diff --git a/static/confirm_instance_details.mts b/static/confirm_instance_details.mts
index 889f891..4a4c808 100644
--- a/static/confirm_instance_details.mts
+++ b/static/confirm_instance_details.mts
@@ -1,10 +1,20 @@
 // This file handles the "Confirm instance details" dialog
 
+import { resize } from "./image.mjs";
 import knownSoftware from "./known_software.mjs";
 
 const blankImage = "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";
 
-export function initializeInstanceDetailsDialog(dialog: HTMLDialogElement): {
+export function initializeInstanceDetailsDialog(
+    dialog: HTMLDialogElement,
+    callback: (
+        instanceName: string,
+        instanceHost: string,
+        instanceHostSecure: boolean,
+        instanceSoftware: string,
+        instanceIcon: string | null
+    ) => void
+): {
     showInstanceDetailsDialog: () => void,
     hideInstanceDetailsDialog: () => void,
     populateInstanceDetailsDialog: (
@@ -13,7 +23,7 @@ export function initializeInstanceDetailsDialog(dialog: HTMLDialogElement): {
         instanceHostSecureValue: boolean,
         instanceSoftwareValue: string,
         instanceIconValue: string | null
-    ) => void,
+    ) => void
 } {
     const showInstanceDetailsDialog = () => dialog.showModal();
     const hideInstanceDetailsDialog = () => dialog.close();
@@ -61,10 +71,16 @@ export function initializeInstanceDetailsDialog(dialog: HTMLDialogElement): {
         instanceHostSecure.checked = instanceHostSecureValue;
         instanceSoftware.value = instanceSoftwareValue;
         instanceIcon.src = instanceIconValue ?? blankImage;
-
     };
 
     form.addEventListener("submit", e => {
+        callback(
+            instanceName.value,
+            instanceHost.value,
+            instanceHostSecure.checked,
+            instanceSoftware.value,
+            instanceIcon.src == blankImage ? null : resize(instanceIcon)
+        );
         form.reset();
     });
 
diff --git a/static/crossroad.mts b/static/crossroad.mts
index 7f3dffb..03e5a8c 100644
--- a/static/crossroad.mts
+++ b/static/crossroad.mts
@@ -10,6 +10,21 @@ export function getMainDialog(): HTMLDialogElement {
     return document.getElementById('mainDialog') as HTMLDialogElement;
 }
 
+const instanceDetailsDialogCallback = (
+    name: string,
+    host: string,
+    hostSecure: boolean,
+    software: string,
+    icon: string | null
+) => {
+    storageManager.storage.instances.push({
+        name,
+        origin: `http${hostSecure ? "s" : ""}://${host}`,
+        software,
+        iconURL: icon ?? undefined
+    });
+};
+
 const detailsDialog = document.querySelector("#instanceDetails");
 if (!(detailsDialog instanceof HTMLDialogElement))
     throw new Error("Couldn't find instanceDetails dialog");
@@ -17,7 +32,7 @@ export const {
     showInstanceDetailsDialog,
     hideInstanceDetailsDialog,
     populateInstanceDetailsDialog
-} = initializeInstanceDetailsDialog(detailsDialog);
+} = initializeInstanceDetailsDialog(detailsDialog, instanceDetailsDialogCallback);
 
 const addInstanceDialogCallback = async (
     host: string,
@@ -36,8 +51,9 @@ const addInstanceDialogCallback = async (
         )
             throw new Error("Invalid API response");
         populateInstanceDetailsDialog(name, host, secure, software, iconURL as string | null);
-    } finally {
+    } catch {
         populateInstanceDetailsDialog("", host, secure, "", null);
+    } finally {
         showInstanceDetailsDialog();
     }
 }