DeckCraft v6 — Harness Engineering#

Version: 6.0.0 · Engine: DeckEngine (python-pptx native charts) + ChartEngine (native)

Required tools: Read, Write, Bash Requires: pip install python-pptx lxml Pillow Render QA: LibreOffice Impress (soffice --headless) + poppler-utils (pdftoppm)

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Anti-Patterns (Read Before Every Generation)#

Anti-Pattern 1: Declaring "Gate Passed" Verbally#

Wrong: "QA found 5 errors but all are minor, gate passed." Correct: Run gate_check.py, read the JSON, only "passed": true means pass.

Anti-Pattern 2: "I Checked In My Head"#

Format errors in content JSON are invisible to mental review. Correct: Run gate_check_content.py, read the JSON output.

Anti-Pattern 3: Skipping the Process for "Simple" Decks#

Even simple decks can have overflow, font issues, or broken layouts. Correct: Use Fast Track (see below), but never skip the QA gate.

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HARD RULES#

1. Every generation must follow the 5-stage flow
2. Gates must be machine-readable — run the script, read the JSON
3. Experience accumulation is recommended — note pattern-level fixes for future improvement
4. All positioning values must use int() wrapping for python-pptx
5. Clear paragraphs before adding runs — never assume p.runs[0] exists

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5-Stage Generation Flow#

text

S1 Brief → S2 Structure → S3 Content → S4 Render+QA → S5 Deliver
                          ⭐ gate        ⭐⭐ gate

Stage 1: Brief#

Collect: audience, goal, duration, key messages, style preference. Output: <project>/brief.md

Design Spec Template (v6.0+): Use templates/design_spec.md to capture structured design decisions (canvas, page count, audience, color scheme, typography, speaker notes). A filled example is at templates/design_spec_demo.md. Recommended for any deck ≥ 8 pages.

Stage 2: Structure#

Assign page types, write key points (full insight sentences). Output: <project>/outline.json

Stage 3: Content#

Fill copy, numbers, chart data. Respect char budgets in designs/layout_matrix.yaml. Output: <project>/content.json

⭐ Gate S3:

bash

python3 scripts/gate_check_content.py <project>/content.json <project>

Read gate_content.json — only "passed": true allows proceeding.

Stage 4: Render + QA#

Generate PPTX from content.json, then run QA.

bash

python3 scripts/gate_check.py <pptx_path> <project>

Read gate_result.json — only "passed": true allows proceeding.

Visual QA (render preview):

bash

# Render PPT → PDF → PNG for visual inspection
soffice --headless --convert-to pdf <pptx_path> --outdir <project>/
pdftoppm -png -r 200 <pdf_path> <project>/preview/slide

Inspect the PNG images to verify layout, fonts, colors, and chart rendering. Fix any visual issues found, regenerate, and re-run gate.

Stage 5: Deliver + Self-Refinement#

Deliver the PPTX.

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Fast Track (Simple Requests)#

When all conditions are met, skip S2/S3 gates:

• Total pages ≤ 5
• No data charts
• User says "quick" / "fast" / "simple"

Still required: S1 + S4 QA gate + S5 delivery.

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Checkpoint Recovery#

When resuming a deck project, check which files exist:

• No brief.md → Stage 1
• No outline.json → Stage 2
• No content.json → Stage 3
• No gate_content.json → Stage 3-gate
• No .pptx → Stage 4
• No gate_result.json → Stage 4-gate
• All present → Stage 5

Resume from the identified stage. Do not restart from S1.

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DeckEngine API#

python

import sys, os
sys.path.insert(0, '<skill-path>')
from engine import DeckEngine

# v5.2+: canvas parameter (16:9 / 9:16 / 1:1 / 4:3 / A4)
eng = DeckEngine(theme_name="business", canvas="16:9")  # default
eng = DeckEngine(theme_name="business", canvas="9:16")   # vertical mobile (TikTok, Reels, Stories)
eng = DeckEngine(theme_name="business", canvas="1:1")    # square (Instagram)
eng = DeckEngine(theme_name="business", canvas="4:3")    # classic projector
eng = DeckEngine(theme_name="business", canvas="A4")     # print landscape

# v6.0+: Multi-role mode (optional strategist → executor workflow)
eng = DeckEngine(theme_name="business", canvas="16:9", role_mode="multi")
plan = eng.strategist_plan({"title": "My Brief"})  # get plan template
# ... fill plan with your LLM ...
eng.execute_plan(filled_plan)                       # generate from plan
eng.cover(title="Title", subtitle="Sub", author="Author", date="2026")
eng.toc(items=[("1", "Chapter", "Description")])
eng.section_divider("Section Title", section_number=1)
eng.content(title="Slide", bullets=["Point 1", "Point 2"], key_point="Insight")
eng.content_with_icon(title="Slide", items=[("01", "Head", "Desc")])
eng.two_col(title="Compare", left_title="A", left_items=[], right_title="B", right_items=[])
eng.vs_compare(title="VS", left_title="Before", right_title="After", rows=[("Dim", "Val1", "Val2")])
eng.table(title="Data", headers=["H1", "H2"], rows=[["a", "b"]], insights=["Key takeaway"])
eng.stat_cards(title="KPIs", stats=[("99%", "Uptime"), ("$2M", "Revenue")])
eng.chart_bar(title="Revenue", data=[[4.2, 3.8]], labels=["A", "B"], series_names=["S1"])
eng.chart_pie(title="Mix", data=[45, 30, 25], labels=["X", "Y", "Z"], donut=True)
eng.chart_line(title="Trend", data=[[1, 2, 3]], labels=["Q1", "Q2", "Q3"])
eng.chart_gauge(title="Score", value=87, max_value=100, label="NPS")
eng.timeline(title="Roadmap", milestones=[("Q1", "Launch"), ("Q2", "Scale")])
eng.process_flow(title="Steps", steps=["Research", "Build", "Launch"])
eng.matrix_2x2(title="Priority", quadrants=[("TL", "desc"), ("TR", "desc"), ("BL", "desc"), ("BR", "desc")])
eng.quote(title="Insight", quote_text="Words matter.", attribution="Author")
eng.image_full(title="Visual", image_path="photo.jpg", caption="Detail")
eng.image_split(title="Split", image_path="photo.jpg", bullets=["Point"])
eng.kpi_dashboard(title="Dashboard", kpis=[("Revenue", 12.4, 15, "M")])
eng.team_grid(title="Team", members=[("Name", "Role")])
eng.checklist(title="Tasks", items=["Task 1", "Task 2"], checked=[True, False])
eng.summary(title="Takeaways", key_points=["Point 1"], conclusion="Next step")
eng.closing(title="Thank You", message="Questions?")  # no page_num (closing slide)
eng.save("output.pptx")

10 themes: business, business_dark, tech, tech_gradient, minimal, elegant, creative, green, red, ocean

Canvas presets (v5.2+): 16:9 (default, widescreen), 9:16 (vertical mobile, TikTok/Reels/Stories), 1:1 (square, Instagram), 4:3 (classic projector), A4 (print landscape), A4-portrait. Aliases: mobile =9:16, square =1:1, ppt =16:9.

List available canvases: from engine.constants import list_canvases; print(list_canvases())

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Design Guide#

Color#

Extract from user's original PPT first. Pick a bold palette matching the topic. One dominant color (60-70%), 1-2 supporting, one sharp accent.

Typography#

ElementSizeNotesSlide title26-36pt boldMust stand outBody text14-16ptNever below 10ptCaptions10-12ptMuted color

CJK: Noto Sans CJK SC / Latin: Arial / Calibri

Spacing#

• Minimum margin: 0.5"
• Between blocks: 0.3-0.5"
• Leave breathing room

Avoid#

• Repeating the same layout on every slide
• Text-only slides — add visual elements
• Center-aligned body text
• Low-contrast text (light on light, dark on dark)

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Dependencies#

ToolInstallpython-pptxpip install python-pptxlxmlpip install lxmlPillowpip install Pillow

Render QA (optional but recommended):

ToolInstallLibreOffice Impressapt install libreoffice-impresspoppler-utilsapt install poppler-utilsNoto Sans CJKapt install fonts-noto-cjk

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Skill File Structure#

text

deckcraft/
├── SKILL.md                     # This file
├── engine/
│   ├── __init__.py
│   ├── constants.py             # 10 theme color palettes, typography, grid
│   ├── core.py                  # Drawing primitives, XML cleanup, CJK font
│   ├── chart_engine.py          # Native bar/pie/line/gauge charts (python-pptx)
│   ├── deck_engine.py           # 20 layout methods, 40+ high-level API
│   └── importers/               # v5.3+ source importers
│       ├── __init__.py
│       ├── base.py              # Shared heuristics
│       ├── pdf.py               # PDF → outline (PyMuPDF)
│       ├── docx.py              # DOCX → outline (python-docx)
│       └── text.py              # TXT/MD → outline
├── scripts/
│   ├── generate_ppt.py          # CLI: outline JSON → PPTX
│   ├── import_source.py         # v5.3+ CLI: PDF/DOCX/MD → outline
│   ├── gate_check.py            # S4 QA gate → gate_result.json
│   └── gate_check_content.py   # S3 content gate → gate_content.json
├── designs/
│   └── layout_matrix.yaml       # 23 layout definitions with char budgets
├── examples/                    # Working code samples
│   ├── 01_basic_cover_to_closing.py
│   ├── 02_multi_canvas.py
│   ├── 03_from_outline_json.py
│   └── 04_from_source.py        # v5.3+
└── tests/
    ├── test_smoke.py            # 95 layout × canvas tests
    ├── test_validation.py       # 20 input validation tests
    └── test_importers.py        # v5.3+ 34 importer tests