mediationReport:generate returns empty response (header + footer only) for all MCM child accounts since ~March 11, 2026

[熊倉一哉]

Hi,

We have been using the AdMob API (`accounts.mediationReport.generate`) to fetch mediation report data for our MCM child accounts (52 publishers), and it had been working fine.

However, since around **2026-03-11**, the API started returning only a header and footer with **no row data** for all accounts.

---

## What doesn't work
- mediationReport:generate returns HTTP 200 with header + footer only (no `row` entries)
- Affects all 52 MCM child accounts and the parent account
- Affects all date ranges, including historical dates that previously returned data
- Affects all dimension/metric combinations, including minimal requests with only `["IMPRESSIONS"]` and no dimensions

## What still works
- AdMob console (UI) shows data correctly for the same accounts and date ranges — the data exists, but the API does not return it
- `networkReport:generate` returns data correctly for the same accounts and date ranges
- `accounts.adUnits.list` returns ad units for child accounts
- `accounts.apps.list` returns apps for child accounts
- `accounts.list` returns the parent account
- OAuth token refresh works correctly

## What we have verified

- Tested with 4 different refresh tokens (re-authorized via OAuth Playground)
- Authorized with the Administrator account
- OAuth scopes: `admob.readonly` + `admob.report`
- AdMob API is enabled in Google Cloud Console
- OAuth consent screen is in production mode
- Added AdMob scopes to OAuth data access configuration (no effect)
- No API errors in Google Cloud Console (all responses are 200)

## Example request

- POST：https://admob.googleapis.com/v1/accounts/pub-XXXXXXXXXXXX/mediationReport:generate

{
  "reportSpec": {
    "dateRange": {
      "startDate": {"year": 2026, "month": 3, "day": 1},
      "endDate": {"year": 2026, "month": 3, "day": 1}
    },
    "metrics": ["IMPRESSIONS"]
  }
}


## Response (same for all accounts and dates)

[
  {
    "header": {
      "dateRange": {
        "startDate": {"year": 2026, "month": 3, "day": 1},
        "endDate": {"year": 2026, "month": 3, "day": 1}
      },
      "localizationSettings": {"currencyCode": "JPY"}
    }
  },
  {
    "footer": {}
  }
]


For comparison, `networkReport:generate` with the same account and date range returns data correctly:

[
  {"header": { "..." : "..." }},
  {"row": {"dimensionValues": {"DATE": {"value": "20260301"}}, "metricValues": {"IMPRESSIONS": {"integerValue": "659777"}}}},
  {"footer": {"matchingRowCount": "1"}}
]


---

This appears similar to the issue reported in [this thread](https://groups.google.com/g/google-admob-api-developer-forum/c/32LRCEhZWM8) where a buggy change caused `mediationGroups.list` to return empty responses (December 2025).

Could you please investigate if a similar change has affected the　mediationReport:generate endpoint?

This is blocking our daily reporting pipeline and we currently have 5+ days of missing mediation data.

Thank you.

[AdMob API Developer Forum]

Hello,

Thanks for reaching out.

Can you please check again now and confirm if the issue still persists?

Most probably, we had a auth related change that only impacted MCM use case. The issue should be resolved by now.

Thanks,

[熊倉一哉]

Hello!

Thank you for the update.

I have just checked, and I can confirm that the reports are now being generated and retrieved without any issues. It seems the fix for the authentication change has successfully resolved the problem.

Thank you for your prompt support and for looking into this.

2026年3月18日水曜日 11:53:07 UTC+9 AdMob API Developer Forum: