+```
+
+## Package build
+```
+make packages
+```
+
+## Build time configuration
+You can customize project global variables using env variables. Default values are placed in the `.env` file.
+
+Example:
+```
+REACT_APP_ARVADOS_CONFIG_URL=config.json yarn build
+```
+
+## Run time configuration
+The app will fetch runtime configuration when starting. By default it will try to fetch `/config.json`. In development mode, this can be found in the `public` directory.
+You can customize this url using build time configuration.
+
+Currently this configuration schema is supported:
+```
+{
+ "API_HOST": "string",
+ "FILE_VIEWERS_CONFIG_URL": "string",
+}
+```
+
+### API_HOST
+
+The Arvados base URL.
+
+The `REACT_APP_ARVADOS_API_HOST` environment variable can be used to set the default URL if the run time configuration is unreachable.
+
+## FILE_VIEWERS_CONFIG_URL
+Local path, or any URL that allows cross-origin requests. See:
+
+[File viewers config file example](public/file-viewers-example.json)
+
+[File viewers config scheme](src/models/file-viewers-config.ts)
+
+To use the URL defined in the Arvados cluster configuration, remove the entire `FILE_VIEWERS_CONFIG_URL` entry from the runtime configuration. Found in `/config.json` by default.
+
+## Plugin support
+
+Workbench supports plugins to add new functionality to the user
+interface. For information about installing plugins, the provided
+example plugins, see [src/plugins/README.md](src/plugins/README.md).
+