Copy text from a web page, an email, or another app and paste it into Editan. It arrives as plain text, without the source’s fonts, colors, or rich-text styling. Edit the words in a consistent workspace, then copy in the format your next destination needs.
Draft in a scratch buffer, refine the words, copy in the right format, and get back to what you were doing. No Editan account or cloud sync. Editing and preview work offline; optional Claude and Notion integrations send text only when you run them.
Early-stage software. Build from source, or use the separately hosted prebuilt downloads. There is no App Store release. The app currently uses Japanese UI labels. English and Japanese documentation are available.
Why Editan?
- Plain text on the way in. Normal ⌘V pastes text in the editor’s own style. Gather text from different apps and start editing immediately. Markdown syntax highlighting is Editan’s own presentation.
- A scratchpad without the housekeeping. Scratch buffers save automatically as Markdown files. Open and edit existing text files, too.
- A clipboard you can predict. Standard ⌘C always copies plain text. Slack-style text and rich text each have their own explicit command.
- Markdown with a view. Syntax highlighting, a split preview, a formatter, list continuation, and copyable code blocks.
- Help with the words, when you want it. Optional Claude Code transforms for polite Japanese, a casual tone, proofreading, summaries, or your own instructions. Review before replacing.
- Made for your Mac. SwiftUI + AppKit, a menu bar companion, a global hotkey, reusable snippets, and editing that respects Japanese IME composition.
One draft, several destinations
| Where it is going | What Editan does | Shortcut |
|---|
| An AI prompt, a terminal, anywhere | Copy plain text without hidden formatting | ⌘C |
| Slack | Convert to Slack-style text and copy it | ⇧⌘C |
| Gmail, Pages, other rich-text apps | Copy HTML with a plain-text fallback | ⌥⌘C |
| Notion | Create a page under your configured parent page | ⇧⌘N |
Slack copy puts text on your clipboard; it does not post a message. Notion export sends the current buffer through the Notion API. How rich text and Slack-style text appear depends on the destination app.
Getting started
For a prebuilt app, see GitHub Releases. Open the DMG and drag Editan to Applications. The following instructions build the current source instead.
Requirements: macOS 14+, full Xcode 26+ (including its command-line tools), and Homebrew. The pinned Markdown dependencies use Swift tools 6.2; Editan's source uses Swift 5 language mode.
brew install xcodegen
git clone https://github.com/kohey18/editan.git
cd editan
./Scripts/install.sh
The script builds Release and installs /Applications/Editan.app, replacing an existing copy. Open Editan from Applications, or press ⌥⌘E once it is running.
- Press ⌘N for a scratch buffer. Paste text with ⌘V, or start writing.
- Toggle the preview with ⇧⌘P or format Markdown with ⇧⌘F.
- Copy with ⌘C, ⇧⌘C, or ⌥⌘C, then paste into the destination.
Scratch buffers auto-save. Existing files use ⌘S. Closing a scratch buffer deletes that draft after confirmation.
Install and authenticate the Claude Code CLI. Use a recent version supporting the flags documented in the security policy.
In Settings (⌘,) → 変換, choose a model and edit transformation templates. Select text, or leave nothing selected to transform the full draft, then use the 変換 menu or ⌥⌘1–9. Review the result before replacing the original or copying it.
Editan runs claude -p with built-in tools, MCP tools, slash commands, hooks, and session persistence disabled (administrator-managed policy may still apply). Your CLI authentication, provider configuration, usage limits, and billing still apply. A Claude subscription is not an unconditional guarantee of zero additional charges.
- Create a Notion internal integration and connect it to the destination parent page.
- In Settings (⌘,) → Notion, enter the integration token and parent page ID.
- Click トークンを Keychain に保存 to save the token to macOS Keychain.
- Press ⇧⌘N to create a new page from the current buffer.
The token is kept in macOS Keychain. Legacy tokens in preferences migrate when the Notion settings or export path is used; preferences are removed only after successful migration. Keychain access may ask for confirmation after rebuilding an ad-hoc signed app.
Keyboard shortcuts
⌘ Command · ⇧ Shift · ⌥ Option · ⌃ Control
| Action | Shortcut | Action | Shortcut |
|---|
| Summon Editan | ⌥⌘E | Plain-text copy | ⌘C |
| New buffer | ⌘N | Copy for Slack | ⇧⌘C |
| Switch buffer | ⌘1–9 | Rich-text copy | ⌥⌘C |
| Close buffer (with confirmation) | ⌘W | Send to Notion | ⇧⌘N |
| Open file | ⌘O | Format Markdown | ⇧⌘F |
| Save / Save As | ⌘S / ⇧⌘S | Toggle preview | ⇧⌘P |
| Find | ⌘F | Insert snippet | ⌃⌘1–9 |
| Paste as plain text | ⌘V | | |
| Settings | ⌘, | Run transform | ⌥⌘1–9 |
Your data
| Data | Location / behavior |
|---|
| Scratch drafts | ~/Library/Application Support/Editan/Buffers/<uuid>.md |
| Buffer index and templates | ~/Library/Application Support/Editan/ |
| Opened files | Their original location; save explicitly |
| Notion token | macOS Keychain; parent page ID remains in preferences |
| Claude transform | Selected text or full draft sent through your configured CLI |
| Notion export | Current buffer sent to the Notion API |
Editan has no analytics, crash-reporting service, automatic update checks, or cloud sync. Drafts are plain files, not encrypted by Editan. The preview blocks remote resources and escapes raw HTML. Exported rich text can contain remote image URLs, which a receiving app may load. See SECURITY.md for the boundaries and reporting process.
Development
xcodegen generate
open Editan.xcodeproj
# Build the native app
xcodebuild -project Editan.xcodeproj -scheme Editan \
-configuration Debug -derivedDataPath build/DerivedData build
# Run the isolated security regression tests
xcodebuild -project Editan.xcodeproj -scheme EditanSecurityTests \
-destination 'platform=macOS' -derivedDataPath build/DerivedData test
project.yml is the source of truth; the generated .xcodeproj is ignored. Regenerate after adding, moving, or removing Swift files. Security tests run without launching the app or reading real Notion credentials.
| Area | Responsibility |
|---|
Models/ | Buffers, persistence, editor commands |
Editor/ | AppKit text view, plain-text clipboard, highlighting, IME handling |
Preview/ | Safe Markdown-to-HTML conversion and the WebKit preview |
Transforms/ · Formats/ | Claude subprocess, Slack conversion, reusable templates |
Notion/ | Block conversion, Keychain credentials, API export |
Views/ · Utils/ | SwiftUI interface, global hotkey, editor access |
docs/ | Static English/Japanese landing page for GitHub Pages |
See CONTRIBUTING.md for checks, website maintenance for Pages, and third-party notices for dependencies.
What's next
Ideas under consideration, not promises of shipped features:
- Preview scroll synchronization
- Buffer search, pinning, and drag reordering
- A diff view for transform results
- More LLM providers and English app localization
- Broader installation testing for downloadable releases
Have a use case or a small improvement? Open an issue or contribute a pull request. Bug reports, documentation, and Japanese IME testing all help.
License
MIT © 2026 kohey18. Built with swift-markdown, swift-cmark, and highlight.js.
