About

/about

systrex is a set of small tools for the people who operate infrastructure. Network engineers, site reliability engineers, platform and DevOps teams.

What it is for

Most of this work involves the same handful of calculations and lookups, done under time pressure, often during an incident. Working out whether two prefixes overlap. Checking which certificate a host is actually serving. Turning an SLO into a number of minutes. Reading a cron line that someone wrote four years ago.

Each tool here does exactly one of those jobs. It loads immediately, it does not ask who you are, and it gets out of the way.

How tools get built

Tools are added when there is a real need for them, not to fill a roadmap. A tool that nobody reaches for does not get written. The catalogue on the front page lists what exists and what is on the list, so nothing is a surprise.

What it will never do

• Ask you to create an account.
• Show an advertisement or an upsell.
• Load a tracker, an analytics script, or a third-party font.
• Send what you paste anywhere it does not have to go.

The last one is the important one. Tools marked local do all their work inside your browser, so a token or a private key you paste in never leaves your machine. See privacy for the detail.

Get in touch

Corrections, bug reports and requests for a tool are all welcome. See contact.