By The Book

Newest update: The Book Speaks Back (2026-09-02)

• Vaelin now notices when you burn yourself before her lesson. Botch Spark on your own in the Forbidden Temple and she explains the backfire on the spot, unseals Mend early, and skips the rigged scroll on turn three (she's sulky about it). And every fall now ends with her verdict on the burnt leaf. In the temple: "You are not worthy to wield so powerful a book. Not yet."

What players say

• @jeon · 2026-09-06 · played 19 min · 1 heart: “Played it again haha. I just noticed that if I misspell the word, I take damage and my character falls down and gets dizzy. Also, could you make a shortcut key to click Next on the dialogue bar? Its kinda hard to keep spamming the click on it haha.”

• @jeon · 2026-09-03 · played 19 min · 1 heart: “Bro you nailed this game with the unique gameplay using words to type and attack haha. I didn’t expect it to be this good, great work there! Hoping there’s much more spells and different types like fire, wind, rock, water and stuff.”

  • @yzykyl (maker) replied 2026-09-03: “Thank you and really glad you enjoyed! I am planning to add more skills and spells along with more chapters within the major updates soon.”

• @mistarpudding · 2026-09-02 · played 56 min · 1 heart: “i love typing games, but this one was very unique. i really love the twist you added here. in a way, i had to strategize my spell selection and keep up with the typing. really cool that you can have a lot of spells too! i'm a typing wizard now 🧙‍♂️ im currently at chapter 2 and im still enjoying this!”

  • @mistarpudding replied 2026-09-02: “this is just personal preference, but it would be really nice to have an option to use the keyboard to select spells. it was kind of hard to switch from the mouse to the keyboard once the letters pop up.”
  • @yzykyl (maker) replied 2026-09-02: “Glad you're enjoying the game! I'll definitely keep your suggestion in mind and add keyboard controls for flipping the pages of the grimoire and casting spells in a future update.”

Join and play, by yourself

This world is @yzykyl/by-the-book. Its play URL is https://www.spawn.co/@yzykyl/by-the-book/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/@yzykyl/by-the-book@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 @yzykyl/by-the-book; 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/@yzykyl/by-the-book/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 — 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.