Anybody could ask for a device code and be handed a link with the user code already in it. Following that link started a sign-in, and finishing the sign-in approved the grant. So sending somebody the link was enough: they saw an ordinary sign-in prompt, completed it, and whoever kept the device code polled and collected their access and refresh tokens. The victim never saw a question, because there was not one. There is now. Signing in says who the browser belongs to; it does not say the person meant to hand an account to a program somewhere else. Those are two questions and only the second authorizes anything, so the flow ends at a page that names the program, shows the code back so it can be compared with what the device is displaying, and offers Approve and Deny. Approving is a POST carrying a value from the cookie, so another site cannot submit it on somebody's behalf. Denial moved onto the same page: it used to be a GET anyone could fire, which meant a link scanner could cancel a real sign-in and a stranger with a user code could grief one. Three more things that were wrong underneath. The grant was read, modified and written back as a whole record. A poll that read a pending grant and then wrote its bookkeeping erased an approval that landed in between, and the client polled a dead grant until it expired. Grants moved to a table, where approving is one conditional update and redeeming is one delete that returns what it deleted, so neither party can undo the other and two polls cannot both be served. Tokens were minted when the person clicked and left sitting in storage until collected. They are minted at redemption now, so the lifetime the client is told about starts when it receives them, and a grant nobody collects leaves no usable refresh token behind. The client identifier was never checked, at either end. It is validated when the grant is created and has to match when the code is redeemed — without that, a leaked code is redeemable by anyone, and the identifier the token carries is whatever the last caller claimed. The device code is also stored as a hash now, since it is the credential the tokens are handed to. The store is an interface because the issuer cannot reach the database, and because the guarantees are the point: every method is one operation, and no caller reads a grant, decides, and writes it back.
Run your games on a GPU you don't own — or one you do. Nestri puts an interactive workload in a hardware-accelerated virtual machine and streams it to you over QUIC, at a latency that lets you play rather than watch.
Note
This repository is mid-rewrite, and the documentation is behind the code. The guest-side components arrived recently and their docs are thin. Nothing here is stable yet: expect directories to move and interfaces to change. Proper documentation is on the way — issues and questions are welcome in the meantime, and are genuinely useful for deciding what to write first.
Try it now — nesdoctor
One thing here is finished and runs on its own machine, today:
# Linux and macOS
curl -fsSL https://doctor.nestri.io/install.sh | sh
# Windows
powershell -c "irm https://doctor.nestri.io/install.ps1 | iex"
It tells you whether your machine could host games for other people, and
measures the number that actually decides whether streaming a game feels
right — not your download speed, but how much latency your connection adds
when it is busy. A 500 Mbps uplink that queues for 300 ms under load cannot
carry a game; a 25 Mbps one with fq_codel can. Almost nobody has seen their
own figure.
upstream 35 Mbps
latency, idle floor 56 ms
latency, loaded 185 ms
added under load +129 ms grade F
presentation path x11 · bspwm
eDP-1 1920x1200 @ 60 Hz, 8-bit
Vulkan decode h264, h265
It also reads your display out of its EDID — resolution, refresh, colour depth, HDR transfer functions, BT.2020, chroma — and what your hardware can decode. Those decide what is worth sending over the wire, and we would otherwise be guessing from one panel in one room.
It does not stream a game. It is the piece that has to exist before
anything else can, and most machines will come back CLIENT — which is a real
answer, not a failure.
Downloads one binary, verifies its checksum, runs it, deletes it. Installs
nothing, needs no administrator rights, touches no system directory. Nothing is
uploaded: it prints a link, lists exactly what the link contains, and opens it
only if you press Enter. The scripts those URLs serve are
apps/nesdoctor/install/ in this repository, so you
can read them before you run them.
Source and the full story: apps/nesdoctor.
What is here
Two halves that meet over the network and share very little else, plus one thing that runs on your own machine.
The control plane — TypeScript, on Cloudflare Workers
apps/api |
The public REST API. Identity, teams, machines, games, pairing. |
apps/auth |
A self-hosted OpenAuth issuer — Steam and SSH-key login. |
packages/core |
The domain: every table, every operation, no HTTP. |
packages/auth |
Shared auth types and subjects. |
Postgres for state, Alchemy for infrastructure. See
docs/alchemy.md.
The guest — Rust, inside the box
These run inside a virtual machine, beside the game. None of them talk to the control plane.
apps/nescope |
A headless Wayland compositor for one fullscreen client. A lighter answer to the same problem gamescope solves. |
apps/nescapture |
A Vulkan implicit layer. It captures frames from inside the workload's own process and encodes them on the GPU that drew them — no copy out to the CPU and back. |
apps/neswire |
Audio capture and transport. |
apps/neshub |
One connection out of the box. Muxes video, audio, cursor and input into a single QUIC stream to the client. |
crates/nesprotocol |
The wire types they all share, so no two ends can drift apart silently. |
On your own machine — Rust
apps/nesdoctor |
Whether a machine can host a box, and what its connection and display can really do. The first executable form of our host requirements — until it existed, a host was qualified by a human reading a table. Four dependencies; everything that could be done with the standard library is. |
The hypervisor the guest components run under is nesbox,
a separate repository: a micro-VM with a real GPU in it, using virtio-gpu native
context rather than passthrough, so one card can host several boxes at once.
Why a virtual machine
A container shares the host kernel, which makes strong isolation hard and a GPU harder. A micro-VM boots in about as long, isolates properly, and — with native context — gets close to bare-metal graphics. That choice is what makes "many sandboxes, one GPU" possible instead of one tenant per card.
Getting started
bun install
bun dev # control plane, local Cloudflare runtime
cargo build --workspace # guest components
cargo test --workspace
The guest components expect a Linux host with a Wayland-capable GPU stack, and are not much use on their own yet — they are pieces of a box, and the thing that assembles a box is not open yet.
nesdoctor is the exception and needs none of that:
cargo run --release -p nesdoctor
Status
Working: nesdoctor — released, and the only part a stranger can operate
today. The API, auth, the domain model, and the guest components listed above.
Not here yet: the box lifecycle, storage, the edge, and the client. Some of that will open as it is written; some is deliberately closed. What decides which is whether it handles your data — that half is open on principle — or decides our capacity, which is the part we sell.
Contributing
Early, and the ground moves. The two most useful things you can do right now
cost a minute each: run nesdoctor and send the result, because we have
almost no idea what the machines on the other end of this look like; and tell
us where the documentation failed you. Conventional commits; explain why in
the body.