Open APIs are free for anyone to use — they're great for building public apps and fostering innovation. Partner APIs are restricted to approved third parties, with strict usage agreements. The India API market forecast shows that open APIs hold the largest share, but partner APIs are the fastest‑growing. Why? Because pharma companies want to control who accesses their data, especially when it comes to patient information or proprietary manufacturing processes.

What's driving partner API growth? Collaborations between drug manufacturers and digital health startups. A pharma company might expose a partner API to a telemedicine platform, allowing doctors to check drug availability and pricing in real time. The India API market analysis notes that the fastest‑growing end‑use industry is telecommunications — because telecoms are building health platforms for their millions of subscribers.

But partner APIs require governance. You need to monitor usage, enforce rate limits, and ensure compliance with data protection laws. That's why API management platforms are becoming essential.

The bottom line: open APIs are for innovation, partner APIs are for control. Choose based on your business model and risk tolerance.