> **pptx-slide-specification** — chapter 124 of 180 in [wshobson/agents](https://skillsdocs.com/wshobson/agents).
>
> Book (all chapters, one file): https://skillsdocs.com/wshobson/agents.md
> Machine manifest: https://skillsdocs.com/wshobson/agents/.well-known/agent-skills/index.json
> Install the book: `npx skills add wshobson/agents`
> Upstream: https://github.com/wshobson/agents/blob/main/plugins/pptx-deck-creation/skills/pptx-slide-specification/SKILL.md @ `main`
> Raw bytes, no header: https://raw.githubusercontent.com/wshobson/agents/main/plugins/pptx-deck-creation/skills/pptx-slide-specification/SKILL.md
> Base for relative paths: https://raw.githubusercontent.com/wshobson/agents/main/plugins/pptx-deck-creation/skills/pptx-slide-specification/
> Licence: MIT — https://spdx.org/licenses/MIT.html
>
> Bundled files (1), referenced from this skill's directory:
>   - `references/layout-contract.md` — https://raw.githubusercontent.com/wshobson/agents/main/plugins/pptx-deck-creation/skills/pptx-slide-specification/references/layout-contract.md
>
> Content © its authors, served unmodified. Takedown: https://github.com/kyleledbetter/skillsdocs/issues/new?labels=takedown&title=Takedown+request

<!-- Verbatim upstream SKILL.md follows, YAML frontmatter included. -->

---
name: pptx-slide-specification
description: "Use when authoring or repairing a coordinate-explicit JSON specification for an editable PPTX deck."
---

# PPTX Slide Specification

Author final coordinates directly in `layout_tree`. No renderer may decide placement, shrink text, or infer layout after the audit.

## Required contract

- The root JSON contains `summary` and `slides`.
- Every slide has a stable `id`, a message-led `title`, an accessibility reading order, and a complete `layout_tree`.
- A layout tree declares slide size, root group, id-keyed groups and objects, final inch bboxes, styles, z-indexes, and classifications.
- Every meaningful object has `id`, `kind`, `role`, `classification`, `content`, `style`, `bbox`, and `z_index`.
- Production `summary` contains an explicit `layout_policy` (safe margin, content bottom, footer top, minimum gap) and accessibility metadata.

## Authoring rules

1. Use stable readable IDs, absolute groups, and positive inch dimensions.
2. Keep normal content inside the safe margin and above the footer rail. Only background `layout_design` objects may be full bleed.
3. Use native `text`, `shape`, `line`, `table`, and `image` objects. Recreate labels and values from any supporting visual as native objects.
4. Give meaningful images alt text. Record `source_ref` for sourced claims.
5. Keep content text at 9 pt or greater; shorten, resize, or split dense content before reducing type.
6. Use shared grids, consistent gaps, explicit color, explicit font size, and an intentional z-order.

## Build contract

A task-local builder starts from a blank slide layout and maps all bboxes with `Inches(...)`. Explicitly set wrapping, disabled auto-size, text insets, anchors, alignment, fonts, colors, line settings, image aspect ratio, and hidden-slide state. Reject zero or negative geometry before adding an object.

See `references/layout-contract.md` for the compact schema and repair guidance.