Agent skill

Channel Acquisition Analysis

Break down sessions and users by traffic source, medium, and channel group to understand where your audience comes from and which channels perform best.

Correct dimension names

Concept	GA4 API name
Channel group	`sessionDefaultChannelGroup`
Source	`sessionSource`
Medium	`sessionMedium`
Source / Medium	`sessionSourceMedium`
Campaign name	`sessionCampaignName`
Campaign ID	`sessionCampaignId`
Ad content	`sessionManualAdContent`

Do not use sessionDefaultChannelGrouping — it does not exist. Do not combine sessionCampaignName with user-scoped metrics like totalUsers.

Step 1 — Channel overview

shell

dimensions: ["sessionDefaultChannelGroup"]
metrics: ["sessions", "totalUsers", "newUsers", "userEngagementDuration",
          "screenPageViewsPerSession", "bounceRate"]
date_range: last 30 days
order_by: sessions DESC

Step 2 — Source / medium detail

shell

dimensions: ["sessionSource", "sessionMedium"]
metrics: ["sessions", "newUsers", "userEngagementDuration", "keyEvents"]
date_range: last 30 days
order_by: sessions DESC
limit: 25

Step 3 — Campaign performance (paid)

shell

dimensions: ["sessionCampaignName", "sessionDefaultChannelGroup"]
metrics: ["sessions", "newUsers", "keyEvents", "userEngagementDuration"]
dimension_filter: {
  "filter": {
    "fieldName": "sessionMedium",
    "stringFilter": {"matchType": "EXACT", "value": "cpc"}
  }
}
date_range: last 30 days
order_by: sessions DESC

Step 4 — Trend by channel over time

shell

dimensions: ["date", "sessionDefaultChannelGroup"]
metrics: ["sessions", "newUsers"]
date_range: last 90 days
order_by: date ASC

What to report

Top 5 channels by sessions and by new users
Engagement quality per channel (userEngagementDuration per session)
Which channel drives the most key events (conversions)
Week-over-week or month-over-month trend for top channels