One account's ledger (Kontoauszug) — every booking that touched it, in date order, with Soll/Haben and the running balance after each line (CompanyMember).

No fiscal-year parameter: the chart is FY-owned, so account_id already fixes the year. Posted and reversed entries are included (a reversal is a second posted entry, so both legs must show or the balance is wrong); drafts are not. The running balance is carried across pages by the server — page_opening_balance enters this page's first row, while closing_balance/total_debit/total_credit describe the whole window. 404 when the account is not this company's; 422 when date_from is later than date_to.