nesdoctor

Finds out whether this machine could host games for other people, and measures what your connection actually does when it is busy.

macOS & Linux

curl -fsSL https://doctor.nestri.io/install.sh | sh

Windows

powershell -c "irm https://doctor.nestri.io/install.ps1 | iex"

Downloads one binary, verifies its checksum, runs it, deletes it. Installs nothing, needs no admin rights, touches no system directory.

If Windows blocks it

It will, and it is not because of what the program does. SmartScreen refuses any executable that is unsigned and has no download history, and a new release starts from zero history every time. Ours is both, for now.

On the dialog: More info → Run anyway. If that is not a trade you want to make, it is a completely reasonable place to stop — or build it yourself, which takes a minute and needs no trust at all:

git clone --depth 1 https://github.com/nestrilabs/nestri
cd nestri
cargo run --release -p nesdoctor

Every binary is built by GitHub Actions from a tagged commit, never from anyone's machine, and SHA256SUMS is published beside it. That proves the file came from the source you can read; it does not make Windows any happier, which is a separate problem we owe money to fix.

The number worth it

Everybody knows their download speed. Almost nobody has seen how much latency their connection adds when it is busy — and for anything interactive, that is the figure that decides it. A 500 Mbps uplink that queues for 300 ms under load cannot carry a game. A 25 Mbps one with fq_codel can.

It asks four questions at the end and shows you exactly what gets sent before anything is sent. You can also just read the output and close it.