Installation Guide

This guide will help you install and configure ExCcxt in your Elixir project.

Prerequisites

Before installing ExCcxt, ensure you have the following installed:

  • Elixir 1.10 or later
  • Node.js 14 or later (required for the JavaScript bridge)
  • npm or yarn (for JavaScript dependencies)

You can verify your installations:

elixir --version
node --version
npm --version

Installation

1. Add ExCcxt to your dependencies

Add ExCcxt to your mix.exs file:

def deps do
  [
    {:ex_ccxt, "~> 0.1.1"}
  ]
end

2. Fetch dependencies

mix deps.get

3. Install JavaScript dependencies

ExCcxt requires the CCXT JavaScript library. Install it by running:

# Navigate to your project directory
cd your_project

# Install JavaScript dependencies (this will install CCXT)
mix deps.compile ex_ccxt

This will automatically:

  • Download the CCXT JavaScript library
  • Bundle the JavaScript code
  • Place the bundled files in the correct location

Configuration

Basic Configuration

ExCcxt works out of the box with default settings. However, you can customize the configuration in your config/config.exs:

config :ex_ccxt,
  pool_size: 16,  # Number of Node.js worker processes
  timeout: 30_000 # Timeout for JavaScript calls in milliseconds

Application Setup

Make sure your application includes ExCcxt in the supervision tree. If you're using ExCcxt in a Phoenix application or another supervised application, this is usually handled automatically.

For a standalone application, ensure ExCcxt is started:

# In your application.ex
def start(_type, _args) do
  children = [
    # Your other children
    ExCcxt.Application
  ]

  opts = [strategy: :one_for_one, name: YourApp.Supervisor]
  Supervisor.start_link(children, opts)
end

Verification

To verify that ExCcxt is installed and working correctly, try fetching a list of available exchanges:

# Start an interactive Elixir session
iex -S mix

# Test the installation
ExCcxt.exchanges()

You should see a list of supported exchanges like:

{:ok, ["aax", "alpaca", "ascendex", "bequant", "bigone", "binance", ...]}

Troubleshooting

Common Issues

Node.js not found

If you get an error about Node.js not being found:

  1. Ensure Node.js is installed and in your PATH
  2. Restart your terminal/IDE after installing Node.js
  3. Try running node --version to verify installation

JavaScript compilation errors

If you encounter errors during JavaScript compilation:

  1. Ensure npm/yarn is installed
  2. Try manually installing dependencies:
    cd deps/ex_ccxt
npm install
  3. Clear and recompile:
    mix deps.clean ex_ccxt
mix deps.compile ex_ccxt

Port/Process errors

If you see errors related to ports or processes:

  1. Check that the configured pool size isn't too large for your system
  2. Reduce the pool size in configuration:
    config :ex_ccxt, pool_size: 4

Memory Considerations

Each Node.js worker process consumes memory. The default pool size of 16 workers should be fine for most applications, but you may want to adjust this based on:

  • Your system's available memory
  • Expected concurrent load
  • Number of different exchanges you'll be calling simultaneously

Performance Tips

  • Pool Size: Increase pool size for high-concurrency applications
  • Timeout: Adjust timeout based on network conditions and exchange response times
  • Caching: Consider implementing caching for frequently requested data
  • Rate Limiting: Be mindful of exchange rate limits and implement appropriate delays

Development Setup

If you're contributing to ExCcxt or running it in development:

# Clone the repository
git clone https://github.com/your-repo/ex_ccxt.git
cd ex_ccxt

# Install Elixir dependencies
mix deps.get

# Build JavaScript bundle
./build_ex_ccxt_js.sh

# Run tests
mix test

# Start interactive session
iex -S mix

Next Steps