Parametrize configurations¡

frontend/src/config.js

@@ -16,5 +16,9 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
-export const API_BASE = import.meta.env.VITE_API_BASE || 'http://localhost:8000';
+const baseUrl = import.meta.env.BASE_URL || '/';
+const defaultApiBase = `${baseUrl.replace(/\/$/, '')}/api`;
+const rawApiBase = import.meta.env.VITE_API_BASE || defaultApiBase;
+
+export const API_BASE = rawApiBase.replace(/\/$/, '');
 export const ENABLE_POLLING = import.meta.env.MODE !== 'test';