diff --git a/src/app/Theme.ts b/src/app/Theme.ts
index 6dd615f..53ace06 100644
--- a/src/app/Theme.ts
+++ b/src/app/Theme.ts
@@ -113,6 +113,18 @@ const darkPalette = {
   boxShadow: '0px 1px 4px 2px rgba(0,0,0,0.6)',
 };
 
+const CARTO_MAP_API_KEY = process.env.NEXT_PUBLIC_CARTO_MAP_API_KEY ?? '';
+
+const buildBasemapTileUrl = (style: 'light_all' | 'dark_all'): string => {
+  const baseUrl = `https://a.basemaps.cartocdn.com/${style}/{z}/{x}/{y}{r}.png`;
+  return CARTO_MAP_API_KEY.length > 0
+    ? `${baseUrl}?key=${CARTO_MAP_API_KEY}`
+    : baseUrl;
+};
+
+const basemapAttribution =
+  '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors &copy; <a href="https://carto.com/attributions">CARTO</a>';
+
 /**
  * Map configuration per color scheme.
  * Extracted from the theme because map tile URLs and canvas colors
@@ -121,8 +133,8 @@ const darkPalette = {
  */
 export const mapConfig = {
   light: {
-    basemapTileUrl:
-      'https://a.basemaps.cartocdn.com/light_all/{z}/{x}/{y}{r}.png',
+    basemapTileUrl: buildBasemapTileUrl('light_all'),
+    basemapAttribution,
     basemapTileOverallColor: '#f6f6f6',
     routeColor: lightPalette.background.default,
     routeTextColor: lightPalette.text.primary,
@@ -131,8 +143,8 @@ export const mapConfig = {
     primaryMain: lightPalette.primary.main,
   },
   dark: {
-    basemapTileUrl:
-      'https://a.basemaps.cartocdn.com/dark_all/{z}/{x}/{y}{r}.png',
+    basemapTileUrl: buildBasemapTileUrl('dark_all'),
+    basemapAttribution,
     basemapTileOverallColor: '#0d0d0d',
     routeColor: darkPalette.background.default,
     routeTextColor: darkPalette.text.primary,
diff --git a/src/app/components/GtfsVisualizationMap.tsx b/src/app/components/GtfsVisualizationMap.tsx
index d9f0ac4..d7752c0 100644
--- a/src/app/components/GtfsVisualizationMap.tsx
+++ b/src/app/components/GtfsVisualizationMap.tsx
@@ -568,8 +568,7 @@ export const GtfsVisualizationMap = ({
                   type: 'raster',
                   tiles: [mapCfg.basemapTileUrl],
                   tileSize: 256,
-                  attribution:
-                    '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors',
+                  attribution: mapCfg.basemapAttribution,
                 },
                 sample: {
                   type: 'vector',
diff --git a/src/app/components/Map.tsx b/src/app/components/Map.tsx
index 8e8b98a..2d341e8 100644
--- a/src/app/components/Map.tsx
+++ b/src/app/components/Map.tsx
@@ -63,8 +63,7 @@ export const Map = (
                 type: 'raster',
                 tiles: [mapCfg.basemapTileUrl],
                 tileSize: 256,
-                attribution:
-                  '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors',
+                attribution: mapCfg.basemapAttribution,
               },
             },
             layers: [
diff --git a/src/app/components/MapGeoJSON.tsx b/src/app/components/MapGeoJSON.tsx
index 4d8aaf4..a4bb03a 100644
--- a/src/app/components/MapGeoJSON.tsx
+++ b/src/app/components/MapGeoJSON.tsx
@@ -94,8 +94,7 @@ export const MapGeoJSON = (
               type: 'raster',
               tiles: [mapCfg.basemapTileUrl],
               tileSize: 256,
-              attribution:
-                '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors',
+              attribution: mapCfg.basemapAttribution,
             },
           },
           layers: [