Skip to content

Streaming Real-Time Quotes for a Symbol

Request: subscribe to real-time bid/ask price updates for a given symbol Opens a streaming channel to receive tick-by-tick quotes as the market changes.

Code Example

// --- Quick use (service wrapper) ---
await _service.ShowRealTimeQuotes("EURUSD", timeoutSeconds: 5);

// --- Low-level (direct account call) ---
// Preconditions: account is connected via ConnectByServerName/ConnectByHostPort.

using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
await foreach (var tick in _mt4.OnSymbolTickAsync(new[] { "EURUSD" }, cts.Token))
{
    var q = tick.SymbolTick; if (q == null) continue;
    var time = q.Time?.ToDateTime().ToString("yyyy-MM-dd HH:mm:ss") ?? "n/a";
    Console.WriteLine($"Tick: {q.Symbol} {q.Bid}/{q.Ask} @ {time}");
    cts.Cancel(); // demo: stop after first tick
    break;
}

Method Signatures

// Service wrapper
Task ShowRealTimeQuotes(string symbol, int timeoutSeconds = 5, CancellationToken ct = default);

// Low-level account call
IAsyncEnumerable<OnSymbolTickData> OnSymbolTickAsync(
    IEnumerable<string> symbols,
    [System.Runtime.CompilerServices.EnumeratorCancellation] CancellationToken cancellationToken = default);

🔽 Input

For ShowRealTimeQuotes

Parameter Type Description
symbol string Required. Symbol to subscribe (e.g., "EURUSD").
timeoutSeconds int (optional) Soft limit for demo/CLI to stop after N seconds.
ct CancellationToken (optional) External cancellation source.

For OnSymbolTickAsync

Parameter Type Description
symbols IEnumerable<string> Required. One or more symbols to subscribe.
cancellationToken CancellationToken (optional) Stream control (stop/cancel).

⬆️ Output

OnSymbolTickAsync returns a stream: IAsyncEnumerable<OnSymbolTickData>.

OnSymbolTickData contains:

Field Type Description
SymbolTick QuoteData Real-time data object for tick.

QuoteData fields:

Field Type Description
Symbol string Symbol name.
Bid double Current bid price.
Ask double Current ask price.
Time Google.Protobuf.WellKnownTypes.Timestamp Server timestamp of the tick (UTC).

🎯 Purpose

Receive live market data for a symbol in real time — suitable for:

  • Streaming UI quote panels
  • Price-driven alerts
  • Feeding pricing logic in automated systems

🧩 Notes & Tips

  • Endless stream. This is a continuous stream; always manage cancellation (see example).
  • Normal completion signals. A RpcException with Status=Cancelled (when you cancel via token) is expected; the client treats it as normal completion. Certain server finalization codes (e.g., ON_SUBSCRIPTION_EA_DEINITIALIZATION_START_WATCHING_MULTI_CHARTS_COUNT_ZERO) are also handled as clean stream end.
  • Inactive symbols. If a symbol is inactive, you may not receive ticks within the timeout; design UI to handle this gracefully.
  • Exact naming. Use symbol names exactly as returned by SymbolsAsync() (brokers may use suffixes like EURUSD.r).

⚠️ Pitfalls

  • Forgetting cancellation. Without a token or timeout, streams keep running indefinitely.
  • Mixed subscriptions. Subscribing a large set of symbols without per-symbol timeouts may block your flow if some are inactive.

🧪 Testing Suggestions

  • Happy path. First tick arrives within a few seconds during active market hours.
  • Edge cases. In after-hours or on illiquid symbols, ensure your timeout/cancellation path logs and exits cleanly.
  • Failure path. Simulate a reconnect (temporary network issue): the client should restart the stream with backoff or end gracefully if you cancel.