The binary cache

cache.solnix.io is a standard Nix binary cache — functionally like cache.nixos.org. Add it as a substituter and pull prebuilt, signed store paths for every architecture solnix targets.

Setup

# /etc/nix/nix.conf
substituters       = https://cache.solnix.io https://cache.nixos.org
trusted-public-keys = cache.solnix.io-1:8UNrVAOSOrI9PGHc8/pD2Yqp265ZeYb3OId+gv4+wm8= cache.nixos.org-1:6NCHdD59EeA7KA8wG4nSXk...

Every store path is signed with the cache.solnix.io-1 key. Nix verifies the signature against your trusted-public-keys before using anything — so it does not matter where the bytes came from, only that they match a signature you trust.

How it is distributed

Cache objects will also be distributed over BitTorrent: each NAR is a torrent, seeded by the hub and by other solnix users. This is not yet enabled — the narinfo served by cache.solnix.io always carries a plain HTTP URL: as the guaranteed fallback, so a stock nix works today over HTTP; the peer layer is an enhancement layered on top.

The property that matters: the more solnix users, the faster and cheaper the cache — bandwidth scales with the community instead of with one origin’s egress bill.

Seeding (please read)

Once you have opted in, a machine using the solnix cache seeds the public, signed cache artifacts it fetches to other solnix users. This is deliberate and is how a multi-arch cache stays sustainable.

• It is default on when you have opted in (solnix.cache.seed.enable = true), and gated by the privacy master switch — a machine whose config never touches it stays completely private and seeds nothing. See Peer-to-peer distribution and Privacy & telemetry.
• It only ever shares public Nix store paths — never your private data.
• Integrity is enforced by the cache signature regardless of source.

We state this plainly so no one is surprised to find their machine seeding.