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

# FAQ

## How does automatic re-authentication work?

When you link credentials to a connection, Kernel runs periodic health checks and can reauthenticate supported credential-based flows in the background. This includes TOTP when Kernel can provide the authenticator code. See [Connection Lifecycle](/docs/auth/connection-lifecycle) for the full lifecycle, cadence options, and `can_reauth` rules.

## What are auth choices?

Auth choices are visible routes a site presents during login, including mfa methods, sso providers, account pickers, and organization selectors. They appear in the canonical `choices` array. Submit the exact returned id with `interaction_id` and `selected_choice_id`. See the [programmatic flow guide](/docs/auth/programmatic#choices) for examples.

## Which authentication methods are supported?

Managed Auth supports common credential, SSO, and multi-step login flows. Automatic reauthentication uses stored credentials and attempts to provide TOTP codes when needed.

<Warning>
  Passkey-only authentication isn't currently supported. If a site's SSO provider requires a passkey, the login returns `unsupported_auth_method`. Switch the account to a supported sign-in method, such as password and TOTP, then start a new login.
</Warning>

## What happens if login fails?

Kernel surfaces an error code (`credentials_invalid`, `account_locked`, `bot_detected`, `captcha_blocked`, etc.). Transient site failures are retried; a conclusive rejection by the site isn't, so Kernel doesn't burn attempts against a locked account or resubmit credentials the site already refused. See [Connection Lifecycle](/docs/auth/connection-lifecycle#when-a-login-fails) for the full list and recovery steps.

## Can I use Managed Auth with any website?

Managed Auth covers common login flows across a broad range of websites. Site-specific authentication and bot detection can require additional configuration. See [what Managed Auth supports](/docs/auth/overview#why-managed-auth) and test your target flow.

## Is Managed Auth available during a trial?

Yes. Managed Auth and browser profiles are available during your trial period with the same capabilities as the plan you're trialing.

## How do I re-authenticate a connection before the next health check?

Call `.login()` on the connection to trigger auth immediately. See [Triggering re-auth manually](/docs/auth/connection-lifecycle#triggering-re-auth-manually) for the pattern.

## What types of flows does Managed Auth support?

Managed Auth navigates login pages, enters stored credentials, follows SSO redirects, guides users through additional authentication steps, and saves the resulting browser session. For post-login work like form filling, sign-ups, or other workflows, use [Kernel's browser automation](/docs/introduction/control) directly.

## How do I debug a managed auth session?

Use the **Browser Sessions** tab in the dashboard for live view, or set `record_session: true` to capture replays of every auth browser session. See [Debugging a flaky connection](/docs/auth/connection-lifecycle#debugging-a-flaky-connection) for details.

## Can I attach multiple auth connections to one profile?

Yes. A profile can have any number of auth connections, each for a different domain. When you create a browser with that profile, it loads the saved authentication state for every connected domain.

This is useful for two common patterns:

* **Multi-site workflows** — Your agent visits multiple sites in a single run (e.g., reads email in Gmail, posts a summary in Slack, and updates a CRM). Attach one auth connection per site to a single profile, and each browser loads the saved authentication state for all of them.
* **User-to-profile mapping** — Each end user on your platform gets one profile. All of that user's accounts (Gmail, LinkedIn, GitHub, etc.) are auth connections on their profile. When the user triggers a workflow, launch a browser with their profile.

See [Profiles — Multiple auth connections per profile](/docs/auth/profiles#multiple-auth-connections-per-profile) for code examples.

## How is Managed Auth billed?

Managed Auth is included on all plans with no per-connection fees. It uses browser sessions for login, health checks, and eligible reauthentication attempts. These count toward your browser usage like any other browser session.

Auth sessions are fast (typically 5-30 seconds each). Kernel monitors session health and can automatically reauthenticate eligible credential-based flows when sessions expire. Most sessions stay valid for days. For example, monitoring 100 auth connections typically costs less than \$5/month in browser usage. See [Pricing & Limits](/docs/info/pricing#managed-auth) for details.