Google Gemini has some: https://ai.google.dev/gemini-api/docs/grounding/search-sugge...
OpenAI has some rules too: https://platform.openai.com/docs/guides/tools-web-search#out...
> "When displaying web results or information contained in web results to end users, inline citations must be made clearly visible and clickable in your user interface."
I'm used to search APIs coming with BIG sets of rules on how you can use the results. I'd be surprised but happy if Anthropic didn't have any.
The Brave Search API is a great example of this: https://brave.com/search/api/
They have a special, much more expensive tier called "Data w/ storage rights" which is $45 CPM, compared to $5 CPM for the tier that doesn't include those storage rights.