# nix repl > Start an interactive environment for evaluating Nix expressions. > See <https://nixos.org/manual/nix/stable/language/index.html> for a description of the Nix expression language. > More information: <https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-repl.html>. - Start an interactive environment for evaluating Nix expressions: `nix repl` - Load all packages from a flake (e.g. `nixpkgs`) into scope: `:lf {{nixpkgs}}` - Build a package from an expression: `:b {{expression}}` - Start a shell with package from the expression available: `:u {{expression}}` - Start a shell with dependencies of the package from the expression available: `:s {{expression}}`