Nix Reference Manual

Nix supports different types of stores:

• Dummy Store
• Experimental SSH Store
• Experimental SSH Store with filesytem mounted
• HTTP Binary Cache Store
• Local Binary Cache Store
• Local Daemon Store
• Local Store
• S3 Binary Cache Store
• SSH Store

Store URL format

Stores are specified using a URL-like syntax. For example, the command

# nix path-info --store https://cache.nixos.org/ --json \
  /nix/store/a7gvj343m05j2s32xcnwr35v31ynlypr-coreutils-9.1

fetches information about a store path in the HTTP binary cache located at https://cache.nixos.org/, which is a type of store.

Store URLs can specify store settings using URL query strings, i.e. by appending ?name1=value1&name2=value2&... to the URL. For instance,

--store ssh://machine.example.org?ssh-key=/path/to/my/key

tells Nix to access the store on a remote machine via the SSH protocol, using /path/to/my/key as the SSH private key. The supported settings for each store type are documented below.

The special store URL auto causes Nix to automatically select a store as follows:

• Use the local store /nix/store if /nix/var/nix is writable by the current user.

• Otherwise, if /nix/var/nix/daemon-socket/socket exists, connect to the Nix daemon listening on that socket.

• Otherwise, on Linux only, use the local chroot store ~/.local/share/nix/root, which will be created automatically if it does not exist.

• Otherwise, use the local store /nix/store.