Trail Quest: Private, On-Device AI for Nature Walks

Anvi Pardhi — Tue, 06 Oct 2026 09:48:24 +0000

This is a submission for the Hacktoberfest Open-Source AI Challenge Week 1: Touch Grass

What I Built

Trail Quest is a mobile-first web app that turns a little time outdoors into a nature-spotting quest. Choose a setting—such as a park, garden, neighborhood, trail, or balcony—and a time limit. Trail Quest gives you three observation challenges, then encourages you to put your phone away and explore.

You can complete or skip challenges, keep private reflection notes, and save completed walks in a local nature journal. There’s also a high-contrast sunlight mode for using the app outdoors.

Demo

Try Trail Quest: https://trail-quest-l6yb.onrender.com

Code

Source code: https://github.com/Anvi-2006/trail-quest

How I Built It

Trail Quest uses WebLLM to run the open-weight SmolLM2-135M-Instruct-q4f16_1-MLC model in the browser with WebGPU. Quest generation happens on the user’s device, so the user’s setting and prompts aren’t sent to an AI API.

If the model can’t run on a device, Trail Quest offers clearly labeled handcrafted quests instead. Handcrafted mode works offline. AI mode needs an initial model download; after that, the browser can reuse its cached model for local generation, subject to browser storage and WebGPU support.

I built the interface around a short, accessible flow: choose a setting and duration, get three quests, and then switch to a “phone away” screen. The app also includes safety guidance, local journal storage, Markdown export, and synthesized chimes made with the Web Audio API.

Why Does Open Innovation Matter?

The open-weight model and browser-based inference make this experience possible without sending a person’s outdoor plans to a hosted AI service. The model can be inspected and swapped, and the handcrafted fallback keeps the app useful when AI inference isn’t available.

That matters for an app whose goal is to help people pay attention to the world around them: it can keep personal inputs on-device, reduce dependence on a paid API, and let the community adapt the experience for different models and devices.

Prize Categories

Best Use of Render — Render hosts the Trail Quest web app.