The Hollow March

Newest update: Companions Rise (2026-10-03)

• Your party now lunges, swings, and looses arrows—watch them fight instead of just dealing damage in silence.
• The Stormcrest Drake's wings are no longer cut off mid-flight.
• Companions hop and animate into their spell casts so you see the magic unfold.

Earlier update: The Mycelial Dominion (2026-10-02)

• The Mycelial Dominion now spreads across its own pixel-textured surface with a new grove bay to explore.

Earlier update: Turning Pages (2026-09-27)

• Tome pages now turn like real paper: the leaf lifts off the spine, curls as it travels, flicks flat as it lands, and casts a shadow sweeping across the page beneath, with a soft second rustle as it settles.

Earlier update: The Living Dominion (2026-09-27)

• The Mycelial Dominion grew up: hand-pixeled rock with glowing mycelium veins, real mushroom clusters with gills and veils, bracket shelves climbing the walls, hanging threads, foxfire, rotting logs, teal glow pools and drifting spores.
• The tome's contents spread now faces a bearer's plate with your hero's seal and record, instead of more list.

Earlier update: The Hero's Tome (2026-09-27)

• The P menu is now a leather tome: a contents page, ribbon bookmarks for every chapter, pages you turn with the wheel or arrow keys, and clearer buttons.
• Crit targets are bigger, glow and pulse, and always sit inside the monster's body.

What players say

• @yzykyl · loved it · 2026-10-02 · played 38 min: “I came back to this game and the aiming issues have been fixed! The weak points are much clearer as well. I appreciate that. I can see you're making improvements to the UI. Tome for menu is a great idea but I suggest moving the X button in the menu.”

• @vladtheimpaler · 2026-09-29 · played 7 min: “Brother, this game is like an arcade game and feels like an arcade game! It's really really good and it's very nostalgic and immersive, I recommend more sounds when hittingn the enemy. It should make this game more addicting”

• @makeriffic · 2026-09-27 · played 43 min: “Yeah!! I just completed twenty roads and it is really satisfying. I like the speed up reward! I was on the 19th road when I realized that I can upgrade the damage and HP of my character aside from the gear upgrades lol.”

  • @makeriffic replied 2026-09-27: “Hey bro, I have tried ascending and pressing confirm, but nothing seems to happen. I am ready to reset my run and do it all over again. I want to exprience the souls”

• @parz1val · 2026-09-25 · played 29 min: “I love playing the mage, but I wish I could cast the magic myself instead of having it auto cast. At least let me aim where the spells go. It would make the mage feel more fun and interactive!”

• @yujiro · loved it · 2026-09-25 · played 5 min: “It’s a nice dungeon-clearing game, and the combat is fun. One improvement would be recreating the 2D characters as 3D models to make the gameplay feel more immersive and interactive.”

Join and play, by yourself

This world is @tech/the-hollow-march. Its play URL is https://www.spawn.co/@tech/the-hollow-march.

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/@tech/the-hollow-march@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":"/@tech/the-hollow-march@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 @tech/the-hollow-march; 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/@tech/the-hollow-march.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/@tech/the-hollow-march/code and pastes it to you — it signs you up, links you to them, and makes you an editor of @tech/the-hollow-march 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.