About Lasto

1 The name

“Lasto” is Sindarin, one of Tolkien’s Elvish languages, for “listen,” because the app listens and never talks out of turn.

2 Who builds it

I’m Chris Johnson⁠ (external site), and I’m building Lasto for my own 2006 GX470. The first thing I want it to answer is how hot the transmission gets on long grades, and whether a regear is worth doing.

The code and docs are written with Claude Code; I review every change, and each one has to pass the test suite and the safety rules.

The source code is on GitHub⁠ (external site). The lasto package on PyPI⁠ (external site) only reserves the name for now.

3 License and warranty

Lasto is free software under GPL-3.0-or-later⁠ (external site). There’s no paid version.

Lasto is read-only by design. Passive mode sends nothing, and polled mode will send only read-only diagnostic requests, through the rules on the Safety page. It comes with no warranty, to the extent the law allows. You use it on your own vehicle at your own risk. Plugging anything into the OBD-II port carries some risk of its own, so route cables away from the pedals and don’t operate a laptop while driving.

4 Trademarks

Toyota, Lexus, PEAK-System, PCAN, OBDLink, Launch, and Creader are trademarks of their respective owners. Lasto isn’t affiliated with or endorsed by any of them, and uses their names only to say what it’s built to work with. Other product names belong to their owners.

5 Privacy

This site has no analytics and no cookies, and it loads nothing from other servers. GitHub Pages hosts it and logs visitor IP addresses for security, under GitHub’s privacy statement. Lasto itself sends nothing over the internet and is built to run offline in the truck. The local GUI planned for Phase 9 will only answer the laptop it runs on.

6 Contact

For bugs and corrections, open an issue on GitHub⁠ (external site). For security problems, use private vulnerability reporting⁠ (external site) instead of a public issue.