How to use the GSC and GA4 Insights API

The GSC and GA4 Insights API lets you pull your Google Search Console and Google Analytics 4 data out of Sitechecker into your own tools and reports.

Both are modules inside the Sitechecker Public REST API, sharing the same key, projects, and error handling.

The value is that Sitechecker has already cleaned and joined the two sources for you.

GSC tells you how you perform in search. GA4 tells you what that traffic then does. The search to conversion endpoints bridge the two, so you can report rankings and revenue in one place.

It is built for agencies and SEO teams automating client reporting, quick win analysis, and revenue attribution.

Who can use it

Public API access is  available on any plan.

You also need your API key, a project, and Google Search Console connected to it. GA4 endpoints and the search to conversion bridge also need GA4 connected.

Missing connections return GSC_NOT_CONNECTED   or GA4_NOT_CONNECTED  .

Setup

Authentication and project setup are the same as the rest of the Public API. Follow the getting started guide for your API key and project_id  .

In short: send the key as Authorization: Bearer <your_api_key>   and use the base path https://sitechecker.pro/api/v1  . You can only access your own account's projects.

Read your project's filter values first, so you pass valid countries, devices, and segments instead of guessing. Unsupported filter values are rejected, not ignored:

curl --url 'https://sitechecker.pro/api/v1/gsc_filter_values?project_id=12345' \
  --header &#39;Authorization: Bearer <your_api_key>&#39;

GA4 has its own ga4_filter_values  .

The endpoints

Most endpoints take date_from   and date_to  , plus limit   and offset  . Filters (segment_id  , country  , device  , keyword  ) go in the query.

GSC Insights

GA4 Insights

Shared: projects  , segments  , segment_details  .

Example, the GSC performance overview:

curl --url 'https://sitechecker.pro/api/v1/gsc_performance_summary?project_id=12345&date_from=2026-06-01&date_to=2026-08-31' \
  --header &#39;Authorization: Bearer <your_api_key>&#39;

Rules to remember

• GSC and GA4 must be connected. Without them, requests return GSC_NOT_CONNECTED   or GA4_NOT_CONNECTED  . Search to conversion needs both.
• Read the dates back. The response carries the dates actually used; the window can be shorter than you requested if data is missing.
• Comparison is built in. Summary endpoints accept a comparison period and return diffs against it, so you do not compute change yourself.
• Filters are validated. Read gsc_filter_values   or ga4_filter_values   first; unsupported values are rejected, never silently ignored.
• Paginate. Use limit   and offset  , and read the total from the response.
• Segments scope everything. Pass segment_id   to focus any report on the pages that matter.

Use cases: how agencies use it

1. White label GSC and GA4 reporting.

   Pull gsc_performance_summary  , ga4_site_summary  , and top keywords and pages on a schedule into branded reports. One API replaces manual exports from two Google tools, and no per seat fees means you can cover every client.

2. AI written performance commentary.

   Pipe the JSON into an AI assistant (for example Claude) to explain why clicks or traffic moved and draft client ready notes.

3. Search to conversion, the revenue story.

   gsc_search_conversion_summary   and gsc_search_conversion_pages   tie rankings to GA4 outcomes, so clients see which search traffic actually converts, not just impressions.

   

4. Quick wins with keyword gaps.

   gsc_keyword_gap_pages   surfaces pages a few positions from breaking through; drill in with gsc_keyword_gap_page_keywords   for the exact terms to optimize.

   

5. Fix cannibalization.

   gsc_cannibalization   finds queries where several of a client's pages compete, and gsc_cannibalization_pages   shows which ones, so you can consolidate.

   

6. Won and lost tracking with alerts.

   gsc_new_lost_keywords   and gsc_new_lost_pages   report movement over the period and drive drop alerts to Slack or email.

   

7. Segment and breakdown reporting.

   Report by gsc_page_segments   for money pages versus blog, or by gsc_countries   and gsc_devices   for local and mobile-first clients.

   

   
   
8. Custom dashboards and BI. Feed clean, pre joined JSON into Looker Studio, a client portal, or a spreadsheet, and refresh it automatically.

Common errors

INVALID_API_KEY   / REVOKED_API_KEY   (bad or revoked key), MISSING_PUBLIC_API_ACCESS   (no entitlement, check plan), ACCESS_DENIED   (project belongs to another account), PROJECT_NOT_FOUND  , GSC_NOT_CONNECTED   / GA4_NOT_CONNECTED   (connect the source in the project), INVALID_FILTER   (unsupported filter, recheck against filter values), RATE_LIMIT_EXCEEDED   (slow down and retry).

FAQ

What is it used for?

Programmatic access to your Search Console and GA4 data, already cleaned and joined, for reports, dashboards, quick win analysis, and revenue attribution.

How do I authenticate and get my project ID?

Bearer token in the Authorization   header plus a project_id  , both covered in the getting started guide.

Do I need both GSC and GA4 connected?

GSC endpoints need Search Console. GA4 endpoints and the search to conversion bridge also need GA4. Each returns a clear error if its source is missing.

Can I compare two periods?

Yes, summary endpoints accept a comparison period and return diffs against it.

Need help?

Questions? Reach us at support@sitechecker.pro, or see the API documentation. Happy reporting!