What is Atmosphère?
~6 min read · Third-party project overview
Atmosphère is an open-source custom firmware (CFW) for the Nintendo Switch — currently the de-facto standard in the Switch homebrew community. It runs alongside Nintendo's Horizon OS and enables homebrew apps, custom system modules, and service API replacements.
Core components
- Fusée / package1 payload — boots over RCM and patches the OS before launch.
- exosphère — replaces TrustZone (TZ) code, hooking the security monitor at the lowest level.
- stratosphère — a suite of custom system modules (sm, fs, loader, ncm…).
- EmuMMC support — runs against an SD-based NAND copy so the real SysMMC stays untouched.
- SD-based file redirection (LayeredFS) — drop files in
/atmosphere/contents/<TitleID>/ to override game assets.
Install overview
Atmosphère is normally launched via the Hekate bootloader. Minimum-viable steps:
- Grab
atmosphere-X.X.X-master.zip + fusee.bin from the GitHub releases page.
- Extract the zip to your microSD root (you'll get
/atmosphere/, /bootloader/, /switch/).
- Place
hekate_ctcaer_X.X.X.bin as a payload in /bootloader/.
- Inject Hekate over RCM (with TegraRcmGUI or similar). From Hekate, choose Launch → CFW (SYSNAND) or CFW (EMUMMC).
Important: launching Atmosphère on SysMMC and going online is a near-certain ban. See
EmuMMC vs SysMMC.
How it differs from the secretchat.tel loader
Our loader requires Atmosphère — the loader itself is a homebrew NRO running under hbmenu, which runs under Atmosphère. The recommended runtime is Atmosphère on SysMMC (EmuMMC = near-certain ban). See SysMMC loader vs EmuMMC cheats for the full setup contrast.
TL;DR: Atmosphère is the prerequisite environment. Whichever method gets Atmosphère running on your console (RCM, modchip, etc.) — the loader will work on top of it.
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