> ## 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

**ssoToken** `String` *required*

**sessionDurationMinutes** `Int` *required*

**locale** `String?`

## Returns

\[B2BSSOAuthenticateResponse] containing the authenticated member session.

```swift theme={null}
let params = B2BSSOAuthEnticateParameters(ssoToken: "token", sessionDurationMinutes: 30)
let response = try await StytchB2B.sso.authenticate(params)
```