Extension fails to install due to Node.js 18 runtime deprecation (Cloud Functions 1st Gen)

[neoassyrian]

Hi team,

The current published version of the Mailchimp Firebase Sync extension fails to install because it attempts to deploy Cloud Functions using the Node.js 18 runtime, which Google Cloud has now officially decommissioned and blocked from new deployments.

During installation, Firebase returns the following error for every function in the extension:

Runtime validation errors:
[error_code: DEPLOYS_NOT_ALLOWED
message: "Runtime nodejs18 is decommissioned and no longer allowed.
Please use the latest Node.js runtime for Cloud Functions."]

This causes the extension to fail during deployment with multiple RESOURCE_ERROR failures like:

Failed to create 1st Gen function:
runtime: Runtime validation errors
status: INVALID_ARGUMENT
message: "Runtime nodejs18 is decommissioned and no longer allowed."

---

Why this is happening

• The extension currently uses 1st Gen Cloud Functions
• The functions are pinned to nodejs18
• As of late October 2025, Node.js 18 has been officially sunset and blocked
• Google no longer allows deployment of new 1st-gen functions using that runtime

Reference (Google decommission schedule):
https://cloud.google.com/functions/docs/runtime-support#deprecation_timeline

---

Suggested fix

To restore installability:

1. Bump the Cloud Functions runtime to Node.js 20 or Node.js 22
2. Optionally migrate to 2nd Gen Cloud Functions (firebase-functions/v2) for longer-term support

Example updates:

"engines": {
  "node": "20"
}

Or in firebase.json:

{
  "functions": {
    "runtime": "nodejs20"
  }
}

---

Impact

This issue affects:

• All new installs of the extension
• Any project attempting to re-deploy the extension functions
• Firebase users unable to complete installation after following the documented steps

[BruSD]

Any update regarding this issue?