my code running?"

— Developers, after trying Hot

Connect Your Services

Pre-built integrations for the tools you use

OpenAI

Anthropic

Gemini

xAI

AWS

Resend

Postmark

Slack

MCP

JSON-RPC

... and more coming soon

Hot Takes

Hot Dev's newsletter for product updates, tutorials, and demos.

Start building with Hot

Install in seconds. Ship your first workflow today.

Get Started View Pricing