| name | ia-presenter |
| description | Author and iterate on iA Presenter presentations (.iapresenter bundles) on macOS. Use whenever the user mentions iA Presenter, .iapresenter, an upcoming talk or slide deck where iA Presenter is the target tool, or wants to script-first / markdown-based slides. Also use when iterating on slide layout, themes, image sizing, multi-image slides, on-slide tables, or when iA Presenter's import is producing wrong slide breaks. Also use when generating diagram PNGs (mermaid, d3, etc.) for embedding in slides — this skill has the chromium-foreignObject transparency gotchas. iA Presenter has no CLI or API — this skill documents the bundle structure and the hot-reload-text.md trick that's the de facto agent-friendly path, plus the small set of image/layout directives that solve 90% of layout issues. |
iA Presenter
iA Presenter is a markdown-first presentation tool for macOS/iOS. The native format is a .iapresenter package — a directory bundle containing the slide markdown plus image assets. Slides are authored as plain markdown, where headings appear on slides, paragraphs become speaker notes, and --- separates slides.
This skill captures the practical workflow: how to bootstrap a deck, how to iterate quickly, and the small handful of layout directives that handle most real-world slide problems.
Core mental model
iA Presenter inverts the usual presentation tool: what you say ≠ what you show. By default, paragraphs are speaker notes (only the presenter sees them) and only headings + tab-indented text + images appear on slides. The philosophy: write the talk first as prose, then surface select bits onto slides.
Concretely:
# Heading → visible on slide as the title## Subheading → visible tab-indented paragraph → visible body text- Plain paragraph (no tab) → speaker notes only
 or /assets/x.png → image on slide--- (or two blank lines) → new slide
A presenter who spits out bullet-point-heavy slides is fighting the tool. Lean into headlines + one strong visual + speaker notes.
No official automation surface — edit the bundle directly
iA Presenter has no CLI, no public API, no AppleScript dictionary, no URL scheme, and no Shortcuts integration. Don't go looking — they don't exist. iA's support docs cover only the GUI.
The de facto agent-friendly path is the bundle's plain-text source: <deck>.iapresenter/text.md. iA watches the file and hot-reloads on external edits. This skill leans on that.
The .iapresenter bundle
A .iapresenter is a directory (macOS treats it as a single file via the bundle bit). Inside:
deck.iapresenter/
├── text.md # the slide markdown — source of truth
├── info.json # metadata (creator, version, file ID)
├── assets/ # images referenced by text.md
│ └── *.png
└── thumb.png # auto-generated cover thumbnail
This matters because: you can edit text.md directly with any editor (Vim, an LLM, a script) and iA Presenter hot-reloads. That's the fast iteration path — much faster than clicking around the app.
info.json minimum:
{
"creatorIdentifier": "net.ia.presenter",
"net.ia.presenter": { "localFileIdentifier": "<UUID>" },
"transient": false,
"type": "net.daringfireball.markdown",
"version": 2
}
You can generate one from scratch — uuidgen for the ID, drop in text.md and assets/, and iA Presenter will open it. But the easier path is to import a .md once (see below) and then edit text.md inside the resulting bundle.
Workflows
Bootstrapping from a markdown draft (most common)
- Write
slides.md in the repo using iA's syntax (headings + paragraphs + ).
- In iA Presenter: File → Import → Markdown / Text, pick
slides.md. Don't use File → Open — that filters out .md and only accepts .iapresenter bundles. (This trips everyone up the first time.)
- In the import dialog, leave all three checkboxes on: "Convert Markdown to Slides," "Convert Paragraphs into Speaker Notes," "Import local images into .iapresenter file."
- iA may pop a "Give Access" dialog asking to read the folder containing the images — approve it.
- Save (Cmd+S) and pick a path inside the repo, e.g.
deck.iapresenter. Now you have a bundle.
- From now on, edit
deck.iapresenter/text.md directly — iA reloads on save.
Bootstrapping from scratch
If the repo has no .md yet, just create deck.iapresenter/ with the structure above (write info.json, drop a text.md, make an empty assets/). Open it in iA. Faster than the import dance for a known-format deck.
Iterating on an existing deck
The bundle's text.md is the source of truth. Edit it directly with whatever tool — iA picks up changes automatically. To add an image, drop the file into <bundle>/assets/ and reference it as /assets/filename.png in text.md.
Slide markdown — the gotchas
Import inserts spurious slide breaks
iA's importer inserts --- between a heading and a following image at the top of a slide. So a clean source like:
# My slide
speaker notes
becomes, after import:
# My slide
---
/assets/chart.png
speaker notes
…which renders as two slides (heading-only, then image-only) instead of one. Fix: open text.md in the bundle and delete the spurious --- lines. Always sanity-check after a first import.
Image directives go on the line(s) immediately following the image path
/assets/diagram.png
size: contain
x: center
y: top
No blank line between the path and the directives, or they get treated as a separate paragraph (and become speaker notes).
Useful image directives
size: contain — fit the image without cropping. Use this for diagrams; cover (the default) crops aggressively for very wide or very tall images.size: cover — fill the cell, crop as needed. Default. Good for photos.x: left|center|right, y: top|center|bottom — alignment within the cell.background: true — image fills the slide as a background; text floats on top. Good for hero shots and full-bleed photos. Bad for diagrams whose detail conflicts with overlaid text. Reach for this when the image is atmospheric; avoid when the image is informational.
Slide title patterns
For a title slide with subtitle:
# Talk Title
Speaker name or one-line tagline
The tab-indented line becomes a subtitle on the slide.
For a scannable list of topics on a slide (an agenda, sub-sections of a discussion), use ####:
# Execution
#### Defining reliability
#### Crawling
#### Normalization
#### "Fun" with feature flags
Each #### renders as a smaller line of text on the slide. This sidesteps the bullet-list anti-pattern while still surfacing a scannable map of what the slide covers — you're showing section titles, not reading sentences aloud.
Tables (and table-charts)
Markdown tables are first-class on slides — reach for them when the data is denser as a table than as a chart, or when an axis chart would imply false precision the numbers don't have. Standard pipe syntax:
| | Series 1 | Series 2 |
| :------ | :------- | :------- |
| Group A | 10 | 15 |
| Group B | 20 | 25 |
iA renders the table at slide width. To turn the same table into a bar/line/pie chart, append a Chart: directive (and optional axis labels) below it:
| | Series 1 |
| :------ | :------- |
| Group A | 10 |
| Group B | 20 |
Chart: Bar
yLabel: Y Axis Label
Useful when you want a real chart from authored data without an external render pipeline. For anything fancy (custom axes, sketchy/illustrative styles, multi-series with bespoke treatments), keep rendering externally and embed as a PNG.
Multiple images on one slide
Stack image blocks (path + directives) separated by a blank line; iA lays them out side-by-side or top/bottom based on the slide's aspect ratio:
/assets/diagram-a.png
size: contain
/assets/diagram-b.png
size: contain
Pairs well with omitting # Heading so the visuals get the full canvas. If the auto-layout sizes them inconsistently, re-render the source images at matching aspect ratios — iA respects intrinsic image dimensions.
Image-then-heading vs heading-then-image
iA's auto-layout picks layout based on element order. Putting the image first tends to make it dominant; putting the heading first tends toward heading-left/image-right. Try both if a slide feels off.
Layout limits — when split layout doesn't fit a wide diagram
Default layout for # Heading + image is a horizontal split: title on the left half, image on the right half. For images with extreme aspect ratios (wide system diagrams, tall flowcharts), this halves the available space and the diagram becomes unreadable.
Mitigations, in order of preference:
- Re-render the image at a more square aspect ratio. This is almost always the right answer — tweak the source (mermaid layout direction, matplotlib figsize, etc.) before reaching for layout hacks.
- Drop the heading on that slide. Let the diagram speak for itself; speaker introduces it verbally. Keeps the rest of the deck consistent without fighting the layout engine.
background: true — only if the diagram is OK with a heading overlaid on it. Usually it isn't.
Don't try to override layouts with CSS classes or position pixel-pushing per slide; you'll fight the responsive engine and the deck will break on different displays.
Generating diagrams as PNG assets
Decks often embed diagrams rendered externally (mermaid, d3, plot images). A few things to get right when rendering specifically for slide use, since slide audiences won't tolerate the rough edges that survive in a long-form web doc:
- Render at a slide-friendly aspect ratio — close to the slide cell's shape (think 4:3 or 16:9, or vertical when paired with another image). Wide system diagrams hit the layout limits described above.
- Render with a transparent background. Slides may use a non-white theme, and even on a white theme, an explicit white panel inside an image reads as a visible rectangle (anti-aliasing edges, slight color mismatch). Transparent fills composite cleanly on whatever background the deck ends up using.
- For mermaid via headless chrome (puppeteer/playwright): set
flowchart: { htmlLabels: false } in mermaid.initialize. Without it, chromium rasterizes <foreignObject> HTML labels with opaque white pixels regardless of CSS overrides — there's no way to fix it from the outside. Mermaid also injects ID-scoped !important CSS (#mermaid-XXXX .edgeLabel { … !important }) that beats class-only stylesheet rules. Patch fills via inline-style after render: el.style.setProperty('fill', 'transparent', 'important'). Sweep over .node rect, .cluster rect, span.edgeLabel, .labelBkg, etc.
- Verify transparency on a colored background, not by eyeballing the PNG in a viewer — most viewers (and Claude Code's image preview) show transparent pixels as white, so a fully white-filled image and a fully transparent image look identical. Composite the PNG onto a non-white page and re-screenshot, or sample alpha values directly with a PNG library.
These are tedious one-time setups, but pay off across the whole deck and any future revisions.
Themes
Themes are picked via Format → Templates (or the right-hand inspector). iA ships with a solid set: San Francisco, Milano, Copenhagen, Garamond, etc. Each theme handles light/dark and varies fonts + accent colors. Pick one after the content is settled — switching is free, so don't agonize early.
For a clean technical/retro deck, the default San Francisco-style theme is usually right. For something more editorial, Garamond. For something dramatic, Copenhagen.
Custom themes are possible (theme.css + template.json) but rarely worth it — you're better off using a built-in and accepting its constraints.
Reference: the built-in tutorial
iA ships a tutorial deck at:
/Applications/iA Presenter.app/Contents/Resources/Default.md
When in doubt about syntax — image positioning, table charts, how to do a TOC slide, etc. — read that file. It's the canonical example of every feature in the tool.
Anti-patterns
- Bullet lists on slides. iA's docs are emphatic: bullets read robotic, increase cognitive load, and tempt the audience to read instead of listen. Convert to a single headline + image, or move to speaker notes.
- Reading the slide aloud. If the slide has the line you're saying, the audience reads ahead of you (~250 wpm reading vs ~150 wpm speaking) and tunes you out.
- Stock imagery. Per iA: "Stock imagery is worthless and will likely insult your audience's intelligence." Use real screenshots, charts, or nothing.
- Editing slides only inside the iA UI. Slow. The text.md hot-reload is the killer feature; use an external editor when you're iterating on prose.
Quick reference
# Title slide
subtitle (tab-indented)
speaker notes go here as plain paragraphs
---
# Slide with one image
/assets/chart.png
size: contain
speaker notes for this slide
---
# Slide with body text on slide
A line of body text shown to the audience.
Another line.
speaker notes
