Groups are not working

[mnapoli]

groupIdentify() doesn't work

            PostHog::groupIdentify([
                'groupType' => 'team',
                'groupKey' => $team->id,
                'properties' => [
                    'name' => $team->name,
                ],
            ]);

It pushes events that are attached to a broken user:

Full payload:

{
  "uuid": "019585bf-7ccf-7ecd-b9c6-1a748a7eab86",
  "event": "$groupidentify",
  "properties": {
    "$group_set": {
      "created_at": "2024-07-11",
      "name": "Team name"
    },
    "$lib": "posthog-php",
    "$lib_version": "3.0.3",
    "$group_key": 1,
    "$lib_consumer": "LibCurl",
    "$active_feature_flags": [],
    "$group_type": "team",
    "$geoip_...": "...",
    "$transformations_succeeded": [],
    "$transformations_failed": []
  },
  "timestamp": "2025-03-11T16:07:53+01:00",
  "team_id": ...,
  "distinct_id": "$team_1",
  "elements_chain": "",
  "created_at": "2025-03-11T16:07:55.062000+01:00"
}

The problem lies here:

"distinct_id": "$team_1",

I think this line is wrong:

posthog-php/lib/PostHog.php

Line 98 in 9010c6d

"distinctId" => "\${$message['groupType']}_{$message['groupKey']}",

$group_type in capture is not working

Because of the problem above, I tried attaching the group to every event instead:

        $properties = [...];

        $properties['$group_type'] = 'team';
        $properties['$group_key'] = $team->id;

        PostHog::capture([
            'distinctId' => $user->id,
            'event' => $event,
            'properties' => $properties,
        ]);

The event is now attached to the user but not the group.

Full payload:

{
  "uuid": "019585d4-62cc-71ec-a70a-bb2dbc06a386",
  "event": "Event name",
  "properties": {
    "$group_type": "team",
    "$lib": "posthog-php",
    "$active_feature_flags": [],
    "$lib_version": "3.0.3",
    "$group_key": 1,
    "$lib_consumer": "LibCurl",
    "$set": {
      "$geoip_...": "...",
    },
    "$set_once": {
      "$initial_geoip_...": "..."
    },
    "$geoip_...": "...",
    "$transformations_succeeded": [],
    "$transformations_failed": []
  },
  "timestamp": "2025-03-11T16:30:43+01:00",
  "team_id": ...,
  "distinct_id": "1",
  "elements_chain": "",
  "created_at": "2025-03-11T16:30:44.506000+01:00"
}

If we only look at user and group-related data:

{
  "properties": {
    "$group_type": "team",
    "$group_key": 1,
  },
  "distinct_id": "1",
}

That looks incorrect. If I compare to an event reported by the web (JavaScript) SDK:

{
  "event": "$pageview",
  "properties": {
    "distinct_id": "1",
    "$user_id": "1",
    "$groups": {
      "team": 1
    },
    "$group_0": 1
  }
}

Properties don't look formatted the same way.

Is the PHP SDK using an obsolete format for the events API?

To be clear:

• events reported by the web SDK are attached to the group
• events reported by the PHP SDK are not attached to the group

[benjackwhite]

Hi, there is a difference between groupIdentify and groups - for server side SDKs we don't "attach" groups to the user as the $groups property has to be sent with every event and hence it is generally a client-sdk thing.

For server side you call $groupidentify to set properties on that group. When capturing events for a given user you would specify the property $groups: { [key]: value }. Those $group_type,$group_key,$group_set properties are unique to the $groupidentify event and are ignored for normal events.

We have a doc explaining this here which hopefully makes more sense https://posthog.com/docs/product-analytics/group-analytics

[mnapoli]

Ah I see, so groupIdentify doesn't set the group for the rest of the session, makes sense. However that creates an invalid "person" in PostHog, is that expected?

As for the fix you suggested for events (not groupIdentify), it works, thank you!

[nclavaud]

However that creates an invalid "person" in PostHog, is that expected?

I'm confused all the same. We track organizations, and when identifying an organization, it appears in the Persons tab:

I am using the PHP SDK and was wondering if this issue is specific to it. However, it seems the Python SDK generates the same ID:

distinct_id = "${}_{}".format(group_type, group_key)

https://github.com/PostHog/posthog-python/blob/18729e33b800db60decc3d48fff67b23509651ed/posthog/client.py#L441

The Go SDK behaves similarly:

distinctId := fmt.Sprintf("$%s_%s", msg.Type, msg.Key)

https://github.com/PostHog/posthog-go/blob/e2351f53af852b5f3192b3a89421b7ca4aba7fa1/group_identify.go#L57

Therefore, I believe the issue is not specific to the PHP SDK. I found a related issue in the main PostHog repository:
PostHog/posthog#7921