King of the Yard

Newest update: Tire Trails (2026-09-17)

• Tricycle tire tracks now draw continuously as you ride instead of fading quickly, leaving a detailed mark of your path across the yard.
• Skid marks appear when you get knocked back or land a boost, showing the moment of impact with wider, more dramatic trails.
• Tire tread textures are now more detailed with realistic lugs and wear patterns, making every track tell a story of your riding style.

What players say

• @flickaboo · 2026-09-21 · played 27 min · 1 heart: “Had fun playing this! 😄 I tried it with AI and drew the circle away from the center, but they didn't really contest that area. It would be cool if the AI tried to fight for the spot wherever the circle is placed. Would definitely be fun to play this with friends!”

  • @chocopuff (maker) replied 2026-09-22: “That is great feedback, I'll be adding that in!”

• @chizkeykkk · 2026-09-19 · played 19 min · 1 heart: “Why does Mosh always win haha?! 😂 It’s so unfair that he gets the Hamster early in the game! I really like the idea behind this though. I just hope the initial item choices could be randomized, since I always seem to get the same 3 items in the first round. Still really fun overall 😂❤️”

  • @chocopuff (maker) replied 2026-09-20: “Thanks Chizkey! Yeah I totally agree with all your feedback. So many things I wanted to add but didn't due to the GameJam time. When I get my main game released I'll probably come update this one!”

• @nosferatu · 2026-09-17 · played 7 min · 1 heart: “Super cool game, I love the upgrades and the drawing of the arena, it adds a lot of variety.”

  • @chocopuff (maker) replied 2026-09-17: “Thanks friend! I imagined people playing this with their friends on a game night”

• @kaya · 2026-09-17 · played 11 min · 1 heart: “i just made the smallest arena and its so funny seeing 4 carts trying to take control of it lol. this was such a unique game. its basically king of the hill with a mix of creativity. really cool concept u got here!”

  • @chocopuff (maker) replied 2026-09-17: “Thanks so much for playing! I wanted players to set the chaos!”

• @arashi · 2026-09-17 · played 5 min · 1 heart: “idk if thats a kid running or obstacle from the mode but its funny hahah i enjoy”

Join and play, by yourself

This world is @chocopuff/king-of-the-yard. Its play URL is https://www.spawn.co/@chocopuff/king-of-the-yard.

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 that any browser plays, headless included, with no sign-in. https://www.spawn.co/@chocopuff/king-of-the-yard@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.

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 @chocopuff/king-of-the-yard; 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/@chocopuff/king-of-the-yard.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/@chocopuff/king-of-the-yard/code and pastes it to you — it signs you up, links you to them, and makes you an editor of @chocopuff/king-of-the-yard 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.