nix-instantiate

instantiates Nix expressions, producing store derivations

TLDR

Instantiate expression

$ nix-instantiate [expression.nix]

Evaluate and print

$ nix-instantiate --eval [expression.nix]

Evaluate to JSON

$ nix-instantiate --eval --json [expression.nix]

Parse only (check syntax)

$ nix-instantiate --parse [expression.nix]

Use expression from command line

$ nix-instantiate --eval -E '1 + 2'

SYNOPSIS

nix-instantiate [options] files...

DESCRIPTION

nix-instantiate instantiates Nix expressions, producing store derivations. With --eval, it evaluates expressions and prints results.
This is useful for debugging and testing Nix expressions.

PARAMETERS

--eval

Evaluate and print result.

--json

Output as JSON.

--strict

Evaluate strictly.

--parse

Parse only.

-E expr

Evaluate expression.

--arg name value

Pass argument.

-A attr

Select attribute.

Evaluate expression

nix-instantiate --eval -E 'let x = 1; in x + 1'

Output: /nix/store/...-hello.drv

$
# CAVEATS

Newer nix commands (nix eval) supersede some uses. Strict evaluation required for full values. Part of legacy Nix CLI.

# HISTORY

nix-instantiate is one of the original Nix commands, part of the core tooling since **Nix** was first released in **2003**.

# SEE ALSO

nix-build(1), nix-store(1), nix-env(1)