Topology
CoplanarNo administrator, no owner, no founder who outranks whoever joined last. Equal standing is the whole arrangement.
mutual.black // a space between established persons
A puzzle on the surface.
Your people underneath.
A private space between people who already know each other. To anyone else, a game. There is no directory, no discovery, and no way in that does not begin with someone already inside.
Consent
N of NEvery matter of consequence takes everyone. Admitting a person above all. One person declining is the end of it.
Surface
A gameThe door is a puzzle, and it is a real puzzle. Anyone who arrives without a reason to be there simply finds one.
Foundational principles
Four things that decide
everything else
01 // Identity
Persons, not devices
A person is the unit. A device is a window onto what that person can already see — it holds nothing of record and is never a principal. Your phone is your primary, and it opens your other windows. Nothing of consequence is ever attributed to, decided by, or counted as a device.
02 // Topology
Coplanar symmetry
There are no roles. Once a person is in, their standing is identical to everyone else’s, and unanimity is counted in persons: someone with four windows open has one voice, and a window has none. The people inside are not the threat this is built against.
03 // Continuity
The whole thread, always
Every window shows all of it, from the first message, however recently you opened it. Replace a lost phone and everything is there. A partial or empty thread is a defect — never a security outcome, and never an acceptable degraded state.
04 // Departure
What you have stays yours
Removing someone stops the server delivering to them. That is the entire guarantee, and nothing here will claim more. What they already hold stays readable. No remote wipe exists, and no mechanism may be added that reaches into a person’s own copy and deletes it.
Recovery
Your people are
the way back in
A phone goes in a river. The browser quietly clears its storage one morning. Either way, any one of the others restores you — alone, without a quorum, without a printed key you were supposed to have kept, and without an email address that hands a mail provider the keys to everything.
That power comes with membership. It is not granted, delegated or configured, and the only thing that removes it is leaving.
Distribution
It is yours, not ours
mutual.black hands you something you deploy yourself — onto a host you already have, or one you point it at. Installed from your browser to your home screen or dock, on whatever you use. No app store, no account with us, nothing to sign up for.
The framework is the product. A running installation is yours, and we have no way to reach it, enumerate it, or learn its name.
The installer
Build your own,
on your own host
The download is source, not a finished build, and that is deliberate. Your installation’s identity is generated on your machine when you build it. A finished build would have had to be made by someone who then knew your installation; this way nobody does, including us.
You need Node 22, npm, a domain with HTTPS, and somewhere to run a Node application. One command builds it. The instructions that come out have your own values already in them.
Building in the open
Where the work is
An honest accounting, kept current. Anything not listed as working is not claimed as working.
✓ Working
- ✓Encrypted text, images and media between members
- ✓The puzzle surface, and the pattern that passes through it
- ✓Unanimous consent, counted in persons and enforced on both sides
- ✓Signed framework updates, pulled and approved locally
- ✓The installer, downloaded here and pointed at your own host
→ In hand
- →Person-held keys, so history follows the person and not the device
- →A door per person, identical to anyone who has no business there
- →Installations founded by any number of people, not only two
· Ahead
- ·Spaces: yours alone, shared with everyone, shared with some
- ·Files and whatever else a group decides to keep together
- ·Independent review of the cryptography
- ·Hosting at cost, for people without a host of their own