Privacy Policy

Hotend (“Hotend”, “we”, “us”) provides a hosted service for controlling, monitoring, and slicing for 3D printers from your phone or browser. This policy explains what data we collect, why, and the choices you have. It applies to the Hotend web app, the Android and iOS apps, and the printer agent you install on your own hardware.

Information we collect

• Account details. Your email address and a securely hashed password, or, if you sign in with Google or GitHub, the basic profile (email and name) those providers return.
• Printer & print data. Data needed to operate your printer — printer status and temperatures, print jobs and history, uploaded models and sliced G-code, filament/spool records, and webcam streams. Webcam video is relayed to your own devices in real time and is not recorded or stored by us.
• AI feature inputs. When you use AI model generation, slicing suggestions, or Print Doctor, the text prompts, images, or model data you provide are sent to our AI providers to produce a result.
• Billing information. If you subscribe, our payment provider (Lemon Squeezy) processes your payment. We receive your subscription status and plan — we never see or store your full card number.
• Technical & usage data. Basic logs such as IP address, device/browser type, and feature usage, used to run, secure, and improve the service.

How we use your data

We use your data only to: operate your account and connect you to your printer; run the features you request (slicing, AI generation, diagnostics, notifications); process subscriptions; keep the service secure and prevent abuse; and provide support. We do not sell your personal data, and we do not use your prompts, models, or printer data to train our own models.

Third-party services

We share the minimum data necessary with the following processors so the service can function:

• AI providers (Anthropic, OpenRouter, and Meshy) — to generate models and produce AI slicing/diagnostic suggestions from your inputs.
• Thingiverse — when you search for or import public models.
• Lemon Squeezy — to process payments and manage subscriptions.
• Resend — to send transactional email (verification, receipts, alerts).
• Google / GitHub — only if you choose to sign in with them.

Each provider handles data under its own privacy policy. We do not authorise them to use your data for their own purposes.

Data retention

We keep your account and printer data for as long as your account is active. You can delete your models, print history, and other content at any time from within the app. When you delete your account, we remove your personal data and stored content within 30 days, except where we must retain limited records to meet legal or accounting obligations.

Security

Account access is protected by signed, encrypted authentication tokens, and traffic to the service is encrypted in transit (HTTPS/TLS). Your printer is reached through an authenticated relay — we never expose it directly to the public internet. No system is perfectly secure, but we take reasonable measures to protect your data.

Your rights

You can access, correct, export, or delete your personal data. Request export or deletion via Support in the app, or email [email protected], and we will help. Depending on where you live, you may have additional rights under laws such as the GDPR or the Australian Privacy Principles.

Children

Hotend is not directed to children under 16, and we do not knowingly collect their personal data.

Changes to this policy

We may update this policy from time to time. Material changes will be reflected by the “Last updated” date above and, where appropriate, an in-app notice.

Contact

Questions about privacy or your data? Email [email protected].