diff --git a/src/actions/actions.spec.ts b/src/actions/actions.spec.ts
index 25af43269..128fcaae0 100644
--- a/src/actions/actions.spec.ts
+++ b/src/actions/actions.spec.ts
@@ -131,6 +131,7 @@ describe('Actions', () => {
           externalId: null,
           metadata: {},
         },
+        authenticationMethod: 'Password',
         ipAddress: '50.141.123.10',
         userAgent: 'Mozilla/5.0',
         deviceFingerprint: 'notafingerprint',
@@ -183,6 +184,7 @@ describe('Actions', () => {
           firstName: 'Jane',
           lastName: 'Doe',
         },
+        authenticationMethod: 'GoogleOAuth',
         ipAddress: '50.141.123.10',
         userAgent: 'Mozilla/5.0',
         deviceFingerprint: 'notafingerprint',
@@ -197,5 +199,19 @@ describe('Actions', () => {
         }),
       });
     });
+
+    it('leaves the authentication method undefined when the payload omits it', async () => {
+      const { authentication_method: _omitted, ...payload } =
+        mockAuthActionContext;
+      const sigHeader = makeSigHeader(payload, secret);
+      const action = await workos.actions.constructAction({
+        payload,
+        sigHeader,
+        secret,
+      });
+
+      expect(action.authenticationMethod).toBeUndefined();
+      expect(action.object).toEqual('authentication_action_context');
+    });
   });
 });
diff --git a/src/actions/fixtures/authentication-action-context.json b/src/actions/fixtures/authentication-action-context.json
index 3dd48e7de..addea1928 100644
--- a/src/actions/fixtures/authentication-action-context.json
+++ b/src/actions/fixtures/authentication-action-context.json
@@ -12,6 +12,7 @@
         "created_at": "2024-10-22T17:12:50.746Z",
         "updated_at": "2024-10-22T17:12:50.746Z"
     },
+    "authentication_method": "Password",
     "ip_address": "50.141.123.10",
     "user_agent": "Mozilla/5.0",
     "device_fingerprint": "notafingerprint",
diff --git a/src/actions/fixtures/user-registration-action-context.json b/src/actions/fixtures/user-registration-action-context.json
index bfd422a17..3fd36a96a 100644
--- a/src/actions/fixtures/user-registration-action-context.json
+++ b/src/actions/fixtures/user-registration-action-context.json
@@ -7,6 +7,7 @@
         "first_name": "Jane",
         "last_name": "Doe"
     },
+    "authentication_method": "GoogleOAuth",
     "ip_address": "50.141.123.10",
     "user_agent": "Mozilla/5.0",
     "device_fingerprint": "notafingerprint",
diff --git a/src/actions/interfaces/action.interface.ts b/src/actions/interfaces/action.interface.ts
index bf1df04c0..c25edc74a 100644
--- a/src/actions/interfaces/action.interface.ts
+++ b/src/actions/interfaces/action.interface.ts
@@ -3,6 +3,7 @@ import {
   OrganizationResponse,
 } from '../../organizations/interfaces';
 import {
+  AuthenticationMethod,
   Invitation,
   InvitationResponse,
   OrganizationMembership,
@@ -17,6 +18,7 @@ interface AuthenticationActionContext {
   user: User;
   organization?: Organization;
   organizationMembership?: OrganizationMembership;
+  authenticationMethod?: AuthenticationMethod;
   ipAddress?: string;
   userAgent?: string;
   deviceFingerprint?: string;
@@ -36,6 +38,7 @@ interface UserRegistrationActionContext {
   object: 'user_registration_action_context';
   userData: UserData;
   invitation?: Invitation;
+  authenticationMethod?: AuthenticationMethod;
   ipAddress?: string;
   userAgent?: string;
   deviceFingerprint?: string;
@@ -50,6 +53,7 @@ interface AuthenticationActionPayload {
   user: UserResponse;
   organization?: OrganizationResponse;
   organization_membership?: OrganizationMembershipResponse;
+  authentication_method?: AuthenticationMethod;
   ip_address?: string;
   user_agent?: string;
   device_fingerprint?: string;
@@ -69,6 +73,7 @@ export interface UserRegistrationActionPayload {
   object: 'user_registration_action_context';
   user_data: UserDataPayload;
   invitation?: InvitationResponse;
+  authentication_method?: AuthenticationMethod;
   ip_address?: string;
   user_agent?: string;
   device_fingerprint?: string;
diff --git a/src/actions/serializers/action.serializer.ts b/src/actions/serializers/action.serializer.ts
index 1080249bc..ea62ccdf8 100644
--- a/src/actions/serializers/action.serializer.ts
+++ b/src/actions/serializers/action.serializer.ts
@@ -33,7 +33,7 @@ export const deserializeAction = (
         invitation: actionPayload.invitation
           ? deserializeInvitation(actionPayload.invitation)
           : undefined,
-
+        authenticationMethod: actionPayload.authentication_method,
         ipAddress: actionPayload.ip_address,
         userAgent: actionPayload.user_agent,
         deviceFingerprint: actionPayload.device_fingerprint,
@@ -51,6 +51,7 @@ export const deserializeAction = (
               actionPayload.organization_membership,
             )
           : undefined,
+        authenticationMethod: actionPayload.authentication_method,
         ipAddress: actionPayload.ip_address,
         userAgent: actionPayload.user_agent,
         deviceFingerprint: actionPayload.device_fingerprint,
diff --git a/src/user-management/interfaces/authentication-response.interface.ts b/src/user-management/interfaces/authentication-response.interface.ts
index 3fe4d329c..ebdd63687 100644
--- a/src/user-management/interfaces/authentication-response.interface.ts
+++ b/src/user-management/interfaces/authentication-response.interface.ts
@@ -2,7 +2,7 @@ import { Impersonator, ImpersonatorResponse } from './impersonator.interface';
 import { OauthTokens, OauthTokensResponse } from './oauth-tokens.interface';
 import { User, UserResponse } from './user.interface';
 
-type AuthenticationMethod =
+export type AuthenticationMethod =
   | 'SSO'
   | 'Password'
   | 'Passkey'
@@ -12,6 +12,8 @@ type AuthenticationMethod =
   | 'GitHubOAuth'
   | 'GitLabOAuth'
   | 'GoogleOAuth'
+  | 'GrokOAuth'
+  | 'XOAuth'
   | 'IntuitOAuth'
   | 'LinkedInOAuth'
   | 'MicrosoftOAuth'