Support

1. Download Lectern.dmg.
2. Open it and drag Lectern into Applications.
3. Open Lectern from Applications. It is signed and notarized by Apple, so it opens without warnings.

Lectern is also coming soon to the Mac App Store. The App Store version doesn't include Ask Claude, because Apple's sandbox doesn't let it start Claude Code; for Ask Claude, use the download above.

macOS 14 Sonoma or later, on a Mac with Apple silicon. For a show, a second display: a projector, a TV or an AirPlay display. With one screen, Lectern opens in rehearsal mode. For Ask Claude, you also need the downloaded version of Lectern (not the Mac App Store one), with Claude Code installed and signed in with your Claude subscription.

Slide decks in a single HTML file. It works best with decks that follow the Presenter Deck spec: Lectern finds every slide and its speaker notes exactly, and you can edit notes and slide text, and use Ask Claude. reveal.js decks and other HTML slide decks play too. Lectern finds their slides and notes as well as it can, and their notes are read-only.

The spec comes with Lectern as a Claude skill. In the Lectern menu, choose Claude Skill, then:

• Install in Claude Code… copies the skill to ~/.claude/skills/presenter-deck.
• Save for Claude.ai… saves presenter-deck.zip. Upload it on claude.ai in Settings › Capabilities › Skills.
• Copy as Prompt puts the spec on the clipboard, to paste into any other assistant.

Then ask for a deck as you normally would, for example "Make a 10-slide Presenter Deck about our field study, with speaker notes."

Connect the projector or TV first. Then open the deck: drop it on Lectern's window, click Open…, pick it under Recent, or use File › Open (⌘O). The show starts at once: the slides go fullscreen on the external display, and the presenter view opens on your Mac. F5 goes back to slide 1. Esc leaves full screen, and pressed again ends the show.

Show › Swap Displays (⇧⌘D). Lectern remembers the choice.

Yes. With one screen, the audience view opens as a small window at the top left, over the presenter view. Everything else works as in a show, including the clicker, the timer and editing. If a display is unplugged during a show, Lectern switches to this mode.

Show › Hide Audience Window (⇧⌘A) takes the slides off the external display, so you can use it for other windows. The same command brings them back.

Yes. Most clickers send Page Down and Page Up, or the arrow keys, and Lectern responds to them whichever of its windows is in front, even while you're editing notes.

Press + or − to make the notes bigger or smaller. Drag the line between the current slide and the right column to make the notes wider, and the line between the next slide and the notes to make them taller. Lectern remembers both. Double-click a line to reset it.

View › Show Timer (⌥⌘T) shows or hides the timer next to the clock. T pauses or resumes it, and ⇧T resets it.

In a Presenter Deck deck, click into the notes and type, as in PowerPoint. This works during a show too. ⌘B, ⌘I and ⌘U make text bold, italic or underlined, and ⌘Z undoes. Type "- " at the start of a line for a bullet; Return continues the list, and Return on an empty bullet ends it. Esc or a click anywhere else finishes editing. Page Up and Page Down still change slides, so your clicker keeps working.

In the deck's own HTML file, as you pause typing, when you click away and when you change slides. Lectern replaces only that slide's notes, or adds them if the slide had none, and leaves the rest of the file exactly as it was.

Lectern won't overwrite a deck it can't save safely. This happens if another app changed that slide's notes in the file since Lectern opened it, or if the file can't be written (for example, it's read-only or on a disk that was removed). Your text stays on screen. Copy it, reopen the deck, and paste it back.

Notes in reveal.js and other HTML decks are read-only. Editing works in Presenter Deck decks.

Double-click the text on the current slide in the presenter view. It gets an amber outline. Type, then press Return to save or Esc to cancel. ⇧Return adds a line break. The change goes into the deck file and shows on the projector straight away. This works during a show too.

Hold ⌥ to outline everything on the current slide. Amber text can be edited. Grey dashed text can't; point at it and the tooltip says why. Lectern edits one heading, paragraph or list item at a time, as plain text, and formatting already in it stays. Text in charts and drawings (SVG), and text that a deck's script writes, can't be edited in place. For bigger changes, use Ask Claude.

Click Ask Claude in the presenter view's top bar (⌘K) to change the current slide, or use Show › Ask Claude to Add Slides After This One… (⇧⌘K). Describe the change, pick a model and effort, and click Ask Claude. When Claude finishes, the deck reloads at the changed slide, and you choose Keep or Undo.

The defaults are Opus and medium effort. Sonnet is quicker for simple changes, and high effort helps when reworking a whole slide. Lectern remembers your choice.

The version of Lectern downloaded from this website: the Mac App Store version doesn't include Ask Claude. And Claude Code, Anthropic's command-line tool, installed on your Mac and signed in with your Claude subscription. Ask Claude works with Presenter Deck decks. Lectern runs Claude Code under your own account, so it counts against your Claude plan's usage. It never uses an Anthropic API key, even if one is set on your Mac.

Install Claude Code from claude.com/claude-code, run claude once in Terminal and sign in with your Claude account, then try again. Lectern looks for claude in the usual install locations and on your shell's PATH.

• Claude works in a temporary folder that holds a copy of the current slide with its speaker notes taken out, a copy of the deck's <head> (its styles and scripts), the deck's title and slide titles, the Presenter Deck spec and your instruction. When you add slides, it also gets an empty copy of the deck's <head> to write them into. Claude never receives any speaker notes, other slides or the deck file itself.
• It can only read and write files in that folder: no shell, web or other tools. Your own Claude Code settings, hooks and plugins aren't loaded.
• Lectern takes back only the slides. The changed slide gets your notes back word for word, and any notes Claude added to it are dropped. Lectern checks that every other slide is unchanged, backs the deck up, and only then saves it. New slides come with notes Claude wrote for them.
• Undo puts back the exact previous file. If the deck has changed since, Undo refuses and points you to the backup.

Lectern stops Claude after 8 minutes, and nothing in the deck changes. Try a smaller request, a lower effort or Sonnet. "Claude couldn't finish" shows what Claude Code reported, such as a usage limit or a sign-in problem. Run claude in Terminal to check.

Before a deck's first edit in a session, and before every Ask Claude change, Lectern copies the deck to ~/Library/Application Support/Lectern/Backups. It keeps the 50 newest copies. To open the folder, press ⇧⌘G in the Finder and paste the path. To restore a deck, copy a backup over it.

The Mac App Store version is updated by the App Store. The downloaded version checks for a new version about once a day and asks before installing it. To check now, choose Lectern › Check for Updates…. Each version's changes are in the release notes.

No, unless your deck loads fonts or images from the web, or you use Ask Claude. Lectern itself only connects to check for updates.

Quit Lectern and drag it from Applications to the Trash. To also delete its backups and settings, delete ~/Library/Application Support/Lectern and ~/Library/Preferences/com.victorshammas.Lectern.plist. If you installed the Claude skill, delete ~/.claude/skills/presenter-deck too. Your decks aren't touched.