> **Building with AI coding agents?** If you're using an AI coding agent, install the official Scalekit plugin. It gives your agent full awareness of the Scalekit API — reducing hallucinations and enabling faster, more accurate code generation.
>
> - **Claude Code**: `/plugin marketplace add scalekit-inc/claude-code-authstack` then `/plugin install <auth-type>@scalekit-auth-stack`
> - **GitHub Copilot CLI**: `copilot plugin marketplace add scalekit-inc/github-copilot-authstack` then `copilot plugin install <auth-type>@scalekit-auth-stack`
> - **Codex**: run the bash installer, restart, then open Plugin Directory and enable `<auth-type>`
> - **Skills CLI** (Windsurf, Cline, 40+ agents): `npx skills add scalekit-inc/skills --list` then `--skill <skill-name>`
>
> `<auth-type>` / `<skill-name>`: `agentkit`, `full-stack-auth`, `mcp-auth`, `modular-sso`, `modular-scim` — [Full setup guide](https://docs.scalekit.com/dev-kit/build-with-ai/)

---

# Enable magic link & OTP based sign in

How to configure magic link & OTP based passwordless authentication for your application
Magic link & OTP authentication allows your users to sign in without entering a password. Users can authenticate using any of the following methods:

- A verification code (OTP) sent by email.
- A magic link sent by email.
- Both a verification code and a magic link sent by email.

This guide shows you how to enable each passwordless login method. You should complete the [quickstart guide](/authenticate/fsa/quickstart/) before following this guide, as it covers building a sign-in page that combines Scalekit's hosted UI.

## Configure magic link & OTP settings

You can modify the magic link & OTP behavior from the Scalekit dashboard without changing your code.

 > Image: Screenshot

### Select magic link & OTP options

1. Navigate to the Authentication tab in your Scalekit dashboard environment.
2. Select one of the following options:

    | Method | Description |
    |--------|-------------|
    | Verification code (OTP) | Users receive a one-time code via email that they must enter to sign in. |
    | Magic link | Users receive a secure link via email that they can click to sign in directly. |
    | Verification code and magic link | Users receive both a verification code and a magic link via email, allowing them to choose their preferred method. |

3. Click Save to apply your changes.

### Enable same browser origin enforcement

This setting improves security by requiring users to complete magic link authentication in the same browser where they initiated the sign-in process. This helps prevent phishing attacks where an attacker could use an intercepted magic link on a different device or browser.

To enable this setting, select the **Enforce same browser origin** checkbox in the **Passwordless** section, and click **Save**.

### Enable new passwordless credentials on resend

This setting improves security by generating a new verification code or magic link each time a user asks to resend one. This invalidates the previously sent credential.

To enable this setting, select the **Enable new passwordless credentials on resend** checkbox in the **Passwordless** section, and click **Save**.

### Customize email templates

You can customize the emails sent to users to match your brand, or you can [bring your own email provider](/guides/passwordless/custom-email-provider/) to handle email sends related to magic link & OTP authentication. Scalekit sends the emails when you use it as your email provider.


---

## More Scalekit documentation

| Resource | What it contains | When to use it |
|----------|-----------------|----------------|
| [/llms.txt](/llms.txt) | Structured index with routing hints per product area | Start here — find which documentation set covers your topic before loading full content |
| [/llms-full.txt](/llms-full.txt) | Complete documentation for all Scalekit products in one file | Use when you need exhaustive context across multiple products or when the topic spans several areas |
| [sitemap-0.xml](https://docs.scalekit.com/sitemap-0.xml) | Full URL list of every documentation page | Use to discover specific page URLs you can fetch for targeted, page-level answers |