The Mycelium — and every app it holds — syncs through a server that is blind by design: it stores and relays ciphertext and never holds a key, so it cannot read anything you keep in it, whoever runs it. If you would rather that “whoever” were you, it is one container away.

Get the server image

One image, one volume

The blind sync server is a single small binary, published as a Docker image: darktrees/blind-sync. It wants a volume for its database and nothing else — no external services, no message broker, no second container to keep alive alongside it.

Point the app at it

Set your server’s URL in The Mycelium’s settings and every device on your recovery phrase syncs through it instead. Encryption and decryption stay on your devices either way — changing servers changes who stores your ciphertext, not who can read it. That answer is still nobody.

Every module, one server

All seven modules sync through the same server, and none of them needs anything of its own from it — a loan, a family calendar and a notebook are all just encrypted documents in a space it can’t open. Voice Notes also stores its recordings there, as encrypted files; the server’s per-space file limit is the one setting worth raising if you record long meetings.

The optional extras are yours to switch on

The two features that reach beyond relaying ciphertext are both server capabilities, and both ship off. Push wake-ups and reminders need a VAPID key pair configured; without one the routes don’t exist and the app knows not to offer notifications. Emailed calendar invites need an SMTP relay and a from-address; without them the route is absent and the feature never appears. Self-host and it’s entirely your call which of the two, if either, you run — and whose mail server carries the invites. (Voice Notes’ transcription never touches the server at all: each notebook talks to the service it was set up with, directly.)