The company the API key is working in (name, IČO, DIČ, IČ DPH, address, VAT-payer flag, bank accounts) and the remaining API quota (SuperFaktura's fair-use policy is 1000 requests per day and 31000 per month; every tool call here uses one request). Good first call. With all_companies=true also the other companies the user can access (their ids are the company_id of the login). GET /users/getUserCompaniesData.