mise2nix

Converts mise.toml into a Nix devShell — no manual Nix required for common toolsets.

mise2nix.lib.mkShellFromMise { tomlPath = ./mise.toml; inherit pkgs; }

Inspired by uv2nix: consume a configuration file, get Nix.

---

Quickstart

This flake provides a simple template which can be initialized with nix flake init -t git+https://codeberg.org/tttffflll/mise2nix.

Alternatively, add mise2nix as a flake input and wire mkShellFromMise into your devShells:

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    mise2nix = {
      url = "git+https://codeberg.org/tttffflll/mise2nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs = {
    nixpkgs,
    mise2nix,
    ...
  }: let
    forAllSystems = nixpkgs.lib.genAttrs nixpkgs.lib.systems.flakeExposed;
  in {
    devShells = forAllSystems (
      system: let
        pkgs = nixpkgs.legacyPackages.${system};
      in {
        default = mise2nix.lib.mkShellFromMise {
            tomlPath = ./mise.toml;
            inherit pkgs;
          };
      }
    );
  };
}

Then run nix develop — mise2nix reads your mise.toml and builds the shell.

---

Supported Tools

Runtimes

Version-specific nixpkgs attributes. Specify major (or major.minor) version in mise.toml.

Tool (mise name)	Supported versions	Notes
node / nodejs	20, 22, 24, 25	"latest" → pkgs.nodejs
python	3.11, 3.12, 3.13, 3.14, 3.15	"latest" → pkgs.python3
go / golang	1.24, 1.25, 1.26	"latest" → pkgs.go
ruby	3.3, 3.4, 3.5, 4.0	"latest" → pkgs.ruby
java	8, 11, 17, 21, 25	"latest" → pkgs.jdk
erlang	26, 27, 28, 29	"latest" → pkgs.erlang
elixir	1.15, 1.16, 1.17, 1.18, 1.19	"latest" → pkgs.elixir
php	8.2, 8.3, 8.4, 8.5	"latest" → pkgs.php
rust	any	Always resolves to pkgs.rustup
deno	any	Single version in nixpkgs
bun	any	Single version in nixpkgs
terraform	any	Single version in nixpkgs
kubectl	any	Single version in nixpkgs

Utilities

All utility versions resolve to the nixpkgs-pinned version (version string is ignored).

bat, cmake, curl, delta, eza, fd, fzf, gh, git, hyperfine, jq, just, make, ripgrep / rg, starship, tokei, wget, zoxide

---

API Reference

mkShellFromMise

mkShellFromMise : { tomlPath, pkgs, overrides ? {}, extraPackages ? [], extraEnvVars ? {}, prefixShellHook ? "", postfixShellHook ? "" } -> derivation

Argument	Type	Description
tomlPath	path	Path to your mise.toml file
pkgs	attrset	nixpkgs package set for the target system
overrides	attrset	Replace a tool's resolved package by mise tool name
extraPackages	list	Additional packages appended to the devShell
extraEnvVars	attrset	Additional environment variables merged into the shell
prefixShellHook	string	Shell script prepended to the generated shellHook
postfixShellHook	string	Shell script appended to the generated shellHook

Resolution order: overrides → runtimes → utilities → builtins.throw

Unknown tools without an override throw a descriptive error at eval time naming the tool and explaining how to fix it.

mkShellInputsFromMise

For advanced use cases where you need to compose the shell yourself:

mkShellInputsFromMise : { tomlPath, pkgs, overrides ? {} } -> { packages, shellHook, envVars }

Returns the raw inputs (packages, shellHook, envVars) rather than a fully built mkShell derivation.

Overrides pattern

Override a single tool (e.g. pin node to a different version than mise.toml requests):

mise2nix.lib.mkShellFromMise {
  tomlPath = ./mise.toml;
  inherit pkgs;
  overrides = { node = pkgs.nodejs_20; };
}

Add packages not present in mise.toml (e.g. a GitHub release tool):

mise2nix.lib.mkShellFromMise {
  tomlPath = ./mise.toml;
  inherit pkgs;
  extraPackages = [ pkgs.some-other-tool ];
}

Environment variables

The [env] section in mise.toml is mapped directly to mkShell environment variables:

[env]
NODE_ENV = "development"
PORT = 8080

Both string and integer values are supported (integers are coerced to strings).

---

Limitations

• Very basic [tasks] section support — task dependencies are and dirs out of scope, task binaries are available in the devShell.
• No exact patch versions (without overrides) — nixpkgs pin determines the exact version installed. Reproducibility comes from pinning nixpkgs in your flake.lock, not from mise version strings.
• No support for mise.local.toml and .mise.toml — Only the provided mise.toml is read by mise2nix.
• No mise.lock support — mise.lock tracks mise's own downloads; it is not used for nixpkgs resolution.
• Limited compat with other dev shell tools — mkShellFromMise produces a fully built pkgs.mkShell. Use mkShellInputsFromMise if you need to compose inputs into your own mkShell.
• nixpkgs only (without overrides) — npm-backend, GitHub release, and pipx tools are not resolved automatically. Use extraPackages or overrides in mkShellFromMise for these.
• Single version per tool (without overrides) — tools like rust, deno, bun, terraform, and kubectl have one version in nixpkgs; the version string in mise.toml is ignored.
• Unknown tool — requesting a tool not in the runtimes or utilities table (and not covered by overrides) causes a builtins.throw at eval time.

License

This software is dual-licensed under the European Union Public License 1.2 (EUPL-1.2) and the GNU Affero General Public License v3.0 (AGPL-3.0). You may use, modify, and distribute this software under the terms of either license, at your option.

SPDX-License-Identifier: EUPL-1.2 OR AGPL-3.0-only