diff --git a/package-lock.json b/package-lock.json
index ae1968b..92fd6bc 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "colyseus.js",
-  "version": "0.15.19",
+  "version": "0.15.24",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "colyseus.js",
-      "version": "0.15.19",
+      "version": "0.15.24",
       "license": "MIT",
       "dependencies": {
         "@colyseus/schema": "^2.0.4",
diff --git a/package.json b/package.json
index a100aa4..4b6283b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "colyseus.js",
-  "version": "0.15.24",
+  "version": "0.15.25",
   "description": "Colyseus Multiplayer SDK for JavaScript/TypeScript",
   "author": "Endel Dreyer",
   "license": "MIT",
diff --git a/src/3rd_party/discord.ts b/src/3rd_party/discord.ts
new file mode 100644
index 0000000..320e99b
--- /dev/null
+++ b/src/3rd_party/discord.ts
@@ -0,0 +1,24 @@
+/**
+ * Discord Embedded App SDK
+ * https://github.com/colyseus/colyseus/issues/707
+ *
+ * All URLs must go through the local proxy from
+ * https://<app_id>.discordsays.com/<backend>/...
+ *
+ * You must configure your URL Mappings with:
+ * - /colyseus/{subdomain} -> {subdomain}.colyseus.cloud
+ *
+ * Example:
+ *  const client = new Client("https://xxxx.colyseus.cloud");
+ *
+ */
+ export function discordURLBuilder (url: URL): string {
+    const localHostname = window?.location?.hostname || "localhost";
+
+    const remoteHostnameSplitted = url.hostname.split('.');
+    const subdomain = (remoteHostnameSplitted.length > 2)
+        ? `/${remoteHostnameSplitted[0]}`
+        : '';
+
+    return `${url.protocol}//${localHostname}/colyseus${subdomain}${url.pathname}${url.search}`;
+ }
\ No newline at end of file
diff --git a/src/Client.ts b/src/Client.ts
index e280d3e..e4e8668 100644
--- a/src/Client.ts
+++ b/src/Client.ts
@@ -3,6 +3,7 @@ import { Room, RoomAvailable } from './Room';
 import { SchemaConstructor } from './serializer/SchemaSerializer';
 import { HTTP } from "./HTTP";
 import { Auth } from './Auth';
+import { discordURLBuilder } from './3rd_party/discord';
 
 export type JoinOptions = any;
 
@@ -33,8 +34,12 @@ export class Client {
     public auth: Auth;
 
     protected settings: EndpointSettings;
+    protected urlBuilder: (url: URL) => string;
 
-    constructor(settings: string | EndpointSettings = DEFAULT_ENDPOINT) {
+    constructor(
+        settings: string | EndpointSettings = DEFAULT_ENDPOINT,
+        customURLBuilder?: (url: URL) => string
+    ) {
         if (typeof (settings) === "string") {
 
             //
@@ -74,6 +79,20 @@ export class Client {
 
         this.http = new HTTP(this);
         this.auth = new Auth(this.http);
+
+        this.urlBuilder = customURLBuilder;
+
+        //
+        // Discord Embedded SDK requires a custom URL builder
+        //
+        if (
+            !this.urlBuilder &&
+            typeof (window) !== "undefined" &&
+            window?.location?.hostname?.includes("discordsays.com")
+        ) {
+            this.urlBuilder = discordURLBuilder;
+            console.log("Colyseus SDK: Discord Embedded SDK detected. Using custom URL builder.");
+        }
     }
 
     public async joinOrCreate<T>(roomName: string, options: JoinOptions = {}, rootSchema?: SchemaConstructor<T>) {
@@ -231,12 +250,18 @@ export class Client {
             endpoint += `${this.settings.hostname}${this.getEndpointPort()}${this.settings.pathname}`;
         }
 
-        return `${endpoint}/${room.processId}/${room.roomId}?${params.join('&')}`;
+        const endpointURL = `${endpoint}/${room.processId}/${room.roomId}?${params.join('&')}`;
+        return (this.urlBuilder)
+            ? this.urlBuilder(new URL(endpointURL))
+            : endpointURL;
     }
 
     protected getHttpEndpoint(segments: string = '') {
         const path = segments.startsWith("/") ? segments : `/${segments}`;
-        return `${(this.settings.secure) ? "https" : "http"}://${this.settings.hostname}${this.getEndpointPort()}${this.settings.pathname}${path}`;
+        const endpointURL = `${(this.settings.secure) ? "https" : "http"}://${this.settings.hostname}${this.getEndpointPort()}${this.settings.pathname}${path}`;
+        return (this.urlBuilder)
+            ? this.urlBuilder(new URL(endpointURL))
+            : endpointURL;
     }
 
     protected getEndpointPort() {
diff --git a/test/client_test.ts b/test/client_test.ts
index df003b7..1f4122b 100644
--- a/test/client_test.ts
+++ b/test/client_test.ts
@@ -2,6 +2,7 @@ import './util';
 import { assert } from "chai";
 import { Client } from "../src";
 import { Schema, type } from '@colyseus/schema';
+import { discordURLBuilder } from '../src/3rd_party/discord';
 
 describe("Client", function () {
     let client: Client;
@@ -68,6 +69,42 @@ describe("Client", function () {
                 assert.strictEqual(expected.wsEndpointPublicAddress, clientWithSettings['buildEndpoint'](roomWithPublicAddress));
             }
         });
+
+        it("discord url builder", () => {
+            const room = { roomId: "roomId", processId: "processId", sessionId: "sessionId", };
+            const roomWithPublicAddress = { publicAddress: "node-1.colyseus.cloud", roomId: "roomId", processId: "processId", sessionId: "sessionId", };
+
+            const settingsByUrl = {
+                'ws://example.com': {
+                    httpEndpoint: "http://localhost/colyseus/",
+                    wsEndpoint: "ws://localhost/colyseus/processId/roomId",
+                    wsEndpointPublicAddress: "ws://localhost/colyseus/node-1/processId/roomId"
+                },
+                'ws://subdomain.colyseus.cloud': {
+                    httpEndpoint: "http://localhost/colyseus/subdomain/",
+                    wsEndpoint: "ws://localhost/colyseus/subdomain/processId/roomId",
+                    wsEndpointPublicAddress: "ws://localhost/colyseus/node-1/processId/roomId"
+                },
+                'https://subdomain.colyseus.cloud/custom/path': {
+                    httpEndpoint: "https://localhost/colyseus/subdomain/custom/path/",
+                    wsEndpoint: "wss://localhost/colyseus/subdomain/custom/path/processId/roomId",
+                    wsEndpointPublicAddress: "wss://localhost/colyseus/node-1/processId/roomId"
+                },
+                // '/api': {
+                //     httpEndpoint: "http://127.0.0.1:2567/api/",
+                //     wsEndpoint: "ws://127.0.0.1:2567/api/processId/roomId",
+                //     wsEndpointPublicAddress: "ws://node-1.colyseus.cloud/processId/roomId"
+                // },
+            };
+
+            for (const url in settingsByUrl) {
+                const expected = settingsByUrl[url];
+                const client = new Client(url, discordURLBuilder);
+                assert.strictEqual(expected.httpEndpoint, client['getHttpEndpoint']());
+                assert.strictEqual(expected.wsEndpoint, client['buildEndpoint'](room));
+                assert.strictEqual(expected.wsEndpointPublicAddress, client['buildEndpoint'](roomWithPublicAddress));
+            }
+        });
     });
 
     xit("join", function () {