Resolve the "auth session is terminal" error

If you receive an "auth session is terminal" error from the Link SDK, the connection attempt has ended — either completed or abandoned — and the session can no longer be queried. This page explains the cause and the correct way to handle it.

What "auth session is terminal" means

An auth session becomes terminal when the user either completes the connection flow or abandons it partway through. Once a session reaches a terminal state, it cannot be reused or resumed. Any attempt to use it returns this error.

Why it happens when retrieving the consent ID

The most common cause is polling the Link SDK for a consent ID immediately after the auth flow completes. By that point the auth session is already terminal, so querying it returns this error instead of the consent ID. This is a race condition built into the polling approach — the session ends before your query lands.

Use webhooks instead

Rather than polling the Link SDK after the flow completes, listen for the consent.received webhook event. Fiskil fires it once the consent has been successfully established, and the payload contains the consent ID along with the end user ID.

1. Register a webhook endpoint and subscribe to consent events — see the webhooks guide.
2. When the user finishes the Link flow, wait for the consent.received event instead of querying the session.
3. Read the consent ID from the webhook payload and continue your onboarding or data-fetch logic from there.

Summary

Don't poll the Link SDK for a consent ID after the auth flow ends. Subscribe to Fiskil webhooks and handle the consent.received event to receive the consent ID reliably. If you still see issues, contact Fiskil support with the end user ID and the auth session details.