MeshCue

Point at the model. Let the Agent read what you meant.

MeshCue is a browser workbench for reviewing 3D models with an AI agent. The agent publishes a draft, you open it in your own browser, mark the surfaces that are wrong — lettered pins and painted regions, on the mesh, in three dimensions — and hand the batch back. The agent reads positions, not a screenshot, and publishes the next version. Every version stays open for marking.

It is not a CAD or sculpting tool. It is the step between "here is a draft" and "here is what to change", which until now was a screenshot and a paragraph.

Why positions

Telling an agent "the fillet on the left bracket is too sharp" costs a sentence and buys an argument about which bracket. A mark carries the mesh, the face, the barycentric coordinate and the version it was made against. The agent gets an address, not a description, and can say back which surface it understood.

Related MCP server: Terrarium

The loop

1. The agent runs precheck on the model file, then open to publish it.

2. You open the URL in Chrome, Safari or any modern WebGL browser.

3. Pick the label tool and click a surface to drop a lettered pin; the paint bucket fills the connected near-flat area around the face you click. The orbit tool places nothing, so turning the model never marks it. Nothing is submitted until you say so.

4. Press Send to Agent. The batch is frozen against the version you marked.

5. The agent calls read, replies in your conversation, and opens the next version. Older versions keep their own marks and stay selectable.

There is no "finish the round" button. The next version is the end of the last one.

Three ways in, one implementation

The core does not know which harness is talking to it. All three entry points drive the same instance manager, with the same actions and the same results.

Ownership decides who may change a draft or switch the displayed version. A second owner asking about the same project is refused with RESUME_REQUIRED until someone says, explicitly, that the review is being continued.

Being told, or asking

Only a host that can write into its own conversation can announce a submission. A client reached over a tool protocol cannot: the protocol has no way to wake a conversation. MeshCue does not pretend otherwise.

status.notifier reports what the host actually offers. Where send is false, a submitted batch has the status waiting — durable, listed, collected by calling read. It is not a delivery that failed, it counts as no attempt, and it never becomes stalled. An agent on such a host should read when the reviewer says they are done rather than waiting for a message that cannot arrive.

Model limits

A mark names a source face, so a model at the cap marks exactly as precisely as a small one — there is no band below these limits where something quietly gets worse. precheck measures a file before open and, when it is over, answers with the ratio to decimate by instead of a refusal after the fact.

Running it

Node.js 22 or newer, and a browser with WebGL.

From a clone, for development:

npm ci
npm run samples      # generate the parametric sample models
npm test             # 189 unit and integration tests
npm run test:browser # 71 real-Chromium tests, isolated port and data

npm run samples writes to ../../media/3d/3d-agent-review/samples, two levels above the clone: the suites publish through the server, which serves models from a workspace rather than from the repository. Clone somewhere that grandparent directory can be created in, or pass --output. Cases that need models this repository does not ship — the LAN case and one heavy-texture case — skip themselves and say why.

For an OpenClaw install, build and install the extension from that clone:

npm run build:integration -- tmp/candidate/package
openclaw plugins install ./tmp/candidate/package

For any MCP client, install a tagged commit and point the client at it:

npm i -g "github:lzyling/meshcue#v1.1.0"

[mcp_servers.meshcue]
command = "meshcue-mcp"

Or start it without installing, at the cost of a fetch and a build each time:

[mcp_servers.meshcue]
command = "npx"
args = ["-p", "github:lzyling/meshcue#v1.1.0", "meshcue-mcp"]

Pin the tag. Without one, npm takes whatever the default branch holds at that second and runs the prepare script in it. A tag is a name its owner can move, so every release states the commit it was cut from: check that against git rev-parse v1.0.1^{commit} and you know what you built.

MeshCue is not published on the npm registry, and the names meshcue, meshcue-mcp and @lzyling/meshcue are not held by this project. A package under any of those names is not this project, whatever it claims. This repository, pinned to a tag, is the only way in — the install commands above use npm as the package manager, not as the source.

The workbench listens on the loopback address by default. LAN mode binds one verified private IPv4 and always requires authorization — see SECURITY.md for the trust model, how a browser is admitted, and how long that lasts.

Documentation

• AGENT-INTERFACE.md — the contract an agent implements

• SECURITY.md — network exposure, browser trust, reporting a flaw

• docs/zh/ — design documents, in Chinese: positioning, requirements, versioning rules, roadmap

License

Apache-2.0. See LICENSE.