cad-viewer

# CAD Viewer Provenance: maintained in [earthtojake/text-to-cad](https://github.com/earthtojake/text-to-cad). Use the installed local skill files as the runtime source of truth; the repository link is only for provenance and release review. Use this skill to open existing or newly generated CAD, implicit 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 Start or reuse one local CAD Viewer with `npm run agent:start`, passing the absolute artifact directory as `--dir`. The `agent:start` launcher owns port selection, compatible-server reuse, directory activation, and the `?dir=` query parameter. It activates reused servers through the Viewer's lightweight directory activation API, without requiring agents to probe ports or trigger catalog scans manually. Use the Viewer URL printed by `agent:start` as-is, then add only a `file=` query value for the artifact you want to review. Choose `--dir` as the absolute directory that contains the model artifacts and sidecars, commonly `/models` or the consuming project's equivalent model directory. The `file=` value must be relative to that `--dir`. Do not manually choose ports, probe servers, rewrite `?dir=`, or start a separate Viewer just to change directories. Always start new local Viewer servers with `--shutdown-after 12h` so forgotten review servers clean themselves up. Do not rely on a default shutdown; the server stays alive until stopped unless this flag or `VIEWER_SERVER_LIFETIME_MS` is set. Run from this skill directory: ```bash npm --prefix scripts/viewer run agent:start -- --host 127.0.0.1 --dir --shutdown-after 12h ``` Use the printed Viewer URL and append `file=`: ```bash http://127.0.0.1:/?dir=/absolute/project/models&file=path/to/model.step ``` If a non-Viewer process or another worktree's Viewer occupies the candidate port, the launcher will continue automatically. In sandboxed agent environments, local binding or probe failures such as `EPERM` or `EACCES` can be expected; rerun the same command with the needed permission/escalation. ## Links - Before returning any `file=` link, resolve `/` and confirm the artifact exists. Pass the generated artifact (e.g. `.step`), not its generator source (e.g. `.py`). If the resolved path is missing, do not return the link, and instead report the problem and point to the correct generated artifact path. - Return one Viewer URL per requested file. - Start/reuse the Viewer once per absolute directory `--dir`, then append `file=` for each requested file. The file path must be relative to `--dir`. - For directory-only review links, return the URL printed by `agent:start` without adding `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