Codex CLI is a clean, modern terminal text editor written in Rust.

It aims to be approachable like Nano, efficient and clean like Vim, and easy to use like VS Code, while keeping a standard non-modal editing model.

---

Status

This repository contains the first usable implementation:

• Rust Cargo workspace
• Rope-backed editor core
• Cursor movement and editing
• Undo/redo
• Save and save-as
• Unsaved-change prompts
• Ratatui/Crossterm terminal UI
• Status/help bars
• Recursive file picker with Ctrl-F
• Fuzzy file filtering
• Large-file warning policy
• Syntax highlighting for common languages with Tree-sitter/lexical fallback
• Simple TOML config loading

Run

cargo run -p lime-cli -- path/to/file.rs

or after installing/building the binary:

lime path/to/file.rs
lime .
lime --force huge.log

Keyboard shortcuts

Shortcut	Action
Ctrl-S	Save
Ctrl-Q	Quit
Ctrl-F	Open file picker
Ctrl-R	Search current file
Ctrl-G	Go to line
Ctrl-Z	Undo
Ctrl-Y	Redo
Ctrl-A	Start of line
Ctrl-E	End of line
Esc	Close popup/cancel prompt

Config

Lime looks for config at:

• macOS: ~/Library/Application Support/lime/config.toml
• Linux: ~/.config/lime/config.toml

Example:

theme = "lime-dark"
tab_width = 4
insert_spaces = true
show_line_numbers = true
confirm_large_files = true

Development

cargo fmt
cargo test

Workspace crates:

• lime-core: pure editor model and editing operations
• lime-syntax: language detection and highlighting
• lime-ui: terminal UI, file picker, prompts, keybindings
• lime-cli: binary entry point