dsh-nobs-cad-step

dsh-noBS-CAD-step

npm package dsh-nobs-cad-step, plugin id nobs-cad-step. Renamed on 2026-09-28 from dsh-nbcad-plate (plugin id nbcad-plate): remove the old package from a profile before adding this one, and rename the id in any config override.

A DeepSeek Harness (dsh) plugin that turns 2D engineering prints of flat plate parts into noBS CAD scripts and STEP files.

It registers:

• the skill nobs-cad-step: the standard workflow for plate parts, from a ten-hole bracket to a dense plate with eighty holes (sheet survey, callout inventory, corner-origin frame, chain arithmetic, one script per part, verification by hole counts, report), with two validated example scripts: skill/plate-example.nbcad.jsonc locates holes by coordinates and shows every modelling idiom, skill/plate-example-chains.nbcad.jsonc builds the same plate with construction chains (lines of the printed lengths from the plate edges, holes anchored to their ends) so the engine does the arithmetic and a reviewer can compare the chains with the print;
• five tools that drive a headless noBS CAD engine and the print:
  • nbcad_run_script(script_path, step_path): run a version 1 .nbcad.jsonc script in a blank document, export STEP, return the engine's feature summary and warnings (a position left out of positions, overlapping holes, holes off the body, blind depths deeper than the body, unused bindings), the holes found, or the failing step and reason;
  • nbcad_inspect_step(step_path): re-import a STEP file and return the same summary, for verification;
  • nbcad_check(step_path, expected, tolerance_mm?): compare the model's feature table with the STEP through the engine: matched, missing and extra holes with offsets, and the bounding box;
  • nbcad_print_probe(action, print_path, ...): the native pixel toolkit (Rust, native/print-probe, packed as a binary for every platform). It reads PDF, PNG and JPG prints itself: render (a PNG of the page or of a window given as page fractions, at any dpi: this is how the model reads the sheet), info, and with the plate size calibrate, crop with a millimetre grid and hole overlay, ring-score (what is drawn at or near each model hole), symbols (circles and dots found in a region, matched against the model). Well under a second per call once a page is rendered; renders are cached;
  • nbcad_overlay_print(print_path, step_path, out_png, length_mm, width_mm, region?, dpi?): draw the model's holes onto the plan view of the print (whole plate, or a high-resolution crop of a millimetre window) so every group can be checked against the drawn hole symbols.

The model reads the print itself (through the probe's render and crop images), writes the script, runs it, compares the hole list with its inventory and fixes what is missing. Everything goes through the ordinary noBS CAD script interpreter; there is no second modelling path.

The "2D → 3D" panel in the Web UI

In a web profile the plugin adds a 2D → 3D entry to the sidebar's panel list. The panel:

• shows, refreshed every two seconds, whether the noBS CAD engine (nbcad-mcp) is reachable, whether a noBS CAD desktop is running (read from the desktop's session registry: a heartbeat.json newer than 30 seconds under /nbcad-sessions/, the same rule the MCP server uses), and whether the print probe binary for this machine is present;
• takes one print (PDF, PNG or JPG), either uploaded from the browser or named by its path on the machine that runs dsh; the probe reads all three directly;
• starts a new session in the chosen workspace with the plate-workflow brief, names it after the part, and follows it: Open conversation switches to it;
• lists every STEP file (and report) the run produces under /out/ and saves it where you choose (Save STEP as…, the browser's save dialog where available, otherwise a download).

The panel is bilingual (English and Chinese) and follows dsh's global language setting (Settings → General → Language, stored as locale.preference in settings.yaml); switching the language re-renders the panel and its sidebar entry at once. When the UI is in Chinese the brief also asks the model to answer and write report.md in Chinese; the script and the field names stay English.

Nothing here bypasses the model: the panel only prepares the workspace, sends the brief and collects the files. The host half serves the panel's routes under /dsh-nbcad/api on dsh's own web server; headless profiles do not mount them.

Requirements

• dsh 0.1.5 to 0.1.9, alphas and release candidates included (the peer ranges name each prerelease line explicitly, as node-semver requires), with a profile based on headless, tui or web; Node 22 or later.
• noBS CAD. The application itself serves stdio MCP: the plugin starts it with --headless, so an installed noBS CAD (the release zip on Windows, the app on macOS, the deb on Linux) is the engine. A developer build of nbcad-mcp (cargo build --manifest-path mcp-server/Cargo.toml in the noBS CAD checkout) works too and needs no flag.

Nothing else: no Python, no poppler, no Rust toolchain. The print probe is packed as a binary under bin/ for macOS (Apple silicon and Intel), Linux (x64 and arm64) and Windows (x64), and it renders PDFs and decodes PNG and JPG prints itself.

Install

From GitHub into a profile of your own (the plugin is plain JavaScript plus the packed binary, so no build approval is needed; use web instead of headless as the template to get the panel):

dsh --profile nbcad --from-default-profile headless --dump-config >/dev/null
dsh plugin --profile nbcad add github:jackControls/dsh-nobs-cad-step

Or from a local checkout:

dsh plugin --profile nbcad add file:/path/to/dsh-nobs-cad-step

The engine is found automatically, in this order: config.server or NBCAD_MCP; nbcad-mcp, nbcad or noBS-CAD on the PATH; the executable of a noBS CAD that is running (read from its session registry); the installed application (on Windows the nbcad:// handler noBS CAD registers on its first normal launch, on macOS /Applications/noBS CAD.app, on Linux /usr/bin/nbcad). The panel's status strip says which one it uses. To pin it, set it in the profile's cordis.patch.yml (~/.dsh/profiles/nbcad/cordis.patch.yml):

- id: nobs-cad-step
  config:
    server: /Applications/noBS CAD.app/Contents/MacOS/nbcad   # or .../nbcad-mcp
    # serverArgs: ['--headless']   # the default for the application; none for nbcad-mcp

probe: (or NBCAD_PRINT_PROBE) overrides the packed print-probe binary with one you built yourself; it is not needed on the packed platforms. Check with dsh --profile nbcad --dump-config that the nobs-cad-step entry is mounted.

Use

From a workspace that contains the print:

dsh --profile nbcad "Model scratch/PART.pdf as a STEP file. Load the nobs-cad-step skill first."

The skill asks for the script, the STEP file, a feature table and a short report in the workspace. Run one part per task; a dense plate is allowed several script runs.

Windows

The plugin runs on Windows without extra tools; the smoke workflow exercises the host code and the packed print-probe.exe on windows-latest at every push. The engine on Windows is the noBS CAD release itself: unzip noBS-CAD--windows-x64.zip, launch noBS-CAD.exe once normally (that registers the nbcad:// handler the plugin reads), and the plugin finds it and starts it with --headless for each run. To pin it instead, name the .exe itself (a .cmd or .bat wrapper cannot be spawned), with forward slashes or a quoted string:

- id: nobs-cad-step
  config:
    server: C:/Users/me/noBS-CAD/noBS-CAD.exe

A bare name is looked up on the PATH through PATHEXT.

The desktop detection reads %TEMP%\nbcad-sessions\, where the noBS CAD desktop publishes its heartbeats on Windows, and the probe caches page renders under %TEMP%\print-probe-cache\ (PRINT_PROBE_CACHE moves it). Windows on ARM falls back to the x64 probe under emulation. Print and part names may use any script (Chinese file names are kept as they are).

Layout

lib/index.js             plugin entry: skill, the four tools, the panel's web routes
lib/cad.js               engine helpers: run a script, export STEP, inspect a STEP, summarise
lib/mcp-client.js        newline JSON-RPC client for nbcad-mcp (plain Node)
lib/client.js            the "2D → 3D" panel (browser half)
bin/
/          packed print-probe binaries (darwin-arm64, darwin-x64, linux-x64, linux-arm64, win32-x64)
native/print-probe/      Rust source of the probe (PDF rendering by hayro, PNG/JPG by image)
skill/SKILL.md           the workflow (also usable as a plain filesystem skill)
skill/plate-example.nbcad.jsonc   validated example with every idiom
tools/make-example.mjs   regenerates (--write) and validates (--validate) the coordinate example
tools/make-chains-example.mjs   the same for the construction-chain example
.github/workflows/probe-binaries.yml   builds the probe for every packed platform
cordis.patch.yml         bundle patch that mounts the plugin

The probe is looked up in this order: config.probe, NBCAD_PRINT_PROBE, bin/ /print-probe, a local native/print-probe/target/release build, then print-probe on the PATH.

Development

NBCAD_MCP=/path/to/nbcad-mcp node tools/make-example.mjs --validate
NBCAD_MCP=/path/to/nbcad-mcp node tools/make-chains-example.mjs --validate

To rebuild the probe for this machine:

cargo build --release --manifest-path native/print-probe/Cargo.toml
cp native/print-probe/target/release/print-probe bin/
/

The probe binaries workflow builds all five packed platforms on GitHub; after a run, gh run download -D dist and copy each dist/print-probe- into bin/ /.

After editing the plugin, refresh the installed copy with dsh plugin --profile nbcad update dsh-nobs-cad-step (or remove and add again; bump the version first, a re-add of the same version keeps the old copy).