p0mpurin/Kasumi

Play your GeForce NOW games on the New Nintendo 3DS.
A native, unofficial GeForce NOW client with a calm, OLED-black design.

Download · Getting started · FAQ · Report a problem

Kasumi (霞, "mist") streams your GeForce NOW library to the New 3DS, New 3DS XL and New 2DS XL: cloud gaming on the 3DS, no PC needed. Play your Steam, Epic and other PC games on a 3DS; they run on NVIDIA's servers, while the 3DS decodes the video in hardware, plays the audio and sends your buttons back. It is not affiliated with NVIDIA or with the OpenNOW project.

_{▶ Watch the showcase on YouTube}

Public beta. Kasumi works well for everyday play, but it is still in active development: expect rough edges, and please report what you find.

Plays like a controller PlayStation-style layout, touch L3 / R3 / PS, and optional gyro aiming.

Readable on a small screen The top screen's 800-pixel mode, zoom, and saved zoom zones per game.

Tuned for 3DS Wi-Fi Smooth frame pacing, loss recovery and a built-in connection check.

• Works in your country: Server on Auto pings every GeForce NOW server and uses the fastest, measured again on each new Wi-Fi network. Where GeForce NOW is sold by a local partner (the GeForce NOW Alliance), pick it in Settings and sign in with that account.
• Gets you into the game: Kasumi follows your place in the queue as NVIDIA moves it between servers, offers to resume or end a game still running on your account, and when NVIDIA is still releasing your last session it counts down and tries again by itself.
• Steadier Wi-Fi while you play: StreetPass, SpotPass and other background Wi-Fi work pause during a game (like Moonlight does), so the radio stays on the stream. If a network was choppy last time, the next session there starts in Weak / hotspot mode by itself.
• Your library with box art, saved on the SD card so it opens instantly, with All / Favourites / Recent tabs and a page for every game.
• Per-game options: bitrate, gyro, button layout and a fully custom button mapping just for that game.
• Queue with an estimate and an alert: the free-tier queue shows a wait time that learns from your own queues. Close the lid while you wait; when the rig is ready the notification light pulses and a chime plays.
• Picks up where you left off: Continue relaunches your last game in one press, and if Kasumi ever closes mid-game, the next start offers to resume the game still running on your rig.
• Stream menu (hold START + SELECT): screenshots, controls sheet, zoom zones, gyro, sound and disconnect.
• Remote keyboard and touchpad for launchers, sign-in screens and chat.
• Comfort: five colour themes, stream volume, session timer, and automatic reconnect, including after closing the lid, back onto the same rig.
• First-run guide that walks you through everything (skippable).
• Updates itself from GitHub, with release notes on the console; the update page opens by itself when a new version is out.

Playing, with live stats	A game's page	Stream menu
Zoom zones for small text	Settings	Remote keyboard

• A New Nintendo 3DS, New 3DS XL or New 2DS XL (the original 3DS lacks the video decoder).
• Custom firmware (Luma3DS) to install homebrew.
• A GeForce NOW account, from NVIDIA or from a GeForce NOW Alliance partner (the free tier works, with a queue and one-hour sessions).
• 2.4 GHz Wi-Fi with a good signal (3 bars is best).

Quickest: open FBI on the 3DS, choose Remote Install > Scan QR Code, and scan the code on the right. FBI downloads and installs the latest Kasumi.cia directly.

Or download Kasumi.cia from the Releases page and install it with FBI, or copy Kasumi.3dsx to sdmc:/3ds/ and start it from the Homebrew Launcher.

After that, Kasumi updates itself: Settings > Updates shows what's new and installs the latest release in place (it checks automatically, only in the menus). Your login, library and settings are kept. Every download is checked against the release's SHA256SUMS before anything is installed.

1. Open Kasumi and follow the short guide.
2. Press A to sign in. Open the web address shown on your phone or computer and enter the code. No password is ever typed on the 3DS. Most accounts are NVIDIA's (the default). If you bought GeForce NOW from a local partner, first pick it in Settings > Account > GeForce NOW provider, then sign in.
3. Your library loads with box art. Press A on a game to open it, then A again to play.
4. During play, hold START + SELECT for the stream menu.

Remote keyboard: tap keys or use the D-Pad and A. B deletes, Y is space, START is Enter, L is Shift (twice for Caps Lock), R switches symbols, ZL is Tab, X closes. Typed text is never stored or logged.

Custom mapping: open a game, press X (Options) and choose Button mapping. Press any 3DS button to pick it, then use the Circle Pad (or the arrows) to choose what it sends: any PlayStation button, trigger, stick click, D-Pad direction, or nothing. Only that game uses the mapping.

• Choppy picture? Move closer to the router, or set Bitrate to Steady 1 Mbps (Settings, or just for one game in its Options).
• Phone hotspot or far from the router? Set Settings > Network > Connection type to Weak / hotspot: a steadier, slightly softer picture that copes with mobile data.
• High ping? Settings > Network > Server on Auto picks the GeForce NOW server with the lowest ping from wherever you are; you can also pick one yourself.
• Small text? Use ZOOM and drag the map; save the spot as a zoom zone.
• Gyro: While aiming only steers while ZL is held, which suits most shooters.
• Connection check (Settings > System) measures Wi-Fi, latency and speed and suggests a bitrate.

Can you cloud game on a 3DS without a PC? Yes. With Kasumi, a New 3DS streams games straight from GeForce NOW's cloud servers. You don't need a gaming PC, only the 3DS, Wi-Fi and a GeForce NOW account.

How do I play Steam or other PC games on a 3DS? Link your Steam, Epic, Ubisoft or other store account in GeForce NOW (on play.geforcenow.com or its app), then launch the game from Kasumi's library. The game runs on NVIDIA's servers using the copy you own, and the 3DS is your screen and controller.

How is Kasumi different from Moonlight? Moonlight streams games from your own PC at home. Kasumi streams from GeForce NOW's servers, so no PC is needed. If you have a gaming PC, Moonlight is a great option too.

Do I need a paid GeForce NOW membership? No. The free tier works, with a queue before each session and a one-hour limit. Kasumi shows the queue with a wait estimate and warns you before the hour ends.

Does it work on an original 3DS or 2DS? No. Kasumi decodes video with the hardware decoder that only the "New" models have.

Why 30 FPS and around 1 Mbps? The 3DS screen and decoder are built for 30 FPS video, and its 2.4 GHz Wi-Fi starts losing packets above roughly 1.2 Mbps. Kasumi is tuned for a smooth, steady picture within those limits.

How is the latency? It depends mostly on your distance to NVIDIA's servers and on your Wi-Fi. In testing, the network round trip was around 60-80 ms, plus one or two frames that Kasumi holds back to keep the picture smooth. It feels fine for adventure, RPG and most action games, less so for competitive shooters. The stream stats show your live ping.

Is my account safe? Should I link Steam? Kasumi signs in through NVIDIA's own device-code page on your phone or PC and never sees your NVIDIA password. It never sees your Steam password either: store accounts are linked inside GeForce NOW itself, not in Kasumi. The code is open source, so anyone can check what it does. It is an unofficial client, so, as with any third-party client, use it at your own discretion.

My game save is gone. Did Kasumi delete it? No. Kasumi never touches saves: they are kept by the game's store (Steam Cloud, Epic, Ubisoft...) or the game's own account. Leaving the stream closes the game at once, so quit from the game's own menu first to let it save and sync. Also check you launched the same store's version as before.

GeForce NOW in my country is sold by a local partner. Does it work? Yes (still new). In some countries GeForce NOW is run by a GeForce NOW Alliance partner with its own accounts and servers. Open **Settings > Account

GeForce NOW provider**, pick your partner, sign out if you were signed in, and sign in again; your library, servers and sessions then go through that partner. The list comes from NVIDIA, and players have confirmed it works with ABYA and Digevo (Chile) and Pentanet (Australia). Keep NVIDIA if your account is NVIDIA's own, even when a partner exists in your country. Partner queues can be much longer than NVIDIA's.

"This account can't stream here" or an empty library? Usually the account and the provider don't match: an NVIDIA account signed in through a partner, or a partner account signed in through NVIDIA. Change Settings > Account > GeForce NOW provider, sign out and sign in again.

"Launch failed" or a countdown before my game starts?

• Session limit (HTTP 403): NVIDIA still counts an earlier session (it can take a few minutes to release one), or GeForce NOW is open on another device. If a game is running elsewhere, Kasumi offers to resume it here or end it; otherwise it counts down and tries again by itself. Closing GeForce NOW on your other devices and browser tabs helps.
• Too many requests (HTTP 429): NVIDIA limits launch attempts after several in a row. Kasumi waits it out and tries again by itself; pressing launch over and over makes it last longer.
• "Limited mode" (HTTP 500): NVIDIA has restricted streaming on the account itself. Check whether it can play on play.geforcenow.com; if not, the account needs sorting out with NVIDIA.

Kasumi asked me to sign in again. Why? Your login is renewed in the background. If NVIDIA can't be reached at that moment (no Wi-Fi yet, a busy server), Kasumi keeps your login and just asks you to try again; you only need to sign in again when NVIDIA no longer accepts the old login.

Does it run on an emulator (Citra / Azahar)? No. Kasumi needs the New 3DS hardware video decoder and a real network connection.

What happens when I close the lid mid-game? The 3DS turns Wi-Fi off when the lid closes, so the stream stops. Kasumi keeps your game on the rig and reconnects on its own when you open the lid again.

Which games work? Any game in your GeForce NOW library. Kasumi shows up as a standard controller, so games with controller support work out of the box, and Steam games work too even without native controller support, because Steam Input translates the controller for them. The touchpad and keyboard are for navigating launchers, sign-in screens and chat, not for playing.

Who Kasumi talks to. NVIDIA (sign-in, your library, servers and game sessions), or your GeForce NOW partner if you picked one; GitHub, to check for and download updates; and Kasumi's report service, only if you allow it (below). When a game starts, the stream also asks NVIDIA's and Google's public STUN servers for your public address, as browsers do for video calls and GeForce NOW in a browser; nothing else is sent to them.

What stays on your SD card (sdmc:/3ds/kasumi/):

• gfn-session.json: your login. Never share that file. No password is in it (you never type one on the 3DS), but it lets anyone use your GeForce NOW account until it expires.
• Your settings, library cache, chosen provider, a random console ID made by Kasumi, and the diagnostic logs.
• The names of Wi-Fi networks you played on, with their fastest server and whether the last session there was choppy. They are used to pick the server and Weak / hotspot mode, and are never logged or sent anywhere.

The diagnostic logs (kasumi-diagnostic.txt and kasumi-diagnostic-previous.txt) exclude tokens, passwords and anything you type, and are safe to attach to bug reports.

Sharing is opt-in. Kasumi asks once, "Help improve Kasumi?". If you choose Share, it sends:

• Problem reports: the log, on its own when something goes wrong (the previous run crashed, froze or lost power, a game failed to launch, or the stream could not reconnect), at most once per run and never during a game.
• Performance stats: after each session of 30 seconds or more, a few numbers (session length, game, server, ping, bitrate, frame rate, lost and repeated frames, reconnects, decode time), and for each launch whether the game started and why not, the provider, queue time and how long it took. Each comes with Kasumi's version and the random install ID, so one console's numbers can be grouped. No log text, no account, no addresses. Kept 90 days.

If you choose No thanks, nothing is ever sent unless you use Send diagnostic report yourself. Change either one anytime under Settings > System (Share problem reports, Share performance stats); turning stats off also deletes the ones not sent yet.

A report holds the logs of this run and the previous one, your settings.json (including the random install ID, which is not linked to your NVIDIA account), and the newest Luma crash dump of Kasumi from the last few days. Public IP addresses in the logs are shortened to their first two numbers, and your login is never included. Reports are kept for 30 days and are only readable by the developer. The service doesn't store your IP address: it only keeps a scrambled hourly counter to stop flooding, deleted after an hour. The service's code is in server/report-worker.

The easiest way: in Kasumi, open Settings > System > Send diagnostic report, then mention the code it shows (like K7F-2QX) in your bug report or message. Kasumi keeps the log of the previous run too, so this works even after a crash or freeze.

You can also attach the files yourself: sdmc:/3ds/kasumi/kasumi-diagnostic.txt (this run) and kasumi-diagnostic-previous.txt (the run before), plus, after a crash, the newest Luma dump from sdmc:/luma/dumps/arm11/. Ideas are welcome as feature requests.

Install devkitPro with the 3DS packages (plus CMake):

pacman -S --needed 3ds-dev 3ds-curl 3ds-jansson 3ds-mbedtls 3ds-libopus 3ds-cmake

From devkitPro MSYS in the repository root, build the WebRTC transport once, then the app:

bash tools/build-transport.sh
make
make cia MAKEROM=/path/to/makerom BANNERTOOL=/path/to/bannertool

make produces Kasumi.3dsx; make cia needs makerom and bannertool. How the stream, pacing and input work is described in docs/TECHNICAL.md.

To publish a release, set the version in the Makefile, write docs/releases/v<version>.md, and run bash tools/make-release.sh (with MAKEROM and BANNERTOOL set); it builds the CIA, the .3dsx and SHA256SUMS and prints the gh release create command.

Kasumi builds on the open-source OpenNOW family of GeForce NOW clients, especially OpenNOW-Switch and OpenNOW-Vita, and on libpeer, libsrtp, usrsctp, mbedTLS, libcurl, jansson, libopus, stb_image, citro2d and libctru. MVD and zoom work was informed by Moonlight-N3DS.

GeForce NOW and NVIDIA are trademarks of NVIDIA Corporation. Nintendo 3DS is a trademark of Nintendo. Kasumi is an unofficial fan project and is not affiliated with or endorsed by either company.

Kasumi is free software under the GNU General Public License v3.0: you may use, study, share and modify it, and anything you distribute that is based on it must stay under the GPL with its source available. Third-party components keep their own licences; see THIRD_PARTY.md.