MJSFX is a native Apple Silicon Mac app for making game sound effects. Start from built-in generators, layer multiple voices with their own effects chains and LFOs, or mutate and randomize to explore (undo on everything). Export WAV at 44.1/22/11 kHz in 16 or 8-bit, including per-layer stems. Light and dark themes plus a theme builder on the site. Custom MIDI controller support. Sound files are JSON. No AI in the app, but the direct download ships with an MCP server.

Howdy Product Hunt 💥!

Matt here, dev behind MJSFX.

Why I built it: I started coding small indie web-based games at infinitetoast.com, then quickly graduated to native iOS (https://toastjuggle.app; Android version coming soon!). When I needed a game sound or effect I'd try rfxgen or jsfxr, which are solid tools, but I wanted something "more" and macOS native and nothing existed.

What MJSFX is:

🤘 Inspired by and stands on the shoulders of jsfxr, rfxgen, and sfxr
🎮 Generators to get you started: pickups, lasers, explosions, jumps, hits, etc.
🥞 Layer multiple voices, each with its own controls
🔗 Per-layer and main sound effects chain
🌊 LFOs that can modulate almost anything including itself and other LFOs
🎲 Mutate or randomize; undo on everything
💾 WAV export at 44.1/22/11 kHz, 16 or 8-bit, plus per-layer stems
⌨️ Keyboard shortcuts for (almost) everything
🎨 Themes: light, dark, and a theme builder on the site
🎛 Custom MIDI controller support (create your own config)
🔌 No in-app AI, but the direct download version ships with an MCP server
📄 Sound files are JSON

Available via Apple signed and notarized direct download and Homebrew. Or download from the Mac App Store: https://apple.co/4y9sQ5f

Free. Fully offline. No accounts, no network access (except dd/hb update checks to https://mjsfx.app), no telemetry, no ads.

Ask me anything.

Is the MCP server purely for AI-assisted sound design hooks, or does it also let me script the app directly from my own tools?

@demirciler41450 Anything that speaks MCP can use the server.