RouteStory (YatraKatha)

Inspiration

Every day, millions of Indians drive past ancient temples, historic forts, and cultural landmarks without knowing their stories. We were inspired to solve this problem after missing countless heritage sites during our own road trips. What if we could turn every commute into a learning experience?

What it does

RouteStory is an AI-powered audio storytelling app that transforms road trips into immersive historical journeys. Using Gemini 3 Flash API, our app:

Detects landmarks along your route using GPS proximity Researches each landmark in real-time using Gemini 3 Flash with Google Search grounding Generates personalized 60-second audio narrations optimized for safe driving Delivers fascinating stories exactly when you need them - no hands, no screens

How we built it

We architected a sophisticated 3-tier Gemini 3 Flash pipeline:

Orchestrator Agent (Vertex AI) - Routes natural language queries to specialized agents Research Engine (Gemini 3 Flash + Google Search grounding) - Verifies facts with source URLs and confidence scoring Narration Generator (Multi-level thinking) - Low-thinking for fast 60s narrations, medium-thinking for deep historical essays The mobile app uses React Native with background GPS tracking, triggering notifications 1km before landmarks. We integrated Google Maps API for route calculation and Google Places API for landmark discovery.

Challenges we ran into

Hallucination prevention: LLMs often generate generic or incorrect facts. We solved this with Google Search grounding, GPS disambiguation (6-decimal precision), and 60+ post-processing rules. Driver safety: Audio narrations needed to be engaging but concise. We enforced strict 150-word limits with short sentences (max 12 words) and banned all stage directions. Same-name landmarks: "Murugan Temple" exists in 1000+ locations in Tamil Nadu. We use precise GPS coordinates to ensure Gemini researches the EXACT landmark. Background processing: React Native limitations required careful state management for notifications across app/background mode switches.

Accomplishments that we're proud of

Built a production-ready app with 22 specialized services working in harmony Achieved 60-80% cost reduction vs Claude API by strategically using Gemini's multi-level thinking Created a comprehensive fact verification system (HIGH/MEDIUM/UNVERIFIED confidence scores with source URLs) Designed a driver-safe, hands-free interface that works seamlessly with Google Maps Made it scalable to ANY route in India with zero pre-defined database (can be made Global easily !!).

What we learned

Gemini 3 Flash's thinking_level parameter is a game-changer: low-thinking for speed (sub-2s), medium-thinking for depth Google Search grounding dramatically improves factual accuracy and traceability Post-processing is critical: even with perfect prompts, LLMs need aggressive artifact removal for audio GPS precision matters: 6-decimal coordinates (±0.1 meters) prevent location confusion Background location tracking on mobile requires careful permission handling and battery optimization

What's next for RouteStory (YatraKatha)

Multilingual support: Leverage Gemini's 100+ language support for Hindi, Tamil, Telugu narrations Voice first queries: "Tell me about that red temple" using Gemini's speech understanding Multimodal input: Point phone at landmark → instant photo-based narration AR overlays: Show historical images overlaid on current view Premium features: Deeper research, personalized narration styles, offline mode B2B partnerships: License to tourism boards, navigation apps, travel agencies

This mobile app is in testing phase in Android. Try out links below

Built With

• asyncstorage-(caching)
• expo-location-(gps-tracking)
• expo-notifications-(local-notifications)
• expo-sdk-54
• expo-speech-(text-to-speech)
• gemini-3-flash-api-(multi-level-thinking:-low-+-medium)
• google-cloud-functions
• google-maps-api-(route-calculation)
• google-places-api-(landmark-discovery)
• google-search-grounding-(fact-verification)
• googlemaps/google-maps-services-js
• react-native
• react-native-paper-(ui)
• sentry-(crash-reporting)
• typescript
• vertex-ai-agents-(orchestrator-deployment)