Backend Workflows for the AI Age

Because observability is hot!

Latest news — Product Updates: MCP, Domains, Webhooks, and More

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 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

Core

Event Handlers

Trigger functions automatically when events occur

Scheduled Runs

Run functions on a cron or natural-language schedule

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

File Storage

Read, write, and manage files in your environment

Configurable Retries

Retry failed runs with configurable attempts, delay, and backoff

Hot App

Real-time dashboard for runs, events, streams, and execution traces

Execution Tracing

Every expression traced with intermediate values, timing, and full call stack

Environments

Setup separate environments for staging, production, or whatever you need

Teams

Invite team members with role-based access to projects and environments

The Hot Language

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.

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

Development Tools

Hot CLI

Run, test, and deploy from the command line

VS Code & LSP

Syntax highlighting, autocomplete, diagnostics

Testing Framework

Built-in test runner for unit and integration tests

Security

Secret Variables

Encrypted secrets and config with AES-256-GCM

API Keys

Create, rotate, and manage API keys

Service Keys & Sessions

Scoped credentials and short-lived tokens for your customers

Granular Permissions

Fine-grained resource and action-level access control

Cloud

Hot Cloud

Deploy with one command, scale automatically

Alerts

Get notified via email, Slack, PagerDuty, or webhooks when events occur

Custom Domains

Serve your API, MCP, and Webhooks from your own custom domains

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.

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