Citation protocol
How we measure AI citations
Agents·Index asks AI answer engines questions about the agents in this index and records which sources their answers cite. This page explains what we measure and how to read it.
On this page
What we measure
We send a question to each engine's API with web search on, then save the answer and the sources it lists. A citation is a source URL or title returned with the answer.
A citation shows that an engine listed a page as a source. It does not show that the page supports a specific claim, or that it sent anyone traffic.
Engines
We query the API versions of ChatGPT, Claude, Perplexity and Gemini. Results can differ from what you see in each app, which also depends on your location, account and settings.
Questions we ask
Questions come from the agents and collections in this index, a short list of broad category questions, and a fixed panel of popular search terms in the category. Together they are a sample of what buyers ask.
How to read a result
Each reading is one answer to one question on one date. Answers vary from one request to the next, so treat a single reading as a snapshot of that day. We collect readings when we run a study, on no fixed schedule.
Corrections
Found an error in the method? Tell us. For how listings are built and ordered, see how we rank.