diff --git a/packages/kbn-optimizer/limits.yml b/packages/kbn-optimizer/limits.yml
index f47843b187235..f14456925a924 100644
--- a/packages/kbn-optimizer/limits.yml
+++ b/packages/kbn-optimizer/limits.yml
@@ -165,7 +165,7 @@ pageLoadAssetSize:
   searchSynonyms: 6371
   security: 79627
   securitySolution: 171101
-  securitySolutionEss: 38689
+  securitySolutionEss: 42592
   securitySolutionServerless: 52082
   serverless: 7412
   serverlessObservability: 19300
diff --git a/src/platform/plugins/shared/navigation/common/index.ts b/src/platform/plugins/shared/navigation/common/index.ts
index b50b74f3f972f..a57db6d686c0d 100644
--- a/src/platform/plugins/shared/navigation/common/index.ts
+++ b/src/platform/plugins/shared/navigation/common/index.ts
@@ -7,4 +7,8 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-export { DEFAULT_ROUTES, DEFAULT_ROUTE_UI_SETTING_ID } from './constants';
+export {
+  DEFAULT_ROUTES,
+  DEFAULT_ROUTE_UI_SETTING_ID,
+  AGENT_BUILDER_NAV_AT_TOP_FLAG,
+} from './constants';
diff --git a/src/platform/plugins/shared/navigation/public/index.ts b/src/platform/plugins/shared/navigation/public/index.ts
index 053babb680f50..adea31e72b489 100644
--- a/src/platform/plugins/shared/navigation/public/index.ts
+++ b/src/platform/plugins/shared/navigation/public/index.ts
@@ -22,6 +22,8 @@ export type {
   AddSolutionNavigationArg,
 } from './types';
 
+export { AGENT_BUILDER_NAV_AT_TOP_FLAG } from '../common';
+
 // Export plugin after all other imports
 import { NavigationPublicPlugin } from './plugin';
 export { NavigationPublicPlugin as Plugin };
diff --git a/x-pack/solutions/security/plugins/security_solution_ess/public/navigation/navigation_tree.ts b/x-pack/solutions/security/plugins/security_solution_ess/public/navigation/navigation_tree.ts
index 28524bc9fd5aa..87904266919cb 100644
--- a/x-pack/solutions/security/plugins/security_solution_ess/public/navigation/navigation_tree.ts
+++ b/x-pack/solutions/security/plugins/security_solution_ess/public/navigation/navigation_tree.ts
@@ -14,6 +14,7 @@ import {
 import { i18nStrings, securityLink } from '@kbn/security-solution-navigation/links';
 import { defaultNavigationTree } from '@kbn/security-solution-navigation/navigation_tree';
 import { STACK_MANAGEMENT_NAV_ID, DATA_MANAGEMENT_NAV_ID } from '@kbn/deeplinks-management';
+import { AGENT_BUILDER_NAV_AT_TOP_FLAG } from '@kbn/navigation-plugin/public';
 import { type Services } from '../common/services';
 import { SOLUTION_NAME } from './translations';
 
@@ -21,6 +22,15 @@ export const createNavigationTree = (
   services: Services,
   chatExperience: AIChatExperience = AIChatExperience.Classic
 ): NavigationTreeDefinition => {
+  const showAgentBuilder = chatExperience === AIChatExperience.Agent;
+  const agentBuilderNavAtTop = services.featureFlags.getBooleanValue(
+    AGENT_BUILDER_NAV_AT_TOP_FLAG,
+    false
+  );
+  const agentBuilderLink = {
+    icon: 'productAgent',
+    link: 'agent_builder' as AppDeepLinkId,
+  };
   const showAlertingV2 = Boolean(services.application.capabilities.alertingVTwo);
   return {
     body: [
@@ -31,6 +41,7 @@ export const createNavigationTree = (
         renderAs: 'home',
         title: SOLUTION_NAME,
       },
+      ...(showAgentBuilder && agentBuilderNavAtTop ? [agentBuilderLink] : []),
       {
         link: 'inbox' as AppDeepLinkId,
         icon: 'email',
@@ -51,14 +62,8 @@ export const createNavigationTree = (
       {
         link: 'workflows',
       },
-      ...(chatExperience === AIChatExperience.Agent
-        ? [
-            {
-              icon: 'productAgent',
-              link: 'agent_builder' as AppDeepLinkId,
-            },
-          ]
-        : []),
+      // TODO: remove this item when agentBuilderNavAtTop is enabled by default and the Agent Builder link is always at the top of the nav
+      ...(showAgentBuilder && !agentBuilderNavAtTop ? [agentBuilderLink] : []),
       {
         id: SecurityPageName.attackDiscovery,
         icon: 'bolt',
diff --git a/x-pack/solutions/security/plugins/security_solution_serverless/kibana.jsonc b/x-pack/solutions/security/plugins/security_solution_serverless/kibana.jsonc
index a3ef47321a2ee..f27eebe746d39 100644
--- a/x-pack/solutions/security/plugins/security_solution_serverless/kibana.jsonc
+++ b/x-pack/solutions/security/plugins/security_solution_serverless/kibana.jsonc
@@ -1,9 +1,7 @@
 {
   "type": "plugin",
   "id": "@kbn/security-solution-serverless",
-  "owner": [
-    "@elastic/security-solution"
-  ],
+  "owner": ["@elastic/security-solution"],
   "group": "security",
   "visibility": "private",
   "description": "Serverless customizations for security.",
@@ -11,10 +9,7 @@
     "id": "securitySolutionServerless",
     "browser": true,
     "server": true,
-    "configPath": [
-      "xpack",
-      "securitySolutionServerless"
-    ],
+    "configPath": ["xpack", "securitySolutionServerless"],
     "requiredPlugins": [
       "kibanaReact",
       "management",
@@ -25,13 +20,9 @@
       "cloud",
       "fleet",
       "actions",
-      "discover"
+      "discover",
+      "navigation"
     ],
-    "optionalPlugins": [
-      "securitySolutionEss",
-      "automaticImport",
-      "usageApi",
-      "workflowsManagement"
-    ]
+    "optionalPlugins": ["securitySolutionEss", "automaticImport", "usageApi", "workflowsManagement"]
   }
-}
\ No newline at end of file
+}
diff --git a/x-pack/solutions/security/plugins/security_solution_serverless/moon.yml b/x-pack/solutions/security/plugins/security_solution_serverless/moon.yml
index 54e0b57292bb1..f991f0bcb40d9 100644
--- a/x-pack/solutions/security/plugins/security_solution_serverless/moon.yml
+++ b/x-pack/solutions/security/plugins/security_solution_serverless/moon.yml
@@ -56,6 +56,7 @@ dependsOn:
   - '@kbn/workflows'
   - '@kbn/usage-api-plugin'
   - '@kbn/workflows-management-plugin'
+  - '@kbn/navigation-plugin'
 tags:
   - plugin
   - prod
diff --git a/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/ai_navigation/ai_navigation_tree.test.ts b/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/ai_navigation/ai_navigation_tree.test.ts
index 6f645186ffd7c..b572a7369e935 100644
--- a/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/ai_navigation/ai_navigation_tree.test.ts
+++ b/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/ai_navigation/ai_navigation_tree.test.ts
@@ -9,8 +9,8 @@ import { AIChatExperience } from '@kbn/ai-assistant-common';
 import { createAiNavigationTree } from './ai_navigation_tree';
 
 describe('createAiNavigationTree', () => {
-  it('returns the Workflows link between Agents and Value report when enabled', () => {
-    const navigationTree = createAiNavigationTree(AIChatExperience.Agent, true);
+  it('returns the Workflows link between Agents and Value report when `workflows` is enabled', () => {
+    const navigationTree = createAiNavigationTree(AIChatExperience.Agent, true, false, false);
 
     const primaryNavSection = navigationTree.body[4];
     const children = 'children' in primaryNavSection ? primaryNavSection.children : [];
@@ -25,8 +25,8 @@ describe('createAiNavigationTree', () => {
     expect(workflowsIndex).toBe((agentsIndex ?? 0) + 1);
   });
 
-  it('does not include the Workflows link when disabled', () => {
-    const navigationTree = createAiNavigationTree(AIChatExperience.Agent, false);
+  it('does not include the Workflows link when `workflows` is disabled', () => {
+    const navigationTree = createAiNavigationTree(AIChatExperience.Agent, false, false, false);
 
     const primaryNavSection = navigationTree.body[4];
     const children = 'children' in primaryNavSection ? primaryNavSection.children : [];
@@ -37,4 +37,25 @@ describe('createAiNavigationTree', () => {
 
     expect(workflowsIndex).toBe(-1);
   });
+
+  it('places the Agent Builder link after `home` when `agentBuilderNavAtTop` is enabled', () => {
+    const navigationTree = createAiNavigationTree(AIChatExperience.Agent, true, false, true);
+
+    const secondNavItem = navigationTree.body[1];
+
+    expect('link' in secondNavItem && secondNavItem.link).toBe('agent_builder');
+  });
+
+  it('places the Agent Builder later in the nav  when `agentBuilderNavAtTop` is disabled', () => {
+    const navigationTree = createAiNavigationTree(AIChatExperience.Agent, true, false, false);
+
+    const primaryNavSection = navigationTree.body[4];
+    const children = 'children' in primaryNavSection ? primaryNavSection.children : [];
+
+    const agentBuilderIndex = children?.findIndex(
+      (item) => 'link' in item && item.link === 'agent_builder'
+    );
+
+    expect(agentBuilderIndex).toBeGreaterThan(0);
+  });
 });
diff --git a/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/ai_navigation/ai_navigation_tree.ts b/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/ai_navigation/ai_navigation_tree.ts
index b569d68b88ed8..b4a312e633197 100644
--- a/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/ai_navigation/ai_navigation_tree.ts
+++ b/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/ai_navigation/ai_navigation_tree.ts
@@ -23,7 +23,8 @@ const SOLUTION_NAME = i18n.translate(
 export const createAiNavigationTree = (
   chatExperience: AIChatExperience = AIChatExperience.Classic,
   workflowsUiEnabled: boolean = false,
-  showAlertingV2: boolean = false
+  showAlertingV2: boolean = false,
+  showAgentBuilderNavAtTop: boolean = false
 ): NavigationTreeDefinition => ({
   body: [
     {
@@ -33,6 +34,14 @@ export const createAiNavigationTree = (
       icon: AiNavigationIcon,
       renderAs: 'home',
     },
+    ...(chatExperience === AIChatExperience.Agent && showAgentBuilderNavAtTop
+      ? [
+          {
+            icon: 'productAgent',
+            link: 'agent_builder' as AppDeepLinkId,
+          },
+        ]
+      : []),
     {
       id: SecurityPageName.alertSummary,
       link: securityLink(SecurityPageName.alertSummary),
@@ -83,7 +92,8 @@ export const createAiNavigationTree = (
           link: 'discover' as AppDeepLinkId,
           icon: 'productDiscover',
         },
-        ...(chatExperience === AIChatExperience.Agent
+        // TODO: remove this item when agentBuilderNavAtTop is enabled by default and the Agent Builder link is always at the top of the nav
+        ...(chatExperience === AIChatExperience.Agent && !showAgentBuilderNavAtTop
           ? [
               {
                 icon: 'productAgent',
diff --git a/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation.test.ts b/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation.test.ts
index 1594474b0a08b..21eb349fc2978 100644
--- a/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation.test.ts
+++ b/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation.test.ts
@@ -73,6 +73,7 @@ describe('Security Side Nav', () => {
     expect(mockedCreateAiNavigationTree).toHaveBeenCalledWith(
       AIChatExperience.Classic,
       false,
+      false,
       false
     );
     expect(mockedCreateNavigationTree).not.toHaveBeenCalled();
@@ -119,6 +120,7 @@ describe('Security Side Nav', () => {
     expect(mockedCreateAiNavigationTree).toHaveBeenCalledWith(
       AIChatExperience.Classic,
       true,
+      false,
       false
     );
   });
diff --git a/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation.ts b/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation.ts
index b75cb72b500fb..1c92482ea01a9 100644
--- a/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation.ts
+++ b/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation.ts
@@ -10,6 +10,7 @@ import { firstValueFrom } from 'rxjs';
 import { AI_CHAT_EXPERIENCE_TYPE } from '@kbn/management-settings-ids';
 import type { AIChatExperience } from '@kbn/ai-assistant-common';
 import { WORKFLOWS_UI_SETTING_ID } from '@kbn/workflows/common/constants';
+import { AGENT_BUILDER_NAV_AT_TOP_FLAG } from '@kbn/navigation-plugin/public';
 import { ProductLine } from '../../common/product';
 import type { SecurityProductTypes } from '../../common/config';
 import { type Services } from '../common/services';
@@ -24,6 +25,11 @@ export const registerSolutionNavigation = async (
     (productType) => productType.product_line === ProductLine.aiSoc
   );
 
+  const agentBuilderNavAtTop = services.featureFlags.getBooleanValue(
+    AGENT_BUILDER_NAV_AT_TOP_FLAG,
+    false
+  );
+
   // Do not pass a defaultOverride: when userValue is unset, get() must use the registered
   // default (e.g. Agent for security spaces from aiAssistantManagementSelection), not Classic.
   const chatExperience$ = services.settings.client.get$<AIChatExperience>(AI_CHAT_EXPERIENCE_TYPE);
@@ -39,7 +45,12 @@ export const registerSolutionNavigation = async (
   const showAlertingV2 = Boolean(services.application.capabilities.alertingVTwo);
 
   const navigationTree = shouldUseAINavigation
-    ? createAiNavigationTree(initialChatExperience, workflowsUiEnabled, showAlertingV2)
+    ? createAiNavigationTree(
+        initialChatExperience,
+        workflowsUiEnabled,
+        showAlertingV2,
+        agentBuilderNavAtTop
+      )
     : await createNavigationTree(services, initialChatExperience);
 
   services.securitySolution.setSolutionNavigationTree(navigationTree);
diff --git a/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation_tree.ts b/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation_tree.ts
index ebfa427f1cfa6..7feb16835c76a 100644
--- a/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation_tree.ts
+++ b/x-pack/solutions/security/plugins/security_solution_serverless/public/navigation/navigation_tree.ts
@@ -15,6 +15,7 @@ import {
 } from '@kbn/security-solution-navigation';
 import { i18nStrings, securityLink } from '@kbn/security-solution-navigation/links';
 import { defaultNavigationTree } from '@kbn/security-solution-navigation/navigation_tree';
+import { AGENT_BUILDER_NAV_AT_TOP_FLAG } from '@kbn/navigation-plugin/public';
 
 import { type Services } from '../common/services';
 import { createManagementFooterItemsTree } from './management_footer_items';
@@ -29,6 +30,17 @@ export const createNavigationTree = async (
   chatExperience: AIChatExperience = AIChatExperience.Classic
 ): Promise<NavigationTreeDefinition> => {
   const showAlertingV2 = Boolean(services.application.capabilities.alertingVTwo);
+
+  const showAgentBuilder = chatExperience === AIChatExperience.Agent;
+  const agentBuilderNavAtTop = services.featureFlags.getBooleanValue(
+    AGENT_BUILDER_NAV_AT_TOP_FLAG,
+    false
+  );
+  const agentBuilderLink = {
+    icon: 'productAgent',
+    link: 'agent_builder' as AppDeepLinkId,
+  };
+
   return {
     body: [
       {
@@ -38,6 +50,7 @@ export const createNavigationTree = async (
         icon: 'logoSecurity',
         renderAs: 'home',
       },
+      ...(showAgentBuilder && agentBuilderNavAtTop ? [agentBuilderLink] : []),
       {
         link: 'inbox' as AppDeepLinkId,
         icon: 'email',
@@ -58,14 +71,8 @@ export const createNavigationTree = async (
       {
         link: 'workflows',
       },
-      ...(chatExperience === AIChatExperience.Agent
-        ? [
-            {
-              icon: 'productAgent',
-              link: 'agent_builder' as AppDeepLinkId,
-            },
-          ]
-        : []),
+      // TODO: remove this item when agentBuilderNavAtTop is enabled by default and the Agent Builder link is always at the top of the nav
+      ...(showAgentBuilder && !agentBuilderNavAtTop ? [agentBuilderLink] : []),
       {
         id: SecurityPageName.attackDiscovery,
         icon: 'bolt',
diff --git a/x-pack/solutions/security/plugins/security_solution_serverless/tsconfig.json b/x-pack/solutions/security/plugins/security_solution_serverless/tsconfig.json
index 37bb3f3e050f1..b5edf184622e2 100644
--- a/x-pack/solutions/security/plugins/security_solution_serverless/tsconfig.json
+++ b/x-pack/solutions/security/plugins/security_solution_serverless/tsconfig.json
@@ -52,5 +52,6 @@
     "@kbn/workflows",
     "@kbn/usage-api-plugin",
     "@kbn/workflows-management-plugin",
+    "@kbn/navigation-plugin",
   ]
 }