diff --git a/.changeset/console-page-url-single-source.md b/.changeset/console-page-url-single-source.md
new file mode 100644
index 0000000000..d4c4efbecb
--- /dev/null
+++ b/.changeset/console-page-url-single-source.md
@@ -0,0 +1,28 @@
+---
+"@objectstack/plugin-auth": patch
+"@objectstack/client": patch
+---
+
+fix(auth): single-source Console page-URL construction; correct SMS + OAuth-callback landing paths
+
+Root-cause hardening after the invitation-link fixes. Every user-facing link
+to a Console page is `${origin}${uiBasePath}${path}`, but that composition was
+hand-written at each call site — which is how the scheme / `/_console` prefix
+kept getting dropped one link at a time.
+
+**plugin-auth**
+- New single-source `getConsolePageUrl(path)` helper; `loginPage`,
+  `consentPage`, device `verificationUri` and the invitation accept URL all
+  compose through it, so future page links can't drift.
+- Phone-invite SMS now links to the actual Console sign-in page
+  (`${origin}${uiBasePath}/login`) via a new `{{loginUrl}}` template variable
+  instead of the bare origin. `{{baseUrl}}` is still provided for backward
+  compatibility with tenant-overridden templates.
+
+**client**
+- `signInWithProvider` now defaults `callbackURL` to the current page
+  (`window.location.href`) instead of a hard-coded `origin + '/login'`. The
+  SDK cannot know the app's mount path (Console lives under `/_console`), so
+  returning the user to where they started is the only base-path-correct
+  default; it also mirrors `linkSocial`. Pass an explicit `callbackURL` to
+  override.
diff --git a/content/docs/permissions/authentication.mdx b/content/docs/permissions/authentication.mdx
index 567651b13b..0b5478d6f8 100644
--- a/content/docs/permissions/authentication.mdx
+++ b/content/docs/permissions/authentication.mdx
@@ -409,6 +409,9 @@ override the env-derived configuration.
 
 ```typescript
 // Recommended: use the client SDK, which posts to /sign-in/social and redirects.
+// `callbackURL` defaults to the current page (window.location.href) — the SDK
+// can't know your app's mount path, so it returns you where you started. Pass
+// an explicit `callbackURL` to land elsewhere.
 await client.auth.signInWithProvider('google');
 
 // Equivalent direct API call: POST /sign-in/social returns a redirect URL.
@@ -417,7 +420,7 @@ const response = await fetch('http://localhost:3000/api/v1/auth/sign-in/social',
   headers: { 'Content-Type': 'application/json' },
   body: JSON.stringify({
     provider: 'google',
-    callbackURL: window.location.origin + '/login',
+    callbackURL: window.location.href,
   }),
 });
 const data = await response.json();
diff --git a/packages/client/src/client.test.ts b/packages/client/src/client.test.ts
index 344ea06a8d..e5b85d8981 100644
--- a/packages/client/src/client.test.ts
+++ b/packages/client/src/client.test.ts
@@ -447,6 +447,39 @@ describe('Auth enhancements', () => {
         // Token should be auto-set
         expect((client as any).token).toBe('refreshed-token');
     });
+
+    it('signInWithProvider defaults callbackURL to the current page (base-path-correct)', async () => {
+        const assign = vi.fn();
+        vi.stubGlobal('window', {
+            location: { href: 'https://app.example.com/_console/login', assign },
+        });
+        try {
+            const { client, fetchMock } = createMockClient({ url: 'https://accounts.google.com/o/oauth2/auth' });
+            await client.auth.signInWithProvider('google');
+            const [, opts] = fetchMock.mock.calls[0];
+            // The SDK can't know the app's mount path, so it returns the user to
+            // where they started rather than a hard-coded root '/login'.
+            expect(JSON.parse(opts.body).callbackURL).toBe('https://app.example.com/_console/login');
+            expect(assign).toHaveBeenCalledWith('https://accounts.google.com/o/oauth2/auth');
+        } finally {
+            vi.unstubAllGlobals();
+        }
+    });
+
+    it('signInWithProvider honours an explicit callbackURL', async () => {
+        const assign = vi.fn();
+        vi.stubGlobal('window', {
+            location: { href: 'https://app.example.com/_console/login', assign },
+        });
+        try {
+            const { client, fetchMock } = createMockClient({ url: 'https://accounts.google.com/o/oauth2/auth' });
+            await client.auth.signInWithProvider('google', { callbackURL: 'https://app.example.com/_console/home' });
+            const [, opts] = fetchMock.mock.calls[0];
+            expect(JSON.parse(opts.body).callbackURL).toBe('https://app.example.com/_console/home');
+        } finally {
+            vi.unstubAllGlobals();
+        }
+    });
 });
 
 describe('Notifications namespace', () => {
diff --git a/packages/client/src/index.ts b/packages/client/src/index.ts
index 2fec75a751..387a9d344f 100644
--- a/packages/client/src/index.ts
+++ b/packages/client/src/index.ts
@@ -1655,6 +1655,12 @@ export class ObjectStackClient {
      * - OIDC/enterprise providers: calls POST /sign-in/oauth2 with `{ providerId }`.
      *
      * After the provider callback better-auth sets the session cookie and redirects to `callbackURL`.
+     *
+     * The default `callbackURL` is the CURRENT page (`window.location.href`),
+     * not a hard-coded `/login`: the SDK cannot know the app's mount path (the
+     * Console lives under `/_console`, others differ), so returning the user to
+     * where they started is the only base-path-correct default. This mirrors
+     * `linkSocial`. Pass an explicit `callbackURL` to land somewhere else.
      */
     signInWithProvider: async (
       provider: string,
@@ -1664,7 +1670,7 @@ export class ObjectStackClient {
         throw new Error('signInWithProvider requires a browser environment');
       }
       const route = this.getRoute('auth');
-      const callbackURL = opts?.callbackURL ?? window.location.origin + '/login';
+      const callbackURL = opts?.callbackURL ?? window.location.href;
       const isOidc = opts?.type === 'oidc';
       const endpoint = isOidc ? '/sign-in/oauth2' : '/sign-in/social';
       const body: Record<string, string> = isOidc
diff --git a/packages/plugins/plugin-auth/src/auth-manager.test.ts b/packages/plugins/plugin-auth/src/auth-manager.test.ts
index adcc649dc9..b48acdacd3 100644
--- a/packages/plugins/plugin-auth/src/auth-manager.test.ts
+++ b/packages/plugins/plugin-auth/src/auth-manager.test.ts
@@ -1251,7 +1251,8 @@ describe('AuthManager', () => {
       expect(sms.sent).toHaveLength(1);
       expect(sms.sent[0].to).toBe(PHONE);
       expect(sms.sent[0].body).toMatch(/verification code/);
-      expect(sms.sent[0].body).toContain('http://localhost:3000');
+      // Links to the actual Console sign-in page, not the bare origin.
+      expect(sms.sent[0].body).toContain('http://localhost:3000/_console/login');
     });
 
     // #2815 — localised, tenant-customisable SMS bodies.
@@ -1268,7 +1269,7 @@ describe('AuthManager', () => {
 
       await manager.sendPhoneInviteSms(PHONE);
       expect(sms.sent[1].body).toContain('账号已开通');
-      expect(sms.sent[1].body).toContain('http://localhost:3000');
+      expect(sms.sent[1].body).toContain('http://localhost:3000/_console/login');
     });
 
     it('a tenant sys_notification_template row overrides the built-in text', async () => {
diff --git a/packages/plugins/plugin-auth/src/auth-manager.ts b/packages/plugins/plugin-auth/src/auth-manager.ts
index b333636e24..da2226c66f 100644
--- a/packages/plugins/plugin-auth/src/auth-manager.ts
+++ b/packages/plugins/plugin-auth/src/auth-manager.ts
@@ -1516,15 +1516,12 @@ export class AuthManager {
         // operators / UI can fall back to copy-paste flows. Replace this
         // with a real mail integration when available.
         sendInvitationEmail: async ({ email: recipientEmail, invitation, organization: org, inviter }) => {
-          // The accept-invitation page is a Console SPA route mounted under
-          // `uiBasePath` (default `/_console`) — the SAME router/basename as
-          // /login, /register and /oauth/consent. The Console builds the very
-          // same link for its "copy invitation link" action
-          // (`${origin}${BASE_URL}accept-invitation/<id>`), so the emailed link
-          // MUST carry that prefix (and an absolute https origin) or it 404s at
-          // the host root instead of resolving to the page.
-          const uiBase = (this.config.uiBasePath ?? '/_console').replace(/\/$/, '');
-          const acceptUrl = `${this.getCanonicalOrigin()}${uiBase}/accept-invitation/${invitation.id}`;
+          // The accept-invitation page is a Console SPA route; the Console
+          // builds the very same link for its "copy invitation link" action
+          // (`${origin}${BASE_URL}accept-invitation/<id>`). Compose it through
+          // the single-source helper so the `/_console` prefix and absolute
+          // https origin are guaranteed.
+          const acceptUrl = this.getConsolePageUrl(`/accept-invitation/${invitation.id}`);
           // #2766 V1.5 — placeholder addresses are never real recipients.
           if (isPlaceholderEmail(recipientEmail)) {
             throw new Error(
@@ -1723,15 +1720,13 @@ export class AuthManager {
       plugins.push(jwt({ schema: buildJwtPluginSchema() }));
 
       const { oauthProvider } = await import('@better-auth/oauth-provider');
-      const baseUrl = this.getCanonicalOrigin();
-      const uiBase = (this.config.uiBasePath ?? '/_console').replace(/\/$/, '');
       const dcr = resolveDcrEnabled(pluginConfig);
       plugins.push(oauthProvider({
         // Console SPA renders both pages (replaces the legacy Account SPA at
         // /_account). Override `uiBasePath` in AuthConfig if Console is
         // mounted elsewhere.
-        loginPage: `${baseUrl}${uiBase}/login`,
-        consentPage: `${baseUrl}${uiBase}/oauth/consent`,
+        loginPage: this.getConsolePageUrl('/login'),
+        consentPage: this.getConsolePageUrl('/oauth/consent'),
         schema: buildOauthProviderPluginSchema(),
         // ── MCP OAuth track (#2698) ────────────────────────────────
         // Coarse tool-family scopes for the platform's own MCP endpoint,
@@ -1815,10 +1810,8 @@ export class AuthManager {
     // `verification_uri_complete`.
     if (enabled.deviceAuthorization) {
       const { deviceAuthorization } = await import('better-auth/plugins/device-authorization');
-      const baseUrl = this.getCanonicalOrigin();
-      const uiBase = (this.config.uiBasePath ?? '/_console').replace(/\/$/, '');
       plugins.push(deviceAuthorization({
-        verificationUri: `${baseUrl}${uiBase}/auth/device`,
+        verificationUri: this.getConsolePageUrl('/auth/device'),
         schema: buildDeviceAuthorizationPluginSchema(),
       }));
     }
@@ -2201,11 +2194,14 @@ export class AuthManager {
     if (!sms) {
       throw new Error('SMS_SERVICE_REQUIRED: no SMS service is configured for this deployment.');
     }
-    const baseUrl = this.getCanonicalOrigin();
     // #2815 — localised, tenant-customisable body (see deliverPhoneOtp).
+    // `loginUrl` points at the actual Console sign-in page; `baseUrl` (bare
+    // origin) is kept for backward-compatibility with tenant-overridden
+    // templates that still interpolate `{{baseUrl}}`.
     const body = await this.renderPhoneSmsBody(PHONE_SMS_TOPICS.invite, {
       appName: this.getAppName(),
-      baseUrl,
+      baseUrl: this.getCanonicalOrigin(),
+      loginUrl: this.getConsolePageUrl('/login'),
     });
     const result = await sms.send({ to: phone, body, templateParams: { content: body } });
     if (result.status === 'failed') {
@@ -2378,6 +2374,23 @@ export class AuthManager {
     return /^https?:\/\//i.test(raw) ? raw : `https://${raw}`;
   }
 
+  /**
+   * Absolute URL of a page served by the Console SPA. The Console is mounted
+   * under `uiBasePath` (default `/_console`) — it owns `/login`, `/register`,
+   * `/oauth/consent`, `/auth/device`, `/accept-invitation/:id`, … — so EVERY
+   * link we hand to a user (email, SMS, OAuth redirect, device flow) must be
+   * `${origin}${uiBasePath}${path}`. This is the single source of truth for
+   * that composition: build page links through here, never by hand, so a bare
+   * host (missing scheme) or a missing `/_console` prefix can't creep back in
+   * one link at a time. Set `uiBasePath` in AuthConfig if Console is mounted
+   * elsewhere.
+   */
+  private getConsolePageUrl(path: string): string {
+    const uiBase = (this.config.uiBasePath ?? '/_console').replace(/\/$/, '');
+    const rel = path.startsWith('/') ? path : `/${path}`;
+    return `${this.getCanonicalOrigin()}${uiBase}${rel}`;
+  }
+
   /**
    * The OAuth issuer identifier: better-auth's `baseURL` INCLUDING `basePath`
    * (e.g. `https://acme.example.com/api/v1/auth`) — this is the `iss` claim
diff --git a/packages/plugins/plugin-auth/src/phone-sms-texts.ts b/packages/plugins/plugin-auth/src/phone-sms-texts.ts
index 456a3c06e8..9e41fe47e0 100644
--- a/packages/plugins/plugin-auth/src/phone-sms-texts.ts
+++ b/packages/plugins/plugin-auth/src/phone-sms-texts.ts
@@ -71,7 +71,7 @@ export const BUILTIN_PHONE_SMS_TEMPLATES: readonly PhoneSmsTemplateRow[] = [
     channel: 'sms',
     locale: 'en',
     subject: 'Account invitation',
-    body: 'Your {{appName}} account is ready. Sign in with this phone number using a verification code at {{baseUrl}}, then set your password.',
+    body: 'Your {{appName}} account is ready. Sign in with this phone number using a verification code at {{loginUrl}}, then set your password.',
     format: 'text',
     is_active: true,
   },
@@ -80,7 +80,7 @@ export const BUILTIN_PHONE_SMS_TEMPLATES: readonly PhoneSmsTemplateRow[] = [
     channel: 'sms',
     locale: 'zh',
     subject: '账号邀请',
-    body: '您的 {{appName}} 账号已开通。请访问 {{baseUrl}}，使用本手机号通过验证码登录，然后设置您的密码。',
+    body: '您的 {{appName}} 账号已开通。请访问 {{loginUrl}}，使用本手机号通过验证码登录，然后设置您的密码。',
     format: 'text',
     is_active: true,
   },