Short version: KLine Diag reads your car through a cable plugged into your Mac and keeps everything on your Mac. It has no account, no analytics, no ads, and no tracking, and the developer never receives your data. The only way data leaves your Mac is the optional AI connection, which is off by default and sends your car’s readings only to a server you choose.
KLine Diag is published by an independent developer (bundle ID rocks.clarke.tech.openvcds). Contact: support@clarke.rocks.
When a cable is connected, the app reads control-module identification (for example the engine computer’s part number), fault codes, and live measuring-block values such as engine speed and temperatures. Older K-Line cars don’t report a VIN over this connection. These readings are shown in the app and kept in memory while it runs.
If you record a drive and choose Export Log, the app writes a CSV file to the place you pick. It is your file; the app doesn’t send it anywhere.
Your preferences are stored in the app’s own sandboxed storage on your Mac. If you set up the AI connection, its access token is stored in your macOS Keychain.
KLine Diag can share your car’s readings with an AI assistant through a Model Context Protocol (MCP) server. This is off by default and nothing is built in: it only runs if you enter a server address and token in Bot Connection and switch it on.
An optional local API, also off by default, lets programs on your own Mac read the same data. It listens only on 127.0.0.1, so other computers can’t reach it.
If you test a beta through Apple’s TestFlight, Apple shares limited information with the developer, such as your name or email as you entered it for the invitation, the build you installed, and any feedback or screenshots you choose to send. That information is used only to run the beta and is handled under Apple’s Privacy Policy.
This site has no cookies, analytics, or trackers. Like any website, the hosting provider (Amazon Web Services) may keep standard server logs such as IP addresses and request times for security and operations.
Clearing fault codes erases them from the control module and can reset emission-readiness monitors. Only clear codes after a repair, with the car parked. Don’t use the app while driving; have a passenger watch the screen when you log a drive.
The app is not directed to children and collects no personal information from anyone.
Everything the app keeps is on your Mac. Deleting the app removes its sandboxed data. The AI connection token can be removed in Bot Connection or in Keychain Access.
If this policy changes, the updated version will be posted on this page with a new date.
Questions or requests: support@clarke.rocks.