Independent dojos
One sensei, a small senior group and a steady stream of new students. C3NTR puts your throws, locks and weapons work in one place. No second tool, no spreadsheet.
For martial arts schools
A knowledge home for your aikido dojo.
Throws, ukemi, the syllabus and the principles of harmony.
→ See a quick tour
Free for up to 30 students
No credit card
UK GDPR · EU (London)
Works offline
Your dojo's curriculum deserves a home
Throw names vary across the kyu syllabus. Ukemi gets corrected differently by every senior, and Japanese terms are used loosely until grading. C3NTR is a quiet place to write it all down once, in your dojo's voice.
Who this is for
Schools with multiple instructors
Two or more sensei, several classes a week. C3NTR holds the shared standard so every uchideshi and visitor teaches from the same library, with your dojo's voice on every page.
Lineage schools
You're carrying a tradition forward. Content locked by grade keeps each kyu progressing safely, and the weapons work appears at the rank your syllabus says.
Built for teachers, not for IT
Your sensei opens the app, taps Edit, and writes the next ikkyo correction in plain prose. The class on Saturday reads it before they step onto the mat.
Write directly in the app
Like a notepad. New articles are drafts until you publish, so nothing goes live by mistake.
Mobile-first authoring
Edit on the phone between classes or on the way home. The same library, the same edit screen.
A working library in under an hour
Import the starter template in a few taps. Edit anything that doesn't fit. Publish when ready.
Kyu and dan grades
Content locked by grade, in your dojo's kyu and dan
Tag any article with a minimum kyu or dan. New students see ukemi and the first throws. Senior students see the weapons work and the advanced applications. The same library, the right view per student.
A glossary in Japanese and English
Every aikido dojo carries Japanese terminology. C3NTR's glossary holds the terms in one place: the romaji, your dojo's translation, and the article each term appears in.
- Aikido
- Aikido (合気道), "the way of harmony with ki." A modern Japanese martial art that neutralises an attack by blending with its force and redirecting it into a throw or pin..
- Dojo
- The training hall (道場), literally "the place of the way." More than a gym..
- Rei
- The bow (礼), the gesture of respect that opens and closes training..
- Kamae
- Posture or stance (構え), the ready position of Aikido..
- Tai sabaki
- Body movement (体捌き), the art of moving the whole body off the line of an attack..
- Tenkan
- The turning movement (転換), pivoting on the front foot and swinging the back foot around..
Gradings, seminars, dojo closures
C3NTR isn't only the library. Schedule the gradings students are working toward, post a quick announcement when a visiting shihan is teaching, and let students see what's coming up at the dojo this month. Announcements land on their Today tab and events sit on the calendar.
Start from our Aikido template
A working starter with 15 articles, 2 short videos, a 9-terms glossary across 5 tags (Getting Started, Foundations, Practice, Progression, Resources). Import in a few taps, then edit anything that doesn't fit your school. Every article, term and tag is yours from the moment you import.
See the Aikido template Template source:assets/templates/martial_arts/aikido.c3t.md
Inside the app
A look at how the library, articles and grade controls feel in your students' hands.
Plays well with what you already have
Bring your existing kata notes and Japanese terminology in with smart Word document import or paste Markdown directly from your dojo's archive.
Word documents
Smart import reads headings and turns them into draft articles. You review before anything publishes.
Markdown from any editor
Notion exports, Obsidian notes, Bear, plain .md files. Paste or import.
C3NTR templates
Open .c3t.md format. Schools can share templates with each other without us in the middle.
UK GDPR · DPA 2018
UK GDPR compliant. Hosted in the EU (London).
C3NTR is built around UK data protection law from the ground up. Your school's data sits in the EU on Google Cloud London, the same region we manage from.
UK GDPR + Data Protection Act 2018
Built around UK GDPR Article 6 lawful bases. Subject access requests answered within one calendar month.
Hosted in the EU (London)
Your school's data sits on Google Cloud in the europe-west2 (London) region. No transfer outside the UK or EEA for core operation.
Encrypted in transit
All data is TLS encrypted. Access restricted to personnel with a clear business need.
Account deletion on request
Permanent deletion of personal data and content via in-app or written request.
What C3NTR is, and what it isn't
A library your school owns
Another booking or billing system
Built for how schools actually teach
A generic course builder
Calm, focused reading for students
A feed competing for attention
Start free. Move up when you outgrow it.
Seed
Free forever
Up to 30 students
All core features. No credit card.
Start freeSchool
£39/mo
£32/mo billed annually
Up to 150 students
Push notifications. 1 GB media storage.
Choose SchoolAcademy
£69/mo
£57/mo billed annually
Unlimited students
Multi-instructor publishing. Engagement analytics. 5 GB media storage.
Choose AcademyStudent? Show this to your sensei.
If you train at an aikido dojo and you'd love a quiet library you can return to between training, share this page with your sensei. Most schools start on the free Seed plan in under five minutes.
Common questions
Can students only see their grade's material?
Yes. Tag any article with a minimum kyu or dan. New students see only ukemi and the first throws. Senior instructors always see everything.
Does it cover Aikikai, Yoshinkan, Ki Society?
C3NTR is lineage neutral. The library is yours to fill: Aikikai, Yoshinkan, Ki Society, Iwama, Tomiki or another transmission. Write in your dojo's voice.
Can students customise the aikido template?
Yes. Every technique, kata and term is editable. Add your style's names, your syllabus and your dojo's etiquette.
How long does it take to set up?
Most schools have a working library in under an hour. Import the starter template in a few taps, then edit anything that doesn't fit. Starting blank takes a little longer. Allow an hour or two to write your first ten articles. Students can use the app the day you publish.
Do I have to stop using my booking system?
No. C3NTR is a knowledge library for your curriculum, terminology and progressions. Booking, billing and scheduling stay with the tools you already use.
Is there a free plan?
Yes. Seed is free forever for up to 30 students, with no credit card required. Move up to School (£39/mo) or Academy (£69/mo) when you outgrow it.
Teach a different style? Tell us.
Whether it's a specific aikido lineage we don't list, or another discipline entirely, drop us a line and we'll add a starter template. In the meantime, the app already works for any structured curriculum, your library starts blank in a few minutes.
Ready to give your aikido students a knowledge home?
Free for the first 30 students. No credit card. A working library in under an hour.
Start free for your school