When a user logs in into your application, the UI component stores the session-token as a cookie. Since user authentication is determined by the session-token (see Protecting Routes), it must be accessible wherever you need to verify the user’s authentication status.

By default, the Domain of the session-token cookie is set to the domain the UI component is integrated on (e.g. if the UI component is integrated on https://www.example.com/auth/ the Domain will be www.example.com).

Thus, there will be different scenarios where the session-token cookie is available and where not:

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1) Frontend and backend are on the same domain

This is the simplest scenario. The session-token cookie is available in both the frontend and the backend because they share the same cookie domain.

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Frontend

  • Frontend runs on https://www.example.com
  • User logs in using the Corbado UI component
  • The session-token is created and stored as cookie with name cbo_session_token and Domain=www.example.com
  • User interacts and frontend (JavaScript) sends requests to the backend on https://www.example.com/api
  • The session-token cookie is sent with the request to the backend because the Domain matches

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Backend

  • Backend reads session-token from cookie cbo_session_token and validates it

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2) Frontend and backend are on different domains

In this scenario, the session-token cookie is not available in the backend because the Domain of the cookie does not match the backend domain (www.example.com != api.example.com).

To make the session-token cookie available in the backend, you have to pass it as bearer token in the Authorization header.

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Frontend

  • Frontend runs on https://www.example.com
  • User logs in using the Corbado UI component
  • The session-token is created and stored as cookie with name cbo_session_token and Domain=www.example.com
  • User interacts and frontend (JavaScript) sends requests to the backend on https://api.example.com
  • The session-token is sent with the request using Authorization header (bearer) to the backend because the Domain does not match

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Backend

  • Backend reads session-token from Authorization header (bearer) and validates it

Write Authorization header

Read Authorization header

Since it is technically possible to pass the session-token using other methods like query parameters or other header fields (like X-Session-Token), we strongly recommend using the Authorization header. This is the most secure way to pass the session-token.

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3) Frontend and multiples backends are on different domains

Scenario 3 is pretty similar to scenario 2. The only difference is that you have multiple backends (like it is common in microservice architectures).

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Frontend

  • Frontend runs on https://www.example.com
  • User logs in using the Corbado UI component
  • The session-token is created and stored as cookie with name cbo_session_token and Domain=www.example.com
  • User interacts and frontend (JavaScript) sends requests to the Shop backend on https://shop.example.com
  • The session-token is sent with the request using Authorization header (bearer) to the backend because the Domain does not match

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Shop backend

  • Shop backend reads session-token from Authorization header (bearer) and validates it
  • Shop backend sends requests to the Payment backend on https://payment.example.com
  • The session-token is sent with the request using Authorization header (bearer) to the backend because no Browser is involved and we have no cookie handling

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Payment backend

  • Payment backend reads session-token from Authorization header (bearer) and validates it

Write Authorization header

Read Authorization header

Since it is technically possible to pass the session-token using other methods like query parameters or other header fields (like X-Session-Token), we strongly recommend using the Authorization header. This is the most secure way to pass the session-token.