Coinbase Advanced Trade API Integration in Delphi

Coinbase Advanced Trade is the professional trading platform from one of the world's most widely used cryptocurrency exchanges. The TsgcWSAPI_Coinbase component for Delphi provides complete access to both the WebSocket and REST APIs, enabling real-time market data streaming, order management, account monitoring, and futures balance tracking from a unified Delphi interface.

Overview

The Coinbase Advanced Trade API replaces the legacy Coinbase Pro API and provides a modern interface for professional cryptocurrency trading. It supports both spot trading for a wide range of crypto assets and futures contracts. The API uses two transport mechanisms:

Configuration

Configure the TsgcWSAPI_Coinbase component with your API credentials to access private endpoints. Public market data endpoints can be accessed without authentication.

var
  oClient: TsgcWebSocketClient;
  oCoinbase: TsgcWSAPI_Coinbase;
begin
  oClient := TsgcWebSocketClient.Create(nil);
  oCoinbase := TsgcWSAPI_Coinbase.Create(nil);
  oCoinbase.Client := oClient;

  // Configure API credentials
  oCoinbase.Coinbase.ApiKey := 'your_api_key';
  oCoinbase.Coinbase.ApiSecret := 'your_api_secret';

  // Connect to Coinbase
  oClient.Active := True;
end;

WebSocket API

The WebSocket API provides real-time streaming channels for market data and private account events. Public channels deliver market-wide data without authentication, while private channels stream account-specific events.

Public Channels

Private Channels

// Subscribe to real-time ticker for BTC-USD
oCoinbase.SubscribeTicker('BTC-USD');

// Subscribe to Level 2 order book updates
oCoinbase.SubscribeLevel2('BTC-USD');

// Subscribe to candle data for charting
oCoinbase.SubscribeCandles('ETH-USD');

// Subscribe to live market trades
oCoinbase.SubscribeMarketTrades('BTC-USD');

// Subscribe to private user channel (requires API key)
oCoinbase.SubscribeUser('BTC-USD');

// Subscribe to futures balance updates
oCoinbase.SubscribeFuturesBalanceSummary;

REST API - Accounts

The Accounts endpoints let you query your Coinbase portfolio. Each account represents a single currency or asset in your portfolio with its available and held balances.

// List all accounts in your portfolio
ShowMessage(oCoinbase.REST_API.ListAccounts);

// Get details for a specific account by UUID
ShowMessage(oCoinbase.REST_API.GetAccount('account-uuid-here'));

REST API - Products and Market Data

The Products endpoints provide market data including available trading pairs, order book snapshots, historical candle data, recent trades, and the current server time. These are all public endpoints and do not require authentication.

Candle Granularity Options

// Get all available products
ShowMessage(oCoinbase.REST_API.GetPublicProducts);

// Get details for BTC-USD
ShowMessage(oCoinbase.REST_API.GetPublicProduct('BTC-USD'));

// Get hourly candles for January 2024
ShowMessage(oCoinbase.REST_API.GetPublicProductCandles(
  'BTC-USD', '2024-01-01', '2024-01-31', 'ONE_HOUR'));

// Get recent trades
ShowMessage(oCoinbase.REST_API.GetTrades('BTC-USD'));

REST API - Orders

The Orders endpoints provide full order lifecycle management. You can place new orders (market, limit, or stop), query existing orders, cancel orders, and preview order outcomes before execution.

// Place a market buy order for 0.001 BTC
ShowMessage(oCoinbase.REST_API.PlaceMarketOrder(cosBuy, 'BTC-USD', 0.001));

// Place a limit buy order at $40,000
ShowMessage(oCoinbase.REST_API.PlaceLimitOrder(cosBuy, 'BTC-USD', 0.001, 40000));

// List all open orders
ShowMessage(oCoinbase.REST_API.ListOrders);

// Cancel an order by ID
oCoinbase.REST_API.CancelOrder('order-id-here');

REST API - Fills

Fills represent the individual executions that make up a completed or partially filled order. A single order may result in multiple fills if it is matched against several resting orders in the book. You can query fills by order ID, product ID, or trade ID.

// Get fills for a specific order
ShowMessage(oCoinbase.REST_API.GetFillsByOrderId('order-id-here'));

// Get all fills for BTC-USD
ShowMessage(oCoinbase.REST_API.GetFillsByProductId('BTC-USD'));

REST API - Positions

The Positions endpoint is used for managing futures positions. It allows you to close an open futures position.

Complete Code Example

The following example demonstrates a complete workflow: connecting to Coinbase, listing accounts, retrieving historical candle data, subscribing to a real-time ticker, and placing a market order.

var
  oClient: TsgcWebSocketClient;
  oCoinbase: TsgcWSAPI_Coinbase;
begin
  // Create and configure the WebSocket client
  oClient := TsgcWebSocketClient.Create(nil);
  oCoinbase := TsgcWSAPI_Coinbase.Create(nil);
  oCoinbase.Client := oClient;

  // Configure API credentials
  oCoinbase.Coinbase.ApiKey := 'your_api_key';
  oCoinbase.Coinbase.ApiSecret := 'your_api_secret';

  // Connect to Coinbase
  oClient.Active := True;

  // REST: List all accounts in your portfolio
  ShowMessage(oCoinbase.REST_API.ListAccounts);

  // REST: Get hourly candles for BTC-USD
  ShowMessage(oCoinbase.REST_API.GetPublicProductCandles(
    'BTC-USD', '2024-01-01', '2024-01-31', 'ONE_HOUR'));

  // WebSocket: Subscribe to real-time ticker
  oCoinbase.SubscribeTicker('BTC-USD');

  // REST: Place a market buy order for 0.001 BTC
  ShowMessage(oCoinbase.REST_API.PlaceMarketOrder(cosBuy, 'BTC-USD', 0.001));
end;

Notes and Best Practices

API Key Permissions

When generating API keys on the Coinbase Developer Platform, follow the principle of least privilege. For a read-only dashboard, enable only the View permission. For a trading bot, add Trade permission but leave Transfer disabled unless your application needs to move funds between accounts.

Order Side Constants

When placing orders, use the Delphi enumeration constants for the order side:

Ticker vs. TickerBatch

Use SubscribeTicker when you need every price update in real time (e.g., for an order execution engine). Use SubscribeTickerBatch when you only need periodic snapshots (e.g., for a dashboard) -- it delivers the same data at a reduced frequency, saving bandwidth and processing overhead.

Rate Limits

Coinbase Advanced Trade imposes rate limits on REST API calls. The limits vary by endpoint category (public vs. private, read vs. write). Avoid polling REST endpoints in tight loops; instead, use WebSocket subscriptions for real-time data and reserve REST calls for on-demand queries and order operations.