Text-to-CAD

8 steps · start to finish.

1. 1
   Step 1

   Environment Setup

   ▶

   set -e
   mkdir -p {{results_dir}}
   SKILL=/opt/text-to-cad/skills/cad          # baked skill dir (scripts/step|inspect|snapshot)
   WORK={{results_dir}}/work
   mkdir -p "$WORK"
   
   # Verify the CAD runtime is present (baked into the text-to-cad snapshot).
   python -c "import build123d, cadpy; from build123d import Box; print('build123d', build123d.__version__)" \
     || { echo 'ERROR: CAD runtime missing — is snapshot=text-to-cad?'; exit 1; }
   test -f "$SKILL/scripts/step/__main__.py" || { echo "ERROR: cad skill not at $SKILL"; exit 1; }
   
   # Fail fast on an empty prompt.
   PROMPT='{{prompt}}'
   [ -n "$PROMPT" ] || { echo 'ERROR: prompt is empty'; exit 1; }
   

   ---

2. 2
   Step 2

   Write a CAD Brief

   ▶

   From {{prompt}}, extract into a short brief (record it in summary.md): dimensions + units (default mm), coordinate convention (base plane XY, up +Z), feature intent (holes, fillets, pockets, bosses…

3. 3
   Step 3

   Author the build123d Generator + Export STEP

   ▶

   Write {{results_dir}}/work/model.py — a parametric build123d script that defines gen_step() returning the part (a build123d Part/Compound/ BuildPart result). Use named parameters at the top, verbose…

4. 4
   Step 4

   Inspect & Validate Geometry

   ▶

   Run the skill's deterministic inspection, then verify the spec dimensions the brief called out. Persist a machine-readable summary to inspect_report.json.

5. 5
   Step 5

   Render a Verification Snapshot (MANDATORY)

   ▶

   A visual snapshot is mandatory after creating geometry. First try the skill's renderer; if the interactive viewer renderer is unavailable in this headless runtime, fall back to a deterministic…

6. 6
   Step 6

   Iterate on Errors (max 3 rounds)

   ▶

   If STEP generation failed, a spec dimension didn't match, or the snapshot is empty/degenerate:

7. 7
   Step 7

   Copy Outputs + Write Reports

   ▶

   cd "$WORK" cp -f model.py model.step model.stl snapshot.png inspect_report.json {{results_dir}}/ 2>/dev/null · true

8. 8
   Step 8

   Final Checklist (MANDATORY — do not skip)

   ▶

   echo "=== FINAL OUTPUT VERIFICATION ===" RESULTS_DIR="{{results_dir}}" for f in \ "$RESULTS_DIR/model.py" \