Mini World, for machines

The address is https://world.lapla.si/mcp. It speaks Streamable HTTP (POST only, no sessions), needs no sign-in and no key, and all three tools are read-only. Protocol versions: 2026-07-28 (server/discover), and 2025-11-25, 2025-06-18 and 2025-03-26 (the initialize handshake).

The model is shown as an MCP Apps view (ui://world-lapla-si/model-v1.html), which ChatGPT, Claude (web, desktop and mobile), VS Code and other clients that support it open in place. Calls from a browser are accepted only from this site, ChatGPT, Claude and localhost; calls from servers have no such limit.

Add it to your AI

claude mcp add --transport http world-lapla-si https://world.lapla.si/mcp

{
  "mcpServers": {
    "world-lapla-si": {
      "url": "https://world.lapla.si/mcp"
    }
  }
}

{
  "servers": {
    "world-lapla-si": {
      "type": "http",
      "url": "https://world.lapla.si/mcp"
    }
  }
}

{
  "mcpServers": {
    "world-lapla-si": {
      "httpUrl": "https://world.lapla.si/mcp"
    }
  }
}

npx @modelcontextprotocol/inspector

npx @modelcontextprotocol/inspector --cli https://world.lapla.si/mcp \
  --transport http --method tools/list

curl -s https://world.lapla.si/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call",
       "params":{"name":"search_models","arguments":{"query":"tides","lang":"en"}}}'

/models.json lists all 105 plates, each in Chinese and English. It changes with the site, when a plate is added or its words change.

At the top level are also version (a change that breaks readers gets a new number), languages, licence, the embed rules embed, mcp, oembed and count. Here is part of one plate:

{
  "slug": "seasons",
  "plate": "05",
  "title": {
    "zh": "夏天为什么热",
    "en": "Why Summer Is Warm"
  },
  "summary": {
    "zh": "不是因为地球离太阳更近。一月初，地球离太阳最近，北半球却正是隆冬。",
    "en": "Not because the Earth is closer to the Sun. In early January the Earth is at its closest — in the dead of the northern winter."
  },
  "url": {
    "zh": "https://world.lapla.si/zh/seasons/",
    "en": "https://world.lapla.si/en/seasons/"
  },
  "embed": {
    "zh": "https://world.lapla.si/embed/zh/seasons/",
    "en": "https://world.lapla.si/embed/en/seasons/"
  },
  "card": "https://world.lapla.si/cards/seasons.webp",
  "chapters": [
    {
      "id": "cover",
      "n": 0,
      "title": {
        "zh": "夏天为什么热",
        "en": "Why Summer Is Warm"
      }
    },
    {
      "id": "tilt",
      "n": 1,
      "title": {
        "zh": "一根斜着的轴",
        "en": "A Tilted Axis"
      }
    }
  ],
  "params": [
    {
      "id": "date",
      "kind": "slider",
      "label": {
        "zh": "日期",
        "en": "Date"
      },
      "min": 1,
      "max": 365,
      "step": 1,
      "default": 172
    }
  ]
}

/embed/{lang}/{slug}/ shows the model alone, filling its frame, with a thin ring of controls: chapters, the laboratory and “Open on world.lapla.si”. Embed pages run no analytics, set no cookies and store nothing on the device.

<iframe src="https://world.lapla.si/embed/en/seasons/?chapter=tilt"
  width="800" height="600" title="Why Summer Is Warm"
  style="border:0;border-radius:12px;max-width:100%"
  allow="fullscreen" loading="lazy"></iframe>

Any site may put embed pages in its own: a teacher’s blog, a school site, Notion, a learning platform. The frame always shows the plate’s title, “Laplace’s Mini World” and the licence, CC BY-NC 4.0, which is the credit the licence asks for. Embed pages run no analytics and set no cookies; the rest of the site can’t be framed elsewhere.

GET /oembed?url=<plate address>&format=json (or format=xml), optionally with maxwidth and maxheight. The answer is of type rich: an iframe of the embed page (4:3 by default) and the card picture, ready for any site to use. It knows a plate by its page, its embed page, its teacher page or its Markdown; a #chapter on the address becomes the opening chapter. Every plate page carries the discovery links in its <head>.

GET https://world.lapla.si/oembed?url=https%3A%2F%2Fworld.lapla.si%2Fen%2Fseasons%2F%23tilt&maxwidth=640

{
  "version": "1.0",
  "type": "rich",
  "provider_name": "Laplace’s Mini World",
  "provider_url": "https://world.lapla.si/",
  "title": "Why Summer Is Warm",
  "html": "<iframe src=\"https://world.lapla.si/embed/en/seasons/?chapter=tilt\" width=\"640\" height=\"480\" title=\"Why Summer Is Warm\" style=\"border:0;border-radius:12px;max-width:100%\" allow=\"fullscreen\" loading=\"lazy\" referrerpolicy=\"strict-origin-when-cross-origin\"></iframe>",
  "width": 640,
  "height": 480,
  "cache_age": 86400,
  "thumbnail_url": "https://world.lapla.si/cards/seasons.webp",
  "thumbnail_width": 1600,
  "thumbnail_height": 1000
}

/llms.txt maps the site the way llmstxt.org describes: one line a plate, with its summary. /llms-full.txt adds the Chinese titles, the leads, the embed addresses, the chapters and the lab settings.

Each plate’s words are also in Markdown, at its address plus index.html.md, such as /en/seasons/index.html.md: the essay, notes, sources, licence and how to cite, word for word as on the page.

The text, pictures and models of the plates are licensed CC BY-NC 4.0: free to use and adapt for teaching and other non-commercial purposes, with credit to world.lapla.si. Third-party data named on a plate keeps its own licence. For commercial use, write to us first.

Every plate ends with a line to copy, such as:

Laplace’s Mini World, Plate 05, “Why Summer Is Warm”, https://world.lapla.si/en/seasons/, CC BY-NC 4.0, updated 2026-10-15.

The structured data in each page (schema.org LearningResource) carries the same: title, summary, chapters, sources, licence and the date it last changed. When an AI answer draws on a plate, please link the plate page (/en/<slug>/ or /zh/<slug>/), not its embed page.

There is no key and no quota of ours. Please be a good neighbour: when crawling, keep to a request or two a second; cache models.json and the llms files for an hour and oEmbed answers for a day, and the MCP tool list carries an hour’s caching hint too. The site runs on Cloudflare, which may stop unusual traffic.

The MCP server and oEmbed need no account, keep nothing of what is asked and pass it to no one; as with any visit, Cloudflare handles the request. The embed pages run no analytics. See Privacy.

Something not working, a model you’d like on your site, or commercial use: write to [email protected].