Skyfold Studio

Create entire MMO worlds in seconds.

Generate the landscape, let your agent sculpt it, and step inside what you create. A free, open-source world builder for macOS, written in Rust on Bevy.

Download for macOS · Website · Marketplace · Build from source

Watch it with sound on skyfoldstudio.com.

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Hundreds of hours. Or a few seconds.

Sculpting terrain, painting biomes and placing every tree by hand takes hundreds of hours. Asking a general-purpose agent to build a world object by object burns through months of tokens.

Skyfold generates the whole world first, then your agent edits it. Pick a shape, a size and a climate and you get terrain, biomes, rivers, lakes, forests and level zones in about 20 seconds. Everything after that is yours to change.

Agent-first, by design.

Skyfold is built agent-first. Every feature in the editor is also an MCP tool: more than 240 of them, covering terrain, nature, water, roads, objects, caves, dungeons, zones, gameplay, lighting, analysis and export. Your agent never draws a single triangle. It reads the world, decides what to do, and calls the same code the editor's own buttons call.

This split plays to each side's strengths. Language models are good at intent: turning “a dense, old pine forest on the north slope” into a plan. Engines are good at volume and precision: placing eighteen thousand trees that follow the slope, avoid the river and match the climate. One tool call carries the plan:

{
  "tool": "nature_scatter",
  "args": {
    "area": { "polygon": [[412, -88], [530, -40], [575, 96], [446, 140], [380, 30]] },
    "preset": "pine_forest",
    "density": 1.4
  }
}

That's around fifty tokens, and the engine turns it into thousands of placed trees. A general agent writing the same forest object by object would spend tens of thousands of tokens and still not know where the slopes are.

What you get from working this way:

Benefit	Why it matters
🪙 Tiny token bills	The agent sends short plans; the engine does the volume. A whole region costs a few calls, not a transcript of coordinates.
⚡ Native speed	Tools run inside the editor's Rust engine between frames, at the speed of a brush stroke.
🎯 Exact and consistent	Every argument is checked against a JSON schema before anything runs, and each tool reuses the editor's own code paths. Agent edits look exactly like hand edits.
↩️ Always undoable	Each call is one undo step. batch groups many calls into one step, and atomic rolls the whole batch back if any call fails.
🧭 Scoped to what you choose	Lasso an area, turn on Mask edits to selection, and the agent's changes stay inside the line.
👀 The agent can see	screenshot, terrain_sample, world_info and the analyze_* tools return pictures, height and biome maps and walkability, so the agent checks its own work and fixes it.
🔌 Bring any agent	Claude Code, Codex, Claude Desktop, Cursor, VS Code or any MCP client. Inside the app, Prompt an area runs on Codex (ChatGPT sign-in), Claude Code or your own Anthropic API key.
📈 Gets better with every model	The engine stays the same while models keep improving. Smarter models make better plans with the same tools.

Edit worlds with your agent.

Start with a prompt, a screenshot or an outline. Shape the result with Skyfold's worldbuilding tools.

A prompt becomes a place.

Lasso a patch of the world and tell your agent what belongs there. Keep it, refine it, or undo it.

From first click to your first zone.

Choose a shape and a climate. Spawn an island, a continent or an archipelago with terrain, biomes and nature already in place.

Start with a 2–16 km world, then paint named zones, set level ranges and give each region its own weather, audio and mood. Guided setup adds a capital, towns, villages and the roads between them, and makes up names from the land if you leave them empty.

Start with an image. End up in a world.

Upload a map, sketch or concept image. Trace a Picture reads its coastline, regions, lakes and rivers and turns them into a draft world you can shape and explore. Undo goes back in one step.

Same world. A different atmosphere.

Switch styles without rebuilding the landscape, and tune the strength to make it yours: Natural, Nordic Mist, Cinematic, Golden Hour, Golden Vintage, Hellfire Dusk and more. Choose a photorealistic world or a hand-painted one.

Step into what you just created.

Come down from the editor and explore at player height. Walk, run, jump, swim or fly. Record a route and feel how the world plays.

Find the dead zones before your players do.

World analysis highlights content gaps, walkability, travel time, level flow and reachability. World Doctor finds floating objects, drowned plants, unreachable places and steep roads, then jumps you to the fix. Your agent can run every check too.

Take it to your favorite game engine.

Export terrain, models, instances, water, roads, lighting and gameplay data with dedicated workflows.

This is the beginning of the README. Read the rest at the original. Read the full README ↗