Load current user state
A client page needs the signed-in user's identity and session details.
Better Auth · Function
getSession
getSession retrieves the currently active Better Auth session. On the client it is called through authClient; on the server, use auth.api.getSession with request headers.
How it works
The client method asks Better Auth for the currently active session. It returns session data containing user and session objects; server-side access instead uses the auth API and requires request headers.
Syntax
await authClient.getSession()Returns
A session response whose data contains user and session objects; server calls require request headers.
Key points
- Use
getSessionwhen code needs the currently active authenticated session. - The session is cookie-based, so the request carries the session information to the server.
- A valid session produces user data after server-side verification.
- The
customSessionplugin can change the shape or contents of the session response. - For reactive client UI updates, use the separate
useSessionaction instead of repeatedly fetching manually.
Common mistakes
- Read the returned data through its
userandsessionproperties rather than expecting a single user value.
Example: Read the current client session
import { authClient } from "@/lib/auth-client"
const { data: session, error } = await authClient.getSession()
if (error) {
console.error(error)
} else if (session) {
console.log(session.user, session.session)
}Calls the client method and reads the returned user and session objects when available.
When to use it
Authenticate an incoming request
A server route must determine which user made a request.
Use custom session data
A customized session payload is required across the application.
Interview questions
QWhat does getSession do?
The client method retrieves the current active session. Its returned data exposes both user and session objects.
Follow-up: How would you call it on the server? Use auth.api.getSession and pass the request headers in the options object.
QWhat is the basic client invocation?
A client call is made with authClient.getSession(). The result can be destructured into data, commonly aliased as session, and error.
Follow-up: What should a server-side implementation provide? The headers containing the user's session information.
QHow does server usage differ from client usage?
On the server, use the Better Auth instance's API: auth.api.getSession({ headers: ... }). The headers are needed so Better Auth can identify the request's session.
Follow-up: How can Node request headers be adapted in Express? Use the documented fromNodeHeaders helper before passing them.
Related
useSessionauthClientauth.api.getSessioncustomSessionfromNodeHeaders