`userId` Not Included in Event Object When Using `@segment/analytics-node`

[kkanyingi]

Description

I've been following the Segment docs to send page and track events using the @segment/analytics-node package in my Node.js API.

However, when I call analytics.page as documented:

analytics.page({
    userId,
    properties,
});

I get the following validation error:

Error: .userId/anonymousId/previousId/groupId is nil

Upon inspecting the event object passed to assertUserIdentity(event), I noticed that userId is missing:

{
  "timestamp": "2025-03-21T15:01:38.730Z",
  "integrations": {},
  "type": "page",
  "properties": {},
  "context": {},
  "messageId": "node-next-...."
}

Interestingly, if I pass userId as the first argument:

analytics.page(userId, {
    userId,
    properties,
});

It bypasses the validation error but then causes issues elsewhere.

Question

Is this the expected behaviour? Am I structuring the call incorrectly, or is there a known issue with how userId is handled? Any guidance would be appreciated!

[silesky]

Howdy! Your first example looks ok, and we have tests for this. This library is used by many people to send millions of events, so not sure what's happening.

analytics-next/packages/node/src/__tests__/integration.test.ts

Line 214 in bc32a3d

expect(ctx2.event.userId).toEqual('user-id')

Are you sure absolutely sure userId is actually defined and not nil when the function is being called? You can try calling with a hardcoded string as the user ID and you shouldn't see any error.

[kkanyingi]

Hi @silesky,
Thank you for the response. I reran the same code as my first example again this morning and all seems to be fine now. Not sure why I was getting errors on Friday as nothing has changed since then. My userID variable was returning a string before I called analytics.page and I can also see it was picked up fine in the analytics.identify validations.
I'll mark this as closed as no longer an issue
Thanks