Issue #719 - Added support for the options contract requesting:

- Added the new `IOptionContract` interface and two related enums: `OptionType` and `OptionStyle`.
- Added the new `IAlpacaTradingClient.ListOptionContractsAsync` method and related `OptionContractsRequest` class.
- Added the new `IAlpacaTradingClient.GetOptionContractByidAsync` and `IAlpacaTradingClient.GetOptionContractBySymbolAsync` methods.

Alpaca.Markets/AlpacaTradingClient.General.cs

@@ -114,4 +114,24 @@ await _httpClient.GetAsync<IReadOnlyList<IAnnouncement>, List<JsonAnnouncement>>
             await request.EnsureNotNull().Validate()
                 .GetUriBuilderAsync(_httpClient).ConfigureAwait(false),
             _rateLimitHandler, cancellationToken).ConfigureAwait(false);
+
+    public async Task<IReadOnlyList<IOptionContract>> ListOptionContractsAsync(
+        OptionContractsRequest request,
+        CancellationToken cancellationToken = default) =>
+        (await _httpClient.GetAsync<JsonOptionContractsPage, JsonOptionContractsPage>(
+            await request.EnsureNotNull().Validate()
+                .GetUriBuilderAsync(_httpClient).ConfigureAwait(false),
+            _rateLimitHandler, cancellationToken).ConfigureAwait(false)).Contracts;
+
+    public Task<IOptionContract> GetOptionContractByIdAsync(
+        Guid contractId,
+        CancellationToken cancellationToken = default) =>
+        _httpClient.GetAsync<IOptionContract, JsonOptionContract>(
+            $"v2/options/contracts/{contractId:D}", _rateLimitHandler, cancellationToken);
+
+    public Task<IOptionContract> GetOptionContractBySymbolAsync(
+        String symbol,
+        CancellationToken cancellationToken = default) =>
+        _httpClient.GetAsync<IOptionContract, JsonOptionContract>(
+            $"v2/options/contracts/{symbol.EnsureNotNull()}", _rateLimitHandler, cancellationToken);
 }

Alpaca.Markets/CompatibilitySuppressions.xml

@@ -1,6 +1,27 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- https://learn.microsoft.com/en-us/dotnet/fundamentals/package-validation/diagnostic-ids -->
 <Suppressions xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Alpaca.Markets.IAlpacaTradingClient.GetOptionContractByIdAsync(System.Guid,System.Threading.CancellationToken)</Target>
+    <Left>lib/net6.0/Alpaca.Markets.dll</Left>
+    <Right>lib/net6.0/Alpaca.Markets.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Alpaca.Markets.IAlpacaTradingClient.GetOptionContractBySymbolAsync(System.String,System.Threading.CancellationToken)</Target>
+    <Left>lib/net6.0/Alpaca.Markets.dll</Left>
+    <Right>lib/net6.0/Alpaca.Markets.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Alpaca.Markets.IAlpacaTradingClient.ListOptionContractsAsync(Alpaca.Markets.OptionContractsRequest,System.Threading.CancellationToken)</Target>
+    <Left>lib/net6.0/Alpaca.Markets.dll</Left>
+    <Right>lib/net6.0/Alpaca.Markets.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0006</DiagnosticId>
     <Target>P:Alpaca.Markets.IAccount.OptionsApprovedLevel</Target>
@@ -29,6 +50,27 @@
     <Right>lib/net6.0/Alpaca.Markets.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Alpaca.Markets.IAlpacaTradingClient.GetOptionContractByIdAsync(System.Guid,System.Threading.CancellationToken)</Target>
+    <Left>lib/netstandard2.0/Alpaca.Markets.dll</Left>
+    <Right>lib/netstandard2.0/Alpaca.Markets.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Alpaca.Markets.IAlpacaTradingClient.GetOptionContractBySymbolAsync(System.String,System.Threading.CancellationToken)</Target>
+    <Left>lib/netstandard2.0/Alpaca.Markets.dll</Left>
+    <Right>lib/netstandard2.0/Alpaca.Markets.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Alpaca.Markets.IAlpacaTradingClient.ListOptionContractsAsync(Alpaca.Markets.OptionContractsRequest,System.Threading.CancellationToken)</Target>
+    <Left>lib/netstandard2.0/Alpaca.Markets.dll</Left>
+    <Right>lib/netstandard2.0/Alpaca.Markets.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0006</DiagnosticId>
     <Target>P:Alpaca.Markets.IAccount.OptionsApprovedLevel</Target>
@@ -57,6 +99,27 @@
     <Right>lib/netstandard2.0/Alpaca.Markets.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Alpaca.Markets.IAlpacaTradingClient.GetOptionContractByIdAsync(System.Guid,System.Threading.CancellationToken)</Target>
+    <Left>lib/netstandard2.1/Alpaca.Markets.dll</Left>
+    <Right>lib/netstandard2.1/Alpaca.Markets.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Alpaca.Markets.IAlpacaTradingClient.GetOptionContractBySymbolAsync(System.String,System.Threading.CancellationToken)</Target>
+    <Left>lib/netstandard2.1/Alpaca.Markets.dll</Left>
+    <Right>lib/netstandard2.1/Alpaca.Markets.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Alpaca.Markets.IAlpacaTradingClient.ListOptionContractsAsync(Alpaca.Markets.OptionContractsRequest,System.Threading.CancellationToken)</Target>
+    <Left>lib/netstandard2.1/Alpaca.Markets.dll</Left>
+    <Right>lib/netstandard2.1/Alpaca.Markets.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0006</DiagnosticId>
     <Target>P:Alpaca.Markets.IAccount.OptionsApprovedLevel</Target>

Alpaca.Markets/Enums/OptionStyle.cs

@@ -0,0 +1,22 @@
+namespace Alpaca.Markets;
+
+/// <summary>
+/// Supported option contract styles for Alpaca REST API.
+/// </summary>
+[JsonConverter(typeof(StringEnumConverter))]
+public enum OptionStyle
+{
+    /// <summary>
+    /// American option contract execution style.
+    /// </summary>
+    [UsedImplicitly]
+    [EnumMember(Value = "american")]
+    American,
+
+    /// <summary>
+    /// European option contract execution style.
+    /// </summary>
+    [UsedImplicitly]
+    [EnumMember(Value = "european")]
+    European
+}

Alpaca.Markets/Enums/OptionType.cs

@@ -0,0 +1,22 @@
+namespace Alpaca.Markets;
+
+/// <summary>
+/// Supported option contract types for Alpaca REST API.
+/// </summary>
+[JsonConverter(typeof(StringEnumConverter))]
+public enum OptionType
+{
+    /// <summary>
+    /// Call option contract.
+    /// </summary>
+    [UsedImplicitly]
+    [EnumMember(Value = "call")]
+    Call,
+
+    /// <summary>
+    /// Put option contract.
+    /// </summary>
+    [UsedImplicitly]
+    [EnumMember(Value = "put")]
+    Put
+}

Alpaca.Markets/Interfaces/IAlpacaTradingClient.cs

@@ -26,7 +26,6 @@ public interface IAlpacaTradingClient : IRateLimitProvider, IDisposable
     [UsedImplicitly]
     Task<IReadOnlyList<IWatchList>> ListWatchListsAsync(
         CancellationToken cancellationToken = default);
-
     /// <summary>
     /// Add new watch list object into Alpaca REST API endpoint.
     /// </summary>
@@ -929,4 +928,79 @@ Task<IAnnouncement> GetAnnouncementAsync(
     Task<IReadOnlyList<IAnnouncement>> ListAnnouncementsAsync(
         AnnouncementsRequest request,
         CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Gets list of active option contracts from Alpaca REST API endpoint. By default, only active contracts that expire before the upcoming weekend are returned.
+    /// </summary>
+    /// <param name="request">Option contracts request parameters.</param>
+    /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
+    /// <exception cref="RequestValidationException">
+    /// The <paramref name="request"/> argument contains invalid data or some required data is missing, unable to create a valid HTTP request.
+    /// </exception>
+    /// <exception cref="HttpRequestException">
+    /// The request failed due to an underlying issue such as network connectivity, DNS failure, server certificate validation or timeout.
+    /// </exception>
+    /// <exception cref="RestClientErrorException">
+    /// The response contains an error message or the received response cannot be deserialized properly due to JSON schema mismatch.
+    /// </exception>
+    /// <exception cref="SocketException">
+    /// The initial TPC socket connection failed due to an underlying low-level network connectivity issue.
+    /// </exception>
+    /// <exception cref="TaskCanceledException">
+    /// .NET Core and .NET 5 and later only: The request failed due to timeout.
+    /// </exception>
+    /// <exception cref="ArgumentNullException">
+    /// The <paramref name="request"/> argument is <c>null</c>.
+    /// </exception>
+    /// <returns>Read-only list of corporate action information objects.</returns>
+    [UsedImplicitly]
+    Task<IReadOnlyList<IOptionContract>> ListOptionContractsAsync(
+        OptionContractsRequest request,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Gets option contract from Alpaca REST API endpoint using contract identifier.
+    /// </summary>
+    /// <param name="contractId">Option contract unique identifier.</param>
+    /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
+    /// <exception cref="HttpRequestException">
+    /// The request failed due to an underlying issue such as network connectivity, DNS failure, server certificate validation or timeout.
+    /// </exception>
+    /// <exception cref="RestClientErrorException">
+    /// The response contains an error message or the received response cannot be deserialized properly due to JSON schema mismatch.
+    /// </exception>
+    /// <exception cref="SocketException">
+    /// The initial TPC socket connection failed due to an underlying low-level network connectivity issue.
+    /// </exception>
+    /// <exception cref="TaskCanceledException">
+    /// .NET Core and .NET 5 and later only: The request failed due to timeout.
+    /// </exception>
+    /// <returns>Read-only list of corporate action information objects.</returns>
+    [UsedImplicitly]
+    Task<IOptionContract> GetOptionContractByIdAsync(
+        Guid contractId,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Gets option contract from Alpaca REST API endpoint using contract symbol name.
+    /// </summary>
+    /// <param name="symbol">Option contract unique symbol name.</param>
+    /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
+    /// <exception cref="HttpRequestException">
+    /// The request failed due to an underlying issue such as network connectivity, DNS failure, server certificate validation or timeout.
+    /// </exception>
+    /// <exception cref="RestClientErrorException">
+    /// The response contains an error message or the received response cannot be deserialized properly due to JSON schema mismatch.
+    /// </exception>
+    /// <exception cref="SocketException">
+    /// The initial TPC socket connection failed due to an underlying low-level network connectivity issue.
+    /// </exception>
+    /// <exception cref="TaskCanceledException">
+    /// .NET Core and .NET 5 and later only: The request failed due to timeout.
+    /// </exception>
+    /// <returns>Read-only list of corporate action information objects.</returns>
+    [UsedImplicitly]
+    Task<IOptionContract> GetOptionContractBySymbolAsync(
+        String symbol,
+        CancellationToken cancellationToken = default);
 }

Alpaca.Markets/Interfaces/IOptionContract.cs

@@ -0,0 +1,108 @@
+namespace Alpaca.Markets;
+
+/// <summary>
+/// 
+/// </summary>
+public interface IOptionContract
+{
+    /// <summary>
+    /// Gets unique option contract identifier used by Alpaca.
+    /// </summary>
+    [UsedImplicitly]
+    Guid ContractId { get; }
+
+    /// <summary>
+    /// Get option contract symbol.
+    /// </summary>
+    String Symbol { get; }
+
+    /// <summary>
+    /// Gets option contract name.
+    /// </summary>
+    [UsedImplicitly]
+    String Name { get; }
+
+    /// <summary>
+    /// Get option contract status in API.
+    /// </summary>
+    [UsedImplicitly]
+    AssetStatus Status { get; }
+
+    /// <summary>
+    /// Returns <c>true</c> if asset is tradable.
+    /// </summary>
+    [UsedImplicitly]
+    Boolean IsTradable { get; }
+
+    /// <summary>
+    /// Get option contract size.
+    /// </summary>
+    [UsedImplicitly]
+    Decimal Size { get; }
+
+    /// <summary>
+    /// Get option contract type.
+    /// </summary>
+    [UsedImplicitly]
+    OptionType OptionType { get; }
+
+    /// <summary>
+    /// Get option contract strike price.
+    /// </summary>
+    [UsedImplicitly]
+    Decimal StrikePrice { get; }
+
+    /// <summary>
+    /// Get option contract expiration date.
+    /// </summary>
+    [UsedImplicitly]
+    DateOnly ExpirationDate { get; }
+
+    /// <summary>
+    /// Get option contract execution style.
+    /// </summary>
+    [UsedImplicitly]
+    OptionStyle OptionStyle { get; }
+
+    /// <summary>
+    /// Get option contract root asset <see cref="IAsset.Symbol"/> property.
+    /// </summary>
+    [UsedImplicitly]
+    String RootSymbol { get; }
+
+    /// <summary>
+    /// Get option contract underlying asset <see cref="IAsset.Symbol"/> property.
+    /// </summary>
+    [UsedImplicitly]
+    String UnderlyingSymbol { get; }
+
+    /// <summary>
+    /// Get option contract underlying asset <see cref="IAsset.AssetId"/> property.
+    /// </summary>
+    [UsedImplicitly]
+    Guid UnderlyingAssetId { get; }
+
+    /// <summary>
+    /// Get option contract open interest.
+    /// </summary>
+    [UsedImplicitly]
+    Decimal? OpenInterest { get; }
+
+    /// <summary>
+    /// Get option contract open interest date.
+    /// </summary>
+    [UsedImplicitly]
+    DateOnly? OpenInterestDate { get; }
+
+    /// <summary>
+    /// Get option contract close price.
+    /// </summary>
+    [UsedImplicitly]
+    Decimal? ClosePrice { get; }
+
+    /// <summary>
+    /// Get option contract close price date.
+    /// </summary>
+    [UsedImplicitly]
+    DateOnly? ClosePriceDate { get; }
+}