---
name: fusebase-portal-specific-apps
description: How to develop apps that show different information based on the portal where they are embedded. Use when a task requires showing different data depending on the parent portal
---

# Apps in portals
A "portal" is a user-customized website configured in the Fusebase web UI. Portals can display different blocks, including blocks that render apps/apps in an `iframe`.
In this case, information about the current portal is automatically added to the auth context, so requests from the embedded app/app carry portal information automatically.

# Developing portal-specific apps
When the user asks for an app that should show different information based on the portal where it is embedded, use a Fusebase database table with a view filter that uses the `{{CurrentPortal}}` dynamic value. See the `filters` reference in the `fusebase-dashboards` skill for details.
**Important!** You **should not** take a portal ID explicitly as a parameter (query, path, input, etc.); it should be resolved automatically when the view is configured correctly.

## Receiving portal-specific entries
Requests for the data in this view automatically receive the current portal in context, and that value is substituted into the view filter. 

## Writing from a portal
If you need to add an entry to the table with a portal-based filter, you need to ensure that the row you have created contains the current portal. Get it via the `/auth/context` request described in the `app-dev-practices` skill. When the app runs within the portal, the response may contain `runtimeContext.portalId`. If it is not present, then the app is currently running outside of the portal; therefore, the current portal should not be written to a filter column.

# Important considerations
- When possible, always use a relation column that links to portal dashboards instead of a plain-text column for portal IDs.
- Pay attention to setting a filter on a column that has a relation to the portal dashboard (or portal ID in case you implemented a column of text type for that).
- **Important!** If you are using a relation column for portals, be sure to set the correct render type for this column.