The default configuration sets up a Bitcoin Core node and c-lightning. The user can enable spark-wallet in `configuration.nix` to make c-lightning accessible with a smartphone using spark-wallet.
A simple webpage shows the lightning nodeid and links to nanopos letting the user receive donations.
A demo installation is running at [http://6tr4dg3f2oa7slotdjp4syvnzzcry2lqqlcvqkfxdavxo6jsuxwqpxad.onion](http://6tr4dg3f2oa7slotdjp4syvnzzcry2lqqlcvqkfxdavxo6jsuxwqpxad.onion).
* You no longer need extra software to connect your hardware wallet to Bitcoin Core. Use Bitcoin Core's own **H**ardware **W**allet **I**nterface with one `configuration.nix` setting.
* **Simplicity:** Only services you select in `configuration.nix` and their dependencies are installed, packages and dependencies are [pinned](pkgs/nixpkgs-pinned.nix), most packages are built from the [nixos stable channel](https://github.com/NixOS/nixpkgs-channels/tree/nixos-19.03), with a few exceptions that are built from the nixpkgs unstable channel, builds happen in a [sandboxed environment](https://nixos.org/nix/manual/), code is continiously reviewed and refined.
* **Integrity:** Nix package manager, NixOS and packages can be built from source to reduce reliance on binary caches, nix-bitcoin merge commits are signed, all commits are approved by multiple nix-bitcoin developers, upstream packages are cryptographically verified where possible, we use this software ourselves.
* **Principle of Least Privilege:** Services operate with least privileges; they each have their own user and are restricted further with [systemd options](modules/nix-bitcoin-services.nix), there's a non-root user *operator* to interact with the various services.
* **Defense-in-depth:** nix-bitcoin is built with a [hardened kernel](https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/profiles/hardened.nix) by default, services are confined through discretionary access control, Linux namespaces, and seccomp-bpf with continuous improvements.
* Disk space: 300 GB (235GB for Bitcoin blockchain + some room)
* Bitcoin Core pruning is not supported at the moment because it's not supported by c-lightning. It's possible to use pruning but you need to know what you're doing.
* RAM: 2GB of memory. ECC memory is better. Additionally, it's recommended to use DDR4 memory with targeted row refresh (TRR) enabled (https://rambleed.com/).
Tested hardware includes [pcengine's apu2c4](https://pcengines.ch/apu2c4.htm), [GB-BACE-3150](https://www.gigabyte.com/Mini-PcBarebone/GB-BACE-3150-rev-10), [GB-BACE-3160](https://www.gigabyte.com/de/Mini-PcBarebone/GB-BACE-3160-rev-10#ov).
Some hardware (including Intel NUCs) may not be compatible with the hardened kernel turned on by default (see https://github.com/fort-nix/nix-bitcoin/issues/39#issuecomment-517366093 for a workaround).
