The U.S. Supreme Court ruled that API reuse can qualify as fair use, but that doesn’t make it a safe assumption for your business. The case, Google LLC v. Oracle America, Inc., involved a legal fight over whether reusing API code from another platform counts as copyright infringement. The Court sided with Google, but the decision turned on specific facts that don’t apply broadly.
If you’re building, integrating or launching software that touches a competitor’s API, here’s what you actually need to understand.
How and why you use the API determines fair use
Courts consider four factors when deciding fair use: purpose, nature, amount used and market impact. If you’re repurposing an API for a new function that doesn’t harm the original’s market, fair use might apply. However, if your use mimics the original too closely or serves the same market, that protection quickly falls apart.
The Oracle ruling doesn’t protect most business use cases
In Google v. Oracle, the Court ruled in Google’s favor because Android transformed how the Java API was used. It wasn’t a substitute for Oracle’s product. Most business use cases aren’t that transformative, especially when they compete with or replace the original software, and that makes fair use a risky fallback.
Copying the structure or naming increases your legal risk
Even without copying implementation code, using the same structure, sequence or naming can still lead to infringement claims. Courts don’t just look at the code; they examine the design and organization of the API itself. That’s where companies often get blindsided.
If it’s going to market, it’s time to get advice
Internal prototypes rarely trigger review, but commercial use does. If your team plans to build with or around someone else’s API, an experienced intellectual property lawyer can assess risk, recommend alternatives and keep your product timeline from stalling over preventable legal issues. A quick gut check now can save you from cleanup later.