A demo project showing Tesla Autopilot-like behavior using Jev by TypeSafe AI.

Sign in with Standard Agents for $0.25 of free Jev play credit. Joining the early-access list is optional.

The hosted /api/decide endpoint requires a valid login session. The browser sends its secure, HttpOnly session cookie; the Jev API key stays on the server.

Interstate 08: start in Millbrook, turn onto the signed on-ramp, merge, cruise, and exit into Cedar Town for the final stop.

Jev receives compact tables of eligible paths, road boundaries, nearby traffic, signals, stop memory, and destination guidance. Shared table values are sent once, and instructions include only relevant situations. The road graph is sent only when choosing an alternative route after staying more than 30 meters off course for six seconds. Detailed geometry and control calculations stay local.

The simulator samples fresh steering-and-speed combinations for each decision. On the road, it favors paths that keep the whole car on asphalt. Off road, it explores a wider field of forward and reverse paths and supplies a recovery target, road boundaries, and collision predictions.

An explicit driving_style describes an aggressive driver: keep progressing, stop at the actual line, and close gaps before stopping behind an obstacle. Jev can choose an approach path that progressively slows to a stop 0.5 m before the line. An immediate stop is offered only within 2.5 m of a blocker or required stop line, at the destination, or when no eligible moving path exists. Candidate speeds taper near required stops. Jev receives recent-stop memory and collision timing; a safety brake handles collision risks.

Use Candidates to show the sampled paths: blue/cyan for forward, purple for reverse, amber for paths leaving the lane, orange for predicted collisions, and bright blue for Jev’s selection. Candidate generation and route searches run in a background worker; the renderer smoothly blends the sampled shapes. Open JSON to inspect road boundaries, recovery state, and actual choice probabilities.

Requests run up to 4 times/second near turns or traffic, and about 1.5 times/second on clear roads. Questions with one eligible answer are resolved locally. JSON → Jev input shows the exact API payload; the cost tooltip and response tab show average payload size and billed input tokens.

npm ci
cp .env.example .env
# Set TYPESAFE_API_KEY in .env.
npm run dev

Add your own TypeSafe AI API key to .env:

TYPESAFE_API_KEY=your_key_here

Open localhost:5173. Local development skips all login, signup, and demo credit limits. No Standard Agents OAuth credentials are needed. Jev calls use your own key and TypeSafe account billing; free play works without a key. The key stays server-side in the gitignored .env—never use a VITE_ variable for it.

This also applies to npm run preview after npm run build. Restart the local server after changing .env.

J toggles autopilot · WASD to drive · Space to brake.

Asset credits and licenses are included in public/.

Cloudflare deployment details: docs/hosting.md.