Privacy Policy

MatMul ("MatMul", "we", "us") operates matmul.cloud and the MatMul service — the console, CLI, SDK and API you use to rent GPU and CPU machines. This policy explains what we collect, why, who helps us process it, and the choices you have. MatMul was previously called Lemnos (lemnos.cloud) and, before that, Slipstream (slipstreamcompute.com); this policy covers data collected under any of those names.

Information we collect

Early-access requests

If you use the request-access form: your name, work email, and anything else you choose to add (company, workload, GPU type, notes), plus the IP address, user-agent and referring page of the submission. If bot protection (Cloudflare Turnstile) is enabled, it processes a challenge token to confirm you're human.

Your account

When you sign in: your name, email and sign-in identifiers from our authentication provider, your organization and role, and a session cookie that keeps you signed in.

Billing

Card payments are handled by Stripe — we never see or store your card number. We keep your prepaid balance, a ledger of credit purchases, usage charges and adjustments, and the Stripe customer and payment identifiers that tie them together.

Machines you run

• The SSH public keys you add (never private keys).
• The settings of each instance: name, container image, machine type, region, price, open ports, status, IP address and timestamps, plus who in your organization launched it.
• Startup arguments and environment variables you pass are sent to the GPU supplier to start the machine; we don't store them in our database. Don't put secrets in them that you wouldn't share with the supplier.
• Usage and metering records (running time and cost) used for billing.

We don't look at the contents of your machines, your data or your workloads, except as needed to investigate abuse reports or a suspected breach of the Acceptable Use Policy.

Product analytics

We use PostHog to understand how the site and console are used (pages viewed, buttons clicked). Once you're signed in, those events are linked to your user id, email, organization and role so we can see how people get started and where they get stuck. We also record key product actions (launching or terminating a machine, adding credit and the amount) and which version of a page you saw when we test changes to it. PostHog stores a random identifier in a first-party cookie and your browser's local storage so visits can be tied together; its requests go through our own domain (matmul.cloud/ingest). We don't record your screen or keystrokes.

We don't currently change this in response to browser "Do Not Track" or Global Privacy Control signals. If you'd rather not be counted, block cookies and site data for matmul.cloud, or block requests to matmul.cloud/ingest; the site works the same either way.

How we use it

• To provide the service: sign you in, start and stop machines, meter usage and bill you.
• To contact you about your account, balance (e.g. low-balance warnings) and early access.
• To secure the service, prevent fraud and abuse, and enforce our terms.
• To understand demand and improve the product.

We do not sell your personal information, and we only share it with the service providers below, or when required by law.

Who processes it

These providers process data on our behalf, under their own terms:

• Cloudflare — website, console, request-access database, bot protection, DNS.
• WorkOS — sign-in and authentication.
• DigitalOcean — hosting for our API.
• Supabase — our main database (accounts, organizations, instances, billing records).
• Stripe — card payments.
• Resend — account and billing emails.
• PostHog — product analytics.
• GPU suppliers (currently Shadeform and the cloud providers it places machines with) — receive your SSH public key, container image and instance settings in order to run your machines.

Our providers store data primarily in the United States.

Retention

We keep account, instance and usage data while your account is open. Billing records are kept as long as needed for accounting and tax purposes. Early-access requests are kept until they're no longer needed to evaluate and contact you. On request, we'll delete or anonymize your data unless we must keep it (for example, billing records).

Your choices

• Ask us to access, correct, export or delete your information at any time.
• Opt out of non-essential email — every such email lets you unsubscribe.
• Close your account by emailing us.

Contact

Questions or requests? Email privacy@matmul.cloud.

Changes

We'll update this policy as the product evolves, revise the "last updated" date above, and notify you by email or in the console before material changes apply.