hey

A minimal command-line application for quickly interacting with OpenAI's chat models, with support for streaming and syntax highlighting. The focus of hey is on ease of use, speed, and a pleasant terminal experience.

Features

• Streaming responses via async-openai
• Syntax highlighting via syntect
• Rich input editor via reedline with Vi mode, multi-line paste, and persistent history
• Command completions - tab completion for all commands (e.g., /h + Tab → /help)
• History search - use Ctrl+R to search through your input history
• Conversation history - quickly save, load, and view past conversations
• Customizable - Vi mode, themes, and more

Installation

Prerequisites

• Rust (for installation via cargo)
• OpenAI API key

Install

cargo install hey-rs

Setup

Set your OpenAI API key:

export OPENAI_API_KEY=your_api_key_here

Usage

Interactive Mode (REPL)

hey

Single Message

hey who was Ada Lovelace?

With Custom Prompt File

hey -p ~/path/to/prompt.txt

Commands

All commands support tab completion - just type / and press Tab to see available commands, or start typing a command (e.g., /h) and press Tab to complete it.

History Search

Press Ctrl+R to search through your input history. Start typing to filter previous inputs, and press Enter to use the selected command. Press Ctrl+R again to cycle through matching results.

Configuration

hey uses a TOML configuration file located at:

• Linux: ~/.config/hey/hey.toml
• macOS: ~/Library/Application Support/hey/hey.toml
• Windows: %APPDATA%/hey/hey.toml

Common Options

# AI Model settings
model = "gpt-4o"                    # or "gpt-4o-mini", "gpt-3.5-turbo"
system_prompt = "You are a helpful coding assistant."
max_tokens = 2048

# Display
syntax_highlighting = true
theme = "ansi"                      # Run /theme to see all options
wrap_width = 100                    # 0 to disable wrapping
ansi_colors = true
animations = true                   # Typewriter effect
greetings = true                  # Show "Hey!" and "Bye!" messages

# Editor
edit_mode = "emacs"                 # or "vi"
bracketed_paste = true
reedline_history = true             # Save input history
history_max_size = 1000             # Max number of inputs to save

# Files
conversations_folder = "~/.hey"     # Where to save conversations

All Configuration Options

See defaults.toml for detailed documentation of all options.

Example Configurations

Minimal setup:

model = "gpt-4o-mini"
system_prompt = "You are a helpful coding assistant."

Plain text output:

syntax_highlighting = false
ansi_colors = false
wrap_width = 0

Vi user setup:

edit_mode = "vi"
theme = "base16"
conversations_folder = "~/Documents/hey-conversations"