Features.

Project workspaces

Switch projects while commands and agents continue running in the others.

• Each project remembers its open files, layout, and reading positions.
• Each open project keeps its unsaved edits and undo history.
• Open a project from your terminal, or find it in your recent workspaces.

Split panes and groups

Each file or terminal opens in a pane. Group panes to display related files and terminal sessions side by side.

• Group files and terminals into one layout, then add or move panes as the work changes.
• Expand one pane to focus, then return to the full layout.
• Rearrange or separate groups without closing files or interrupting terminals.

Overview

Overview displays open files and terminals as a grid of live previews. Select a preview to open that view.

• Search by filename, terminal name, folder, or text visible in a preview.
• Select previews to bring related work together in a group.
• Move through previews with a mouse, keyboard, or controller.

Multiple views of one file

Open the same file in several panes to see different sections at once. Edits appear in every view of the document.

• Scroll, select, and zoom independently in each pane.
• Share edits, saves, and undo history across every view of the file.
• Close an extra view when you are done; the file stays open in the other.

Text editing

Edit individual lines or make the same change in several places using multiple cursors and selections.

• Edit several places at once with multiple cursors, or select every occurrence of a word.
• Use automatic indentation, matching brackets and quotes, comments, and line sorting.
• Read code with syntax highlighting for languages including Rust, JavaScript, TypeScript, Python, Go, and Swift. Adjust wrapping, text size, and the miniature file overview to suit you.

Large files

Open and edit large logs, generated data, and source files.

• Continue working while large files load or save.
• Search large files to find the lines you need.
• Edit while syntax highlighting updates.

Designed for text files up to 1 GB.

File and content search

Search inside the current document or across a project, including changes you have not saved yet.

• Find and replace words, exact phrases, or patterns with regular expressions.
• Choose which folders and file types to include, and whether to search hidden or ignored files.
• Browse folders and open related files together. Drop a file into the editor to open it.

Code completion and formatting

Turn on completion, error checking, and code navigation for a project. These tools only start when you enable them.

• Jump to a definition, find where a function is used, or preview a rename before applying it.
• Use built-in configurations for Rust, JavaScript, TypeScript, and Python.
• Format code on demand or when saving, using rustfmt, Prettier, or Ruff.

Integrated terminals

Run tests, start a server, or use a terminal agent with your usual terminal setup.

• Keep separate terminals for different tasks, and name them so they are easy to find.
• Search previous output and follow file links from an error directly into the source.
• Adjust fonts, colors, cursor style, and how much output each terminal remembers.

Attention View

Attention View brings up terminals when an agent asks for input or a command finishes. Read the output and respond there.

• Reply in the same terminal, with its previous output still available.
• Check off a terminal once you have handled it. New requests join without taking over your focus.
• Choose sound, Dock, or desktop notifications when you want a prompt to return.

Workspace agent

The agent can inspect selected code, files, and terminal output to answer questions or carry out instructions in the workspace.

• Let the agent inspect files and terminal output, make edits, or navigate the workspace.
• Review its text changes with normal editor tools. Edits can be undone and stay unsaved until you save them.
• Choose whether actions run directly, ask before possible data loss, or wait for your review each time.

Model providers

Connect a model using an API key, an existing Codex sign-in, or a compatible local service.

• Connect OpenAI, Claude, Gemini, xAI, DeepSeek, OpenRouter, or a custom service with an OpenAI-compatible interface.
• Use your existing Codex sign-in with Codex installed on your machine.
• Editing, terminals, and controller navigation work without an AI account.

The provider receives the code, terminal output, and other information sent to the agent. Usage charges depend on your provider.

Push-to-talk

Hold a keyboard shortcut or controller trigger, speak, and release to send. Your instruction refers to the file or view you are looking at.

• Give an instruction about a file, terminal, or other part of the workspace without typing it out.
• Speak a follow-up or answer when the agent asks you to choose.
• Use macOS speech recognition, or configure a separate transcription service such as OpenAI or xAI.

To keep speech on your Mac, require on-device recognition in settings where supported. Choosing a cloud speech service sends your audio to that service.

Controller support

Use a wired or Bluetooth controller to navigate projects, review changes, and give spoken instructions through push-to-talk.

• Browse files, move between panes, and organize your open work.
• Scroll through code, select text, review Git changes, and handle waiting terminals.
• Remap the buttons to suit you. On-screen hints follow your mappings.

Session restore

Reopen sh/redder and return to your files, terminals, layout, and unfinished edits.

• Return to the same places in your open files.
• Terminals reopen in the same folders with recent output preserved, so you can see where you left off.
• Continue with unsaved edits, including files you have not named yet.
• Keep your undo history, so you can revisit earlier changes after a restart.

Git comparison

Compare a file with its last Git commit or the version prepared for your next commit. Review unsaved edits alongside changes already on disk.

• Move between added and removed sections without leaving the editor.
• Choose individual changes to keep or undo, then apply your choices together.
• Review with a keyboard, controller, or agent. If you discard a change by mistake, you can undo that too.

Color palettes and profiles

Choose from 32 light and 32 dark palettes that coordinate your code, terminals, and interface.

• Preview colors and adjust brightness, contrast, and saturation.
• Choose your fonts, text sizes, cursors, and keyboard shortcuts.
• Save different setups as named profiles and switch between them.

Visual effects and custom shaders

Apply color adjustments and visual effects across the app.

• Try scanlines, screen curvature, bloom, grain, and other effects with a live preview.
• Switch effects off with a shortcut whenever you want a clean view.
• For deeper customization, load your own WGSL shaders.

Game Boy and Game Boy Color

Open Game Boy and Game Boy Color games as workspace panes. Terminal sessions continue running while you play.

• Bring your own ROMs—the game files—and organize them in a searchable library.
• Play with a keyboard or controller. Games retain progress saved through their own save feature.
• Games pause and mute when you switch back to work. Terminal attention stays available while you play.

macOS

Available for macOS 13 and later, with standard Mac menus, copy and paste, and notifications.

• Find an action by name in the command palette instead of remembering every shortcut.
• Open source under the MIT license.

Windows and Linux are coming soon.