Flow Control: a programmer's text editor

This is my Zig text editor. It is under active development, but very stable and is my daily driver for almost everything.

Features

• Lightning Fast TUI with ≤6ms frame times, low latency input handling and smooth animated scrolling
• Intuitive UI with tabs, scrollbars and palettes with full mouse support for all UI elements
• Support for more than 70 programming languages, zero configuration needed, via tree-sitter powered syntax highlighting
• Language Server Protocol pre configured support for most language servers
• Powerful multi-cursor editing and integrated clipboard history
• Powerful configurable keybinding system that supports modal and non-modal editing styles
• Multiple pre-configured keybinding modes
  • Flow Control - GUI IDE style bindings (similar to vscode)
  • Emacs
  • Vim
  • Helix
  • User created
• Hybrid rope/piece-table buffer system, edit very large files with thousands of cursors
• Infinite undo (at least until you run out of ram)
• Full unicode support, including support for the kitty text sizing protocol
• Plenty of themes included and support for vscode themes via the flow-themes project
• Runs on Linux, FreeBSD, MacOS, Windows and Android (under termux) with easy cross-compilation to all supported targets

Requirements

• A modern terminal with 24bit color and, ideally, kitty keyboard protocol support. Kitty, Foot and Ghostty are the recommended terminals at this time. Zellij also works well. Most other terminals will work, but likely with reduced functionality.
• NerdFont support. Either via terminal font fallback or a patched font.
• A UTF-8 locale

Roadmap

See our devlog for on-going updates from the development team.

In Development

• LSP completion support
• Persistent undo/redo
• File watcher integration

Future

• Collaborative editing
• Plugin system
• Multi-terminal sessions

Installer and manual downloads

There is an installation guide on the main website with instructions for using the installer script. Direct downloads of source tarballs and release and nightly binary builds are listed on the downloads page.

Or check your favorite local system package repository.

Building

Make sure your system meets the requirements listed above.

Flow builds with zig 0.16 at this time. Build with:

zig build -Doptimize=ReleaseSafe

Zig will by default build a binary optimized for your specific CPU. If you get illegal instruction errors add -Dcpu=baseline to the build command to produce a binary with generic CPU support.

Thanks to Zig you may also cross-compile from any host to pretty much any target. For example:

zig build -Doptimize=ReleaseSafe -Dtarget=x86_64-windows --prefix zig-out/x86_64-windows
zig build -Doptimize=ReleaseSafe -Dtarget=x86_64-macos-none --prefix zig-out/x86_64-macos
zig build -Doptimize=ReleaseSafe -Dtarget=aarch64-linux-musl --prefix zig-out/aarch64-linux

When cross-compiling zig will build a binary with generic CPU support.

The output binary is:

zig-out/bin/flow

It is statically built (by default) and contains all the required tree-sitter parsers and queries. No additional runtime files are required.

Running Flow Control

The Flow Control binary is called flow.

Place it in your path for convenient access:

sudo cp zig-out/bin/flow /usr/local/bin

Or if you prefer, let zig install it in your home directory:

zig build -Doptimize=ReleaseSafe --prefix ~/.local

Flow Control is a single statically linked binary. No further runtime files are required. You may install it on another system by simply copying the binary.

scp zig-out/bin/flow root@otherhost:/usr/local/bin

Files to load may be specifed on the command line:

flow fileA.zig fileB.zig

The last file will be opened and the previous files will be placed in reverse order at the top of the recent files list. Switch to recent files with Ctrl-e.

Common target line specifiers are supported too:

flow file.txt:123

Or Vim style:

flow file.txt +123

Use the --language option to force the file type of a file:

flow --language bash ~/.bash_profile

Show supported language names with --list-languages.

See flow --help for the full list of command line options.

Documentation

User manual

A basic user manual is available inside flow. You can open it with the Open help command (F1).

It is also available in the website documentation section.

Development Resources

Additional developer resources can be found on the Flow Control website at.

There is also an AI generated developer guide at . Accuracy may vary. Check details against the referenced source code.

Configuration

Configuration is mostly dynamically maintained with various commands in the UI. It is stored under the standard user configuration path. Usually ~/.config/flow on Linux. %APPDATA%\Roaming\flow on Windows. Somewhere magical on MacOS.

There are commands to open the various configuration files, so you don't have to manually find them. Look for commands starting with Edit in the command palette.

File types may be configured with the Edit file type configuration command. You can also create a new file type by adding a new .conf file to the file_type directory. Have a look at an existing file type to see what options are available.

Logs, traces and per-project most recently used file lists are stored in the standard user application state directory. Usually ~/.local/state/flow on Linux and %APPDATA%\Roaming\flow on Windows.

Key bindings and commands

Press F1 to view the online manual. Press F4 to switch the current keybinding mode. (flow, vim, emacs, etc.) Press ctrl+shift+p or alt+x to show the command palette. Press ctrl+F2 to see a full list of all current keybindings and commands.

Run the Edit keybindings command to customize the current keybinding mode. It opens a file in your keys directory (under the same name) that inherits from the built-in mode, so you can add or override individual keybindings. Keybindings added by future updates ar inherited automatically. Keybinding changes take effect on restart.

Terminal configuration

Kitty, Ghostty and most other terminals have default keybindings that conflict with common editor commands. I highly recommend rebinding them to keys that are not generally used anywhere else.

For Kitty rebinding kitty_mod is usually enough:

kitty_mod ctrl+alt

For Ghostty each conflicting binding has to be reconfigured individually.

Community

Join our Discord server or use the discussions section here on GitHub to meet with other Flow users!