Terminal Crypto Candle Graph Watcher

A high-performance, fully responsive Go terminal UI application that displays live ASCII candlestick charts for cryptocurrency pairs. Built with Charm Bracelet's Bubble Tea, ensuring snappy key responsiveness and smooth event handling. Pulls OHLCV data from multiple free sources and renders real-time, interactive charts in a auto-tiling grid layout.

Features

Works on Windows, Linux and MacOSX!

• 🕯️ ASCII Candlestick Charts – Beautiful colored candles rendered directly in the terminal
• ⚡ Fully Responsive – Powered by Bubble Tea for instant key responsiveness, no freezing or lag
• 🔄 Multi-Source Data – Automatic fallback between CoinGecko and Coinbase APIs
• 🎨 Auto-Tiling Layout – Charts intelligently rearrange as you add/remove symbols
• ➕ Dynamic Symbol Management – Press A to add/remove crypto pairs via interactive modal (and press c inside modal to type any custom symbol)
• 💾 Persistent Configuration – Current symbol list and settings saved to ~/.crypto-graph-tui.json
• ⏱️ Configurable Timeframes – Toggle between 1D, Weekly, Monthly, and Yearly views
• 🛡️ Signal-Safe – Respects Ctrl+C (quit)
• 📊 Real-Time Refresh – Continuous updates with countdown timer

Requirements

• Go 1.24+
• Terminal with 256-color support

Installation

Download binary for your operation system from latest releases or build from source.

cd /path/to/graph_watcher
make build

The binary will be created as ./crypto-graph-tui-<OS>-<ARCH>. For example, building on Linux x86_64 produces ./crypto-graph-tui-linux-amd64 (Windows builds produce a .exe suffix).

Usage

Basic usage (default symbols: BTC-USD, ETH-USD, LTC-USD, SOL-USD)

./crypto-graph-tui-<OS>-<ARCH>

# Example (Linux):
./crypto-graph-tui-linux-amd64

# Example (Windows PowerShell):
.\crypto-graph-tui-windows-amd64.exe

Command-line options

The application now supports traditional CLI flags in addition to the single-argument symbol list. Available options:

./crypto-graph-tui-<OS>-<ARCH> \ 
  --symbols="BTC-USD,ETH-USD,ADA-USD" \ 
  --api-key="<CMC-key>" \ 
  --interval=30 \ 
  --theme=dark

# Example (Windows PowerShell):
.\crypto-graph-tui-windows-amd64.exe --symbols="BTC-USD,ETH-USD"

You can specify one of the built-in themes (default, dark, retro).

• --symbols: comma-separated list of symbols; overrides config.
• --api-key: optional API key for providers like CoinMarketCap.
• --interval: refresh interval in seconds (overrides config).

You can still supply a bare symbol string as the first argument for quick runs:

./crypto-graph-tui-<OS>-<ARCH> "BTC,ETH"

# Example (Linux):
./crypto-graph-tui-linux-amd64 "BTC,ETH"

Symbol names can be uppercase or lowercase; -USD suffix is optional.

Controls

Key	Action
Z	Zoom in/out on the selected chart
←↑→↓ or hjkl	Select a chart to zoom
Space	Refresh all charts
A	Open symbol selection modal
1	Switch to 1D (daily) view
2	Switch to WTD (week-to-date) view
3	Switch to MTD (month-to-date) view
4	Switch to YTD (year-to-date) view
Q	Show quit confirmation
Space (in modal)	Toggle symbol selection
C (in modal)	Enter custom symbol by typing (e.g. BTC)
Enter (in modal)	Apply changes
Esc (in modal)	Cancel and close modal
↑/↓ or K/J (in modal)	Navigate symbol list
Ctrl+C	Quit immediately

Configuration

Configuration is stored at:

• $XDG_CONFIG_HOME/crypto-graph-tui/config.json (preferred), or
• ~/.crypto-graph-tui.json (fallback)

Example config:

{
  "symbols": ["BTC-USD", "ETH-USD", "SOL-USD"],
  "view": "1D",
  "refresh_interval_secs": 60,
  "api_key": ""
}

The app automatically saves your symbol selections and preferred timeframe.

Data Sources

Debug logging

Set the environment variable CMC_DEBUG=1 to enable verbose HTTP logging from the CoinGecko/Coinbase providers. Useful for troubleshooting network errors or examining request URLs.

Charts are powered by:

1. CoinGecko – Free OHLC endpoint (primary)
2. Coinbase – Public exchange API (fallback)

Both sources are free and do not require authentication. If one fails, the app automatically tries the other.

Common Symbols

The built-in symbol list includes major cryptocurrencies, for example:

• BTC (Bitcoin)
• ETH (Ethereum)
• SOL (Solana)
• LTC (Litecoin)
• ADA (Cardano)
• MATIC (Polygon)
• AVAX (Avalanche)
• DOGE (Dogecoin)
• XRP (Ripple)
• XMR (Monero)

Layout Behavior

• 1 symbol: Full-width chart
• 2+ symbols: Multi-column grid with automatic sizing
• Charts auto-fit their space and re-render on window resize

Development

git checkout -b new_branch

Do your changes, and fixes

git commit -a
git push

Make a pull requests

Running Tests

make test

All modules include unit tests:

• config_test.go – Configuration loading, saving, and merging
• chart_test.go – ASCII rendering and layout math
• provider_test.go – Data provider logic and fallback mechanism

Building

make build

Cleaning

make clean

Architecture

• main.go – Entry point, signal handling, config integration
• ui.go – Bubble Tea Model implementation, event handling, rendering
• config.go – Persistence and loading of user settings
• provider.go – CoinGecko and Coinbase API clients with fallback
• chart.go – ASCII rendering and layout utilities
• types.go – Core data structures (Candle)

Error Handling

• API failures display an error message in the affected chart tile
• Network timeouts (10s per request) are respected
• The app never crashes or hangs—it closes gracefully on signal or error
• All background loops are reactive and non-blocking

Future Enhancements

• Additional data sources (Binance, Kraken, etc.)
• Volume visualization in charts
• Per-symbol refresh intervals
• Color themes and alternate renderers

Contributing

Pull requests welcome! Please include tests for any new functionality.

Support and donations

Support the Project

ETH/ERC20: 0x9b4FfDADD87022C8B7266e28ad851496115ffB48

SOL: 68L4XzSbRUaNE4UnxEd8DweSWEoiMQi6uygzERZLbXDw

BTC: bc1qkmzc6d49fl0edyeynezwlrfqv486nmk6p5pmta