Decks

Make slides by commenting on them. You leave a comment under a slide, your coding agent (Claude Code or Codex) changes the deck, and it replies on the slide: what it did, a question for you, or why it left something alone.

Why I built this

I teach people consulting skills and a big part of my work is getting people to make better and more compelling decks in PowerPoint. I made most of my slides in PowerPoint too. Of course I did, I'm a former consultant.

With Astra and Opus 5.5, we've reached a tipping point. I think that bulky software like Google Slides and PowerPoint increasingly doesn't make sense, especially for a solo operator like me. Handling basic formatting is trivial now and you can play project manager or partner, with the latest models as your Senior Associate. While I assume this may continue to evolve and I'm sure Claude's slide project may eventually kick my ass, for now, I am putting this out there as a simple harness that you can open in Claude or Codex and work in iteratively.

Decks is built that way. You say what should change, your agent changes it, and it tells you on the slide what it did and why. I have a tab, Checks, that offers some of the tests I teach to teams and also still run on my own slides: five- and ten-second tests, title tests, and horizontal and vertical flow. You can use AI as both a doer and a teacher, so you learn the method and apply it at the same time, on your own work.

When I make slides now, this is my daily driver and harness. I'm not sure I'll ever align boxes in PowerPoint again.

A builder with a strong opinion

Decks is built on the ideas I teach at StrategyU, and the agent follows them every time it writes or fixes a slide:

• Answer first. Lead with the recommendation, then the evidence. Build up to it only when the audience is skeptical.
• Ghost deck first. Write every title, in order, before building a single slide. It's the cheapest moment to fix the story. (Ghost decks)
• Action titles. Every title is a full sentence that says the point: "Q3 revenue grew 22%, driven by enterprise expansion", not "Q3 Revenue". (Action titles)
• Vertical flow. The title matches the content: the body proves the title, and there's no takeaway box at the bottom. (The principles of flow)
• Horizontal flow. Read only the titles, in order, and they tell the whole story.
• The five-second test. For a slide you present: glance at it for five seconds, and the one point comes through.
• The ten-second test. For a slide people read: they can take it in within ten seconds. One point, a clear hierarchy, a chart that reads without study. (The ten-second test)
• "So what?" A slide can be easy to read and still say nothing. Every slide tells the audience what to think. (Pretty slide syndrome)
• One idea per slide. If it needs "and also", it's two slides.
• Charts prove the title. Bars, columns, and lines; the number that matters stands out; never a pie chart.
• Draw the relationship. No grids of identical boxes. Show the process, the spectrum, or the chart instead.

Most of these are one keypress away in Checks. The agent's version of the method is in .claude/skills/decks/SKILL.md, and the full one is in my strategy-slides skill.

Recommended setup

I use Decks in the Claude and Codex apps, with the deck open in the app's built-in browser, so the agent and I look at the same page. Models: Opus 5.5 or Sol 6.1. I haven't tried others yet.

Each deck is one file on your machine

Each deck is one HTML file in its own folder, with its own git history. It opens in any browser, presents full screen, and prints to PDF. Decks runs on your machine and keeps nothing anywhere else (your agent sends what it reads to its model provider, as it does with any file). When you need to send a deck, Client copy gives you one file with only the slides.

Install

You need Python 3.9 or newer, Node.js 18 or newer, and git (optional, but decks get version history with it). macOS and Linux.

git clone <this repository> decks
cd decks
./setup.sh
python3 server.py

Open http://localhost:8790/. The first start makes ~/slide-decks/ with the deck registry (decks.json) and a demo deck to practice on.

The server needs only Python. Screenshots, the audit, PDF export, and dashboard thumbnails use Node.js and a headless Chrome. setup.sh installs playwright-core into tools/ and, if it can't find a usable Chrome, Playwright's Chromium (about 150 MB, in ~/Library/Caches/ms-playwright on macOS or ~/.cache/ms-playwright on Linux). On Linux, if screenshots or PDFs fail, Chrome is missing system libraries: (cd tools && sudo npx playwright-core install-deps chromium).

Updates

Decks has numbered versions. CHANGELOG.md says what changed in each, and the dashboard footer shows the version you're running. When a new version is out, the dashboard says so. To update, run git pull here and restart the server. To hear by email, watch the repository on GitHub (Watch › Custom › Releases).

To know about new versions, the server asks GitHub once a day which release is newest: one small request, read from a redirect. GitHub sees your IP address and that a check happened. Nothing about your decks is sent. To turn it off, set "check_updates": false in config.json, or SB_CHECK_UPDATES=0.

Settings

Defaults: port 8790, listening on 127.0.0.1, decks in ~/slide-decks. To change them, copy config.example.json to config.json, or set environment variables (they win):

python3 server.py --port 8799 changes the port for one run.

How a round works

1. You comment. Write what should change in the box under a slide, or click any text on the slide and fix it yourself. It saves to disk next to the deck as you type.
2. You hand it to the agent. Click Ask Claude in the top bar. It copies a prompt with the deck file and the steps; paste it into Claude Code or Codex. With the decks skill installed, you can just say "process changes".
3. The agent edits and replies. It reads your comments and edits with sb comments and sb edits, changes the deck file, and answers each comment on its slide with sb reply. You see "Claude working" on the slide while it goes.
4. The agent checks its work. It screenshots the slides it touched, runs the audit, exports the next numbered PDF, records the round, and commits the deck folder.
5. You review. The page reloads once you stop typing. Replies sit under their slides, and changed slides carry a badge. Looks good clears a comment; Reopen sends it back.

Each slide keeps its history in the side panel: every comment, the agent's reply, and how it ended.

Checks: the tests I teach, one key each

Press C, or a number key from any view to run that check on the slide you're on. Not sure which? Help me choose asks what you want to know and opens the check that answers it.

1. 5-second test. Can you get the point of the slide at a glance?

2. 10-second test. Can a reader take it in, in the time they'll give it? A miss on either timed test (M) leaves a comment on the slide for the next round.

3. Horizontal flow. The titles alone, in order, as paragraphs or one per line. They should tell the whole story. You can edit them right there.

4. Vertical flow. The title first, with the body hidden. Say what the slide has to prove, then press Space and check that it does. It finds the title wherever your layout puts it, even inside a column or panel.

5. Guides. Four basic rules drawn on every slide, with a list of the slides that break one:

   • the protected border, kept for the logo, source line, and page number;
   • titles of two lines at most (title, section, closing, and statement slides are exempt);
   • no text under 12 px on the 1000 px slide;
   • no more than four text sizes on a slide.

   They're guidelines. They flag problems and never block you. Ask Claude to fix adds what a slide breaks to its comment (Comment on all does every flagged slide), and the agent fixes it next round. sb audit runs the same check, plus overflow and overlapping labels.

You can comment from any check except the timed tests: the comment box stays under the slide.

Working in a deck

Four views, each with the slides on the left and the notes on the right:

• Focus (F): one slide, its comment box, and the agent's reply.
• Scroll (S): the whole deck, with comments and replies under each slide.
• Sorter (G): drag thumbnails to reorder, × to leave a