What my last company did was to find any way to integrate with the apis without contacting them. Throttle and cache calls to avoid hitting limits, use web scrap

What my last company did was to find any way to integrate with the apis without contacting them. Throttle and cache calls to avoid hitting limits, use web scrapping to access any data you can to avoid restrictions. Some companies may never interact with you whilst you are small. But if your customer is also their customer you might be able to make headway, and if you can onboard without the relationship then it may lead to one