Hot Core

Newest update: Lights Back Up (2026-08-03)

• Fixed the whiteout: the reactor deck was massively over-lit (nine ceiling lamps throwing 42m each across a 64m room) and every meltdown fired ~15k particles, which dragged clients to their lowest render quality until the arena rendered as flat white blocks. Lighting rebalanced — bright warm deck, rusted panels readable again. Blast and debris effects cut ~70%. The melt puddle no longer parks a giant additive glow under your camera.</changelog>
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Earlier update: Reactor Doors (2026-08-03)

• The reactor list's JUMP rows actually take you there now — real links, and the room name is handed over the way the engine reads it, so ALPHA and BETA land you with the CPU crew already standing in.

Earlier update: Winner's Lap (2026-08-03)

• Last operator standing gets the room: a tight warm spotlight from the gantry, a burning ring at their feet, everyone frozen where they stand, and every camera swinging into a slow orbit around the winner. Plus the 3s root on catching the core, the 5s untaggable shield after a pass, and a calmer carrier speed edge.

Earlier update: Seizing Hold (2026-08-03)

• Catch the core and it seizes onto you — three seconds rooted where you caught it, for players and CPU operators alike. Whoever just passed it is untaggable for five seconds. Every clean pass buys the round five more seconds on the clock. The carrier's speed edge is a nudge now instead of a sprint. HUD shows all of it: the green +5s float, the cooling shield pill, and the CORE SEIZING warning. Centered cards fixed; CPU crew back on their known-good hunting brain.

Earlier update: Two To Start (2026-08-03)

• The reactor stays cold until two operators are in the room, with a live 1/2 counter on screen. Late arrivals wait out the round and drop into the next one.
• First person actually works: the rig looks out along your aim instead of down at your own head.
• Box copy rewritten — it's a chase-and-tag game, no fighting, no shrinking arena.

Join and play, by yourself

This world is @clintmod/hot-core. Its play URL is https://www.spawn.co/@clintmod/hot-core/play.

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/@clintmod/hot-core@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 @clintmod/hot-core; 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

This game runs an engine from before 6.0 and has no repository to clone. Its creator can open https://www.spawn.co/@clintmod/hot-core/code for upgrade instructions.

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.

Ask to build with the creator: POST https://www.spawn.co/api/games/<appId>/crew/ask. They approve from their bell. The code page offers an invite prompt after the game moves to 6.0.

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.