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SDKs .NET

FlashAlpha .NET SDK

Official .NET 8+ SDK. Strongly typed async/await access to exposure, volatility, pricing, and the live options screener — from C#, F#, or VB. Works standalone or with IHttpClientFactory.

Install
dotnet add package FlashAlpha
Version
0.3.0 · .NET 8+
GitHub NuGet No external deps System.Text.Json

What the SDK gives you

Full endpoint coverage

All REST endpoints — market data, exposure, volatility, pricing, screener, account — as async methods on FlashAlphaClient.

DI & IHttpClientFactory

Inject a pre-configured HttpClient from the factory. Register the client in your DI container and let ASP.NET manage its lifetime.

CancellationToken everywhere

Every async method accepts a CancellationToken so requests can participate in structured cancellation.

Typed exceptions

AuthenticationException, TierRestrictedException, RateLimitException, NotFoundException, ServerException — all derive from FlashAlphaException.

Strongly typed screener

Build filter/sort/select queries via ScreenerRequest, ScreenerGroup, and ScreenerLeaf. Or pass a raw anonymous object when you just want flexibility.

No runtime deps

Built on System.Net.Http and System.Text.Json. No Newtonsoft, no pollyfills, no conflicts.

Install

dotnet add package FlashAlpha

# or in .csproj
<PackageReference Include="FlashAlpha" Version="0.3.0" />

Targets .NET 8.0 and newer. Requires C# 12 language features for the most idiomatic usage but works fine from any .NET 8-compatible language.

Quick start

using FlashAlpha;

using var client = new FlashAlphaClient("YOUR_API_KEY");

// All methods return JsonElement — navigate with GetProperty / indexer
var gex = await client.GexAsync("SPY");
Console.WriteLine($"Net GEX: {gex.GetProperty("net_gex").GetDouble():N0}");
Console.WriteLine($"Flip:    {gex.GetProperty("gamma_flip").GetDouble()}");

// Key support / resistance levels
var key = (await client.ExposureLevelsAsync("SPY")).GetProperty("levels");
Console.WriteLine($"Call wall: {key.GetProperty("call_wall").GetDouble()}");
Console.WriteLine($"Put wall:  {key.GetProperty("put_wall").GetDouble()}");

// BSM greeks for a single contract
var g = await client.GreeksAsync(
    spot: 655, strike: 660, dte: 7, sigma: 0.18, type: "call");
Console.WriteLine($"delta={g.GetProperty("delta").GetDouble()}");
Response shape: every method returns System.Text.Json.JsonElement. Navigate with GetProperty() / EnumerateArray(), or project into your own record via Deserialize<T>() — see the recipes below.

Live options screener

var screen = await client.ScreenerAsync(new ScreenerRequest
{
    Filters = new ScreenerGroup
    {
        Op = "and",
        Conditions = new List<object>
        {
            new ScreenerLeaf { Field = "regime",        Operator = "eq",  Value = "positive_gamma" },
            new ScreenerLeaf { Field = "harvest_score", Operator = "gte", Value = 65 },
        },
    },
    Sort   = new List<ScreenerSort> { new() { Field = "harvest_score", Direction = "desc" } },
    Select = new List<string> { "symbol", "price", "harvest_score" },
});

foreach (var row in screen.GetProperty("data").EnumerateArray())
{
    Console.WriteLine($"{row.GetProperty("symbol").GetString()} : " +
                      $"{row.GetProperty("harvest_score").GetDouble()}");
}

ASP.NET Core & DI

// Program.cs
builder.Services.AddHttpClient<FlashAlphaClient>((sp, http) =>
{
    http.BaseAddress = new Uri("https://lab.flashalpha.com");
    http.DefaultRequestHeaders.Add("X-Api-Key",
        builder.Configuration["FlashAlpha:ApiKey"]);
});

// Consume via constructor injection
public class ExposureService(FlashAlphaClient client)
{
    public Task<JsonElement> GetSpyAsync(CancellationToken ct) =>
        client.GexAsync("SPY", ct: ct);
}

Common recipes

Deserialize JsonElement into your own DTO

Responses are System.Text.Json.JsonElement for flexibility. Project into your own record when you want strong typing:

using System.Text.Json;
using System.Text.Json.Serialization;

public record GexSummary(
    [property: JsonPropertyName("net_gex")]    double NetGex,
    [property: JsonPropertyName("gamma_flip")] double GammaFlip);

var raw = await client.GexAsync("SPY");
var typed = raw.Deserialize<GexSummary>()!;
Console.WriteLine($"{typed.NetGex:N0} / {typed.GammaFlip}");

Flexible screener via anonymous object

ScreenerAsync has two overloads: typed (ScreenerRequest) and object for ad-hoc JSON:

var screen = await client.ScreenerAsync(new {
    filters = new {
        op = "and",
        conditions = new object[] {
            new { field = "regime",        @operator = "eq",  value = "positive_gamma" },
            new { field = "harvest_score", @operator = "gte", value = 65 },
        },
    },
    sort   = new[] { new { field = "harvest_score", direction = "desc" } },
    select = new[] { "symbol", "price", "harvest_score" },
});

Handle cancellations cleanly

using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
try
{
    var gex = await client.GexAsync("SPY", ct: cts.Token);
}
catch (OperationCanceledException) when (cts.IsCancellationRequested)
{
    Console.WriteLine("Gave up after 5 seconds");
}

Method catalog

CategoryMethodsTier
Market dataStockQuoteAsync, OptionQuoteAsync, StockSummaryAsync, SurfaceAsyncFree / Growth
Historical replay (point-in-time)HistoricalStockQuoteAsync, HistoricalOptionQuoteAsync, plus the full live API mirrored on historical.flashalpha.com via new FlashAlphaClient(apiKey, baseUrl: "https://historical.flashalpha.com") with at paramAlpha
Exposure (basic)GexAsync, ExposureLevelsAsyncFree+ (equities); Basic+ for ETFs & indexes
Exposure (Greeks)DexAsync, VexAsync, ChexAsync, MaxPainAsyncBasic+
Exposure (Growth)ExposureSummaryAsync, NarrativeAsync, ZeroDteAsync, ExposureHistoryAsyncGrowth+
PricingGreeksAsync, IvAsync, KellyAsyncFree / Growth
VolatilityVolatilityAsync, AdvVolatilityAsyncGrowth / Alpha
ScreenerScreenerAsyncGrowth+
ReferenceTickersAsync, OptionsAsync, SymbolsAsyncFree+
AccountAccountAsync, HealthAsyncFree+

Error handling

try
{
    await client.NarrativeAsync("SPY");
}
catch (TierRestrictedException ex)
{
    Console.WriteLine($"Upgrade from {ex.CurrentPlan} to {ex.RequiredPlan}");
}
catch (RateLimitException ex)
{
    Console.WriteLine($"Retry after {ex.RetryAfter}s");
}
catch (NotFoundException)
{
    Console.WriteLine("Symbol not found");
}
catch (FlashAlphaException ex)
{
    Console.WriteLine($"API error {ex.StatusCode}: {ex.Message}");
}
HTTPExceptionProperties
401AuthenticationException—
403TierRestrictedExceptionCurrentPlan, RequiredPlan
404NotFoundException—
429RateLimitExceptionRetryAfter
5xxServerExceptionStatusCode
otherFlashAlphaExceptionStatusCode

Client configuration

// Simple
using var client = new FlashAlphaClient(
    apiKey: "...",
    baseUrl: "https://lab.flashalpha.com",   // default
    timeout: 30                               // seconds
);

// Or inject a pre-configured HttpClient
using var client2 = new FlashAlphaClient(httpClient);

Links

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