Frequently asked questions

Quick answers to the questions we hear most often. For detailed walkthroughs, explore the guides in the sidebar.

What types of schools can use C3NTR?

Any school with a structured curriculum and grades. C3NTR supports eight discipline categories: Martial Arts, Dance, Music, Yoga, Gymnastics, Fitness, Wellness, and Academic. There are 73 sub-disciplines to choose from. See Disciplines for the full list.

Is C3NTR free?

Yes. The Seed plan is free forever and includes all core features for up to 30 members. Paid plans (School and Academy) add video support, AI writing, and higher member limits. See Billing & tiers for details.

Does C3NTR use AI?

C3NTR has two AI features, both optional:

Is my AI API key stored on your servers?

No. Your API key is stored in your device's secure storage only. It is never sent to C3NTR servers, saved in any database, or accessible to anyone else. When you use the AI draft feature, the request goes directly from your device to the AI provider (Anthropic or OpenAI) through our Cloud Function, which passes the key through without storing it.

Can students see draft content?

No. Draft articles and terms are visible only to members with a content-editing role (instructor or above). Students never see content until a teacher or school leader publishes it. See The editor for how publishing works.

How do grades restrict content?

Each article or term can have a minimum grade level. Members below that grade will not see the content in their Explore tab, search results, or favourites. This lets you release material progressively as students advance. See Roles & grades.

Can I use C3NTR for non-martial-arts schools?

Yes. C3NTR was originally built for martial arts, but it works for any school with structured knowledge. Dance studios, music academies, yoga schools, gymnastics clubs, and academic tutoring centres all use it. The discipline system adapts templates and AI context to your field.

What happens when I go offline?

Articles you have already opened are cached on your device and can be read without internet. Search falls back to keyword-only mode. A banner shows when you are offline, and a snackbar appears when connectivity returns. See Offline access.

How do I switch between schools?

If you belong to more than one school, tap your school name at the top of the home screen to open the school selector. Choose a different school to switch. Your profile is shared, but content and favourites are separate per school.

What is the difference between tags and sections?

Tags replaced sections in a recent update. Tags are a more flexible way to organise content — an article can belong to more than one tag. If you see "sections" mentioned anywhere, it refers to the old system. Everything now uses tags. See Tags & organisation.

Can I import my existing curriculum?

Yes. C3NTR supports importing from Word documents (.docx), PDF files, Markdown (.md), plain text (.txt), and rich text (.rtf). You can also share web pages directly from Safari or any browser. Use the share sheet from any app and choose "Import to C3NTR", or pick a file from within the app. The Document Map screen shows you how the content will be split into articles before you confirm. See Import a document.

How does the AI draft feature work?

You enter a topic and optional bullet points. C3NTR sends this to your chosen AI provider (Claude Haiku or GPT-4o mini) along with your school's discipline for context. The AI returns a Markdown draft that appears in the editor. You can undo it instantly or edit it like any other content. See AI writing assistant.

How does on-device search work?

C3NTR includes a small AI model (MiniLM-L6-v2, about 22 MB) that runs directly on your phone. When you search, it compares the meaning of your query with the meaning of each article, not word-for-word matches. This means searching for "blocking techniques" can find an article called "Defensive postures" even though the words are different. All processing happens on your device. See Search.

Is there a web version?

Yes. School leaders and teachers can manage content, members, and settings from a computer. Link an email to your account first. See Your profile.

How do I invite members to my school?

Go to your member management screen and add phone numbers individually or in bulk. Members receive a text or can enter your school's join code in the app. You approve each pending member before they gain access. See Members.

Can I customise how my school looks?

Yes. The Theme Studio lets you set your brand colour, choose dark or light mode, upload your logo and hero image, and adjust surface depth. Changes apply immediately for all members. See Branding & theme.

What are templates?

Templates are pre-written collections of articles for specific disciplines. C3NTR includes 49 system templates across eight disciplines. You can import any template into your school and edit the content freely. You can also save your own documents as templates. See Templates.

Can I change my phone number?

Yes. Go to Edit Profile and tap "Change phone number". You will verify the new number with an OTP code, and it replaces your old number immediately. See Your profile.

Can I delete my account?

Yes. Go to Edit Profile, scroll to the bottom, and tap "Delete account". You will be asked to type DELETE to confirm. This permanently removes your profile, favourites, memberships, uploaded files, and sign-in credentials. It cannot be undone. See Your profile.

How is my data stored?

Your school's data is stored securely on Google Cloud (Firebase) in the europe-west2 region. Data is encrypted at rest and in transit. We do not sell or share your data with third parties. For full details, see our Privacy Policy.

How do I contact support?

Email us at hello@c3ntr.app. We aim to respond within 24 hours.

Still have a question?

Get in touch at hello@c3ntr.app