devenv-init

name	devenv-init
description	Scaffold a per-language devenv.sh project from Eotel/devenv-templates. Use when the user wants to set up a new Python (optionally with Django, FastAPI, or Flask), or future Node/Go/Rust development environment with reproducible Nix-based tooling. Wraps `nix flake init -t github:Eotel/devenv-templates` and patches feature toggles (direnv, delta, treefmt, git-hooks, postgres, mysql, redis, lsp, strict-types) plus Python version and project name in a single command.
license	MIT

devenv-init

Scaffold a reproducible per-language development environment in the current directory using Eotel/devenv-templates.

When to invoke

User says any of:

• "set up a python/django/fastapi/flask devenv"
• "scaffold a devenv for python here"
• "make a new project with devenv"
• "/devenv-init …"

Prerequisites

• nix (Nix 2.18+)
• devenv CLI
• direnv (system-installed via nix-darwin / home-manager)

Options

Option	Values	Default	Notes
--lang	python	(required)	Other languages added incrementally.
--framework	django / fastapi / flask	(none)	Pairs with --lang python.
--python	3.10 / 3.11 / 3.12 / 3.13	3.12	Patches languages.python.version, requires-python, target-version, pythonVersion.
--name	string	dirname	Patches pyproject.toml name and packages = ["src/<name>"].
--with-direnv / --no-direnv	flag	enabled	direnv hint module.
--with-delta / --no-delta	flag	enabled	delta as local git pager.
--with-treefmt / --no-treefmt	flag	enabled	treefmt + nixfmt.
--with-git-hooks / --no-git-hooks	flag	enabled	devenv git-hooks (pre-commit).
--with-lsp / --no-lsp	flag	disabled	Claude Code LSP integration hint.
--strict-types / --no-strict-types	flag	disabled	Flips pyrightconfig.json to strict.
--with-postgres / --no-postgres	flag	varies	python+django defaults ON, others OFF.
--with-mysql / --no-mysql	flag	disabled	mysqlclient build env + service.
--with-redis / --no-redis	flag	disabled	devenv redis service.
--with-sqlite / --no-sqlite	flag	enabled	sqlite CLI in PATH.

Flow

1. Resolve template name: --lang python --framework django → python+django.
2. nix flake init -t github:Eotel/devenv-templates#<template> (in CWD).
3. Patch devenv.nix features = { … }; block with toggles.
4. Patch python version in devenv.nix / pyproject.toml / pyrightconfig.json.
5. Patch project name in pyproject.toml if --name was given.
6. Patch pyrightconfig.json typeCheckingMode if --strict-types.
7. Run nix-instantiate --parse devenv.nix for syntax validation.
8. Print next-step hints (direnv allow / uv sync).

The actual implementation lives at scripts/scaffold.sh. Invoke it directly with the parsed arguments — do not reimplement the patching logic in Codex.

Reference material

• references/options-matrix.md — option × template combinations with notes.
• references/python.md — Python-specific details (db, framework, strict types).
• references/nodejs.md, references/golang.md, references/rust.md — placeholders for future templates.

Project-level rules to honor

• Always run nix flake check (or nix-instantiate --parse) after every Nix file edit.
• git-hooks.hooks is the modern devenv pre-commit (not the deprecated pre-commit.hooks).
• After scaffolding, use uv add to install Python deps; do not edit pyproject.toml dependencies directly.