In order to use the API, you have to know the company ASN.
There are only two (main) endpoints
First one is /company/key_name_map.json. This endpoint can be used to obtain ASN to Name mappings.
Once you know the ASN, you can call /company/{ASN}.json. This endpoint will return the info about the company.
Please, don't spam the endpoints and cache as much as you can on your side, since the responses can be quite large (see /company/0.json).