better-auth-security-best-practiceslisted
Install: claude install-skill arthjean/skills
## Secret Management
### Configuring the Secret
```ts
import { betterAuth } from "better-auth";
export const auth = betterAuth({
secret: process.env.BETTER_AUTH_SECRET, // or via `BETTER_AUTH_SECRET` env
});
```
Better Auth looks for secrets in this order:
1. `options.secret` in your config
2. `BETTER_AUTH_SECRET` environment variable
3. `AUTH_SECRET` environment variable
### Secret Requirements
- Rejects default/placeholder secrets in production
- Warns if shorter than 32 characters or entropy below 120 bits
- Generate: `openssl rand -base64 32`
- Never commit secrets to version control
## Rate Limiting
Enabled in production by default. Applies to all endpoints. Plugins can override per-endpoint.
### Default Configuration
```ts
import { betterAuth } from "better-auth";
export const auth = betterAuth({
rateLimit: {
enabled: true, // Default: true in production
window: 10, // Time window in seconds (default: 10)
max: 100, // Max requests per window (default: 100)
},
});
```
### Storage Options
Options: `"memory"` (resets on restart, avoid on serverless), `"database"` (persistent), `"secondary-storage"` (Redis, default when available).
```ts
rateLimit: {
storage: "database",
}
```
### Custom Storage
Implement your own rate limit storage:
```ts
rateLimit: {
customStorage: {
get: async (key) => {
// Return { count: number, expiresAt: number } or null
},
set: async (key, data) => {
// Store the rate limit data
},