List the sites this API key can read. Response: {"sites":[{"site_id":123,"name":"<as entered by the owner — often a full URL like https://example.com/>","hash":"07k1eD84d2","timezone":"Europe/Amsterdam","hobby":false,"stats_start_date":"YYYY-MM-DD"|null,"created_at":"RFC3339"}]}. hobby=true is a free-plan site: it counts only through the bundled /t/ script get_tracking_snippet returns, so install that snippet verbatim. Use site_id with the other tools. With date_range each site also carries metrics NESTED under stats.metrics (never flat on the site object). An account with no sites gets {"sites":[],"next_step":"…"} — follow next_step: usually ask the user for their website and call create_site, then get_tracking_snippet. Units: visit_duration = average seconds per visit; bounce_rate = percent 0-100; views_per_visit = pageviews/visits ratio; visitors/pageviews/visits = counts. Stats period boundaries are server-time approximations; use query_stats for timezone-exact numbers.