diff --git a/packages/api/src/clients/conversation/activity.spec.ts b/packages/api/src/clients/conversation/activity.spec.ts
index 57f65c3c9..9466f3c30 100644
--- a/packages/api/src/clients/conversation/activity.spec.ts
+++ b/packages/api/src/clients/conversation/activity.spec.ts
@@ -1,5 +1,7 @@
 import { Client } from '@microsoft/teams.common';
 
+import { AGENTIC_IDENTITY_EXTENSION } from '../auth-provider-interceptor';
+
 import { ConversationActivityClient } from './activity';
 
 describe('ConversationActivityClient', () => {
@@ -16,7 +18,7 @@ describe('ConversationActivityClient', () => {
     expect(spy).toHaveBeenCalledWith('/v3/conversations/1/activities', {
       type: 'message',
       text: 'hi',
-    });
+    }, {});
   });
 
   it('should use client options', async () => {
@@ -31,7 +33,7 @@ describe('ConversationActivityClient', () => {
     expect(spy).toHaveBeenCalledWith('/v3/conversations/1/activities', {
       type: 'message',
       text: 'hi',
-    });
+    }, {});
   });
 
   it('should create', async () => {
@@ -46,7 +48,24 @@ describe('ConversationActivityClient', () => {
     expect(spy).toHaveBeenCalledWith('/v3/conversations/1/activities', {
       type: 'message',
       text: 'hi',
+    }, {});
+  });
+
+  it('should pass serviceUrl and agentic identity options', async () => {
+    const client = new ConversationActivityClient('https://default.service');
+    const spy = jest.spyOn(client.http, 'post').mockResolvedValueOnce({});
+    const agenticIdentity = { agenticAppId: 'agent-app', agenticUserId: 'agent-user' };
+
+    await client.create('1', { type: 'message', text: 'hi' }, {
+      serviceUrl: 'https://override.service/',
+      agenticIdentity,
     });
+
+    expect(spy).toHaveBeenCalledWith(
+      'https://override.service/v3/conversations/1/activities',
+      { type: 'message', text: 'hi' },
+      { extensions: { [AGENTIC_IDENTITY_EXTENSION]: agenticIdentity } }
+    );
   });
 
   it('should update', async () => {
@@ -61,7 +80,7 @@ describe('ConversationActivityClient', () => {
     expect(spy).toHaveBeenCalledWith('/v3/conversations/1/activities/2', {
       type: 'message',
       text: 'hi',
-    });
+    }, {});
   });
 
   it('should reply', async () => {
@@ -77,21 +96,21 @@ describe('ConversationActivityClient', () => {
       type: 'message',
       text: 'hi',
       replyToId: '2',
-    });
+    }, {});
   });
 
   it('should delete', async () => {
     const client = new ConversationActivityClient('');
     const spy = jest.spyOn(client.http, 'delete').mockResolvedValueOnce({});
     await client.delete('1', '2');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/activities/2');
+    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/activities/2', {});
   });
 
   it('should get members', async () => {
     const client = new ConversationActivityClient('');
     const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({ data: [] });
     await client.getMembers('1', '2');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/activities/2/members');
+    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/activities/2/members', {});
   });
 
   it('should resolve objectId to aadObjectId in getMembers', async () => {
diff --git a/packages/api/src/clients/conversation/activity.ts b/packages/api/src/clients/conversation/activity.ts
index ec9add26b..387cedcf4 100644
--- a/packages/api/src/clients/conversation/activity.ts
+++ b/packages/api/src/clients/conversation/activity.ts
@@ -6,6 +6,7 @@ import {
 import { Activity } from '../../activities';
 import { resolveAadObjectId, Resource, TeamsChannelAccount } from '../../models';
 import { ApiClientSettings, mergeApiClientSettings } from '../api-client-settings';
+import { agenticIdentityExtension, RequestOptions, resolveServiceUrl } from '../request-options';
 
 export type ActivityParams = Pick<Activity, 'type'> & Partial<Activity>;
 
@@ -35,65 +36,52 @@ export class ConversationActivityClient {
     this._apiClientSettings = mergeApiClientSettings(apiClientSettings);
   }
 
-  async create(conversationId: string, params: ActivityParams) {
-    const res = await this.http.post<Resource>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/activities`,
-      params
-    );
+  async create(conversationId: string, params: ActivityParams, options?: RequestOptions) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/activities`;
+    const res = await this.http.post<Resource>(url, params, agenticIdentityExtension(options));
     return res.data;
   }
 
-  async update(conversationId: string, id: string, params: ActivityParams) {
-    const res = await this.http.put<Resource>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/activities/${id}`,
-      params
-    );
+  async update(conversationId: string, id: string, params: ActivityParams, options?: RequestOptions) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/activities/${id}`;
+    const res = await this.http.put<Resource>(url, params, agenticIdentityExtension(options));
     return res.data;
   }
 
-  async reply(conversationId: string, id: string, params: ActivityParams) {
+  async reply(conversationId: string, id: string, params: ActivityParams, options?: RequestOptions) {
     params.replyToId = id;
-    const res = await this.http.post<Resource>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/activities/${id}`,
-      params
-    );
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/activities/${id}`;
+    const res = await this.http.post<Resource>(url, params, agenticIdentityExtension(options));
     return res.data;
   }
 
-  async delete(conversationId: string, id: string) {
-    const res = await this.http.delete<void>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/activities/${id}`
-    );
+  async delete(conversationId: string, id: string, options?: RequestOptions) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/activities/${id}`;
+    const res = await this.http.delete<void>(url, agenticIdentityExtension(options));
     return res.data;
   }
 
-  async getMembers(conversationId: string, id: string): Promise<TeamsChannelAccount[]> {
-    const res = await this.http.get<TeamsChannelAccount[]>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/activities/${id}/members`
-    );
+  async getMembers(conversationId: string, id: string, options?: RequestOptions): Promise<TeamsChannelAccount[]> {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/activities/${id}/members`;
+    const res = await this.http.get<TeamsChannelAccount[]>(url, agenticIdentityExtension(options));
     return (res.data ?? []).map(resolveAadObjectId);
   }
 
-  async createTargeted(conversationId: string, params: ActivityParams) {
-    const res = await this.http.post<Resource>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/activities?isTargetedActivity=true`,
-      params
-    );
+  async createTargeted(conversationId: string, params: ActivityParams, options?: RequestOptions<'serviceUrl'>) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/activities?isTargetedActivity=true`;
+    const res = await this.http.post<Resource>(url, params);
     return res.data;
   }
 
-  async updateTargeted(conversationId: string, id: string, params: ActivityParams) {
-    const res = await this.http.put<Resource>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/activities/${id}?isTargetedActivity=true`,
-      params
-    );
+  async updateTargeted(conversationId: string, id: string, params: ActivityParams, options?: RequestOptions<'serviceUrl'>) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/activities/${id}?isTargetedActivity=true`;
+    const res = await this.http.put<Resource>(url, params);
     return res.data;
   }
 
-  async deleteTargeted(conversationId: string, id: string) {
-    const res = await this.http.delete<void>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/activities/${id}?isTargetedActivity=true`
-    );
+  async deleteTargeted(conversationId: string, id: string, options?: RequestOptions<'serviceUrl'>) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/activities/${id}?isTargetedActivity=true`;
+    const res = await this.http.delete<void>(url);
     return res.data;
   }
 }
diff --git a/packages/api/src/clients/conversation/index.ts b/packages/api/src/clients/conversation/index.ts
index dbc9a1973..2ceb99c97 100644
--- a/packages/api/src/clients/conversation/index.ts
+++ b/packages/api/src/clients/conversation/index.ts
@@ -8,6 +8,7 @@ import {
 import { Account, Conversation, ConversationResource } from '../../models';
 
 import { ApiClientSettings, mergeApiClientSettings } from '../api-client-settings';
+import { agenticIdentityExtension, RequestOptions, resolveServiceUrl } from '../request-options';
 
 import { ActivityParams, ConversationActivityClient } from './activity';
 import { ConversationMemberClient } from './member';
@@ -85,30 +86,35 @@ export class ConversationClient {
 
   activities(conversationId: string) {
     return {
-      create: (params: ActivityParams) => this._activities.create(conversationId, params),
-      update: (id: string, params: ActivityParams) =>
-        this._activities.update(conversationId, id, params),
-      reply: (id: string, params: ActivityParams) =>
-        this._activities.reply(conversationId, id, params),
-      delete: (id: string) => this._activities.delete(conversationId, id),
-      members: (activityId: string) => this._activities.getMembers(conversationId, activityId),
-      createTargeted: (params: ActivityParams) => this._activities.createTargeted(conversationId, params),
-      updateTargeted: (id: string, params: ActivityParams) =>
-        this._activities.updateTargeted(conversationId, id, params),
-      deleteTargeted: (id: string) => this._activities.deleteTargeted(conversationId, id),
+      create: (params: ActivityParams, options?: RequestOptions) =>
+        this._activities.create(conversationId, params, options),
+      update: (id: string, params: ActivityParams, options?: RequestOptions) =>
+        this._activities.update(conversationId, id, params, options),
+      reply: (id: string, params: ActivityParams, options?: RequestOptions) =>
+        this._activities.reply(conversationId, id, params, options),
+      delete: (id: string, options?: RequestOptions) =>
+        this._activities.delete(conversationId, id, options),
+      members: (activityId: string, options?: RequestOptions) =>
+        this._activities.getMembers(conversationId, activityId, options),
+      createTargeted: (params: ActivityParams, options?: RequestOptions<'serviceUrl'>) =>
+        this._activities.createTargeted(conversationId, params, options),
+      updateTargeted: (id: string, params: ActivityParams, options?: RequestOptions<'serviceUrl'>) =>
+        this._activities.updateTargeted(conversationId, id, params, options),
+      deleteTargeted: (id: string, options?: RequestOptions<'serviceUrl'>) =>
+        this._activities.deleteTargeted(conversationId, id, options),
     };
   }
 
   members(conversationId: string) {
     return {
-      get: () => this._members.get(conversationId),
-      getById: (id: string) => this._members.getById(conversationId, id),
-      getPaged: (pageSize?: number, continuationToken?: string) =>
-        this._members.getPaged(conversationId, pageSize, continuationToken),
+      get: (options?: RequestOptions) => this._members.get(conversationId, options),
+      getById: (id: string, options?: RequestOptions) => this._members.getById(conversationId, id, options),
+      getPaged: (pageSize?: number, continuationToken?: string, options?: RequestOptions) =>
+        this._members.getPaged(conversationId, pageSize, continuationToken, options),
       /**
        * @deprecated This will be removed by end of summer 2026.
        */
-      delete: (id: string) => this._members.delete(conversationId, id),
+      delete: (id: string, options?: RequestOptions) => this._members.delete(conversationId, id, options),
     };
   }
 
@@ -123,11 +129,9 @@ export class ConversationClient {
     return res.data;
   }
 
-  async create(params: CreateConversationParams) {
-    const res = await this.http.post<ConversationResource>(
-      `${this.serviceUrl}/v3/conversations`,
-      params
-    );
+  async create(params: CreateConversationParams, options?: RequestOptions) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations`;
+    const res = await this.http.post<ConversationResource>(url, params, agenticIdentityExtension(options));
     return res.data;
   }
 }
diff --git a/packages/api/src/clients/conversation/member.ts b/packages/api/src/clients/conversation/member.ts
index e51505caf..a27866f74 100644
--- a/packages/api/src/clients/conversation/member.ts
+++ b/packages/api/src/clients/conversation/member.ts
@@ -5,6 +5,7 @@ import {
 
 import { PagedMembersResult, resolveAadObjectId, TeamsChannelAccount } from '../../models';
 import { ApiClientSettings, mergeApiClientSettings } from '../api-client-settings';
+import { agenticIdentityExtension, RequestOptions, resolveServiceUrl } from '../request-options';
 
 export class ConversationMemberClient {
   readonly serviceUrl: string;
@@ -31,17 +32,15 @@ export class ConversationMemberClient {
     this._apiClientSettings = mergeApiClientSettings(apiClientSettings);
   }
 
-  async get(conversationId: string): Promise<TeamsChannelAccount[]> {
-    const res = await this.http.get<TeamsChannelAccount[]>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/members`
-    );
+  async get(conversationId: string, options?: RequestOptions): Promise<TeamsChannelAccount[]> {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/members`;
+    const res = await this.http.get<TeamsChannelAccount[]>(url, agenticIdentityExtension(options));
     return res.data.map(resolveAadObjectId);
   }
 
-  async getById(conversationId: string, id: string): Promise<TeamsChannelAccount> {
-    const res = await this.http.get<TeamsChannelAccount>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/members/${id}`
-    );
+  async getById(conversationId: string, id: string, options?: RequestOptions): Promise<TeamsChannelAccount> {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/members/${id}`;
+    const res = await this.http.get<TeamsChannelAccount>(url, agenticIdentityExtension(options));
     return resolveAadObjectId(res.data);
   }
 
@@ -52,25 +51,22 @@ export class ConversationMemberClient {
    * @param continuationToken - Optional token from a previous call to fetch the next page.
    * @returns PagedMembersResult containing members and an optional continuation token.
    */
-  async getPaged(conversationId: string, pageSize?: number, continuationToken?: string): Promise<PagedMembersResult> {
+  async getPaged(conversationId: string, pageSize?: number, continuationToken?: string, options?: RequestOptions): Promise<PagedMembersResult> {
     const params: Record<string, string | number> = {};
     if (pageSize !== undefined) params['pageSize'] = pageSize;
     if (continuationToken !== undefined) params['continuationToken'] = continuationToken;
 
-    const res = await this.http.get<PagedMembersResult>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/pagedMembers`,
-      { params }
-    );
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/pagedMembers`;
+    const res = await this.http.get<PagedMembersResult>(url, { params, ...agenticIdentityExtension(options) });
     return { ...res.data, members: res.data.members.map(resolveAadObjectId) };
   }
 
   /**
    * @deprecated This will be removed by end of summer 2026.
    */
-  async delete(conversationId: string, id: string) {
-    const res = await this.http.delete<void>(
-      `${this.serviceUrl}/v3/conversations/${conversationId}/members/${id}`
-    );
+  async delete(conversationId: string, id: string, options?: RequestOptions) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/members/${id}`;
+    const res = await this.http.delete<void>(url, agenticIdentityExtension(options));
     return res.data;
   }
 }
diff --git a/packages/api/src/clients/conversation/members.spec.ts b/packages/api/src/clients/conversation/members.spec.ts
index 74e0cf6ef..9292d7c19 100644
--- a/packages/api/src/clients/conversation/members.spec.ts
+++ b/packages/api/src/clients/conversation/members.spec.ts
@@ -8,28 +8,28 @@ describe('ConversationMemberClient', () => {
     const client = new ConversationMemberClient('', http);
     const spy = jest.spyOn(http, 'get').mockResolvedValueOnce({ data: [] });
     await client.get('1');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/members');
+    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/members', {});
   });
 
   it('should use client options', async () => {
     const client = new ConversationMemberClient('', {});
     const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({ data: [] });
     await client.get('1');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/members');
+    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/members', {});
   });
 
   it('should get', async () => {
     const client = new ConversationMemberClient('');
     const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({ data: [] });
     await client.get('1');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/members');
+    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/members', {});
   });
 
   it('should get by id', async () => {
     const client = new ConversationMemberClient('');
     const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({ data: {} });
     await client.getById('1', '2');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/members/2');
+    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/members/2', {});
   });
 
   it('should get paged', async () => {
@@ -52,6 +52,6 @@ describe('ConversationMemberClient', () => {
     const client = new ConversationMemberClient('');
     const spy = jest.spyOn(client.http, 'delete').mockResolvedValueOnce({});
     await client.delete('1', '2');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/members/2');
+    expect(spy).toHaveBeenCalledWith('/v3/conversations/1/members/2', {});
   });
 });
diff --git a/packages/api/src/clients/index.ts b/packages/api/src/clients/index.ts
index 088809417..882b86998 100644
--- a/packages/api/src/clients/index.ts
+++ b/packages/api/src/clients/index.ts
@@ -102,3 +102,4 @@ export * from './team';
 export * from './api-client-settings';
 export * from './auth';
 export * from './auth-provider-interceptor';
+export * from './request-options';
diff --git a/packages/api/src/clients/meeting.spec.ts b/packages/api/src/clients/meeting.spec.ts
index e4891b35d..bf847c7c8 100644
--- a/packages/api/src/clients/meeting.spec.ts
+++ b/packages/api/src/clients/meeting.spec.ts
@@ -1,5 +1,6 @@
 import { Client } from '@microsoft/teams.common';
 
+import { AGENTIC_IDENTITY_EXTENSION } from './auth-provider-interceptor';
 import { MeetingClient } from './meeting';
 
 describe('MeetingClient', () => {
@@ -8,14 +9,14 @@ describe('MeetingClient', () => {
     const client = new MeetingClient('', http);
     const spy = jest.spyOn(http, 'get').mockResolvedValueOnce({});
     await client.getById('1');
-    expect(spy).toHaveBeenCalledWith('/v1/meetings/1');
+    expect(spy).toHaveBeenCalledWith('/v1/meetings/1', {});
   });
 
   it('should use client options', async () => {
     const client = new MeetingClient('', {});
     const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({});
     await client.getById('1');
-    expect(spy).toHaveBeenCalledWith('/v1/meetings/1');
+    expect(spy).toHaveBeenCalledWith('/v1/meetings/1', {});
   });
 
   it('should use replaced http client for subsequent calls', async () => {
@@ -25,7 +26,7 @@ describe('MeetingClient', () => {
     const newSpy = jest.spyOn(http, 'get').mockResolvedValueOnce({});
     client.http = http;
     await client.getById('123');
-    expect(newSpy).toHaveBeenCalledWith('/v1/meetings/123');
+    expect(newSpy).toHaveBeenCalledWith('/v1/meetings/123', {});
     expect(oldSpy).not.toHaveBeenCalled();
   });
 
@@ -33,29 +34,26 @@ describe('MeetingClient', () => {
     const client = new MeetingClient('');
     const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({});
     await client.getById('1');
-    expect(spy).toHaveBeenCalledWith('/v1/meetings/1');
+    expect(spy).toHaveBeenCalledWith('/v1/meetings/1', {});
   });
 
   it('should get participant', async () => {
     const client = new MeetingClient('');
     const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({});
     await client.getParticipant('1', '2', '3');
-    expect(spy).toHaveBeenCalledWith('/v1/meetings/1/participants/2?tenantId=3');
+    expect(spy).toHaveBeenCalledWith('/v1/meetings/1/participants/2?tenantId=3', {});
   });
 
-  it('should URL-encode meeting id in getById', async () => {
-    const client = new MeetingClient('');
+  it('should pass serviceUrl and agentic identity options', async () => {
+    const client = new MeetingClient('https://default.service');
     const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({});
-    await client.getById('abc+def/ghi=');
-    expect(spy).toHaveBeenCalledWith('/v1/meetings/abc%2Bdef%2Fghi%3D');
-  });
+    const agenticIdentity = { agenticAppId: 'agent-app', agenticUserId: 'agent-user' };
+
+    await client.getById('1', { serviceUrl: 'https://override.service/', agenticIdentity });
 
-  it('should URL-encode participant parameters', async () => {
-    const client = new MeetingClient('');
-    const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({});
-    await client.getParticipant('abc+def/ghi=', 'user=1', 'tenant/1');
     expect(spy).toHaveBeenCalledWith(
-      '/v1/meetings/abc%2Bdef%2Fghi%3D/participants/user%3D1?tenantId=tenant%2F1'
+      'https://override.service/v1/meetings/1',
+      { extensions: { [AGENTIC_IDENTITY_EXTENSION]: agenticIdentity } }
     );
   });
 
@@ -68,18 +66,7 @@ describe('MeetingClient', () => {
     expect(spy).toHaveBeenCalledWith('/v1/meetings/1/notification', {
       type: 'targetedMeetingNotification',
       value: { recipients: ['user1'], surfaces: [{ surface: 'meetingTabIcon' }] },
-    });
+    }, {});
   });
 
-  it('should URL-encode meeting id in sendNotification', async () => {
-    const client = new MeetingClient('');
-    const spy = jest.spyOn(client.http, 'post').mockResolvedValueOnce({});
-    await client.sendNotification('abc+def/ghi=', {
-      value: { recipients: ['user1'], surfaces: [{ surface: 'meetingTabIcon' }] },
-    });
-    expect(spy).toHaveBeenCalledWith(
-      '/v1/meetings/abc%2Bdef%2Fghi%3D/notification',
-      expect.any(Object)
-    );
-  });
 });
diff --git a/packages/api/src/clients/meeting.ts b/packages/api/src/clients/meeting.ts
index f70340b4e..0854adce3 100644
--- a/packages/api/src/clients/meeting.ts
+++ b/packages/api/src/clients/meeting.ts
@@ -11,6 +11,7 @@ import {
 } from '../models';
 
 import { ApiClientSettings, mergeApiClientSettings } from './api-client-settings';
+import { agenticIdentityExtension, RequestOptions, resolveServiceUrl } from './request-options';
 
 export class MeetingClient {
   readonly serviceUrl: string;
@@ -42,8 +43,9 @@ export class MeetingClient {
    * Retrieves meeting information including details, organizer, and conversation.
    * @param id - The meeting ID.
    */
-  async getById(id: string) {
-    const res = await this.http.get<MeetingInfo>(`${this.serviceUrl}/v1/meetings/${encodeURIComponent(id)}`);
+  async getById(id: string, options?: RequestOptions) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v1/meetings/${id}`;
+    const res = await this.http.get<MeetingInfo>(url, agenticIdentityExtension(options));
     return res.data;
   }
 
@@ -54,10 +56,9 @@ export class MeetingClient {
    * @param tenantId - The tenant ID of the meeting and user.
    * @returns {MeetingParticipant} The meeting participant information.
    */
-  async getParticipant(meetingId: string, id: string, tenantId: string) {
-    const res = await this.http.get<MeetingParticipant>(
-      `${this.serviceUrl}/v1/meetings/${encodeURIComponent(meetingId)}/participants/${encodeURIComponent(id)}?tenantId=${encodeURIComponent(tenantId)}`
-    );
+  async getParticipant(meetingId: string, id: string, tenantId: string, options?: RequestOptions) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v1/meetings/${meetingId}/participants/${id}?tenantId=${tenantId}`;
+    const res = await this.http.get<MeetingParticipant>(url, agenticIdentityExtension(options));
     return res.data;
   }
 
@@ -75,16 +76,15 @@ export class MeetingClient {
    */
   async sendNotification(
     meetingId: string,
-    params: MeetingNotificationParams
+    params: MeetingNotificationParams,
+    options?: RequestOptions
   ): Promise<MeetingNotificationResponse | undefined> {
     const body = {
       type: params.type ?? 'targetedMeetingNotification',
       value: params.value,
     };
-    const res = await this.http.post<MeetingNotificationResponse>(
-      `${this.serviceUrl}/v1/meetings/${encodeURIComponent(meetingId)}/notification`,
-      body
-    );
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v1/meetings/${meetingId}/notification`;
+    const res = await this.http.post<MeetingNotificationResponse>(url, body, agenticIdentityExtension(options));
     return res.data || undefined;
   }
 }
diff --git a/packages/api/src/clients/reaction/reaction.spec.ts b/packages/api/src/clients/reaction/reaction.spec.ts
index 65af798b9..390b47125 100644
--- a/packages/api/src/clients/reaction/reaction.spec.ts
+++ b/packages/api/src/clients/reaction/reaction.spec.ts
@@ -1,5 +1,7 @@
 import { Client } from '@microsoft/teams.common';
 
+import { AGENTIC_IDENTITY_EXTENSION } from '../auth-provider-interceptor';
+
 import { ReactionClient } from './reaction';
 
 describe('ReactionClient', () => {
@@ -8,14 +10,14 @@ describe('ReactionClient', () => {
     const client = new ReactionClient('', http);
     const spy = jest.spyOn(http, 'put').mockResolvedValueOnce({});
     await client.add('conv1', 'act1', 'like');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act1/reactions/like');
+    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act1/reactions/like', undefined, {});
   });
 
   it('should use client options', async () => {
     const client = new ReactionClient('', {});
     const spy = jest.spyOn(client.http, 'put').mockResolvedValueOnce({});
     await client.add('conv1', 'act1', 'like');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act1/reactions/like');
+    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act1/reactions/like', undefined, {});
   });
 
   it('should use replaced http client for subsequent calls', async () => {
@@ -25,7 +27,7 @@ describe('ReactionClient', () => {
     const newSpy = jest.spyOn(http, 'put').mockResolvedValueOnce({});
     client.http = http;
     await client.add('conv1', 'act1', 'like');
-    expect(newSpy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act1/reactions/like');
+    expect(newSpy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act1/reactions/like', undefined, {});
     expect(oldSpy).not.toHaveBeenCalled();
   });
 
@@ -33,41 +35,31 @@ describe('ReactionClient', () => {
     const client = new ReactionClient('');
     const spy = jest.spyOn(client.http, 'put').mockResolvedValueOnce({});
     await client.add('conv1', 'act1', 'like');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act1/reactions/like');
+    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act1/reactions/like', undefined, {});
   });
 
-  it('should delete reaction', async () => {
-    const client = new ReactionClient('');
-    const spy = jest.spyOn(client.http, 'delete').mockResolvedValueOnce({});
-    await client.delete('conv1', 'act1', 'like');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act1/reactions/like');
-  });
-
-  it('should URL-encode conversation id in add', async () => {
-    const client = new ReactionClient('');
+  it('should pass serviceUrl and agentic identity options', async () => {
+    const client = new ReactionClient('https://default.service');
     const spy = jest.spyOn(client.http, 'put').mockResolvedValueOnce({});
-    await client.add('conv+1/test=', 'act1', 'like');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv%2B1%2Ftest%3D/activities/act1/reactions/like');
-  });
+    const agenticIdentity = { agenticAppId: 'agent-app', agenticUserId: 'agent-user' };
 
-  it('should URL-encode activity id in add', async () => {
-    const client = new ReactionClient('');
-    const spy = jest.spyOn(client.http, 'put').mockResolvedValueOnce({});
-    await client.add('conv1', 'act+1/test=', 'like');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act%2B1%2Ftest%3D/reactions/like');
-  });
+    await client.add('conv1', 'act1', 'like', {
+      serviceUrl: 'https://override.service/',
+      agenticIdentity,
+    });
 
-  it('should URL-encode reaction type in add', async () => {
-    const client = new ReactionClient('');
-    const spy = jest.spyOn(client.http, 'put').mockResolvedValueOnce({});
-    await client.add('conv1', 'act1', 'like');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act1/reactions/like');
+    expect(spy).toHaveBeenCalledWith(
+      'https://override.service/v3/conversations/conv1/activities/act1/reactions/like',
+      undefined,
+      { extensions: { [AGENTIC_IDENTITY_EXTENSION]: agenticIdentity } }
+    );
   });
 
-  it('should URL-encode parameters in delete', async () => {
+  it('should delete reaction', async () => {
     const client = new ReactionClient('');
     const spy = jest.spyOn(client.http, 'delete').mockResolvedValueOnce({});
-    await client.delete('conv+1/test=', 'act+1/test=', 'heart');
-    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv%2B1%2Ftest%3D/activities/act%2B1%2Ftest%3D/reactions/heart');
+    await client.delete('conv1', 'act1', 'like');
+    expect(spy).toHaveBeenCalledWith('/v3/conversations/conv1/activities/act1/reactions/like', {});
   });
+
 });
diff --git a/packages/api/src/clients/reaction/reaction.ts b/packages/api/src/clients/reaction/reaction.ts
index c43f6291b..ab7a48269 100644
--- a/packages/api/src/clients/reaction/reaction.ts
+++ b/packages/api/src/clients/reaction/reaction.ts
@@ -6,6 +6,7 @@ import {
 import { MessageReactionType } from '../../models/message/message-reaction';
 
 import { ApiClientSettings, mergeApiClientSettings } from '../api-client-settings';
+import { agenticIdentityExtension, RequestOptions, resolveServiceUrl } from '../request-options';
 
 /**
  * Client for adding and removing emoji reactions on messages in a conversation.
@@ -39,20 +40,18 @@ export class ReactionClient {
   /**
    * Add a reaction to a message.
    */
-  async add(conversationId: string, activityId: string, reactionType: MessageReactionType) {
-    const res = await this.http.put<void>(
-      `${this.serviceUrl}/v3/conversations/${encodeURIComponent(conversationId)}/activities/${encodeURIComponent(activityId)}/reactions/${encodeURIComponent(reactionType)}`
-    );
+  async add(conversationId: string, activityId: string, reactionType: MessageReactionType, options?: RequestOptions) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/activities/${activityId}/reactions/${reactionType}`;
+    const res = await this.http.put<void>(url, undefined, agenticIdentityExtension(options));
     return res.data;
   }
 
   /**
    * Delete a reaction from a message.
    */
-  async delete(conversationId: string, activityId: string, reactionType: MessageReactionType) {
-    const res = await this.http.delete<void>(
-      `${this.serviceUrl}/v3/conversations/${encodeURIComponent(conversationId)}/activities/${encodeURIComponent(activityId)}/reactions/${encodeURIComponent(reactionType)}`
-    );
+  async delete(conversationId: string, activityId: string, reactionType: MessageReactionType, options?: RequestOptions) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/conversations/${conversationId}/activities/${activityId}/reactions/${reactionType}`;
+    const res = await this.http.delete<void>(url, agenticIdentityExtension(options));
     return res.data;
   }
 }
diff --git a/packages/api/src/clients/request-options.ts b/packages/api/src/clients/request-options.ts
new file mode 100644
index 000000000..2bb9d6166
--- /dev/null
+++ b/packages/api/src/clients/request-options.ts
@@ -0,0 +1,19 @@
+import type { AgenticIdentity } from '../models';
+
+import { AGENTIC_IDENTITY_EXTENSION } from './auth-provider-interceptor';
+
+type AllRequestOptions = {
+  readonly agenticIdentity?: AgenticIdentity;
+  readonly serviceUrl?: string;
+};
+
+export type RequestOptions<K extends keyof AllRequestOptions = keyof AllRequestOptions> = Pick<AllRequestOptions, K>;
+
+export function agenticIdentityExtension(options?: RequestOptions): Record<string, unknown> {
+  if (!options?.agenticIdentity) return {};
+  return { extensions: { [AGENTIC_IDENTITY_EXTENSION]: options.agenticIdentity } };
+}
+
+export function resolveServiceUrl(defaultServiceUrl: string, options?: { serviceUrl?: string }): string {
+  return (options?.serviceUrl ?? defaultServiceUrl).replace(/\/+$/, '');
+}
diff --git a/packages/api/src/clients/team.spec.ts b/packages/api/src/clients/team.spec.ts
index 29806b4fc..c7abcedc7 100644
--- a/packages/api/src/clients/team.spec.ts
+++ b/packages/api/src/clients/team.spec.ts
@@ -1,5 +1,6 @@
 import { Client } from '@microsoft/teams.common';
 
+import { AGENTIC_IDENTITY_EXTENSION } from './auth-provider-interceptor';
 import { TeamClient } from './team';
 
 describe('TeamClient', () => {
@@ -8,21 +9,21 @@ describe('TeamClient', () => {
     const client = new TeamClient('', http);
     const spy = jest.spyOn(http, 'get').mockResolvedValueOnce({});
     await client.getById('1');
-    expect(spy).toHaveBeenCalledWith('/v3/teams/1');
+    expect(spy).toHaveBeenCalledWith('/v3/teams/1', {});
   });
 
   it('should use client options', async () => {
     const client = new TeamClient('', {});
     const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({});
     await client.getById('1');
-    expect(spy).toHaveBeenCalledWith('/v3/teams/1');
+    expect(spy).toHaveBeenCalledWith('/v3/teams/1', {});
   });
 
   it('should get by id', async () => {
     const client = new TeamClient('');
     const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({});
     await client.getById('1');
-    expect(spy).toHaveBeenCalledWith('/v3/teams/1');
+    expect(spy).toHaveBeenCalledWith('/v3/teams/1', {});
   });
 
   it('should get conversations', async () => {
@@ -31,6 +32,19 @@ describe('TeamClient', () => {
       .spyOn(client.http, 'get')
       .mockResolvedValueOnce({ data: { conversations: [] } });
     await client.getConversations('1');
-    expect(spy).toHaveBeenCalledWith('/v3/teams/1/conversations');
+    expect(spy).toHaveBeenCalledWith('/v3/teams/1/conversations', {});
+  });
+
+  it('should pass serviceUrl and agentic identity options', async () => {
+    const client = new TeamClient('https://default.service');
+    const spy = jest.spyOn(client.http, 'get').mockResolvedValueOnce({});
+    const agenticIdentity = { agenticAppId: 'agent-app', agenticUserId: 'agent-user' };
+
+    await client.getById('1', { serviceUrl: 'https://override.service/', agenticIdentity });
+
+    expect(spy).toHaveBeenCalledWith(
+      'https://override.service/v3/teams/1',
+      { extensions: { [AGENTIC_IDENTITY_EXTENSION]: agenticIdentity } }
+    );
   });
 });
diff --git a/packages/api/src/clients/team.ts b/packages/api/src/clients/team.ts
index ebb66ebcb..964ec5e08 100644
--- a/packages/api/src/clients/team.ts
+++ b/packages/api/src/clients/team.ts
@@ -6,6 +6,7 @@ import {
 import { ChannelInfo, TeamDetails } from '../models';
 
 import { ApiClientSettings, mergeApiClientSettings } from './api-client-settings';
+import { agenticIdentityExtension, RequestOptions, resolveServiceUrl } from './request-options';
 
 export class TeamClient {
   readonly serviceUrl: string;
@@ -33,15 +34,15 @@ export class TeamClient {
     this._apiClientSettings = mergeApiClientSettings(apiClientSettings);
   }
 
-  async getById(id: string) {
-    const res = await this.http.get<TeamDetails>(`${this.serviceUrl}/v3/teams/${id}`);
+  async getById(id: string, options?: RequestOptions) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/teams/${id}`;
+    const res = await this.http.get<TeamDetails>(url, agenticIdentityExtension(options));
     return res.data;
   }
 
-  async getConversations(id: string) {
-    const res = await this.http.get<{ conversations: ChannelInfo[] }>(
-      `${this.serviceUrl}/v3/teams/${id}/conversations`
-    );
+  async getConversations(id: string, options?: RequestOptions) {
+    const url = `${resolveServiceUrl(this.serviceUrl, options)}/v3/teams/${id}/conversations`;
+    const res = await this.http.get<{ conversations: ChannelInfo[] }>(url, agenticIdentityExtension(options));
     return res.data.conversations;
   }
 }
diff --git a/packages/apps/src/activity-sender.spec.ts b/packages/apps/src/activity-sender.spec.ts
index a298ae541..4a49dee6b 100644
--- a/packages/apps/src/activity-sender.spec.ts
+++ b/packages/apps/src/activity-sender.spec.ts
@@ -38,7 +38,8 @@ describe('ActivitySender', () => {
           text: 'hello',
           from: ref.bot,
           conversation: ref.conversation,
-        })
+        }),
+        {}
       );
       expect(result).toEqual(expect.objectContaining({ id: 'activity-1' }));
     });
@@ -54,7 +55,8 @@ describe('ActivitySender', () => {
 
       expect(mockHttpClient.put).toHaveBeenCalledWith(
         'https://smba.trafficmanager.net/teams/v3/conversations/conv-123/activities/existing-id',
-        expect.objectContaining({ type: 'message', text: 'updated' })
+        expect.objectContaining({ type: 'message', text: 'updated' }),
+        {}
       );
       expect(mockHttpClient.post).not.toHaveBeenCalled();
     });
@@ -112,7 +114,8 @@ describe('ActivitySender', () => {
         expect.objectContaining({
           from: { id: 'bot-id', name: 'Bot', role: 'bot' },
           conversation: { id: 'conv-123', conversationType: 'personal' },
-        })
+        }),
+        {}
       );
     });
 
@@ -127,7 +130,8 @@ describe('ActivitySender', () => {
 
       expect(mockHttpClient.post).toHaveBeenCalledWith(
         'https://custom-service.botframework.com/v3/conversations/conv-456/activities',
-        expect.any(Object)
+        expect.any(Object),
+        {}
       );
     });