mould

mould is a modern Terminal User Interface (TUI) tool designed for interactively generating and editing configuration files from templates. Whether you are setting up a .env file from an example, creating a docker-compose.override.yml, or editing nested JSON, YAML, or TOML configurations, mould provides a fast, Vim-inspired workflow to get your environment ready.

Features

• Universal Format Support: Handle .env, JSON, YAML, and TOML seamlessly.
• Tree View Navigation: Edit nested data structures (JSON, YAML, TOML) in a beautiful, depth-colored tree view.
• Smart Template Comparison: Automatically discovers .env.example vs .env relationships and highlights missing or modified keys.
• Add Missing Keys: Instantly pull missing keys and their default values from your template into your active configuration with a single keystroke.
• Neovim Integration: Comes with a built-in Neovim plugin for seamless in-editor configuration management.
• Docker Compose Integration: Automatically generate docker-compose.override.yml from docker-compose.yml.
• Vim-inspired Workflow: Navigate with j/k, gg/G, edit with i, search with /, and save with :w.
• Modern UI: A polished, rounded interface featuring a semantic Catppuccin Mocha palette.
• Highly Configurable: Customize keybindings and semantic themes via a simple TOML configuration.

Installation

CLI Application

Ensure you have Rust and Cargo installed, then run:

cargo install --path .

Alternatively, you can build from source:

git clone <repository_url>
cd mould
cargo build --release

Neovim Plugin

If you use a plugin manager like mini.deps, you can add the repository directly:

add({
	source = 'https://git.narl.io/nvrl/mould-rs',
	checkout = 'main',
})

Usage

Provide an input template file to start editing. mould is smart enough to figure out if it's looking at a template or an active file, and will search for its counterpart to provide diffing.

mould .env.example
mould docker-compose.yml
mould config.template.json -o config.json

Keybindings (Default)

• Normal Mode

  • j / Down: Move selection down
  • k / Up: Move selection up
  • gg: Jump to the top
  • G: Jump to the bottom
  • i: Edit value (cursor at start)
  • A: Edit value (cursor at end)
  • S: Substitute value (clear and edit)
  • o: Append a new item to the current array
  • O: Prepend a new item to the current array
  • dd: Delete the currently selected variable or group
  • u: Undo the last change
  • a: Add missing value from template to active config
  • /: Search for configuration keys (Jump to matches)
  • n: Jump to the next search match
  • N: Jump to the previous search match
  • :w or Enter: Save the current configuration to the output file
  • :q or q: Quit the application
  • :wq: Save and quit
  • Esc: Clear current command prompt

• Insert Mode

  • Type your value for the selected key.
  • Arrow keys: Navigate within the input field
  • Enter / Esc: Commit the value and return to Normal Mode

Configuration

mould can be configured using a config.toml file located in your user configuration directory (e.g., ~/.config/mould/config.toml on Linux/macOS).

Example configuration:

[keybinds]
down = "j"
up = "k"
edit = "i"
save = ":w"
quit = ":q"
normal_mode = "Esc"
search = "/"
next_match = "n"
previous_match = "N"
jump_top = "gg"
jump_bottom = "G"

[theme]
# Enable transparency to let your terminal background show through
transparent = false

# Custom color palette (Semantic Catppuccin Mocha defaults)
bg_normal = "#1e1e2e"
bg_highlight = "#89b4fa"
bg_active = "#a6e3a1"
bg_search = "#cba6f7"
fg_normal = "#cdd6f4"
fg_dimmed = "#6c7086"
fg_highlight = "#1e1e2e"
fg_warning = "#f38ba8"
fg_modified = "#fab387"
fg_accent = "#b4befe"
border_normal = "#45475a"
border_active = "#a6e3a1"
tree_depth_1 = "#b4befe"
tree_depth_2 = "#cba6f7"
tree_depth_3 = "#89b4fa"
tree_depth_4 = "#fab387"

License

This project is licensed under the MIT License. See the LICENSE file for details.