@yohangel / auth-express

1.0.0 ▾

1.0.0

MIT

GitHub

Express 5 用 Better Auth：認証ルートをマウントし requireAuth で API を保護

コード3 ファイルコンテキスト約 405 トークンスキャン合格

インストール

$genpm add @yohangel/auth-express

含まれるもの

src/lib/auth-express/ にソースコード（3 ファイル）。 (4.3 KB)
src/lib/auth-express/AGENTS.md に AI ルール、加えて IDE 用のルールファイル。
@yohangel/auth を自動で解決します。

README

このパッケージには README がありません。

約 405 トークン→ src/lib/auth-express/AGENTS.md→ .cursor/rules/genpm-yohangel-auth-express.mdc

これは AI が src/lib/auth-express で作業するときに読む内容そのものです。それ以外はコンテキストに追加されません。

@yohangel/auth-express — rules for AI agents

Purpose

Connects @yohangel/auth to Express 5: mounts Better Auth on /api/auth/* and provides requireAuth / optionalAuth middleware that put the session in res.locals.

Module map

index.ts — mountAuth(app, opts), requireAuth, optionalAuth, AuthLocals type, createAuth re-export.

Integration (do this after installing)

Order matters — mount auth BEFORE body parsers:

import express from 'express';
import { mountAuth, requireAuth } from './lib/auth-express/index.js';
const app = express();
mountAuth(app, { sendEmail });          // /api/auth/*
app.use(express.json());
app.get('/api/me', requireAuth, (req, res) => res.json({ id: res.locals.user.id }));

Frontend on another origin: app.use(cors({ origin: ['https://app.example.com'], credentials: true })) before mountAuth, and list that origin in AUTH_TRUSTED_ORIGINS.
Behind a proxy/CDN set app.set('trust proxy', 1) and AUTH_IP_HEADER so rate limits use the real client IP.
Express 4 is not supported (route syntax *splat is Express 5). Project must be ESM ("type": "module").

Conventions

Protect routes with requireAuth; read res.locals.user / res.locals.session (typed by AuthLocals).
Authorization (who can do what) goes in your handlers after requireAuth, never on the client.

Don't

Don't put express.json() before mountAuth (Better Auth must read the raw body).
Don't use cors({ origin: '*', credentials: true }).
Don't return res.locals.session (contains the token) to the client.

# @yohangel/auth-express — rules for AI agents

## Purpose
Connects `@yohangel/auth` to Express 5: mounts Better Auth on `/api/auth/*` and provides `requireAuth` / `optionalAuth` middleware that put the session in `res.locals`.

## Module map
- `index.ts` — `mountAuth(app, opts)`, `requireAuth`, `optionalAuth`, `AuthLocals` type, `createAuth` re-export.

## Integration (do this after installing)
1. Order matters — mount auth BEFORE body parsers:
   ```ts
   import express from 'express';
   import { mountAuth, requireAuth } from './lib/auth-express/index.js';
   const app = express();
   mountAuth(app, { sendEmail });          // /api/auth/*
   app.use(express.json());
   app.get('/api/me', requireAuth, (req, res) => res.json({ id: res.locals.user.id }));
   ```
2. Frontend on another origin: `app.use(cors({ origin: ['https://app.example.com'], credentials: true }))` before `mountAuth`, and list that origin in `AUTH_TRUSTED_ORIGINS`.
3. Behind a proxy/CDN set `app.set('trust proxy', 1)` and `AUTH_IP_HEADER` so rate limits use the real client IP.
4. Express 4 is not supported (route syntax `*splat` is Express 5). Project must be ESM (`"type": "module"`).

## Conventions
- Protect routes with `requireAuth`; read `res.locals.user` / `res.locals.session` (typed by `AuthLocals`).
- Authorization (who can do what) goes in your handlers after `requireAuth`, never on the client.

## Don't
- Don't put `express.json()` before `mountAuth` (Better Auth must read the raw body).
- Don't use `cors({ origin: '*', credentials: true })`.
- Don't return `res.locals.session` (contains the token) to the client.