3DPACK.ING MCP server

Container and truck load planning for AI assistants. Describe a shipment in plain English; get back the containers it fits in, how full each one is, what did not fit, and a link to an interactive 3D load plan.

Backed by the 3DPACK.ING solver — the same one behind the web planner. Asked "will 500 cartons fit in a 40-foot", an assistant without this will do arithmetic on volumes, which ignores stacking rules, orientation and weight limits and overstates what fits by a wide margin on real cargo.

Install

Hosted (no install)

The server runs at https://3dpack.ing/mcp over streamable HTTP. Add the address to your assistant and sign in with your 3DPACK.ING account when it asks — OAuth, the way Claude, ChatGPT and Claude Code connect to any service. A free account works, on its free monthly packs.

Claude (web, desktop): Settings → Connectors → Add custom connector → paste https://3dpack.ing/mcp and choose sign-in.

ChatGPT (developer mode): add the same address with OAuth.

Claude Code:

claude mcp add --transport http 3dpacking https://3dpack.ing/mcp
# then /mcp → Authenticate

With an API key instead of signing in. Pass the key and the account it belongs to in the query string:

https://3dpack.ing/mcp?apiKey=your-key&username=your-username

or keep the key out of the URL: X-API-Key: your-key (or Authorization: Bearer your-key, or X-3dpacking-Api-Key) with ?username=your-username in the URL. Claude's connector dialog only sends approved header names, so there use x-api-key. The shared demo account is ?apiKey=test&username=test.

A request with no credentials at all is answered 401 with a pointer to the sign-in metadata (/.well-known/oauth-protected-resource/mcp), which is what makes a client show the login.

Local (npm)

Claude Desktop — add to claude_desktop_config.json:

{
  "mcpServers": {
    "3dpacking": {
      "command": "npx",
      "args": ["-y", "@3dpacking/mcp-server"]
    }
  }
}

Claude Code:

claude mcp add 3dpacking -- npx -y @3dpacking/mcp-server

It works immediately, with no account — the first call runs against a shared demo account on the free plan. For your own limits, sign up at https://3dpack.ing/login and add:

{
  "mcpServers": {
    "3dpacking": {
      "command": "npx",
      "args": ["-y", "@3dpacking/mcp-server"],
      "env": {
        "THREEDPACKING_API_KEY": "your-key",
        "THREEDPACKING_USERNAME": "your-username"
      }
    }
  }
}

Both must be set together — the API rejects a key without a username.

The 3D plan inside Claude

In hosts that support MCP Apps — Claude on the web and desktop — the answer comes with the load drawn under it in 3D: drag to turn, scroll to zoom, one colour per kind of piece, a pager for loads that take several containers. The view is ui://3dpacking/load-plan-<hash>.html (named after its contents, so a changed view is never served from a host cache), drawing the placements the tool result carries in _meta (so they reach the view, not the model). It needs your own key: the shared demo account gets the answer and the link, not the placements. Other hosts get the same answer as text with the link.

The tool

pack_shipment — one required argument, prompt, describing the cargo in plain English, and two optional settings: a speed of fast, normal or thorough, and a stability of 75 to 100.

stability is how much of a box must rest on what is underneath it, as a percentage of its own footprint. Omit it for 75, the standard rule, which lets a quarter of a box overhang and packs the most. Raise it for cargo that must not lean — drums, glass, anything top-heavy — and use 100 when every stacked box has to sit fully supported. It is the one constraint the prompt cannot carry, because it governs how the solver stacks rather than what is being shipped, and a higher value fits fewer items.

Things it understands:

Pack 50 boxes of 60x40x30 cm into a 20ft container
Load 30 fragile boxes 80x60x40cm, max stack 3, into a 20ft container
Ship mixed pallets: 10x euro pallets, 15x US pallets, best container mix
Ship 24 pcs 200.3x120.2x100.2 cm (non-tiltable), optimal mix of 40ft and 20ft

What comes back:

Everything fits: 1 container.

Container 1 (589.3 x 235 x 239 cm internal)
  items: 50
  of which: 50x Boxes
  used: volume 10.9%
  5 empty gaps left

Interactive 3D load plan: https://3dpack.ing/app?g=6c4b9488-...

Notes on the shaping

The API returns the geometry of every unfilled cuboid in every container, with coordinates. That is what the 3D viewer needs and it is most of the payload on a real shipment. Spending a model's context on the coordinates of empty space, when the link opens a picture of exactly that, is a poor trade — so the summary keeps the count of gaps and drops the geometry. On a small pack that is 791 bytes down to 341; on a large one it is the difference between a usable answer and a flooded context.

A plan limit is not reported as an error. The API returns HTTP 500 for NotSubscribed, the same status it uses for a solver crash; left alone, an assistant reads that as "the service is broken" and tells the user to try again later, when what actually happened is that they asked for a Pro feature. This server sorts the two apart and relays the offer.

Anything that answers with non-JSON — a proxy, a VPN, a corporate egress allowlist — is reported as a network problem naming what actually replied, rather than as a packing failure. Only one of those is something the user can fix.

Environment

Variable	Purpose
THREEDPACKING_API_KEY	Your API key. Falls back to the shared demo account.
THREEDPACKING_USERNAME	The account the key belongs to. Required with the key.
THREEDPACKING_ENDPOINT	Override the endpoint — staging, self-hosted, or a stub.

Development

npm install
npm run smoke     # calls the live solver with demo credentials and checks the shape

smoke.js is deliberately not mocked for the live checks. The thing that will break this package is 3dpack.ing changing the shape of its answer, and no amount of mocking catches that. Run it before publishing. To exercise the success path without spending a calculation, point THREEDPACKING_ENDPOINT at a stub.

Licence

MIT.