Covers MDEngine for macOS, the command-line tools, the MCP server, the MDEngine Runs iPhone app, and the hosted GPU service. Last updated 9 September 2026.
The short version
Gitinama Inc. (“we”) makes MDEngine. The desktop app and the command-line tools work entirely on your own computer and send us nothing. If you choose to buy GPU credit and run jobs on our hosted service, we receive the simulation input you submit, the results we produce for you, and the billing record. We do not sell anything to anyone. There is no advertising and no analytics SDK in any of our software.
What runs locally and sends us nothing
MDEngine for macOS, mdengine-cli and mdengine-mcp open and analyse files on your machine. Loading a trajectory, running an analysis tool, exporting an image or a video, and running LAMMPS locally involve no network request to us. We have no telemetry, no crash-reporting SDK, no analytics and no advertising identifiers in any build.
What we receive if you use the hosted GPU service
Hosted runs are opt-in: they require an API key you get by buying credit.
- Your API key, so we can identify your account and its balance. We store only a SHA-256 hash of it, never the key itself.
- Your email address, from the payment, stored with your account. We do not currently send you email: your key is shown to you once on the purchase page rather than emailed.
- What you submit: the deck you choose to run, meaning its input files, data files and potentials. We cannot run your simulation without receiving it.
- What we produce: the results archive, the log and the thermodynamic output of your run.
- Billing records: job ids, GPU type, billed seconds and cost.
We do not read your simulation data, other than automatically parsing the LAMMPS log to measure how much work a run did, which is how it is priced, and to show you your own thermodynamic output. We do not use your data to train anything.
How long we keep it
Deck and result archives are deleted 30 days after a run reaches a terminal state. This is enforced by the service itself on a recurring sweep, not by policy alone. You can also delete a finished run’s files yourself at any time before then. Billing records are kept as long as we need them for accounting.
Where your key is stored on your own devices
- macOS:
~/.mdengine/credentials, a file readable only by your user account. - iPhone (MDEngine Runs): your device’s Keychain, marked available only when the device is unlocked and only on that device, so it is not included in device backups and does not sync. If a build cannot use the Keychain, the app stores the key in its own sandbox and says so on screen rather than implying otherwise.
Your key never leaves your device except as an Authorization header to api.forcefieldsilicon.com.
Third parties
- Stripe processes payments. We never see or store your card details. Stripe receives what it needs to take the payment and tells us the amount, the email address and whether it succeeded.
- RunPod provides the GPU machines. Your deck is copied to a rented GPU host for the duration of your run, and that host is destroyed afterwards.
- Hetzner hosts the service endpoint that stores your account record, your job metadata and your archives during the retention window.
We do not sell, rent or share your data with anyone else, and there are no advertising or analytics third parties in any of our software.
Your choices
- Delete a run’s files whenever you like; they are in any case deleted after 30 days.
- Ask us to delete your account and its records, by email to the address below.
- Stop using the hosted service, and the desktop app keeps working, offline and unchanged.
Children
MDEngine is a professional scientific tool and is not directed at children.
Changes
If this policy changes we will update this page and the date at the top. If we make a material change to what we collect, we may also use the email address on your account to tell you.
Contact
Gitinama Inc., a Delaware corporation registered in Massachusetts. Privacy questions and deletion requests: arvand@gitinama.tech.
MDEngine Runs collects no data. There is no account to create inside the app, no analytics and no third-party SDK.
Forcefield Silicon 