devenv

Initialize the environment

$ devenv init

$ devenv shell --impure

$ devenv info --verbose

$ devenv up --config [path/to/file]

$ devenv --clean --offline

$ devenv gc

devenv [OPTIONS] <SUBCOMMAND> [ARGS]>

init [URL]
    Initialize a new devenv.nix file, optionally from a template URL

shell
    Enter a development shell with configured environment

up
    Start managed processes and services (use devenv up -d for detached)

run SCRIPT
    Execute a predefined script from devenv.nix

overlay
    Enter a shell with Nix overlays applied

search [QUERY]
    Search available package templates

-h, --help
    Print help information

--version
    Print version

--impure
    Allow impure Nix builds

--flake URL
    Use a specific flake URL instead of directory

Devenv is a powerful CLI tool for creating reproducible, declarative development environments powered by Nix. It enables developers to define entire dev shells—including packages, services, environment variables, scripts, processes, and more—in a single devenv.nix file using Nix expressions.

Key features include:
• Shell activation: devenv shell drops you into a fully configured shell.
• Services management: devenv up starts background services like PostgreSQL, Redis, or custom processes.
• Direnv integration: Automatic environment loading in project directories.
• Polyglot support: Handles multiple languages, language servers, and tools seamlessly.
• Overlays and flakes: Leverages Nix flakes for pinning dependencies.

Ideal for teams seeking consistency across machines, it avoids global installations and supports quick onboarding. Unlike plain nix-shell, devenv excels at managing long-running services and complex setups. Install via Nix: nix profile install github:Astral-Software/Devenv. Usage starts with devenv init to bootstrap a project.

Requires Nix >= 2.4 with flakes enabled; initial setup downloads can be large and slow on first use.
Services only run in project dir; not for production. Watch memory usage with many services.

Add use devenv to .envrc for auto-activation: devenv shell loads on cd.

{ pkgs, ... }: { packages = [ pkgs.nodejs ]; scripts.hello.exec = ''echo hello''; } – Run with devenv run hello.

Developed by Astral (makers of Helix editor) starting 2022. v1.0 released 2023 with flake support. Evolved from community needs for better Nix dev tooling beyond nix-shell.

nix-shell(1), direnv(1), lorri(1), nix(1)