How to set runtime of node ?

[realtebo]

Description

I just deployed my first agent.
All is using node 22 on my project, but when deployed on aws, the lambda is setup on node 20.x, triggering a end-of-life alert on health dashboard

Acceptance Criteria

My agent core json is

{
  "name": "MyAgent",
  "version": 1,
  "managedBy": "CDK",
  "runtimes": [
    {
      "name": "MyAgent",
      "build": "Container",
      "entrypoint": "src/main.ts",
      "codeLocation": "app/my-agent-node/",
      "runtimeVersion": "NODE_22",
      "networkMode": "PUBLIC",
      "protocol": "HTTP"
    }
  ],
  "memories": [],
  "credentials": [],
  "evaluators": [],
  "onlineEvalConfigs": [],
  "agentCoreGateways": [],
  "policyEngines": []
}

Additional Context

I add relevant part of generated cloudformation template

"ApplicationAgentMyAgentContainerImageBuilderContainerBuildHandlerxxxxx": {
      "Type": "AWS::Lambda::Function",
      "Properties": {
        "Code": {
          "ZipFile": "....",
        "Handler": "index.handler",
        "MemorySize": 256,
        "Role": {....},
        "Runtime": "nodejs20.x",
        "Timeout": 900
      },
.....
    },

[jariy17]

Hi! Thanks for reporting this.

The nodejs20.x Lambda you're seeing in the CloudFormation template is not your agent's runtime — it's an infrastructure Lambda used internally by the CDK constructs to trigger CodeBuild container image builds at deploy time. Your runtimeVersion: "NODE_22" config is correctly controlling your agent's execution environment on AgentCore Runtime.

That said, you're right that having nodejs20.x in the stack triggers EOL alerts on the health dashboard, which is a valid concern. We've opened a fix in the CDK constructs package to upgrade this infrastructure Lambda to nodejs22.x:

https://github.com/aws/agentcore-l3-cdk-constructs/pull/152

Once that PR is merged and a new version of @aws/agentcore-cdk is released, the EOL alert should go away on your next deployment.

[realtebo]

Thanks. Please upgrade to latest stable.... Node 25

[jolo-dev]

@jariy17 @aidandaly24 this is still not fixed.

AgentCore CDK synthesis failed: Unsupported Python runtime value: NODE_22

And the L3- CDK Construct repository is gone.