cad-viewer

# CAD Viewer Use this skill to open existing or newly generated CAD, robot-description, DXF, or plain FDM G-code files in CAD Viewer and hand back live review links. The expected input is one or more explicit file paths. ## Start Viewer Always start CAD Viewer with the root directory that owns the model files (.step, .stl, .urdf, etc). Always pass `--root-dir /path/to/root`; the flag is required. This flag is the full Viewer root directory; do not treat it as a subdirectory inside another repo root. Port reuse depends on passing the same resolved root directory every time. `serve:ensure` probes the Viewer port range, asks each live server what root directory it serves, and reuses a port only when that server's root directory matches the current `--root-dir` and the requested file is available in its catalog. Passing a model subfolder, a different checkout path, or relying on a different current directory changes the resolved root and can cause `serve:ensure` to start a new port. Always pass the same project root directory with `--root-dir` for handoffs from the same project. New Viewer servers started by `serve:ensure` shut down automatically after 12 hours. Use the default unless the user explicitly asks for a different lifetime; then pass `--shutdown-after <duration>` with an `ms`, `s`, `m`, or `h` suffix. This flag only applies when a new server starts; reusing an existing matching port does not change that server's existing shutdown timer. If the user has a Viewer URL open, treat that port as the first reuse candidate. Return a URL on that same port whenever it already serves the same root directory, changing only the `?file=` query. Do not start a separate Viewer with a different root directory just to make a file appear faster; wait for the existing server/catalog, rerun `serve:ensure` with the same project root directory, or report the startup/catalog failure. Run from this skill directory with the project root directory explicitly set: ```bash npm --prefix scripts/viewer run serve:ensure -- \ --root-dir /path/to/root \ --file path/to/model.step ``` Use only the URL printed by `serve:ensure`; do not assume a fixed port. By default, `serve:ensure` starts probing at port `4178` and scans the configured port range for a reusable server before binding a new port. It reuses a matching root directory when possible, and otherwise starts the packaged production server at the requested root directory. In sandboxed agent environments, local binding/probing failures such as `EPERM` or `EACCES` can be expected; rerun the same command with the needed permission/escalation instead of choosing an arbitrary port or changing the root directory. Pass exactly one `--file` per `serve:ensure` invocation. For multiple requested files, run the command once per file and return each printed URL. ## Links - Return the printed Viewer link for each requested file. - If a server is already running for the same root directory, reuse its port and vary the `?file=` query only when that points at the requested file. - Do not stop an existing Viewer server unless the user asks. - If Viewer startup fails, report the failure and continue with the owning skill's non-GUI validation or artifacts. ## References - Read `references/development.md` when the user asks to modify, debug, or iterate on CAD Viewer source. - Read `references/viewer-features.md` when you need supported file types, Viewer controls, or file-specific feature details. - Read `references/moveit2-server.md` only when the user specifically needs optional SRDF MoveIt2 IK or path-planning controls.