diff --git a/packages/api/src/auth/callbacks/createRedirectCallback.js b/packages/api/src/auth/callbacks/createRedirectCallback.js
index 59be3e5fd..3750697ca 100644
--- a/packages/api/src/auth/callbacks/createRedirectCallback.js
+++ b/packages/api/src/auth/callbacks/createRedirectCallback.js
@@ -25,20 +25,17 @@ function createRedirectCallback({ authConfig, plugins }) {
 
   if (redirectCallbackPlugins.length === 0) return undefined;
 
+  if (redirectCallbackPlugins.length !== 1) {
+    throw new Error('More than one auth redirect callbacks are configured. Only one is allowed.');
+  }
+  const [plugin] = redirectCallbackPlugins;
+
   async function redirectCallback({ url, baseUrl }) {
-    let callbackUrl;
-
-    // TODO: Is there a point in running all the callbacks if only the last one is used?
-    // Else we can enforce only one.
-    for (const plugin of redirectCallbackPlugins) {
-      callbackUrl = await plugin.fn({
-        properties: plugin.properties ?? {},
-        baseUrl,
-        url,
-      });
-    }
-
-    return callbackUrl;
+    return plugin.fn({
+      properties: plugin.properties ?? {},
+      baseUrl,
+      url,
+    });
   }
   return redirectCallback;
 }
diff --git a/packages/build/src/build/buildAuth/validateAuthConfig.js b/packages/build/src/build/buildAuth/validateAuthConfig.js
index 5aacf3ee9..2cf5a9101 100644
--- a/packages/build/src/build/buildAuth/validateAuthConfig.js
+++ b/packages/build/src/build/buildAuth/validateAuthConfig.js
@@ -39,6 +39,9 @@ async function validateAuthConfig({ components }) {
   if (type.isNone(components.auth.providers)) {
     components.auth.providers = [];
   }
+  if (type.isNone(components.auth.theme)) {
+    components.auth.theme = {};
+  }
 
   const { valid } = validate({
     schema: lowdefySchema.definitions.authConfig,
diff --git a/packages/client/src/auth/createAuthMethods.js b/packages/client/src/auth/createAuthMethods.js
index 9f54f3098..143a9016f 100644
--- a/packages/client/src/auth/createAuthMethods.js
+++ b/packages/client/src/auth/createAuthMethods.js
@@ -37,7 +37,7 @@ function getCallbackUrl({ lowdefy, callbackUrl = {} }) {
 function createAuthMethods(lowdefy, auth) {
   // login and logout are Lowdefy function that handle action params
   // signIn and signOut are the next-auth methods
-  function login({ providerId, callbackUrl, authUrl = {} }) {
+  function login({ providerId, callbackUrl, authUrl = {} } = {}) {
     // TODO: if only one provider exists, pass provider here
     // to link directly to provider
     auth.signIn(
diff --git a/packages/server-dev/manager/watchers/nextBuildWatcher.mjs b/packages/server-dev/manager/watchers/nextBuildWatcher.mjs
index ff5aee299..7b768282b 100644
--- a/packages/server-dev/manager/watchers/nextBuildWatcher.mjs
+++ b/packages/server-dev/manager/watchers/nextBuildWatcher.mjs
@@ -23,6 +23,7 @@ import setupWatcher from '../utils/setupWatcher.mjs';
 const hashes = {};
 
 const watchedFiles = [
+  'build/auth.json',
   'build/config.json',
   'build/plugins/actions.js',
   'build/plugins/blocks.js',
@@ -86,6 +87,7 @@ async function nextBuildWatcher(context) {
     watchDotfiles: true,
     watchPaths: [
       path.join(context.directories.build, 'plugins'),
+      path.join(context.directories.build, 'auth.json'),
       path.join(context.directories.build, 'config.json'),
       path.join(context.directories.server, 'package.json'),
     ],