Hey guys. I was playing around recently with creating a Postman collection. You can do some pretty cool stuff like creating environments: https://learning.getpostman.com/docs/postman/environments_and_globals/manage_environments/, environment variables: https://learning.getpostman.com/docs/postman/environments_and_globals/variables_complete_reference/, writing test scripts: https://learning.getpostman.com/docs/postman/scripts/test_scripts, etc. So if you have any questions about it, feel free to follow up here. But we don’t currently have a shareable collection.
As for searching companies through the API, currently you can search by an exact domain name match: https://developers.hubspot.com/docs/methods/companies/search_companies_by_domain. For searching a company by owner, I’d suggest voting on the idea thread here: https://community.hubspot.com/t5/HubSpot-Ideas/Search-contacts-companies-and-deals-by-custom-properties/idi-p/32113#comments. The more votes it gets, the more visibility and traction it’ll receive. Otherwise I’d suggest pulling all companies via the endpoint documented here: Accounts Dashboard | HubSpot, along with adding a parameter of &properties=hubspot_owner_id , and then filtering after.