Doggo Bit's Blog

Speed up your Nix builds with caching

2025-03-24

This is hopefully one of many posts about what I wish I knew when I started using NixOS. I'm not an expert by any stretch of the imagination, so keep in mind that I might be wrong about a lot of this stuff.

Just give me my configuration.nix

If all you want to know is how to pull in the official NixOS caches, here's how:

{ config, pkgs, ... }:
{
	nix.settings.substituters = [
		"https://cache.nixos.org"
		"https://nix-community.cachix.org"
	];
	nix.settings.trusted-public-keys = [
		"nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
	];
}

That's going to check the official NixOS cache first, and then the community Cachix cache. You can add more caches to the substituters list, and more public keys to the trusted-public-keys list.