Pathpal

Inspiration

Malls, airports and stations are easy to get lost in, and harder still with a wheelchair, stroller or suitcase. Phone maps almost dont work indoors. I wanted an easy guide that walks with you. That potentially can be used offline for places where internet connection is challenging.

What it does

Find Your Way Inside turns Snap Specs into an indoor guide. Scan a sign to start, and a robot or pet companion walks ahead of you. It can lead you to a place you name, or point out places that match your preferences while you wander. Step-free mode avoids stairs, and looking at a shop shows its offers.

How we built it

We used Lens Studio and TypeScript, with Snap's CLAD plugin and an AI coding agent connected through MCP. Each building is a graph $G = (V, E)$. In step-free mode, stairs cost $w(e) = \infty$, and Dijkstra's algorithm finds the route:

$$d(v) = \min_{(u,v) \in E} \big( d(u) + w(u,v) \big)$$

Everything was built test-first.

Challenges

• A companion that behaves. Keeping it about 6 m ahead without cutting through walls or shop doors.
• Minimal interface. On glasses every panel blocks the view, so menus had to fold away once set.
• No hardware. We built and tested everything in the Lens Studio preview, which resets roughly every 50 minutes, so test runs had to be split into short batches.
• Fragile tooling. Lens Studio once added packages on its own that broke the build, and a preview automation tool crashed it, so we scripted our own test and recording runs.
• Paradigm switch. It is not the same to code for screen then code for the glases. Think needs to be more subtle.

What we learned

On glasses, less interface is better. Indoor mapping still is a problem and creating a map in automated or manual way it is also a challeng. As addon we included map builder mode. AI agents need guardrails. An AI agent can write code fast, but you need guardrails and TDD provides nice initial setup and allows to show the final goal.

Built With

• ar
• clad
• dijkstra
• github
• lens
• openspec
• typescript