A local development environment for macOS. Drop a project folder in and DevCatz works out its stack, runs it, and serves every site on its own https://<name>.localhost with a certificate your browser trusts — next to every runtime, database, storage, search engine, mail catcher, WebSocket server, tunnel and Docker setup it needs. One app instead of a Dock full of them.
Part of Catzoid — free, open-source developer tools with nine lives. All cats, no catch: no
account, no Pro tier, nothing locked behind a payment.
What it does
- Sites — PHP, Node.js / Bun, Python and Go projects detected with their framework (Laravel, Next.js, Django, Gin …), each on
https://*.localhost, monorepos and Git worktrees included.
- Runtimes — any PHP, Node.js, Bun, Python or Go version per site, installed for you.
- Services — MySQL, MariaDB, PostgreSQL, Redis, Valkey, MongoDB, Elasticsearch; S3-compatible storage; search engines; WebSocket servers; a mail catcher; gateways; tunnels to share a site.
- Per site — logs,
.env editing, database links and migrations, the site’s API, Git with AI-written commit messages, Docker files generated from the stack.
- AI, optional — bring your own provider (Claude, OpenAI, Gemini, Ollama …); off until you switch it on.
- The family — databases open in DBCatz, sites become DialCatz environments.
Install
Download the DMG from catzoid.com/devcatz/download — it picks the right
build for your Mac (Apple silicon or Intel, macOS 13 or later). Or with Homebrew — it asks you to trust a tap
that is not its own the first time:
brew tap catzoidhub/catz && brew trust catzoidhub/catz
brew install --cask devcatz
The app is signed and notarized by Apple and updates itself (Settings → About → Check for Updates). Windows builds
are on the way.
Build from source
bun install
bun run dev # run it in development
bun run typecheck
bun run package # a signed DMG in dist/ (notarized when a notarytool profile is set up)
Found a bug? Use Help → Report a Bug… in the app, or open an issue.
Code signing
Windows: the installer is built by GitHub Actions from this repository but is not code-signed yet, so Windows
SmartScreen warns when you open it (More info → Run anyway). Signing is free for open-source projects through the
SignPath Foundation, which asks for a project with more public use first — stars, forks,
issues, pull requests and write-ups all help us get there. macOS builds are signed with a Developer ID and notarized
by Apple. Full policy: catzoid.com/legal/code-signing.
How it is made
DevCatz is made by one person, with two others helping, and its code is written together with
Claude by Anthropic, an AI assistant. They decide what the cat does, designs
it, tries every feature on a real computer and reviews every change before it ships — Claude writes and explains the
code with them. Every commit Claude helped with says so (Co-Authored-By: Claude), so you can read, test or question
any of it. Found something that looks wrong? Open an issue — a person reads every report.
Catzoid is an independent project; it is not made, sponsored or endorsed by Anthropic.
Licence
DevCatz is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License
as published by the Free Software Foundation, version 3. It comes with no warranty. See LICENSE.
The names Catzoid and DevCatz and the Catzoid cat are trademarks and are not covered by the licence: a fork must
use its own name and icon. See TRADEMARKS.md.
Contributions are welcome — see CONTRIBUTING.md. Before your first pull request is merged you
sign the contributor licence agreement through the CLA check on the pull request — you keep the copyright of
your work. Questions and bug reports: SUPPORT.md; security problems, privately: SECURITY.md.
Copyright © 2026 Mahryan Rakhmatullah
