You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
dsarkar 9f51176f84
Merge pull request #764 from MikeMcC399/lock-node-to-v14
2 days ago
.github Lock repository to lts/fermium (node v14) 7 days ago
images Rework image subtitles and numbering 1 month ago
translations Fix German translation to name correct pinning method 3 months ago
.alexignore feat: no detection of inconsiderate language in the 1 year ago
.alexrc.yaml feat: Use makefile targets for document linting (#215) 1 year ago
.gitignore feat: Use makefile targets for document linting (#215) 1 year ago
.markdownlint.json Linted all MD files, enabled MD linter for each commit 1 year ago
.spelling Linted all MD files, enabled MD linter for each commit 1 year ago
2020_06_24_Corona_API_measurements.pdf Add attenuation measurements by Fraunhofer IIS 1 year ago
CODEOWNERS change CODEOWNERS to reference teams 7 months ago Linted all MD files, enabled MD linter for each commit 1 year ago Fix failing test 9 months ago Update regarding node and npm version 7 days ago
LICENSE Corona-Warn-App: First set of documentation files 2 years ago
NOTICE Add the backend infrastructure architeture with a hint document 1 year ago Add supported languages to README 3 months ago Improve backend-infrastructure-architecture documentation 3 months ago
backend-infrastructure-architecture.pdf Add the backend infrastructure architeture with a hint document 1 year ago Add references to V1.5, V1.9 and FAQ 9 months ago Correct link reg. minimum required app version 3 months ago Merge pull request #745 from tmechen/master 2 weeks ago Update 1 month ago Update solution architecture document 2 months ago
package-lock.json Merge pull request #632 from corona-warn-app/dependabot/npm_and_yarn/trim-newlines-3.0.1 6 months ago
package.json Correct Apache license syntax 1 week ago Fix English translation to name correct key pinning method 3 months ago Move "user_journey.png" to images folder 3 months ago Remove double word from solution architecture 1 month ago
transmission_risk.Rmd Updated version of transmission risk level 1 year ago
transmission_risk.pdf Uploaded new PDF of transmission risk level 1 year ago
transmission_risk_references.bib Updated transmission risk references 1 year ago The corresponding German screenshots ... 9 months ago

About this ProjectWho We AreCreditsData PrivacyCode of ConductWorking LanguageOur DocumentationLicensingHow to ContributeWeb Site

Corona-Warn-App: Documentation

NOTE: This README is also available in German. Thank you for understanding that the German version might not always be up-to-date with the English one.

HINWEIS: Diese README ist ebenfalls auf Deutsch verfügbar. Bitte haben Sie Verständnis, dass die deutsche Version nicht immer auf dem gleichen Stand wie die englische Version ist.

About this Project

We are developing the official COVID-19 exposure notification app for Germany, called "Corona-Warn-App". This project has the goal to develop an app based on technology with a decentralized approach - heavily inspired by the DP-3T (Decentralized Privacy-Preserving Proximity Tracing, see this comic for concept explanation) and TCN protocols and based on the Privacy-Preserving Contact Tracing specifications by Apple and Google. Like DP-3T and the TCN Protocol, the apps and backend infrastructure will be entirely open source - licensed under the Apache 2.0 license! The apps (for iOS and Android) will collect pseudonymous data from nearby mobile phones using Bluetooth technology. The data will be stored locally on each device preventing access and control over data by authorities or anyone else. We will meet the applicable data protection standards and guarantee a high level of IT security. By doing so, we are addressing people's privacy concerns and thereby aiming to increase the adoption of the app.

Who We Are

The German government has commissioned SAP and Deutsche Telekom to develop the Corona-Warn-App for Germany as open source software. Deutsche Telekom is providing the network and mobile technology and will operate and run the backend for the app in a safe, scalable and stable manner. SAP is responsible for the app development, its framework and the underlying platform. Therefore, development teams of SAP and Deutsche Telekom are contributing to this project. At the same time our commitment to open source means that we are enabling -in fact encouraging- all interested parties to contribute and become part of its developer community.


We'd like to thank all the partners who have been involved in this enormous project from the beginning. The project would not be where it is today without all the exploration and great work that had already been done around the PEPP-PT approach by partners on a European and national level. We will build on top of some of these components and appreciate how everyone is dedicated to making this new approach successful. Moreover, we would like to thank GitHub for their great support.

Data Privacy

In this project we are strictly observing the principles of the General Data Protection Regulation (GDPR) to protect the users’ privacy. We are processing necessary data only - exclusively for the purpose to let users know if they have come into close contact with other infected users, without revealing each other's identity. The compliance with these regulations is safeguarded by several procedures, e.g. by implementing technical and organizational measures adhering diligently to the high standards of the GDPR. Of course, the app will provide users with a comprehensive privacy statement to be as transparent and clear as possible. As we are developing the app as an open source project, the community can review it. We appreciate your feedback!

Code of Conduct

This project has adopted the Contributor Covenant in version 2.0 as our code of conduct. Please see the details in our All contributors must abide by the code of conduct.

Working Language

We are building this application for Germany. We want to be as open and transparent as possible, also to interested parties in the global developer community who do not speak German. Consequently, all content will be made available primarily in English. We also ask all interested people to use English as language to create issues, in their code (comments, documentation etc.) and when you send requests to us. The application itself, documentation and all end-user facing content has - of course - been made available in German. Apart from the initial release in English and German, other languages have been added over time including Bulgarian, Polish, Romanian and Turkish. See the FAQ available languages entry for more details. We also try to make developer documentation available in German, but please understand that focusing on the Lingua Franca of the global developer community makes the development of this application as efficient as possible.

Our Documentation

This repository contains the developer documentation and related content.

Project Scope

The project scope has been agreed on jointly by Deutsche Telekom AG and SAP SE as contractors and the German Federal Government and the Robert-Koch-Institut as clients. The project scope might change over time as new requirements need to be included or existing ones change. We appreciate feedback to all elements of this project scope document. However, additional features or any other content changes beyond fixes to grammatical issues or typos need to be aligned on by these partners before they can be included in the document. Thank you for your understanding!

Technical Documentation

The technical documents are intended for a technical audience and represent the most recent state of the architecture. The solution architecture and concepts might change over time as external dependencies (e.g. the framework provided by Apple/Google) are still changing and new requirements need to be included or existing ones change. We appreciate feedback to all elements of these technical documents.

To be published:

  • System Operation


For an easier understanding of the used acronyms and special terms in our documents please see our glossary.


Repository Description    
cwa-documentation Project overview, general documentation, and white papers.           
cwa-app-ios Native iOS app using the Apple/Google exposure notification API.           
cwa-app-android Native Android app using the Apple/Google exposure notification API.           
cwa-website The official website for the Corona-Warn-App.     
cwa-wishlist Community feature requests.           
cwa-server Backend implementation for the Apple/Google exposure notification API.           
cwa-ppa-server Backend implementation for the privacy-preserving analytics server.           
cwa-verification-server Backend implementation of the verification process.           
cwa-verification-portal The portal to interact with the verification server.           
cwa-verification-iam The identity and access management to interact with the verification server.            
cwa-testresult-server Receives PCR test results from connected laboratories.     
cwa-log-upload Counterpart of the log upload in the app.           
cwa-quicktest-onboarding Documentation about onboarding procedure for rapid antigen test partners.
cwa-quick-test-frontend Frontend implementation of the rapid antigen test portal for participating partners.        
cwa-quick-test-backend Backend implementation of the rapid antigen test portal and API for participating partners.
 cwa-event-landingpage Landing page for CWA which opens if the user does not have the app installed.  
 cwa-event-qr-code Utility to generate QR codes for Event Registration.  
 cwa-hotline Contains all issues reg. the hotlines of the CWA


Copyright (c) 2020-2021 Deutsche Telekom AG and SAP SE or an SAP affiliate company.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.

You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the LICENSE for the specific language governing permissions and limitations under the License.

The "Corona-Warn-App" logo is a registered trademark of The Press and Information Office of the Federal Government. For more information please see

How to Contribute

Please see our for details on how to contribute, our team setup, the project structure and additional details which you need to know to work with us.