Lambda node 24 callback error even on resolutionMode PROMISE

[giorgio-zamparelli]

Lambda node 24 is throwing callback deprecated error even when using resolutionMode PROMISE.

Node 24 runtime is available for Lambda.
https://aws.amazon.com/blogs/compute/node-js-24-runtime-now-available-in-aws-lambda/

I tried to switch from node 22 to 24 but I'm seeing the error Runtime.CallbackHandlerDeprecated:

{
    "errorType": "Runtime.CallbackHandlerDeprecated",
    "errorMessage": "ERROR: AWS Lambda has removed support for callback-based function handlers starting with Node.js 24. You need to modify this function to use a supported handler signature to use Node.js 24 or later. For more information see https://docs.aws.amazon.com/lambda/latest/dg/nodejs-handler.html.",
    "name": "Runtime.CallbackHandlerDeprecated",
    "stack": [
        "Runtime.CallbackHandlerDeprecated: ERROR: AWS Lambda has removed support for callback-based function handlers starting with Node.js 24. You need to modify this function to use a supported handler signature to use Node.js 24 or later. For more information see https://docs.aws.amazon.com/lambda/latest/dg/nodejs-handler.html.",
        "    at errorOnDeprecatedCallback (file:///var/runtime/index.mjs:617:11)",
        "    at createRuntime (file:///var/runtime/index.mjs:1222:5)",
        "    at async ignition (file:///var/runtime/index.mjs:1637:21)"
    ]
}

I've tried both the currently latest versions:
@vendia/serverless-express 4.12.6
AND
@codegenie/serverless-express 4.17.0

This is my code:

import serverlessExpress from '@vendia/serverless-express'
import app from './express.js'

export default serverlessExpress({
  app,
  binarySettings: {
    isBinary: () => true,
    contentEncodings: [],
  },
  resolutionMode: 'PROMISE',
})

A basic promise handler like this one did work so it seems not to be a generic problem with the new Lambda node 24:

export default async function handler(event, context) {
  return {
    statusCode: 200,
    headers: {
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      healthy: true,
      status: 200,
    }),
  }
}

Did anyone ever managed to use @vendia/serverless-express with lambda runtime node 24?

[ibnuda]

@giorgio-zamparelli have you tried this, mate?

[denyo]

@giorgio-zamparelli the first beta release for node 24 came out yesterday: https://github.com/CodeGenieApp/serverless-express/releases/tag/v5.0.0-beta.1