diff --git a/galaxy.js b/galaxy.js
index 0039300..3aac816 100644
--- a/galaxy.js
+++ b/galaxy.js
@@ -124,8 +124,9 @@ export function initGalaxy({
     onLoggedInChanged
 }) {
     return new Promise((accept, reject) => {
-        acceptedOrigins = acceptedOrigins ?? ["https://galaxy.click"];
-        if (acceptedOrigins.includes(document.referrer)) {
+        acceptedOrigins = acceptedOrigins?.map(url =>
+            url.replace(/\/?$/, '/')) ?? ["https://galaxy.click/"];
+        if (acceptedOrigins.includes(document.referrer.replace(/\/?$/, '/'))) {
             // Callbacks to resolve promises
             /** @type function(SaveListResponse["list"]):void */
             let saveListAccept,
@@ -143,7 +144,7 @@ export function initGalaxy({
                 supportsSaveManager,
                 ignoreApiVersion,
                 onLoggedInChanged,
-                origin: window.origin,
+                origin: document.referrer.replace(/\/?$/, "/"),
                 apiVersion: 0,
                 loggedIn: false,
                 postMessage: function (message) {
@@ -163,7 +164,7 @@ export function initGalaxy({
                     if (slot in saveCallbacks) {
                         return Promise.reject(`save action for slot ${slot} already in progress.`);
                     }
-                    galaxy.postMessage({ action: "save", slot, content, label });
+                    galaxy.postMessage({ action: "save", slot, data: content, label });
                     return new Promise((accept, reject) => {
                         saveCallbacks[slot] = { accept, reject };
                     });
@@ -180,7 +181,7 @@ export function initGalaxy({
             };
 
             window.addEventListener("message", e => {
-                if (e.origin === galaxy.origin) {
+                if (e.origin.replace(/\/?$/, '/') === galaxy.origin.replace(/\/?$/, '/')) {
                     console.log("Received message from Galaxy", e.data);
                     /** @type GalaxyResponse */
                     const data = e.data;