Create a New TikZ Diagram

Scaffold a diagram from templates/tikz-snippets/, check it against the prevention rules, compile standalone, run the reviewer with measurement citations, and loop until the diagram passes. Use this instead of writing TikZ from scratch; the snippets embed the invariants that tikz-prevention.md requires.

Inputs

• $0 (optional) — snippet name (without .tex). One of the filenames in templates/tikz-snippets/. If omitted, list the gallery and ask the user to pick.
• $1 (optional) — output path. Defaults to Figures/new_diagram.tex — ask the user if this target exists so we don't clobber.

Workflow

Step 1: Pick a snippet

ls -1 templates/tikz-snippets/*.tex

Current gallery (see [templates/tikz-snippets/README.md](../../../templates/tikz-snippets/README.md) for descriptions):

• dag-basic — 3-node causal DAG (X → Y with confounder U)
• dag-mediation — X → M → Y with direct path
• did-two-period — two-period difference-in-differences
• event-study — event-time coefficients with 95% CIs
• timeline — horizontal timeline with staggered events
• regression-scatter — scatter + OLS fit + confidence band
• flowchart-3step — vertical flow with decision diamond
• supply-demand — supply/demand with shifted demand

If $0 is not one of these, or is omitted, ask the user which to use.

Step 2: Copy the snippet to the output path

SRC="templates/tikz-snippets/$0.tex"
DST="${1:-Figures/new_diagram.tex}"

# Confirm before overwriting
if [ -f "$DST" ]; then
  echo "Output path already exists: $DST"
  # Ask the user whether to overwrite. Do NOT clobber silently.
fi

mkdir -p "$(dirname "$DST")"
cp "$SRC" "$DST"

Step 3: Edit the content to fit the user's intent

Ask the user what the diagram should show. Edit $DST with the Edit tool:

1. Update the comment block at the top so the intent sentence matches the user's goal.
2. Update the coordinate map comment if coordinates change.
3. Rename nodes and edit labels. Keep node style (dag-node, flow-node, etc.) unless the meaning actually changes.
4. Do not add a bare scale=X to the tikzpicture options. Coordinates shrink, text does not — collisions follow. Allowed forms: scale=X, every node/.style={scale=X} or scale=X, transform shape. See [tikz-prevention.md P3](../../rules/tikz-prevention.md) for the full rule and tikz-visual-quality.md for the scale=1.1 convention.
5. Every new edge label must carry a directional keyword (above, below, left, right, above left, etc.). midway alone is a path position, not a direction — P4 violation.

Step 4: Prevention pre-check (MANDATORY)

Run the same shared Python checker /extract-tikz uses — this is the one tool that enforces both P3 and P4 consistently across the two skills:

python3 scripts/check-tikz-prevention.py "$DST"

• Exit 0 → passed, continue.
• Exit 1 → violations (stderr reports line, rule, snippet). Fix $DST and re-run until zero.
• Exit 2 → usage error (missing file etc.).

Do NOT re-implement the grep inline. The Python checker correctly handles multi-line \begin{tikzpicture}[...] options and multi-line \draw ... node {...} spans that a line-oriented grep cannot see.

Step 5: Standalone compile

All snippets are \documentclass[border=4pt]{standalone} so they compile without a Beamer frame and without Preambles/header.tex:

cd "$(dirname "$DST")"
xelatex -interaction=nonstopmode "$(basename "$DST")" > /tmp/tikz-compile.log 2>&1

Check exit code and *.pdf file size. If compile fails, read /tmp/tikz-compile.log and fix the .tex source.

Step 6: Visual review via tikz-reviewer

Spawn the tikz-reviewer agent with Task (subagent_type=tikz-reviewer). Pass the .tex source and the compiled .pdf path. The reviewer is now required to cite the pass and formula from [tikz-measurement.md](../../rules/tikz-measurement.md) for every CRITICAL/MAJOR finding — vague reports are rejected.

Loop:

1. If APPROVED → go to Step 7.
2. If NEEDS REVISION or REJECTED → apply fixes to $DST, re-run Step 4 (prevention pre-check), re-compile (Step 5), re-invoke reviewer.

Max 5 rounds. If after 5 rounds the reviewer is still reporting CRITICAL issues, surface the situation to the user — the snippet or the requested content may need redesign, not just tweaking.

Step 7: Optional — convert to SVG for Quarto

If the user plans to use the diagram in Quarto slides (not just Beamer), convert the compiled PDF to SVG:

pdf2svg "${DST%.tex}.pdf" "${DST%.tex}.svg" 1

Snippet-based diagrams are single-page, so a single .svg with the same basename as .tex is correct here. This differs from /extract-tikz, which produces a multi-page PDF from a Figures/LectureN/extracttikz.tex master and names outputs tikzexact00.svg, tikzexact_01.svg, ... (0-based filenames over 1-indexed PDF pages). If you need multi-page output for slide-by-slide reveals, use /extract-tikz instead.

Step 8: Clean up build artifacts

cd "$(dirname "$DST")"
rm -f *.aux *.log *.out *.synctex.gz

Leave the .pdf and .svg (if generated). They're what downstream tools use.

Step 9: Report

Print a summary:

• Snippet used → output path
• Reviewer verdict and number of rounds
• .pdf size and page count
• .svg path if generated
• Reminder to \input or \includegraphics the diagram in the target Beamer/Quarto file

Why start from a snippet?

Writing TikZ from scratch reliably produces collisions because the author cannot visually estimate where curves and labels will land. The snippets embed the invariants that tikz-prevention.md requires — coordinate maps, explicit node dimensions, directional edge labels — so the diagram passes the prevention pre-check by construction. You can always deviate from the snippet; the rules still apply.

Cross-references

• [.claude/rules/tikz-prevention.md](../../rules/tikz-prevention.md) — the P1–P6 authoring rules.
• [.claude/rules/tikz-measurement.md](../../rules/tikz-measurement.md) — the six-pass protocol with formulas the reviewer cites.
• [.claude/rules/tikz-visual-quality.md](../../rules/tikz-visual-quality.md) — general visual standards.
• [.claude/skills/extract-tikz/SKILL.md](../extract-tikz/SKILL.md) — for pulling TikZ out of an existing Beamer deck instead of creating new.
• [templates/tikz-snippets/README.md](../../../templates/tikz-snippets/README.md) — gallery inventory and adaptation guide.