> ## Documentation Index
> Fetch the complete documentation index at: https://docs.syntaxia.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Authentication

> How passwordless authentication works in Syntaxia.

Syntaxia uses passwordless authentication through magic link codes. When you sign in, you enter your email and receive a 6-character verification code. Codes use uppercase letters (excluding O, I, L) and digits 2 through 9 to avoid ambiguity. Each code expires after 15 minutes. Your session is tied to your browser and your identity (email address).