# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Commands

- `mix compile` - Compile source files
- `mix test` - Run all tests
- `mix test test/path/to/test.exs` - Run a specific test file
- `mix test test/path/to/test.exs:LINE` - Run a specific test at a line number
- `mix deps.get` - Install dependencies
- `mix clean` - Clean build artifacts

## Architecture

This is an Elixir library that provides email allowlist functionality for restricting account creation. The library consists of two main modules:

1. **BasicSignupAllowlist** (lib/basic_signup_allowlist.ex) - Public API module that reads the `SIGNUP_ALLOWLIST_EMAILS` environment variable and delegates to the functional core
2. **FunCore.BasicSignupAllowlist** (lib/fun_core/basic_signup_allowlist.ex) - Pure functional core that handles the allowlist logic without side effects

The architecture follows a functional core/imperative shell pattern where:
- The functional core contains pure functions for email normalization and allowlist checking
- The outer module handles environment variable reading and provides the public interface

## Environment Variables

- `SIGNUP_ALLOWLIST_EMAILS` - Comma-separated list of allowed email addresses, or "*" to allow all emails

## Project Configuration

- Elixir version: ~> 1.18 (managed via mise)
- No external dependencies currently
- Test framework: ExUnit with async: false for integration tests that modify environment variables