trolls.dev
03 The map — case study

Thyseus

Live object detection & GPS mapping from public cameras.

Thyseus turns the internet's thousands of public traffic cameras into one live, shared map. Detection runs right in your browser — no install, no server farm — and every vehicle, person, and sign it spots lands on the map with real GPS coordinates.

Status
Live
Platform
Web
Price
Free — community-powered
Field
Computer vision · Mapping
Open the live map ↗ All work
thyseus.com Live
cam · I-80 EB
car 0.97
2 detections · 39.53°N, -119.81°W detected in your browser
Every open browser tab is a sensor. Together, they're a map. The bet behind it

Why we built it

Thousands of public eyes, and no shared picture.

Every state transportation department streams hundreds of public traffic cameras. They're open to anyone — but each is its own tiny window. To see anything across a city, you'd have to watch them all at once.

Running detection on all of them from a central server means renting a GPU farm and paying for every frame, forever. That's the wall most "smart camera" projects hit, and why so few of them stay free or stay up.

But everyone who opens a feed is already decoding that video on a device with an idle neural engine. The compute to watch the cameras already exists — it's just scattered across everyone's browsers.

The cameras are already public and the compute is already yours. Thyseus just connects the two.

What we made Four moves
  1. 01

    Detection in the browser

    Open a public camera feed and a computer-vision model runs on your own device, frame by frame. Nothing to install, no GPU farm to rent — and no video ever leaves your machine, only the labels it finds.

  2. 02

    Coordinates, not just camera names

    Every sighting is placed with calculated GPS coordinates from the camera's known position and field of view. A detection becomes a point on a map, not a line in a log.

  3. 03

    One shared, live map

    Each contributor's detections stream to the same map in real time. Browse the country's live traffic cameras by state and watch the map fill in as more tabs come online.

  4. 04

    A reason to keep a tab open

    Submit new cameras, rack up detections, and climb the contributor leaderboard. The map is only as alive as the tabs pointed at it — so contributing is the whole game.

Choices we sweated

A camera network with nobody's servers at the center.

The edge, not a server farm

We could have centralized detection and billed for every frame. Pushing the model into the browser instead means the network scales with its contributors, not with our cloud bill — and it stays free.

Public feeds, and only public feeds

Thyseus reads the same government traffic cameras anyone can already pull up in a browser. It's a sharper lens on public data — not a new source of it.

Honest coordinates

A detection is only as trustworthy as its location. We place each sighting from real camera geometry and show the coordinates, so the map can be checked rather than just believed.

Further reading from the journal

Why we only build things we run ourselves — Thyseus very much included — is in Why we only build what we run, and the case for keeping software small enough for a night shift is in In defense of small software.

Thyseus reads publicly available government traffic-camera feeds and runs detection on the viewer's own device. It is an independent project and is not affiliated with or endorsed by any transportation department.

Colophon End of Case Study 03

The map is live right now.

Open a camera and your browser becomes one more sensor on the network — every detection it makes lands on the shared map for everyone.

Open the live map ↗ More case studies →