diff --git a/front/src/Connexion/Room.ts b/front/src/Connexion/Room.ts
index a76e3f31..a3be5f53 100644
--- a/front/src/Connexion/Room.ts
+++ b/front/src/Connexion/Room.ts
@@ -130,6 +130,7 @@ export class Room {
                 this._canReport = data.canReport ?? false;
                 this._loadingLogo = data.loadingLogo ?? undefined;
                 this._loginSceneLogo = data.loginSceneLogo ?? undefined;
+                this.instance = data.instance;
                 return new MapDetail(data.mapUrl);
             } else {
                 console.log(data);
diff --git a/messages/JsonMessages/MapDetailsData.ts b/messages/JsonMessages/MapDetailsData.ts
index 5ee5432c..503ddbf1 100644
--- a/messages/JsonMessages/MapDetailsData.ts
+++ b/messages/JsonMessages/MapDetailsData.ts
@@ -13,6 +13,7 @@ export const isMapDetailsData = z.object({
     roomSlug: z.nullable(z.string()), // deprecated
     contactPage: z.nullable(z.string()),
     group: z.nullable(z.string()),
+    instance: z.string(),
 
     iframeAuthentication: z.optional(z.nullable(z.string())),
     // The date (in ISO 8601 format) at which the room will expire
diff --git a/pusher/src/Controller/MapController.ts b/pusher/src/Controller/MapController.ts
index 19131a24..be910c09 100644
--- a/pusher/src/Controller/MapController.ts
+++ b/pusher/src/Controller/MapController.ts
@@ -76,6 +76,10 @@ export class MapController extends BaseHttpController {
          *                   type: string|null
          *                   description: The group this room is part of (maps the notion of "world" in WorkAdventure SAAS)
          *                   example: myorg/myworld
+         *                 instance:
+         *                   type: string
+         *                   description: The instance of this map. In a public URL: the second part of the URL (_/[instance]/map.json)
+         *                   example: global
          *                 iframeAuthentication:
          *                   type: string|null
          *                   description: The URL of the authentication Iframe
@@ -111,14 +115,15 @@ export class MapController extends BaseHttpController {
             if (!ADMIN_API_URL) {
                 const roomUrl = new URL(query.playUri);
 
-                const match = /\/_\/[^/]+\/(.+)/.exec(roomUrl.pathname);
+                const match = /\/_\/([^/]+)\/(.+)/.exec(roomUrl.pathname);
                 if (!match) {
                     res.status(404);
                     res.json({});
                     return;
                 }
 
-                const mapUrl = roomUrl.protocol + "//" + match[1];
+                const instance = match[1];
+                const mapUrl = roomUrl.protocol + "//" + match[2];
 
                 res.json({
                     mapUrl,
@@ -128,6 +133,7 @@ export class MapController extends BaseHttpController {
                     tags: [],
                     contactPage: null,
                     authenticationMandatory: DISABLE_ANONYMOUS,
+                    instance,
                 } as MapDetailsData);
 
                 return;