Search Console is a free service that enables you to monitor your site's performance in Google Search, to ensure that Google can crawl your site or app correctly, and to test the validity and performance of a given page. Search Console provides programmatic access to the service through the APIs documented here.
Search Console API
Query your search analytics data, manage sitemaps, and see crawl errors.
URL Testing Tools API (Experimental)
Run a set of validation tests against a single URL.