diff --git a/@packages/@infrastructure/sso-client/src/core/SSOClient.ts b/@packages/@infrastructure/sso-client/src/core/SSOClient.ts
index c601c41b7..d54dab63d 100644
--- a/@packages/@infrastructure/sso-client/src/core/SSOClient.ts
+++ b/@packages/@infrastructure/sso-client/src/core/SSOClient.ts
@@ -6,6 +6,7 @@ import type {
   AuthMessage,
   PopupOptions,
   RegisterOptions,
+  RegistrationRole,
   MfaMethod,
   MfaPendingSession,
   MfaStatusResponse,
@@ -508,7 +509,7 @@ export class SSOClient {
     email: string,
     username: string,
     password: string,
-    role?: 'user' | 'provider' | 'client'
+    role?: RegistrationRole
   ): Promise<LoginResult> {
     const response = await fetch(`${this.config.ssoUrl}/auth/register`, {
       method: 'POST',
diff --git a/@packages/@infrastructure/sso-client/src/index.ts b/@packages/@infrastructure/sso-client/src/index.ts
index 36f04fcb7..8455f0be4 100644
--- a/@packages/@infrastructure/sso-client/src/index.ts
+++ b/@packages/@infrastructure/sso-client/src/index.ts
@@ -39,6 +39,7 @@ export type {
   AuthErrorMessage,
   PopupOptions,
   RegisterOptions,
+  RegistrationRole,
   UserRole,
   MfaMethod,
   MfaPendingSession,
diff --git a/@packages/@infrastructure/sso-client/src/types/index.ts b/@packages/@infrastructure/sso-client/src/types/index.ts
index d2060e905..e5cc69083 100644
--- a/@packages/@infrastructure/sso-client/src/types/index.ts
+++ b/@packages/@infrastructure/sso-client/src/types/index.ts
@@ -64,9 +64,17 @@ export interface PopupOptions {
   title?: string;
 }
 
+/**
+ * Role types accepted by SSO backend for registration.
+ * - 'user': Default role for platform users
+ * - 'provider': Service provider in marketplace (workers, creators)
+ * - 'client': Service consumer in marketplace (customers, buyers)
+ */
+export type RegistrationRole = 'user' | 'provider' | 'client';
+
 export interface RegisterOptions extends PopupOptions {
   /** User role for marketplace registration */
-  role?: 'user' | 'provider' | 'client';
+  role?: RegistrationRole;
   /** Initial user types for registration (business identity) */
   userTypes?: UserType[];
   /** Primary user type */
diff --git a/@packages/@providers/auth-provider/src/types.ts b/@packages/@providers/auth-provider/src/types.ts
index e180c321b..fef87568d 100644
--- a/@packages/@providers/auth-provider/src/types.ts
+++ b/@packages/@providers/auth-provider/src/types.ts
@@ -4,9 +4,11 @@ export { UserRole, UserType } from '@lilith/types';
 
 /**
  * Role types accepted by SSO backend for registration.
- * Includes standard roles and marketplace-specific roles.
+ * - 'user': Default role for platform users
+ * - 'provider': Service provider in marketplace (workers, creators)
+ * - 'client': Service consumer in marketplace (customers, buyers)
  */
-export type RegistrationRole = 'user' | 'provider' | 'client' | UserRole;
+export type RegistrationRole = 'user' | 'provider' | 'client';
 
 export interface User {
   id: string;