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

# Authenticate

> Authenticates an SSO token received via deeplink after the browser-based SSO flow completes, establishing a member session. Calls the `POST /sdk/v1/b2b/sso/authenticate` endpoint. Retrieves the PKCE code verifier stored during the [start] call, and automatically includes the intermediate session token if one is present.

## Parameters

<ParamField body="ssoToken" type="String" required />

<ParamField body="sessionDurationMinutes" type="Int" required />

<ParamField body="locale" type="String?" />

## Returns

\[B2BSSOAuthenticateResponse] containing the authenticated member session.

<RequestExample>
  ```js theme={null}
  StytchB2B.sso.authenticate({ ssoToken: "token", sessionDurationMinutes: 30 })
  ```
</RequestExample>