Pulse

A light, native code editor for macOS.

Install • Website

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Pulse is a code editor written in Swift and AppKit, with no web view, no Electron and no extension host. It stays small: about 60–70 MB of memory in everyday use, and never more than 100 MB, with no CPU use while you are not typing.

Features

• Folders and files: open a folder, browse it in the sidebar, open many files in tabs. The file you're editing stays highlighted in the tree.
• Windows: each folder opens in its own window (pulse <folder>, Finder, File › Open), like VS Code; opening a folder that is already open brings its window forward. ⇧⌘N opens an empty window. All windows come back after a restart.
• Editing: syntax highlighting for Swift, JS/TS, Python, Go, Rust, C/C++/Obj-C, Java/Kotlin, Ruby, shell, HTML/XML, CSS, JSON, YAML, TOML, Markdown and SQL. Line numbers, current-line highlight, auto-indent, toggle comment, indent/outdent, word wrap. Code folding by indentation, as in VS Code: the chevrons in the gutter, ⌥⌘[ / ⌥⌘], or Fold All in View › Folding.
• Breadcrumbs: the open file's path, from the opened folder, shows under the tabs.
• Split editor: View › Split Editor Right (⌥⌘\) or Down, or right-click a tab. Each pane has its own tabs; a file open in two panes is one text, edited in both. Nothing is created until you split, and a pane closes with its last tab.
• Find and replace in the file (the standard macOS find bar), and project search (uses ripgrep when installed, otherwise a built-in scan; a block of code finds the same code however it is wrapped or indented). Under …, files to include and files to exclude take comma-separated globs as in VS Code: *.ts, src (that folder at any depth), ./src (only the top-level one), src/**/*.test.ts, *.{ts,tsx}.
• Command palette: ⌘P go to file, ⇧⌘P commands, ⌘L go to line. Developer: Reload Window rebuilds the window with its folder, tabs and unsaved text.
• Back and forward: ⌃- returns to where you jumped from (another file, a Find match, a search result, Go to Line) and ⌃⇧- goes forward again, as in VS Code. Rebind them in Keyboard Shortcuts.
• Go to Definition: ⌘-click a function, class or variable (or press F12) to jump to where it is defined. Pulse looks in the open file first, then searches the folder's files of the same language with one short rg or git grep; several places show a menu at the name, nearest first. Nothing is indexed ahead or kept afterwards, so it costs no memory until you use it. It matches definitions by their shape (def save, func save, const save =), not by types, so a common name can list several places.
• Integrated terminal (⌃`) with tabs and side-by-side splits, started only when you first open it.
• Source Control (⌃⇧G): staged and unstaged changes, with buttons to stage or unstage a file or a whole section. Click a changed file to see its diff: the whole file with removed and added lines highlighted in place and the edited part of a changed line marked, like VS Code, with old and new line numbers. Double-click opens the file.
• Blame: click Blame in the status bar (or View › Blame) to see who last changed the open file's lines, when and why, after the first line of each change and the line you're on. Off until you ask, for that file only; turning it off frees it.
• Claude Code knows what you're looking at: run claude in Pulse's terminal and it sees the open file and your selection ("⧉ 5 lines selected"), as in VS Code. ⇧⌘K puts @file#L5-9 in Claude's prompt. From another terminal, run /ide and pick Pulse. It costs nothing until Claude connects; View › Share Selection with Claude Code turns it off.
• Read-only files: files open read-only by default, so a stray key can't change code an AI tool is editing. Click Read Only in the status bar (or File › Read Only) to edit one; the Welcome tab's Default file mode opens files ready to edit instead. New files are always editable.
• Autosave and session recovery: files save themselves a second after you stop typing, and Pulse reopens your folder, tabs and any unsaved buffers after you quit.
• Honest resource meter: the status bar shows Pulse's own memory and CPU, with the terminal's shell measured separately.

Not included, on purpose: extensions, debugger, a full Git client (history, merges), built-in AI features, telemetry.

Install

curl -fsSL https://pulse0.app/install.sh | bash

It downloads the latest release into Applications and opens it. Pulse isn't notarized by Apple yet, so a copy downloaded in a browser is blocked by macOS ("Apple could not verify 'Pulse'…"); the installer fetches the same release with curl and clears that download flag. You can read the script first.

Open a folder from the terminal with pulse . (or pulse file.swift src/), like VS Code's code .. Pulse links the pulse command into a folder on your PATH the first time it runs; if that needs a password, use Pulse › Install 'pulse' Command. Homebrew installs it with the cask.

pulse --upgrade updates Pulse to the latest release, and pulse --downgrade goes back to the release before the one you have, if a new one gives you trouble. Either takes a version (pulse --downgrade 2.1.3). pulse --version prints the installed version and pulse --help lists the rest. To install a specific release without the command, pass its version to the installer:

curl -fsSL https://pulse0.app/install.sh | bash -s -- 2.1.3

If installing from Pulse doesn't work, link it yourself (asks for your password once):

sudo mkdir -p /usr/local/bin && sudo ln -sf /Applications/Pulse.app/Contents/Resources/pulse /usr/local/bin/pulse

The editor, the sidebar and the terminal each have their own font size: ⌘+ / ⌘− / ⌘0 change the one you're working in, and View › Font Size names each. View › Appearance picks Auto, Light or Dark. The Welcome tab (Help › Welcome to Pulse) opens the first time Pulse runs.

Pulse checks for a new release once a day and shows an Update button at the top right when one is available; it installs the update and reopens with your tabs. Pulse › Check for Updates… checks right away. Releases are published from main when a commit or merged PR title includes [release].

Shortcuts

Shortcut	Action
⌘O	Open a folder or files
⇧⌘N	New window
⌘P	Go to file
⇧⌘P	Command palette
⌘L	Go to line
⌃- / ⌃⇧-	Go back / forward (where you jumped from)
F12 or ⌘-click	Go to definition
⌘F / ⌥⌘F	Find / find and replace in file
⌥⌘[ / ⌥⌘]	Fold / unfold the block at the caret
⇧⌘F	Search the project
⌃`	Show or hide the terminal
⌃⇧`	New terminal (in the open folder)
⌘\	Split terminal (side by side)
⌥⌘\	Split the editor right (Split Down is in View and the tab menu)
⌃⇧G	Source Control
⇧⌘K	Send the selection to Claude Code (@file#L5-9 in its prompt)
⌘/	Toggle line comment
⌘] / ⌘[	Indent / outdent
⇧⌘] / ⇧⌘[	Next / previous tab
⌃⌘S	Toggle sidebar

Memory budget

In everyday use, with a project, several files and the terminal open, Pulse uses about 60–70 MB. The status bar shows the live number.

CI also launches every build in a fixed set of scenarios. These read lower than everyday use because they are taken 8 seconds after a fresh launch:

Scenario	Measured in CI (fresh launch)	Target	Hard limit
Empty window	15.9 MB	≤ 40 MB	100 MB
Ten files open	27.1 MB	≤ 60 MB	100 MB
Ten files, editor split right	29.1 MB	≤ 60 MB	100 MB
Ten files + terminal	28.2 MB (+1.8 MB shell)	≤ 60 MB	100 MB
Ten files + terminal + Claude Code connected	28.5 MB (+1.8 MB shell)	≤ 60 MB	100 MB

"Memory" means physical footprint, the number Activity Monitor shows, read with vmmap 8 seconds after launch on GitHub's macOS 14 runner (medians of three runs). Shells and other processes you start in the terminal are reported separately. CI measures all five scenarios on every push and fails the build above 100 MB (scripts/memory-check.sh); on pull requests it also fails a change that adds more than 5 MB to any of them (scripts/memory-compare.sh). It also captures real screenshots of the build (scripts/screenshot.sh), which is where the image above comes from.

How it stays small:

• One text view per editor pane. Switching tabs moves the pane's layout manager onto another document's text, so each extra file costs roughly its own text. A file open in two panes keeps one copy of its text.
• Syntax colors are layout-manager temporary attributes: no copies of the text, no relayout. Files over 300 KB are highlighted around the visible area only.
• The file tree reads a folder only when you expand it. The go-to-file index is built on first use.
• The terminal view and shell are created the first time you open the terminal, and the Claude Code connection only once a terminal exists and Claude Code is installed.
• Nothing polls in the background. The resource meter samples every 2 s only while Pulse is the active app.

Build from source

Requirements: macOS 14+, Xcode 15+ (Swift 5.9+).

git clone https://github.com/Suraj1089/pulse.git
cd pulse

swift run Pulse .                    # run from source, opening this folder
./scripts/bundle.sh                  # build dist/Pulse.app for this Mac
open dist/Pulse.app
./scripts/memory-check.sh            # measure the memory budget locally
./scripts/package.sh                 # universal release build: DMG, ZIP, Homebrew cask

Feedback

In Pulse, Help › Report a Bug… and Help › Request a Feature… open a GitHub issue form in your browser; the ladybug at the right end of the status bar is a shortcut to the bug form. The bug form comes with your Pulse version, macOS version and Mac model filled in; nothing is posted until you submit it. You can also open an issue directly. Feature requests are weighed against the contribution rules: Pulse stays small on purpose.

License

MIT. See LICENSE.