refactor: Auto-detect AgentCore network type from VPC configuration

- Remove agentCoreNetworkType parameter from user input
- Add isAgentCoreNetworkPrivate computed in parameter.ts
- Automatically set to true when both agentCoreVpcId and agentCoreSubnetIds are provided
- Add validation to ensure VPC settings are provided together
- Update GenericAgentCore to use boolean flag instead of enum
- Applies to both Generic Runtime and Agent Builder Runtime

Author: nakayukl-demo

packages/cdk/cdk.json

@@ -68,7 +68,6 @@
     "createGenericAgentCoreRuntime": false,
     "agentCoreRegion": null,
     "agentCoreExternalRuntimes": [],
-    "agentCoreNetworkType": "PUBLIC",
     "agentCoreVpcId": null,
     "agentCoreSubnetIds": null,
     "allowedIpV4AddressRanges": null,

packages/cdk/lib/agent-core-stack.ts

@@ -22,7 +22,7 @@ export class AgentCoreStack extends Stack {
         env: params.env,
         createGenericRuntime: params.createGenericAgentCoreRuntime,
         createAgentBuilderRuntime: params.agentBuilderEnabled,
-        agentCoreNetworkType: params.agentCoreNetworkType,
+        isAgentCoreNetworkPrivate: params.isAgentCoreNetworkPrivate,
         agentCoreVpcId: params.agentCoreVpcId,
         agentCoreSubnetIds: params.agentCoreSubnetIds,
       });

packages/cdk/lib/construct/generic-agent-core.ts

@@ -38,7 +38,7 @@ export interface GenericAgentCoreProps {
   env: string;
   createGenericRuntime?: boolean;
   createAgentBuilderRuntime?: boolean;
-  agentCoreNetworkType: 'PUBLIC' | 'PRIVATE';
+  isAgentCoreNetworkPrivate?: boolean;
   agentCoreVpcId?: string | null;
   agentCoreSubnetIds?: string[] | null;
   agentCoreEnvironmentVariables?: Record<string, string>;
@@ -67,7 +67,7 @@ export class GenericAgentCore extends Construct {
       env,
       createGenericRuntime = false,
       createAgentBuilderRuntime = false,
-      agentCoreNetworkType = 'PUBLIC',
+      isAgentCoreNetworkPrivate = false,
       agentCoreVpcId = null,
       agentCoreSubnetIds = null,
     } = props;
@@ -85,11 +85,7 @@ export class GenericAgentCore extends Construct {
     let vpc: IVpc | undefined;
     let subnets: ISubnet[] | undefined;
 
-    if (
-      agentCoreNetworkType === 'PRIVATE' &&
-      agentCoreVpcId &&
-      agentCoreSubnetIds
-    ) {
+    if (isAgentCoreNetworkPrivate && agentCoreVpcId && agentCoreSubnetIds) {
       vpc = Vpc.fromLookup(this, 'AgentCoreVpc', { vpcId: agentCoreVpcId });
       subnets = agentCoreSubnetIds.map((subnetId, index) =>
         Subnet.fromSubnetId(this, `AgentCoreSubnet${index}`, subnetId)
@@ -126,7 +122,7 @@ export class GenericAgentCore extends Construct {
     this.resources = this.createResources(
       createGenericRuntime,
       createAgentBuilderRuntime,
-      agentCoreNetworkType,
+      isAgentCoreNetworkPrivate,
       vpc,
       subnets,
       securityGroup
@@ -184,7 +180,7 @@ export class GenericAgentCore extends Construct {
   private createResources(
     createGeneric: boolean,
     createAgentBuilder: boolean,
-    agentCoreNetworkType: 'PUBLIC' | 'PRIVATE',
+    isAgentCoreNetworkPrivate: boolean,
     vpc?: IVpc,
     subnets?: ISubnet[],
     securityGroup?: SecurityGroup
@@ -201,7 +197,7 @@ export class GenericAgentCore extends Construct {
         'Generic',
         this.genericRuntimeConfig,
         role,
-        agentCoreNetworkType,
+        isAgentCoreNetworkPrivate,
         vpc,
         subnets,
         securityGroup
@@ -213,7 +209,7 @@ export class GenericAgentCore extends Construct {
         'AgentBuilder',
         this.agentBuilderRuntimeConfig,
         role,
-        agentCoreNetworkType,
+        isAgentCoreNetworkPrivate,
         vpc,
         subnets,
         securityGroup
@@ -228,13 +224,13 @@ export class GenericAgentCore extends Construct {
     type: string,
     config: AgentCoreRuntimeConfig,
     role: Role,
-    agentCoreNetworkType: 'PUBLIC' | 'PRIVATE',
+    isAgentCoreNetworkPrivate: boolean,
     vpc?: IVpc,
     subnets?: ISubnet[],
     securityGroup?: SecurityGroup
   ): Runtime {
     const networkConfig = this.createNetworkConfiguration(
-      agentCoreNetworkType,
+      isAgentCoreNetworkPrivate,
       vpc,
       subnets,
       securityGroup
@@ -253,15 +249,15 @@ export class GenericAgentCore extends Construct {
   }
 
   private createNetworkConfiguration(
-    agentCoreNetworkType: 'PUBLIC' | 'PRIVATE',
+    isAgentCoreNetworkPrivate: boolean,
     vpc?: IVpc,
     subnets?: ISubnet[],
     securityGroup?: SecurityGroup
   ): RuntimeNetworkConfiguration {
-    if (agentCoreNetworkType === 'PRIVATE') {
+    if (isAgentCoreNetworkPrivate) {
       if (!vpc || !subnets) {
         throw new Error(
-          'VPC and Subnets are required for PRIVATE network type'
+          'VPC and Subnets are required for private network configuration'
         );
       }
 

packages/cdk/lib/stack-input.ts

@@ -161,7 +161,6 @@ const baseStackInputSchema = z.object({
     )
     .default([]),
   // Agent Core Network Configuration
-  agentCoreNetworkType: z.enum(['PUBLIC', 'PRIVATE']).default('PUBLIC'),
   agentCoreVpcId: z.string().nullish(),
   agentCoreSubnetIds: z.array(z.string()).nullish(),
   // MCP
@@ -222,20 +221,18 @@ export const stackInputSchema = baseStackInputSchema
   )
   .refine(
     (data) => {
-      // Validate AgentCore network configuration
-      if (data.agentCoreNetworkType === 'PRIVATE') {
-        return (
-          data.agentCoreVpcId &&
-          data.agentCoreSubnetIds &&
-          data.agentCoreSubnetIds.length > 0
-        );
-      }
-      return true;
+      // Validate AgentCore VPC configuration consistency
+      const hasVpcId = !!data.agentCoreVpcId;
+      const hasSubnetIds =
+        data.agentCoreSubnetIds && data.agentCoreSubnetIds.length > 0;
+
+      // Both must be provided or both must be empty
+      return hasVpcId === hasSubnetIds;
     },
     {
       message:
-        'VPC ID and Subnet IDs are required when agentCoreNetworkType is PRIVATE',
-      path: ['agentCoreNetworkType'],
+        'Both VPC ID and Subnet IDs must be provided together for AgentCore network configuration',
+      path: ['agentCoreVpcId'],
     }
   );
 
@@ -277,6 +274,8 @@ export const processedStackInputSchema = baseStackInputSchema.extend({
   ),
   // Processed agentCoreRegion (null -> modelRegion)
   agentCoreRegion: z.string(),
+  // Computed from VPC configuration (computed in parameter.ts)
+  isAgentCoreNetworkPrivate: z.boolean().optional(),
   // Branding configuration
   brandingConfig: z
     .object({

packages/cdk/parameter.ts

@@ -78,6 +78,12 @@ export const getParams = (app: cdk.App): ProcessedStackInput => {
     ),
     // Process agentCoreRegion: null -> modelRegion
     agentCoreRegion: params.agentCoreRegion || params.modelRegion,
+    // Compute isAgentCoreNetworkPrivate from VPC configuration
+    isAgentCoreNetworkPrivate: !!(
+      params.agentCoreVpcId &&
+      params.agentCoreSubnetIds &&
+      params.agentCoreSubnetIds.length > 0
+    ),
     // Load branding configuration
     brandingConfig: loadBrandingConfig(),
   };

packages/cdk/test/generative-ai-use-cases.test.ts

@@ -215,9 +215,9 @@ describe('GenerativeAiUseCases', () => {
 
     const params = processedStackInputSchema.parse({
       ...stackInput,
-      agentCoreNetworkType: 'PRIVATE',
       agentCoreVpcId: 'vpc-12345678',
       agentCoreSubnetIds: ['subnet-12345678', 'subnet-87654321'],
+      isAgentCoreNetworkPrivate: true,
     });
 
     const {