messageId gets overwritten when set manually on .track calls.

[julio-poplin]

Me and my team are running into a situation where we need to take advantage of the deduplication Segment offers using the messageId field, as described in the documentation

https://segment.com/docs/guides/duplicate-data/#99-deduplication

So to achieve this, our paylod looks like this

  const event = {
    messageId: "internalUniqueIdWeControl",
    event: eventType,
    userId,
    properties: {...},
  };

Based off the payload structure showed here, https://segment.com/docs/connections/spec/track/#example where messageId is on the top level of the payload object.

Yet when we call segmentClient.track(event) The messageId always gets overwritten by a library generated messageId that looks something like this: "messageId": "node-next-1741121581880-774db6ae-0dac-4d17-b7d9-785f42d45a68" effectively removing the ability to use the deduplication feature.

[silesky]

What library are you using, and can you give an example of a function call? segmentClient.track(event) is not an API for analytics.js 🤔 I don’t think we added support for overriding in analytics.js, as that’s not a library that is generally used for interacting with our segment API programmatically (e.g. through scripts) — the HTTP API or the node library is more common here.

@segment/analytics-node does have the API that you’re describing, with a field to override messageID, and it is usable in a web env (it won’t manage user ID inside of localstorage or support any device mode destinations, obviously)

[julio-poplin]

I'm somewhat confused by your reply, the library is indeed @segment/analytics-node.

I already have provided an example of a function call, segmentClient is just the variable name, but it is an instance of Analytics.

Basically the call that is documented here:
https://segment.com/docs/connections/sources/catalog/libraries/server/node/#track

You say

@segment/analytics-node does have the API that you’re describing, with a field to override messageID

But that's literally what the issue I'm reporting is. If you try to override it, it doesn't actually get overwritten.

[julio-poplin]

Closing this issue, support replied, the reason is I'm using 1.1.3, upgrading to 2.2.1 made it work as expected.