Midnight Gambit

Newest update: Five AI Opponents (2026-10-04)

• Pick your AI opponent's strength before the match—from Pawn, learning the moves, all the way up to Queen, the master who punishes every slip.
• The AI now thinks its toughest moves off the game loop, so even the sharpest opponent never slows down your board.
• Play against Pawn for a gentle introduction, Knight to learn from mistakes, Bishop as the club regular, Rook reading three moves deep, or Queen playing flawlessly.

Earlier update: The Hollow Night (2026-09-25)

• Face five haunted chess trials hosted by Jack the pumpkin cat — beat them all to earn the Hollow table theme.
• Every trial is a mate-in-one puzzle set in a haunted corner of the club: the Pumpkin Patch, Cobweb Stair, Ghost Lantern Hall, Moonlit Crypt, and the Witching Hour.
• Earn 25 coins per trial and 100 coins for the final Witching Hour challenge, with full credit for any you've already cleared.
• Replay any trial anytime for the challenge — no coin payout on replays.
• The home screen now fits your phone with no scrolling: a gilded icon dock, polished buttons, and a dev log showing every update.

Earlier update: Midnight Gambit Update (2026-09-16)

• Story grows to 24 chapters across four illustrated volumes, with earned Hard and Master rematches—216 challenges in all. Added 32 new quests (36 total), four-per-page browsing, one-tap ready rewards, and credit for your existing progress. Coins, purchases, and saves stay with you.

What players say

• @alongzera · 2026-09-25 · played 6 min · shown first by the maker: “good chess game all features are functioning well! very good graphics as well”

  • @erika (maker) replied 2026-09-25: “Thanks I’m glad you enjoyed it :)”

• @flickaboo · 2026-09-22 · played 22 min · 1 heart: “Had a lot of fun with this! ♟️ The AI is actually pretty challenging, and Story Mode makes it even more interesting. I really enjoyed playing through it and would definitely come back for another game! 😄”

  • @erika (maker) replied 2026-09-23: “Thanks I’m”
  • @erika (maker) replied 2026-09-23: “I’m glad you liked it :) I’ll be sure to add more content soon”

• @lego · 2026-09-20 · played 42 min · 1 heart: “Thanks for adding more chapters to Story Mode! Not sure if I missed this before, but you even added difficulty settings too, that's cool. Also, I have so many coins that I could probably buy the whole Shop lol”

  • @erika (maker) replied 2026-09-20: “Yup and dam I gotta add more to the store then 😂 I’m glad your enjoying the game I plan on adding more stuff to it soon :)”

• @yzykyl · 2026-09-16 · played 16 min · 1 heart: “Wow this is a creative take on chess. Chess puzzles with a story and quests, I've never really been too good at chess but this game would give me a reason to play. Great job!”

  • @erika (maker) replied 2026-09-16: “Thanks :) I’m glad you like the game.”

• @lego · 2026-09-16 · played 42 min · 1 heart: “I just finished all of your Story Mode, love it! Wish there were more chapters. Another huge W from Erika! Keep cooking!”

  • @erika (maker) replied 2026-09-16: “Thanks :) I’ll be sure to add some more chapters”

Join and play, by yourself

This world is @erika/midnight-gambit. Its play URL is https://www.spawn.co/@erika/midnight-gambit.

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/@erika/midnight-gambit@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 @erika/midnight-gambit; 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/@erika/midnight-gambit.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/@erika/midnight-gambit/code and pastes it to you — it signs you up, links you to them, and makes you an editor of @erika/midnight-gambit 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 — 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.