--- title: Flows --- Flows are a method of describing a sequence of stages. A stage represents a single verification or logic step. They are used to authenticate users, enroll them, and more. Upon flow execution, a plan containing all stages is generated. This means that all attached policies are evaluated upon execution. This behaviour can be altered by enabling the **Re-evaluate Policies** option on the binding. To determine which flow is linked, passbook searches all flows with the required designation and chooses the first instance the current user has access to. ## Permissions Flows can have policies assigned to them. These policies determine if the current user is allowed to see and use this flow. ## Designation Flows are designated for a single purpose. This designation changes when a flow is used. The following designations are available: ### Authentication This is designates a flow to be used for authentication. The authentication flow should always contain a [**User Login**](stages/user_login.md) stage, which attaches the staged user to the current session. ### Invalidation This designates a flow to be used to invalidate a session. This stage should always contain a [**User Logout**](stages/user_logout.md) stage, which resets the current session. ### Enrollment This designates a flow for enrollment. This flow can contain any amount of verification stages, such as [**email**](stages/email/index.md) or [**captcha**](stages/captcha/index.md). At the end, to create the user, you can use the [**user_write**](stages/user_write.md) stage, which either updates the currently staged user, or if none exists, creates a new one. ### Unenrollment This designates a flow for unenrollment. This flow can contain any amount of verification stages, such as [**email**](stages/email/index.md) or [**captcha**](stages/captcha/index.md). As a final stage, to delete the account, use the [**user_delete**](stages/user_delete.md) stage. ### Recovery This designates a flow for recovery. This flow normally contains an [**identification**](stages/identification/index.md) stage to find the user. It can also contain any amount of verification stages, such as [**email**](stages/email/index.md) or [**captcha**](stages/captcha/index.md). Afterwards, use the [**prompt**](stages/prompt/index.md) stage to ask the user for a new password and the [**user_write**](stages/user_write.md) stage to update the password. ### Setup This designates a flow for general setup. This designation doesn't have any constraints in what you can do. For example, by default this designation is used to configure Factors, like change a password and setup TOTP.