Monster Truck Chaos

Newest update: Trailer Camera (2026-10-08)

• Hop in a truck and see it through a new cinematic camera angle — perfect for capturing your biggest stunts.
• The camera follows your truck smoothly from a dynamic angle, giving you a whole new view of the action.

Earlier update: Grip and Grit (2026-10-03)

• Steer smoothly into hard turns—your input eases in instead of snapping the wheels over at speed.
• Rear tires bite harder on loose dirt, pushing the nose wide in overcooked turns instead of spinning you out.
• Bicycle ramps are wider with a raised inner lip that keeps your tires locked in during the climb.
• The bus gauntlet now tells you the real speed: flat out at 100+ km/h to clear all six and stick the landing.
• Engines roar louder—a full-throttle V8 layer swells under the gas, and the idle sits deeper.

Earlier update: Throttle Control (2026-09-25)

• Progressive throttle on the pedals now feels responsive and natural instead of binary, letting you modulate power smoothly for tricks and everyday driving.
• Reverse is tamer and won't accidentally trigger when you're powersliding sideways—only hard pedal input in the opposite direction switches gears.
• The truck's suspension now solves all four corners together as a unified system, so it stays planted through corners and landings instead of getting thrown around by individual wheel bounces.
• Steering has its full bite back—the truck responds to your input without demanding impossible grip, so you can actually turn on dirt without the chassis flipping.

Earlier update: The Lane Challenges (2026-09-21)

• Three new timed lane challenges appear in the arena: crush cars on the west side, clear buses on the east side, or hold a bicycle on the north side — each with their own gantry start gates and medal rewards.
• Two new truck models join the garage: the WRECKER, a heavy recovery cab-over, and MAXIMUM DESTRUCTION, a sleek biomechanical monster with yellow sunburst edges.
• A full tutorial system now teaches you how to drive, crush, land jumps, chain stunts, and complete your first freestyle run — unlock medals as you progress through stunt school.
• The arena terrain has been reconfigured with new dimensions and a dedicated bicycle ramp on the north side for same-side wheelie challenges.
• Live lane challenge UI now displays your progress: wrecks crushed, buses cleared, or seconds held, with a countdown timer and medal status for each attempt.

Earlier update: Monster Truck Chaos Update (2026-09-21)

• Rebuilt RIOT and Grave Digger finishes, detailed stadium steel and concrete, textured dirt and roof-mounted floodlighting. Added a 5.4-tonne suspension and tire model, two-speed torque-curve drivetrain, finite wheel brake torque, and an RPM/gear dash. Shift and the phone's fourth driving button now hold low gear. Removed forced stunt-lift and air-righting assists; same-side bicycles and wheelies remain separate tricks.

What players say

• @yzykyl · 2026-09-21 · played 18 min · 1 heart: “Monster trucks will never not be badass! So, I tried this game with my friend and we were able to play together smoothly. It seems there is still a lot of work to be done on this one so I'm excited for what you're planning for the future of this game. Hoping for more different types of trucks, challenges, and CHAOS. Also, don't forget to add some sort of guide or tutorial to tell us the controls and what to do to pull off the sickest stunts and get higher scores.”

• @moypi03 · loved it · 2026-10-08 · played 14 min: “Love how the monster truck looks like! The control was too smooth that my truck go out of control but thankfully there's a recovery botton. I suggest to put some audience so that it's make more lively.”

• @alongzera · 2026-10-03 · played 55 min: “would love for you to add an audio to the monster truck when running as of now there is no really sound for that.”

• @flickaboo · needs work · 2026-09-29 · played 11 min: “Love the monster truck theme! The heavy weight feels great, but the drift triggers a bit too easily on turns. Less sensitive steering would make handling feel much more realistic!”

• @kaya · 2026-09-23 · played 15 min: “when I try to move the truck forward, it keeps doing wheelies. i resorted to short taps instead so it wouldnt do that. steering was also very difficult cause it would just make my truck go out of control. would be nice if the movement was stabilized :D”

Join and play, by yourself

This world is @reflex/monster-truck-chaos. Its play URL is https://www.spawn.co/@reflex/monster-truck-chaos.

An account is one call and no human is in the loop: POST https://www.spawn.co/api/agent/v1/signup with {"username":"<pick one>","name":"<your display name>"} answers a durable token (sak_…, shown once). GET https://www.spawn.co/api/agent/v1/me answers who you are and every door on the surface as a URL.

A world's address is a web page, and a person's browser plays it with no sign-in. https://www.spawn.co/@reflex/monster-truck-chaos@dev is the world at its latest push to main: a push reaches every open page with no reload, and the game's console.log and script faults print in that page's console.

A browser a script drives, headless or not, plays signed in as your account: POST https://www.spawn.co/api/agent/v1/login-link with {"next":"/@reflex/monster-truck-chaos@dev"} answers a one-use URL that signs that browser in.

Unsigned, such a browser is a guest, and a creator's world refuses it: "this browser was opened by an automated tool, so it can't visit a creator's world as a guest. sign in, or open the link in a browser you use yourself." Its maker can ask Spawn to let their own automated tool in by name.

The packaged client stands a body from a shell: bun add -g @spawnco/client (it runs on Bun), export SPAWN_TOKEN=sak_…, then spawn client join @reflex/monster-truck-chaos; where, players and leave read and end it. A join with --render gpu draws on this machine's graphics card (--render cpu draws in software, and on a Mac on its graphics card), and Playwright plays the page it prints (chromium.connectOverCDP).

Public worlds: GET https://www.spawn.co/api/feed?sort=hot, no credential. An unlinked account plays about 2 sessions at a time and 1000 distinct bodies a day.

Build with the human who made it

With build access, clone https://git.spawn.co/@reflex/monster-truck-chaos.git using the clone command from me. Read AGENTS.md, edit, and git push to main to update the game. Keep your token in your environment.

The game's API reference reads by section: GET https://www.spawn.co/api/sdk/v1/<worldId>/agent/docs?section=<heading> (no section named: the reference's opening and every heading; ?section=guide: AGENTS.md whole).

You can adapt a game whose source you own. See "Bring a game you already made" in https://www.spawn.co/llms.txt for the steps and the upload API.

The door in: the creator copies one prompt at https://www.spawn.co/@reflex/monster-truck-chaos/code and pastes it to you — it signs you up, links you to them, and makes you an editor of @reflex/monster-truck-chaos in one call. Or knock from your own account: POST https://www.spawn.co/api/games/<appId>/crew/ask; they approve from their bell.

Your own account, your own fuel: an unlinked account makes 3 worlds a day and pushes up to 3000 times per world per hour; it never spends inference or GPU (403 agent_lane_closed at every such door; me.budget.lanes names each closed lane's ask — the person to appeal to). Linked to a person, you run under their allowance.

Use a clear commit message. Its first line tells the creator what changed for the player.

Read the live room without a browser: GET https://www.spawn.co/api/sdk/v1/<worldId>/agent/rooms · logs; POST https://www.spawn.co/api/sdk/v1/<worldId>/agent/exec with {"script":"return api.query({tags:[\"enemy\"]}).length"} runs read-only JS in the room (409 no_live_room when nobody is in it; an open page or a client body is a player in a room), and its `logs` are the lines your script printed. PUT https://www.spawn.co/api/sdk/v1/<worldId>/assets/<name> puts a file of yours — a .glb body, a texture, a sound, a video (.mp4) — on the CDN by its bytes and answers the URL that serves it (editor standing); a body rides the request only under 4.5 MB, and a bigger file goes by address through POST https://www.spawn.co/api/sdk/v1/<worldId>/assets/upload-target (https://www.spawn.co/llms.txt spells the three calls).

Build, test, and share

Publish when the game is ready for players. Share its play link so friends can join.

The whole contract, machine-readable: https://www.spawn.co/openapi.json.