started with Multi-Tenant OpenID.

TODO:
working code but needs some refactoring and cleaning up.

client/src/components/Auth/MultiTenantOpenID.tsx

@@ -0,0 +1,104 @@
+import React from 'react';
+import { useForm } from 'react-hook-form';
+import { OpenIDIcon } from '~/components';
+
+interface MultiTenantOpenIDProps {
+    serverDomain: string;
+    openidLabel: string;
+    openidImageUrl: string;
+    localize: (key: string) => string;
+}
+
+/**
+ * When multi‑tenant mode is enabled (startupConfig.emailLoginEnabled === true),
+ * we render a form for the user to enter their email. When submitted, we perform a GET
+ * request (via redirect) to /oauth/openid with the email as a query parameter.
+ * If, for some reason, no email is provided, we simply redirect to /oauth/openid.
+ */
+function MultiTenantOpenID({
+  serverDomain,
+  openidLabel,
+  openidImageUrl,
+  localize,
+}: MultiTenantOpenIDProps) {
+  const {
+    register,
+    handleSubmit,
+    formState: { errors },
+  } = useForm<{ email: string }>();
+
+  const onSubmit = (data: { email: string }) => {
+    // If an email is provided, include it as a query parameter.
+    // Otherwise, simply redirect without an email.
+    const emailQuery =
+            data.email && data.email.trim() !== ''
+              ? `?email=${encodeURIComponent(data.email)}`
+              : '';
+    window.location.href = `${serverDomain}/oauth/openid${emailQuery}`;
+  };
+
+  const renderError = (fieldName: string) => {
+    const errorMessage = errors[fieldName]?.message;
+    return errorMessage ? (
+      <span role="alert" className="mt-1 text-sm text-red-500 dark:text-red-900">
+        {String(errorMessage)}
+      </span>
+    ) : null;
+  };
+
+  return (
+    <form onSubmit={handleSubmit(onSubmit)} className="mt-2">
+      <div className="mb-4">
+        <div className="relative">
+          <input
+            type="email"
+            id="email"
+            autoComplete="email"
+            aria-label={localize('com_auth_email')}
+            {...register('email', {
+              required: localize('com_auth_email_required'),
+              maxLength: { value: 120, message: localize('com_auth_email_max_length') },
+              pattern: {
+                value: /\S+@\S+\.\S+/,
+                message: localize('com_auth_email_pattern'),
+              },
+            })}
+            aria-invalid={!!errors.email}
+            className="
+              webkit-dark-styles transition-color peer w-full rounded-2xl border border-border-light
+              bg-surface-primary px-3.5 pb-2.5 pt-3 text-text-primary duration-200 focus:border-green-500 focus:outline-none
+            "
+            placeholder=" "
+          />
+          <label
+            htmlFor="email"
+            className="
+              absolute start-3 top-1.5 z-10 origin-[0] -translate-y-4 scale-75 transform bg-surface-primary px-2 text-sm text-text-secondary-alt duration-200
+              peer-placeholder-shown:top-1/2 peer-placeholder-shown:-translate-y-1/2 peer-placeholder-shown:scale-100
+              peer-focus:top-1.5 peer-focus:-translate-y-4 peer-focus:scale-75 peer-focus:px-2 peer-focus:text-green-600 dark:peer-focus:text-green-500
+              rtl:peer-focus:left-auto rtl:peer-focus:translate-x-1/4
+            "
+          >
+            {localize('com_auth_email_address')}
+          </label>
+        </div>
+        {renderError('email')}
+      </div>
+
+      <button
+        type="submit"
+        className="flex w-full items-center space-x-3 rounded-2xl border border-border-light bg-surface-primary px-5 py-3 text-text-primary transition-colors duration-200 hover:bg-surface-tertiary"
+        data-testid="openid"
+      >
+        {openidImageUrl ? (
+          <img src={openidImageUrl} alt="OpenID Logo" className="h-5 w-5" />
+        ) : (
+          <OpenIDIcon />
+        )}
+        <p>{openidLabel}</p>
+      </button>
+    </form>
+  );
+}
+
+export default MultiTenantOpenID;

client/src/components/Auth/SocialLoginRender.tsx

@@ -1,10 +1,16 @@
-import { GoogleIcon, FacebookIcon, OpenIDIcon, GithubIcon, DiscordIcon, AppleIcon } from '~/components';
-
+import React from 'react';
+import {
+  GoogleIcon,
+  FacebookIcon,
+  OpenIDIcon,
+  GithubIcon,
+  DiscordIcon,
+  AppleIcon,
+} from '~/components';
 import SocialButton from './SocialButton';
-
 import { useLocalize } from '~/hooks';
-
 import { TStartupConfig } from 'librechat-data-provider';
+import MultiTenantOpenID from './MultiTenantOpenID';
 
 function SocialLoginRender({
   startupConfig,
@@ -73,23 +79,37 @@ function SocialLoginRender({
         id="apple"
       />
     ),
-    openid: startupConfig.openidLoginEnabled && (
-      <SocialButton
-        key="openid"
-        enabled={startupConfig.openidLoginEnabled}
-        serverDomain={startupConfig.serverDomain}
-        oauthPath="openid"
-        Icon={() =>
-          startupConfig.openidImageUrl ? (
-            <img src={startupConfig.openidImageUrl} alt="OpenID Logo" className="h-5 w-5" />
-          ) : (
-            <OpenIDIcon />
-          )
-        }
-        label={startupConfig.openidLabel}
-        id="openid"
-      />
-    ),
+    openid:
+        startupConfig.openidLoginEnabled &&
+        (startupConfig.openidMultiTenantEnabled ? (
+          <MultiTenantOpenID
+            key="openid"
+            openidImageUrl={startupConfig.openidImageUrl}
+            serverDomain={startupConfig.serverDomain}
+            openidLabel={startupConfig.openidLabel}
+            localize={localize}
+          />
+        ) : (
+          <SocialButton
+            key="openid"
+            enabled={startupConfig.openidLoginEnabled}
+            serverDomain={startupConfig.serverDomain}
+            oauthPath="openid"
+            Icon={() =>
+              startupConfig.openidImageUrl ? (
+                <img
+                  src={startupConfig.openidImageUrl}
+                  alt="OpenID Logo"
+                  className="h-5 w-5"
+                />
+              ) : (
+                <OpenIDIcon />
+              )
+            }
+            label={startupConfig.openidLabel}
+            id="openid"
+          />
+        )),
   };
 
   return (