cds-federation-synonyms

Welcome to @cap-js/cds-federation-synonyms

About this project

CDS plugin for SAP HANA synonym-based data federation.

This plugin is still experimental.

For CAP applications using SAP HANA as database, this plugin enables CAP-to-CAP data federation by integration on the database layer via synonyms.

In the database schema of the application that consumes the data ("consumer"), the imported entities are represented as synonyms that point to the respective tables or views in the database schema of the application that provides the data ("provider"). Acess to the producer is read-only.

Visit CAP-level Data Federation to learn about the basics.

Requirements

• @sap/cds-dk version 9.9 or higher.
• Both "provider" and "consumer" are CAP apps, using SAP HANA as database.
• Both "provider" and "consumer" run in the same SAP HANA instance, and, if Native Multitenancy in SAP HANA Cloud is switched on, live in the same tenant.

The plugin uses two components which are under SAP properity licesenses. You need to review and accept them if you consume the plugin:

• @sap/hdi
• @sap/xssec

Usage

Install the plugin both in the provider and in the consumer app. If the consumer uses multi-tenancy, install the plugin in the consumer's MTX sidecar, too.

npm install git+https://github.com/cap-js/cds-federation-synonyms.git

Provider

Define an API package with a data service annotated with @data.product: 'via-synonym' and export it. For more information on API packages, see CAP-level Data Federation.

Consumer

Import the API package, define consumption views on top of the imported entities and use them in your app's CDS model as described in CAP-level Data Federation.

On HANA, the entities in the imported data service are represented by synonyms that can either point to local mock tables (synonyms are "unconnected"), or to the respective tables/views in the provider app (synonyms are "connected").

The choice between connected and unconnected is made on service level. For a single tenant app, it is a deployment decision. For the tenants of a multi tenant app, you can use a static configuration or the synonyms can alternatively also be switched between connected and unconnected during runtime via an API provided by the plugin.

Schematic example

Consumer app:

// --- consumption view
@federated entity consumption.Books as projection on datasrv.Books { /* ... */ }

// --- imported API
@data.product: 'via-synonym' @cds.external
service datasrv {
  @readonly entity Books { /*...*/};
  // ...
}

Provider app:

// --- API definition / data service
@data.product: 'via-synonym'
service datasrv {
  @readonly entity Books as projection on bookshop.Books
  // ...
}

// --- base entity
entity bookshop.Books {
  // ...
}

Database objects:

In the producer app, table bookshop.Books is exposed in service datasrv via the synonym technique. For access control, a HANA role datasrv is generated that grants SELECT privileges to all entities in the service.

In the consumer app, the imported entity datasrv.books is represented by a synonym. The synonym can point to a local mock table ("unconnected") or to the corresponding view in the producer app ("connected").

Walkthrough

For a detailed example, go to Walkthrough.

Support, Feedback, Contributing

This project is open to feature requests/suggestions, bug reports etc. via GitHub issues. Contribution and feedback are encouraged and always welcome. For more information about how to contribute, the project structure, as well as additional contribution information, see our Contribution Guidelines.

Security / Disclosure

If you find any bug that may be a security problem, please follow the instructions found in our security policy on how to report it. Please do not create GitHub issues for security-related doubts or problems.

Code of Conduct

We as members, contributors, and leaders pledge to make participation in our community a harassment-free experience for everyone. By participating in this project, you agree to abide by its Code of Conduct at all times.

Licensing

Copyright 2026 SAP SE or an SAP affiliate company and cds-federation-synonyms contributors. Please see our LICENSE for copyright and license information. Detailed information including third-party components and their licensing/copyright information is available via the REUSE tool.