diff --git a/x-pack/plugins/security_solution/common/endpoint/schema/policy.ts b/x-pack/plugins/security_solution/common/endpoint/schema/policy.ts
index 17d0cdff57ee..35ba1266066e 100644
--- a/x-pack/plugins/security_solution/common/endpoint/schema/policy.ts
+++ b/x-pack/plugins/security_solution/common/endpoint/schema/policy.ts
@@ -7,6 +7,6 @@ import { schema } from '@kbn/config-schema';
 
 export const GetPolicyResponseSchema = {
   query: schema.object({
-    hostId: schema.string(),
+    agentId: schema.string(),
   }),
 };
diff --git a/x-pack/plugins/security_solution/public/graphql/introspection.json b/x-pack/plugins/security_solution/public/graphql/introspection.json
index cc91d2390581..30dec34ab39b 100644
--- a/x-pack/plugins/security_solution/public/graphql/introspection.json
+++ b/x-pack/plugins/security_solution/public/graphql/introspection.json
@@ -1412,6 +1412,14 @@
             "isDeprecated": false,
             "deprecationReason": null
           },
+          {
+            "name": "agent",
+            "description": "",
+            "args": [],
+            "type": { "kind": "OBJECT", "name": "AgentFields", "ofType": null },
+            "isDeprecated": false,
+            "deprecationReason": null
+          },
           {
             "name": "cloud",
             "description": "",
@@ -1458,6 +1466,25 @@
         "enumValues": null,
         "possibleTypes": null
       },
+      {
+        "kind": "OBJECT",
+        "name": "AgentFields",
+        "description": "",
+        "fields": [
+          {
+            "name": "id",
+            "description": "",
+            "args": [],
+            "type": { "kind": "SCALAR", "name": "String", "ofType": null },
+            "isDeprecated": false,
+            "deprecationReason": null
+          }
+        ],
+        "inputFields": null,
+        "interfaces": [],
+        "enumValues": null,
+        "possibleTypes": null
+      },
       {
         "kind": "OBJECT",
         "name": "CloudFields",
diff --git a/x-pack/plugins/security_solution/public/graphql/types.ts b/x-pack/plugins/security_solution/public/graphql/types.ts
index 52598b5f4494..17f8e19a6055 100644
--- a/x-pack/plugins/security_solution/public/graphql/types.ts
+++ b/x-pack/plugins/security_solution/public/graphql/types.ts
@@ -490,6 +490,8 @@ export interface HostsEdges {
 export interface HostItem {
   _id?: Maybe<string>;
 
+  agent?: Maybe<AgentFields>;
+
   cloud?: Maybe<CloudFields>;
 
   endpoint?: Maybe<EndpointFields>;
@@ -501,6 +503,10 @@ export interface HostItem {
   lastSeen?: Maybe<string>;
 }
 
+export interface AgentFields {
+  id?: Maybe<string>;
+}
+
 export interface CloudFields {
   instance?: Maybe<CloudInstance>;
 
@@ -1728,6 +1734,8 @@ export namespace GetHostOverviewQuery {
 
     _id: Maybe<string>;
 
+    agent: Maybe<Agent>;
+
     host: Maybe<Host>;
 
     cloud: Maybe<Cloud>;
@@ -1737,6 +1745,12 @@ export namespace GetHostOverviewQuery {
     endpoint: Maybe<Endpoint>;
   };
 
+  export type Agent = {
+    __typename?: 'AgentFields';
+
+    id: Maybe<string>;
+  }
+
   export type Host = {
     __typename?: 'HostEcsFields';
 
diff --git a/x-pack/plugins/security_solution/public/hosts/containers/hosts/details/host_overview.gql_query.ts b/x-pack/plugins/security_solution/public/hosts/containers/hosts/details/host_overview.gql_query.ts
index 89937d0adf81..c0724ea3dd41 100644
--- a/x-pack/plugins/security_solution/public/hosts/containers/hosts/details/host_overview.gql_query.ts
+++ b/x-pack/plugins/security_solution/public/hosts/containers/hosts/details/host_overview.gql_query.ts
@@ -18,6 +18,9 @@ export const HostOverviewQuery = gql`
       id
       HostOverview(hostName: $hostName, timerange: $timerange, defaultIndex: $defaultIndex) {
         _id
+        agent {
+          id
+        }
         host {
           architecture
           id
diff --git a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/store/middleware.ts b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/store/middleware.ts
index 17e0101426b0..80b2d2b0192f 100644
--- a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/store/middleware.ts
+++ b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/store/middleware.ts
@@ -314,7 +314,7 @@ export const endpointMiddlewareFactory: ImmutableMiddlewareFactory<EndpointState
       // call the policy response api
       try {
         const policyResponse = await coreStart.http.get(`/api/endpoint/policy_response`, {
-          query: { hostId: selectedEndpoint },
+          query: { agentId: selectedEndpoint },
         });
         dispatch({
           type: 'serverReturnedEndpointPolicyResponse',
diff --git a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/store/mock_endpoint_result_list.ts b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/store/mock_endpoint_result_list.ts
index ff3bd2d9973c..cd8ebb4d0ec5 100644
--- a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/store/mock_endpoint_result_list.ts
+++ b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/store/mock_endpoint_result_list.ts
@@ -164,7 +164,7 @@ const endpointListApiPathHandlerMocks = ({
   if (endpointsResults) {
     endpointsResults.forEach((host) => {
       // @ts-expect-error
-      apiHandlers[`/api/endpoint/metadata/${host.metadata.host.id}`] = () => host;
+      apiHandlers[`/api/endpoint/metadata/${host.metadata.agent.id}`] = () => host;
     });
   }
 
diff --git a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/details/endpoint_details.tsx b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/details/endpoint_details.tsx
index 47f4fbb8830a..c0763a21f094 100644
--- a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/details/endpoint_details.tsx
+++ b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/details/endpoint_details.tsx
@@ -89,16 +89,16 @@ export const EndpointDetails = memo(({ details }: { details: HostMetadata }) =>
         getEndpointDetailsPath({
           name: 'endpointPolicyResponse',
           ...currentUrlParams,
-          selected_endpoint: details.host.id,
+          selected_endpoint: details.agent.id,
         })
       ),
       getEndpointDetailsPath({
         name: 'endpointPolicyResponse',
         ...currentUrlParams,
-        selected_endpoint: details.host.id,
+        selected_endpoint: details.agent.id,
       }),
     ];
-  }, [details.host.id, formatUrl, queryParams]);
+  }, [details.agent.id, formatUrl, queryParams]);
 
   const agentDetailsWithFlyoutPath = `${agentDetailsAppPath}${openReassignFlyoutSearch}`;
   const agentDetailsWithFlyoutUrl = `${agentDetailsUrl}${openReassignFlyoutSearch}`;
@@ -112,7 +112,7 @@ export const EndpointDetails = memo(({ details }: { details: HostMetadata }) =>
         {
           path: getEndpointDetailsPath({
             name: 'endpointDetails',
-            selected_endpoint: details.host.id,
+            selected_endpoint: details.agent.id,
           }),
         },
       ],
diff --git a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/details/index.tsx b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/details/index.tsx
index 43d3b39474fc..6bc3445c8e74 100644
--- a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/details/index.tsx
+++ b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/details/index.tsx
@@ -131,16 +131,16 @@ const PolicyResponseFlyoutPanel = memo<{
         getEndpointListPath({
           name: 'endpointList',
           ...queryParams,
-          selected_endpoint: hostMeta.host.id,
+          selected_endpoint: hostMeta.agent.id,
         })
       ),
       getEndpointListPath({
         name: 'endpointList',
         ...queryParams,
-        selected_endpoint: hostMeta.host.id,
+        selected_endpoint: hostMeta.agent.id,
       }),
     ],
-    [hostMeta.host.id, formatUrl, queryParams]
+    [hostMeta.agent.id, formatUrl, queryParams]
   );
   const backToDetailsClickHandler = useNavigateByRouterEventHandler(detailsRoutePath);
   const backButtonProp = useMemo((): FlyoutSubHeaderProps['backButton'] => {
diff --git a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/index.test.tsx b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/index.test.tsx
index debdde901407..12a76ae0772a 100644
--- a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/index.test.tsx
+++ b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/index.test.tsx
@@ -397,13 +397,13 @@ describe('when on the list page', () => {
 
   describe('when there is a selected host in the url', () => {
     let hostDetails: HostInfo;
-    let agentId: string;
+    let elasticAgentId: string;
     let renderAndWaitForData: () => Promise<ReturnType<AppContextTestRender['render']>>;
     const mockEndpointListApi = (mockedPolicyResponse?: HostPolicyResponse) => {
       const {
         // eslint-disable-next-line @typescript-eslint/naming-convention
         host_status,
-        metadata: { host, ...details },
+        metadata: { agent, ...details },
         // eslint-disable-next-line @typescript-eslint/naming-convention
         query_strategy_version,
       } = mockEndpointDetailsApiResult();
@@ -412,15 +412,15 @@ describe('when on the list page', () => {
         host_status,
         metadata: {
           ...details,
-          host: {
-            ...host,
+          agent: {
+            ...agent,
             id: '1',
           },
         },
         query_strategy_version,
       };
 
-      agentId = hostDetails.metadata.elastic.agent.id;
+      elasticAgentId = hostDetails.metadata.elastic.agent.id;
 
       const policy = docGenerator.generatePolicyPackagePolicy();
       policy.id = hostDetails.metadata.Endpoint.policy.applied.id;
@@ -618,7 +618,7 @@ describe('when on the list page', () => {
       expect(linkToReassign).not.toBeNull();
       expect(linkToReassign.textContent).toEqual('Reassign Policy');
       expect(linkToReassign.getAttribute('href')).toEqual(
-        `/app/ingestManager#/fleet/agents/${agentId}/activity?openReassignFlyout=true`
+        `/app/ingestManager#/fleet/agents/${elasticAgentId}/activity?openReassignFlyout=true`
       );
     });
 
diff --git a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/index.tsx b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/index.tsx
index b514707da6f6..36c5b0d1037e 100644
--- a/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/index.tsx
+++ b/x-pack/plugins/security_solution/public/management/pages/endpoint_hosts/view/index.tsx
@@ -261,11 +261,11 @@ export const EndpointList = () => {
 
     return [
       {
-        field: 'metadata.host',
+        field: 'metadata',
         name: i18n.translate('xpack.securitySolution.endpoint.list.hostname', {
           defaultMessage: 'Hostname',
         }),
-        render: ({ hostname, id }: HostInfo['metadata']['host']) => {
+        render: ({ host: { hostname }, agent: { id } }: HostInfo['metadata']) => {
           const toRoutePath = getEndpointDetailsPath(
             {
               ...queryParams,
@@ -342,7 +342,7 @@ export const EndpointList = () => {
           const toRoutePath = getEndpointDetailsPath({
             name: 'endpointPolicyResponse',
             ...queryParams,
-            selected_endpoint: item.metadata.host.id,
+            selected_endpoint: item.metadata.agent.id,
           });
           const toRouteUrl = formatUrl(toRoutePath);
           return (
diff --git a/x-pack/plugins/security_solution/server/endpoint/routes/metadata/handlers.ts b/x-pack/plugins/security_solution/server/endpoint/routes/metadata/handlers.ts
index cc371f9120ba..c8e0292e8d93 100644
--- a/x-pack/plugins/security_solution/server/endpoint/routes/metadata/handlers.ts
+++ b/x-pack/plugins/security_solution/server/endpoint/routes/metadata/handlers.ts
@@ -255,11 +255,11 @@ async function enrichHostMetadata(
   const log = metadataRequestContext.logger;
   try {
     /**
-     * Get agent status by elastic agent id if available or use the host id.
+     * Get agent status by elastic agent id if available or use the endpoint-agent id.
      */
 
     if (!elasticAgentId) {
-      elasticAgentId = hostMetadata.host.id;
+      elasticAgentId = hostMetadata.agent.id;
       log.warn(`Missing elastic agent id, using host id instead ${elasticAgentId}`);
     }
 
diff --git a/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders.test.ts b/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders.test.ts
index cb79263ef6b3..ac1de377124f 100644
--- a/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders.test.ts
+++ b/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders.test.ts
@@ -230,7 +230,7 @@ describe('query builder', () => {
 
       expect(query).toEqual({
         body: {
-          query: { match: { 'HostDetails.host.id': mockID } },
+          query: { match: { 'HostDetails.agent.id': mockID } },
           sort: [{ 'HostDetails.event.created': { order: 'desc' } }],
           size: 1,
         },
diff --git a/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders.ts b/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders.ts
index 0b166e097af9..7980fc83358b 100644
--- a/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders.ts
+++ b/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders.ts
@@ -116,14 +116,14 @@ function buildQueryBody(
 }
 
 export function getESQueryHostMetadataByID(
-  hostID: string,
+  agentID: string,
   metadataQueryStrategy: MetadataQueryStrategy
 ) {
   return {
     body: {
       query: {
         match: {
-          [metadataQueryStrategy.hostIdProperty]: hostID,
+          [metadataQueryStrategy.hostIdProperty]: agentID,
         },
       },
       sort: metadataQueryStrategy.sortProperty,
diff --git a/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders_v1.test.ts b/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders_v1.test.ts
index 899fe4b880ac..ca65d18bb9f6 100644
--- a/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders_v1.test.ts
+++ b/x-pack/plugins/security_solution/server/endpoint/routes/metadata/query_builders_v1.test.ts
@@ -31,7 +31,7 @@ describe('query builder v1', () => {
             match_all: {},
           },
           collapse: {
-            field: 'host.id',
+            field: 'agent.id',
             inner_hits: {
               name: 'most_recent',
               size: 1,
@@ -41,7 +41,7 @@ describe('query builder v1', () => {
           aggs: {
             total: {
               cardinality: {
-                field: 'host.id',
+                field: 'agent.id',
               },
             },
           },
@@ -92,7 +92,7 @@ describe('query builder v1', () => {
               },
             },
             collapse: {
-              field: 'host.id',
+              field: 'agent.id',
               inner_hits: {
                 name: 'most_recent',
                 size: 1,
@@ -102,7 +102,7 @@ describe('query builder v1', () => {
             aggs: {
               total: {
                 cardinality: {
-                  field: 'host.id',
+                  field: 'agent.id',
                 },
               },
             },
@@ -165,7 +165,7 @@ describe('query builder v1', () => {
             },
           },
           collapse: {
-            field: 'host.id',
+            field: 'agent.id',
             inner_hits: {
               name: 'most_recent',
               size: 1,
@@ -175,7 +175,7 @@ describe('query builder v1', () => {
           aggs: {
             total: {
               cardinality: {
-                field: 'host.id',
+                field: 'agent.id',
               },
             },
           },
@@ -251,7 +251,7 @@ describe('query builder v1', () => {
               },
             },
             collapse: {
-              field: 'host.id',
+              field: 'agent.id',
               inner_hits: {
                 name: 'most_recent',
                 size: 1,
@@ -261,7 +261,7 @@ describe('query builder v1', () => {
             aggs: {
               total: {
                 cardinality: {
-                  field: 'host.id',
+                  field: 'agent.id',
                 },
               },
             },
@@ -289,7 +289,7 @@ describe('query builder v1', () => {
 
       expect(query).toEqual({
         body: {
-          query: { match: { 'host.id': mockID } },
+          query: { match: { 'agent.id': mockID } },
           sort: [{ 'event.created': { order: 'desc' } }],
           size: 1,
         },
diff --git a/x-pack/plugins/security_solution/server/endpoint/routes/metadata/support/query_strategies.ts b/x-pack/plugins/security_solution/server/endpoint/routes/metadata/support/query_strategies.ts
index df4c37726246..f1614cc19e8c 100644
--- a/x-pack/plugins/security_solution/server/endpoint/routes/metadata/support/query_strategies.ts
+++ b/x-pack/plugins/security_solution/server/endpoint/routes/metadata/support/query_strategies.ts
@@ -23,7 +23,7 @@ export function metadataQueryStrategyV1(): MetadataQueryStrategy {
   return {
     index: metadataIndexPattern,
     elasticAgentIdProperty: 'elastic.agent.id',
-    hostIdProperty: 'host.id',
+    hostIdProperty: 'agent.id',
     sortProperty: [
       {
         'event.created': {
@@ -33,7 +33,7 @@ export function metadataQueryStrategyV1(): MetadataQueryStrategy {
     ],
     extraBodyProperties: {
       collapse: {
-        field: 'host.id',
+        field: 'agent.id',
         inner_hits: {
           name: 'most_recent',
           size: 1,
@@ -43,7 +43,7 @@ export function metadataQueryStrategyV1(): MetadataQueryStrategy {
       aggs: {
         total: {
           cardinality: {
-            field: 'host.id',
+            field: 'agent.id',
           },
         },
       },
@@ -78,7 +78,7 @@ export function metadataQueryStrategyV2(): MetadataQueryStrategy {
   return {
     index: metadataCurrentIndexPattern,
     elasticAgentIdProperty: 'HostDetails.elastic.agent.id',
-    hostIdProperty: 'HostDetails.host.id',
+    hostIdProperty: 'HostDetails.agent.id',
     sortProperty: [
       {
         'HostDetails.event.created': {
diff --git a/x-pack/plugins/security_solution/server/endpoint/routes/policy/handlers.test.ts b/x-pack/plugins/security_solution/server/endpoint/routes/policy/handlers.test.ts
index 8d4524e06c49..7dddc357fe53 100644
--- a/x-pack/plugins/security_solution/server/endpoint/routes/policy/handlers.test.ts
+++ b/x-pack/plugins/security_solution/server/endpoint/routes/policy/handlers.test.ts
@@ -51,7 +51,7 @@ describe('test policy response handler', () => {
 
     mockScopedClient.callAsCurrentUser.mockImplementationOnce(() => Promise.resolve(response));
     const mockRequest = httpServerMock.createKibanaRequest({
-      params: { hostId: 'id' },
+      params: { agentId: 'id' },
     });
 
     await hostPolicyResponseHandler(
@@ -62,7 +62,7 @@ describe('test policy response handler', () => {
 
     expect(mockResponse.ok).toBeCalled();
     const result = mockResponse.ok.mock.calls[0][0]?.body as GetHostPolicyResponse;
-    expect(result.policy_response.host.id).toEqual(response.hits.hits[0]._source.host.id);
+    expect(result.policy_response.agent.id).toEqual(response.hits.hits[0]._source.agent.id);
   });
 
   it('should return not found when there is no response policy for host', async () => {
@@ -77,7 +77,7 @@ describe('test policy response handler', () => {
     );
 
     const mockRequest = httpServerMock.createKibanaRequest({
-      params: { hostId: 'id' },
+      params: { agentId: 'id' },
     });
 
     await hostPolicyResponseHandler(
diff --git a/x-pack/plugins/security_solution/server/endpoint/routes/policy/handlers.ts b/x-pack/plugins/security_solution/server/endpoint/routes/policy/handlers.ts
index fd685efb94aa..f3a7b08a4cd4 100644
--- a/x-pack/plugins/security_solution/server/endpoint/routes/policy/handlers.ts
+++ b/x-pack/plugins/security_solution/server/endpoint/routes/policy/handlers.ts
@@ -8,16 +8,16 @@ import { TypeOf } from '@kbn/config-schema';
 import { policyIndexPattern } from '../../../../common/endpoint/constants';
 import { GetPolicyResponseSchema } from '../../../../common/endpoint/schema/policy';
 import { EndpointAppContext } from '../../types';
-import { getPolicyResponseByHostId } from './service';
+import { getPolicyResponseByAgentId } from './service';
 
 export const getHostPolicyResponseHandler = function (
   endpointAppContext: EndpointAppContext
 ): RequestHandler<undefined, TypeOf<typeof GetPolicyResponseSchema.query>, undefined> {
   return async (context, request, response) => {
     try {
-      const doc = await getPolicyResponseByHostId(
+      const doc = await getPolicyResponseByAgentId(
         policyIndexPattern,
-        request.query.hostId,
+        request.query.agentId,
         context.core.elasticsearch.legacy.client
       );
 
diff --git a/x-pack/plugins/security_solution/server/endpoint/routes/policy/service.test.ts b/x-pack/plugins/security_solution/server/endpoint/routes/policy/service.test.ts
index f05d9ef5b821..40a691c1ddbd 100644
--- a/x-pack/plugins/security_solution/server/endpoint/routes/policy/service.test.ts
+++ b/x-pack/plugins/security_solution/server/endpoint/routes/policy/service.test.ts
@@ -5,13 +5,13 @@
  */
 
 import { GetPolicyResponseSchema } from '../../../../common/endpoint/schema/policy';
-import { getESQueryPolicyResponseByHostID } from './service';
+import { getESQueryPolicyResponseByAgentID } from './service';
 
 describe('test policy handlers schema', () => {
   it('validate that get policy response query schema', async () => {
     expect(
       GetPolicyResponseSchema.query.validate({
-        hostId: 'id',
+        agentId: 'id',
       })
     ).toBeTruthy();
 
@@ -21,13 +21,13 @@ describe('test policy handlers schema', () => {
 
 describe('test policy query', () => {
   it('queries for the correct host', async () => {
-    const hostID = 'f757d3c0-e874-11ea-9ad9-015510b487f4';
-    const query = getESQueryPolicyResponseByHostID(hostID, 'anyindex');
-    expect(query.body.query.bool.filter.term).toEqual({ 'host.id': hostID });
+    const agentId = 'f757d3c0-e874-11ea-9ad9-015510b487f4';
+    const query = getESQueryPolicyResponseByAgentID(agentId, 'anyindex');
+    expect(query.body.query.bool.filter.term).toEqual({ 'agent.id': agentId });
   });
 
   it('filters out initial policy by ID', async () => {
-    const query = getESQueryPolicyResponseByHostID(
+    const query = getESQueryPolicyResponseByAgentID(
       'f757d3c0-e874-11ea-9ad9-015510b487f4',
       'anyindex'
     );
diff --git a/x-pack/plugins/security_solution/server/endpoint/routes/policy/service.ts b/x-pack/plugins/security_solution/server/endpoint/routes/policy/service.ts
index 1b3d232f9421..0019c97a6cce 100644
--- a/x-pack/plugins/security_solution/server/endpoint/routes/policy/service.ts
+++ b/x-pack/plugins/security_solution/server/endpoint/routes/policy/service.ts
@@ -9,14 +9,14 @@ import { ILegacyScopedClusterClient } from 'kibana/server';
 import { GetHostPolicyResponse, HostPolicyResponse } from '../../../../common/endpoint/types';
 import { INITIAL_POLICY_ID } from './index';
 
-export function getESQueryPolicyResponseByHostID(hostID: string, index: string) {
+export function getESQueryPolicyResponseByAgentID(agentID: string, index: string) {
   return {
     body: {
       query: {
         bool: {
           filter: {
             term: {
-              'host.id': hostID,
+              'agent.id': agentID,
             },
           },
           must_not: {
@@ -39,12 +39,12 @@ export function getESQueryPolicyResponseByHostID(hostID: string, index: string)
   };
 }
 
-export async function getPolicyResponseByHostId(
+export async function getPolicyResponseByAgentId(
   index: string,
-  hostId: string,
+  agentID: string,
   dataClient: ILegacyScopedClusterClient
 ): Promise<GetHostPolicyResponse | undefined> {
-  const query = getESQueryPolicyResponseByHostID(hostId, index);
+  const query = getESQueryPolicyResponseByAgentID(agentID, index);
   const response = (await dataClient.callAsCurrentUser('search', query)) as SearchResponse<
     HostPolicyResponse
   >;
diff --git a/x-pack/plugins/security_solution/server/graphql/hosts/schema.gql.ts b/x-pack/plugins/security_solution/server/graphql/hosts/schema.gql.ts
index 48bb0cbe37af..4623fa6514e7 100644
--- a/x-pack/plugins/security_solution/server/graphql/hosts/schema.gql.ts
+++ b/x-pack/plugins/security_solution/server/graphql/hosts/schema.gql.ts
@@ -26,6 +26,10 @@ export const hostsSchema = gql`
     type: String
   }
 
+  type AgentFields {
+    id: String
+  }
+
   type CloudInstance {
     id: [String]
   }
@@ -55,6 +59,7 @@ export const hostsSchema = gql`
 
   type HostItem {
     _id: String
+    agent: AgentFields
     cloud: CloudFields
     endpoint: EndpointFields
     host: HostEcsFields
diff --git a/x-pack/plugins/security_solution/server/graphql/types.ts b/x-pack/plugins/security_solution/server/graphql/types.ts
index 7730cea2b984..bda0fed494a6 100644
--- a/x-pack/plugins/security_solution/server/graphql/types.ts
+++ b/x-pack/plugins/security_solution/server/graphql/types.ts
@@ -492,6 +492,8 @@ export interface HostsEdges {
 export interface HostItem {
   _id?: Maybe<string>;
 
+  agent?: Maybe<AgentFields>;
+
   cloud?: Maybe<CloudFields>;
 
   endpoint?: Maybe<EndpointFields>;
@@ -503,6 +505,10 @@ export interface HostItem {
   lastSeen?: Maybe<string>;
 }
 
+export interface AgentFields {
+  id?: Maybe<string>;
+}
+
 export interface CloudFields {
   instance?: Maybe<CloudInstance>;
 
@@ -2268,6 +2274,8 @@ export namespace HostItemResolvers {
   export interface Resolvers<TContext = SiemContext, TypeParent = HostItem> {
     _id?: _IdResolver<Maybe<string>, TypeParent, TContext>;
 
+    agent?: AgentResolver<Maybe<AgentFields>, TypeParent, TContext>;
+
     cloud?: CloudResolver<Maybe<CloudFields>, TypeParent, TContext>;
 
     endpoint?: EndpointResolver<Maybe<EndpointFields>, TypeParent, TContext>;
@@ -2284,6 +2292,11 @@ export namespace HostItemResolvers {
     Parent,
     TContext
   >;
+  export type AgentResolver<
+    R = Maybe<AgentFields>,
+    Parent = HostItem,
+    TContext = SiemContext
+  > = Resolver<R, Parent, TContext>;
   export type CloudResolver<
     R = Maybe<CloudFields>,
     Parent = HostItem,
@@ -2311,6 +2324,19 @@ export namespace HostItemResolvers {
   > = Resolver<R, Parent, TContext>;
 }
 
+export namespace AgentFieldsResolvers {
+  export interface Resolvers<TContext = SiemContext, TypeParent = AgentFields> {
+    id?: IdResolver<Maybe<string>, TypeParent, TContext>;
+  }
+
+  export type IdResolver<
+    R = Maybe<string>,
+    Parent = AgentFields,
+    TContext = SiemContext
+  > = Resolver<R, Parent, TContext>;
+}
+
+
 export namespace CloudFieldsResolvers {
   export interface Resolvers<TContext = SiemContext, TypeParent = CloudFields> {
     instance?: InstanceResolver<Maybe<CloudInstance>, TypeParent, TContext>;
@@ -6043,6 +6069,7 @@ export type IResolvers<TContext = SiemContext> = {
   HostsData?: HostsDataResolvers.Resolvers<TContext>;
   HostsEdges?: HostsEdgesResolvers.Resolvers<TContext>;
   HostItem?: HostItemResolvers.Resolvers<TContext>;
+  AgentFields?: AgentFieldsResolvers.Resolvers<TContext>;
   CloudFields?: CloudFieldsResolvers.Resolvers<TContext>;
   CloudInstance?: CloudInstanceResolvers.Resolvers<TContext>;
   CloudMachine?: CloudMachineResolvers.Resolvers<TContext>;
diff --git a/x-pack/plugins/security_solution/server/lib/ecs_fields/index.ts b/x-pack/plugins/security_solution/server/lib/ecs_fields/index.ts
index d1c8290b3462..099160b7e4d6 100644
--- a/x-pack/plugins/security_solution/server/lib/ecs_fields/index.ts
+++ b/x-pack/plugins/security_solution/server/lib/ecs_fields/index.ts
@@ -85,6 +85,7 @@ export const processFieldsMap: Readonly<Record<string, string>> = {
 
 export const agentFieldsMap: Readonly<Record<string, string>> = {
   'agent.type': 'agent.type',
+  'agent.id': 'agent.id',
 };
 
 export const userFieldsMap: Readonly<Record<string, string>> = {
diff --git a/x-pack/plugins/security_solution/server/lib/hosts/elasticsearch_adapter.ts b/x-pack/plugins/security_solution/server/lib/hosts/elasticsearch_adapter.ts
index ff2796e6852d..36244ecbff72 100644
--- a/x-pack/plugins/security_solution/server/lib/hosts/elasticsearch_adapter.ts
+++ b/x-pack/plugins/security_solution/server/lib/hosts/elasticsearch_adapter.ts
@@ -95,19 +95,19 @@ export class ElasticsearchHostsAdapter implements HostsAdapter {
       response: [inspectStringifyObject(response)],
     };
     const formattedHostItem = formatHostItem(options.fields, aggregations);
-    const hostId =
-      formattedHostItem.host && formattedHostItem.host.id
-        ? Array.isArray(formattedHostItem.host.id)
-          ? formattedHostItem.host.id[0]
-          : formattedHostItem.host.id
+    const ident = // endpoint-generated ID, NOT elastic-agent-id
+      formattedHostItem.agent && formattedHostItem.agent.id
+        ? Array.isArray(formattedHostItem.agent.id)
+          ? formattedHostItem.agent.id[0]
+          : formattedHostItem.agent.id
         : null;
-    const endpoint: EndpointFields | null = await this.getHostEndpoint(request, hostId);
+    const endpoint: EndpointFields | null = await this.getHostEndpoint(request, ident);
     return { inspect, _id: options.hostName, ...formattedHostItem, endpoint };
   }
 
   public async getHostEndpoint(
     request: FrameworkRequest,
-    hostId: string | null
+    id: string | null
   ): Promise<EndpointFields | null> {
     const logger = this.endpointContext.logFactory.get('metadata');
     try {
@@ -121,8 +121,8 @@ export class ElasticsearchHostsAdapter implements HostsAdapter {
         requestHandlerContext: request.context,
       };
       const endpointData =
-        hostId != null && metadataRequestContext.endpointAppContextService.getAgentService() != null
-          ? await getHostData(metadataRequestContext, hostId)
+        id != null && metadataRequestContext.endpointAppContextService.getAgentService() != null
+          ? await getHostData(metadataRequestContext, id)
           : null;
       return endpointData != null && endpointData.metadata
         ? {
diff --git a/x-pack/plugins/security_solution/server/lib/hosts/mock.ts b/x-pack/plugins/security_solution/server/lib/hosts/mock.ts
index 97aa68c0f9bb..e9dcee35005d 100644
--- a/x-pack/plugins/security_solution/server/lib/hosts/mock.ts
+++ b/x-pack/plugins/security_solution/server/lib/hosts/mock.ts
@@ -299,6 +299,7 @@ export const mockGetHostOverviewOptions: HostOverviewRequestOptions = {
   defaultIndex: DEFAULT_INDEX_PATTERN,
   fields: [
     '_id',
+    'agent.id',
     'host.architecture',
     'host.id',
     'host.ip',
@@ -328,7 +329,7 @@ export const mockGetHostOverviewRequest = {
     operationName: 'GetHostOverviewQuery',
     variables: { sourceId: 'default', hostName: 'siem-es' },
     query:
-      'query GetHostOverviewQuery($sourceId: ID!, $hostName: String!, $timerange: TimerangeInput!) {\n  source(id: $sourceId) {\n    id\n    HostOverview(hostName: $hostName, timerange: $timerange) {\n      _id\n      host {\n        architecture\n        id\n        ip\n        mac\n        name\n        os {\n          family\n          name\n          platform\n          version\n          __typename\n        }\n        type\n        __typename\n      }\n      cloud {\n        instance {\n          id\n          __typename\n        }\n        machine {\n          type\n          __typename\n        }\n        provider\n        region\n        __typename\n      }\n      __typename\n    }\n    __typename\n  }\n}\n',
+      'query GetHostOverviewQuery($sourceId: ID!, $hostName: String!, $timerange: TimerangeInput!) {\n  source(id: $sourceId) {\n    id\n    HostOverview(hostName: $hostName, timerange: $timerange) {\n      _id\n      agent {\n        id\n      }\n      host {\n        architecture\n        id\n        ip\n        mac\n        name\n        os {\n          family\n          name\n          platform\n          version\n          __typename\n        }\n        type\n        __typename\n      }\n      cloud {\n        instance {\n          id\n          __typename\n        }\n        machine {\n          type\n          __typename\n        }\n        provider\n        region\n        __typename\n      }\n      __typename\n    }\n    __typename\n  }\n}\n',
   },
 };
 
@@ -461,6 +462,17 @@ export const mockGetHostOverviewResponse = {
         },
       ],
     },
+    agent_id: {
+      doc_count_error_upper_bound: 0,
+      sum_other_doc_count: 0,
+      buckets: [
+        {
+          key: '9f48a9ab-749a-4ff0-b4e2-7e53910a985',
+          doc_count: 611894,
+          timestamp: { value: 1554826117972, value_as_string: '2019-04-09T16:08:37.972Z' },
+        },
+      ],
+    },
   },
 };
 
@@ -474,6 +486,9 @@ export const mockGetHostOverviewResult = {
     response: [JSON.stringify(mockGetHostOverviewResponse, null, 2)],
   },
   _id: 'siem-es',
+  agent: {
+    id: '9f48a9ab-749a-4ff0-b4e2-7e53910a985',
+  },
   host: {
     architecture: 'x86_64',
     id: 'b6d5264e4b9c8880ad1053841067a4a6',
diff --git a/x-pack/plugins/security_solution/server/lib/hosts/query.detail_host.dsl.ts b/x-pack/plugins/security_solution/server/lib/hosts/query.detail_host.dsl.ts
index 10dcb7ee7e74..00769b75a8ce 100644
--- a/x-pack/plugins/security_solution/server/lib/hosts/query.detail_host.dsl.ts
+++ b/x-pack/plugins/security_solution/server/lib/hosts/query.detail_host.dsl.ts
@@ -5,7 +5,7 @@
  */
 
 import { reduceFields } from '../../utils/build_query/reduce_fields';
-import { cloudFieldsMap, hostFieldsMap } from '../ecs_fields';
+import { cloudFieldsMap, hostFieldsMap, agentFieldsMap } from '../ecs_fields';
 
 import { buildFieldsTermAggregation } from './helpers';
 import { HostOverviewRequestOptions } from './types';
@@ -19,7 +19,7 @@ export const buildHostOverviewQuery = ({
   },
   timerange: { from, to },
 }: HostOverviewRequestOptions) => {
-  const esFields = reduceFields(fields, { ...hostFieldsMap, ...cloudFieldsMap });
+  const esFields = reduceFields(fields, { ...hostFieldsMap, ...cloudFieldsMap, ...agentFieldsMap });
 
   const filter = [
     { term: { 'host.name': hostName } },
diff --git a/x-pack/test/security_solution_endpoint/apps/endpoint/endpoint_list.ts b/x-pack/test/security_solution_endpoint/apps/endpoint/endpoint_list.ts
index 5b5949821580..0b018cdb37cc 100644
--- a/x-pack/test/security_solution_endpoint/apps/endpoint/endpoint_list.ts
+++ b/x-pack/test/security_solution_endpoint/apps/endpoint/endpoint_list.ts
@@ -162,7 +162,7 @@ export default ({ getPageObjects, getService }: FtrProviderContext) => {
       describe.skip("has a url with an endpoint host's id", () => {
         before(async () => {
           await pageObjects.endpoint.navigateToEndpointList(
-            'selected_host=fc0ff548-feba-41b6-8367-65e8790d0eaf'
+            'selected_endpoint=3838df35-a095-4af4-8fce-0b6d78793f2e'
           );
         });
 
diff --git a/x-pack/test/security_solution_endpoint_api_int/apis/policy.ts b/x-pack/test/security_solution_endpoint_api_int/apis/policy.ts
index 66bcc0e75991..1a4e69267f9c 100644
--- a/x-pack/test/security_solution_endpoint_api_int/apis/policy.ts
+++ b/x-pack/test/security_solution_endpoint_api_int/apis/policy.ts
@@ -19,20 +19,20 @@ export default function ({ getService }: FtrProviderContext) {
       // to do it manually
       after(async () => await deletePolicyStream(getService));
 
-      it('should return one policy response for host', async () => {
-        const expectedHostId = '4f3b9858-a96d-49d8-a326-230d7763d767';
+      it('should return one policy response for an id', async () => {
+        const expectedAgentId = 'a10ac658-a3bc-4ac6-944a-68d9bd1c5a5e';
         const { body } = await supertest
-          .get(`/api/endpoint/policy_response?hostId=${expectedHostId}`)
+          .get(`/api/endpoint/policy_response?agentId=${expectedAgentId}`)
           .send()
           .expect(200);
 
-        expect(body.policy_response.host.id).to.eql(expectedHostId);
+        expect(body.policy_response.agent.id).to.eql(expectedAgentId);
         expect(body.policy_response.Endpoint.policy).to.not.be(undefined);
       });
 
       it('should return not found if host has no policy response', async () => {
         const { body } = await supertest
-          .get(`/api/endpoint/policy_response?hostId=bad_host_id`)
+          .get(`/api/endpoint/policy_response?agentId=bad_id`)
           .send()
           .expect(404);