Your Gemini Answer Has Citations. Is It Actually Grounded?

Adding citations to an AI answer feels like the moment the system becomes trustworthy. The response looks researched. Source links appear beside the text. The model is no longer answering only from its training data. But a cited answer can still be wrong. A citation may support a nearby sentence rather than the claim the user cares about. A source may be authoritative while the retrieved passage is stale. File Search may query the wrong store or document version. The model may retrieve good evidence and then write a conclusion that goes beyond it. Grounding is a capability. Trust still requires an application contract. Series note: This is Part 6 of Reliable Google AI Agents in TypeScript . The Interactions API examples use its post-May-2026 steps schema and were checked against @google/genai 2.21.0. The API remains beta, so pin and retest the SDK before copying production code. Retrieval success is not answer success Gemini can ground responses with Google Search for current public information and File Search for indexed domain-specific documents. The Interactions API exposes the execution steps and inline citation annotations, giving the application more evidence than a text completion alone. A minimal Google Search interaction looks like this: import { GoogleGenAI } from " @google/genai " ; const ai = new GoogleGenAI ({}); const interaction = await ai . interactions . create ({ model : process . env . GEMINI_MODEL ?? " gemini-3.8-flash " , input : " What changed in the public policy this week? " , tools : [{ type : " google_search " }], }); The synthesized text is only one part of the result. The steps show whether search occurred and where citations attach. type Citation = { title ?: string ; url ?: string ; citedText : string ; }; const citations : Citation [] = []; for ( const step of interaction . steps ?? []) { if ( step . type !== " model_output " ) continue ; for ( const contentBlock of step . content ?? []) { if ( contentBlock . type !== " text " ) contin