Updated to version 8.7.0

Added SetOptions method to update client settings
Added SocketConnection parameter to PeriodicQuery callback
Added setting of DefaultProxyCredentials on HttpClient instance when client is not provided by DI
Added support for overriding request time out per request
Changed max wait time for close handshake response from 5 seconds to 1 second
Fixed exception in trade tracker when there is no data in the initial snapshot

.github/workflows/dotnet.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Setup .NET
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 8.0.x
+        dotnet-version: 9.0.x
     - name: Restore dependencies
       run: dotnet restore
     - name: Build

CryptoExchange.Net.UnitTests/CryptoExchange.Net.UnitTests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 

CryptoExchange.Net/Attributes/NullableAttributes.cs

@@ -1,4 +1,4 @@
-#if !NETSTANDARD2_1
+#if NETSTANDARD2_0
 namespace System.Diagnostics.CodeAnalysis
 {
     using System;

CryptoExchange.Net/Authentication/AuthenticationProvider.cs

@@ -369,7 +369,7 @@ namespace CryptoExchange.Net.Authentication
             var rsa = RSA.Create();
             if (_credentials.CredentialType == ApiCredentialsType.RsaPem)
             {
-#if NETSTANDARD2_1_OR_GREATER
+#if NETSTANDARD2_1_OR_GREATER || NET9_0_OR_GREATER
                 // Read from pem private key
                 var key = _credentials.Secret!
                         .Replace("\n", "")
@@ -403,10 +403,14 @@ namespace CryptoExchange.Net.Authentication
         /// <returns></returns>
         protected static string BytesToHexString(byte[] buff)
         {
+#if NET9_0_OR_GREATER
+            return Convert.ToHexString(buff);
+#else
             var result = string.Empty;
             foreach (var t in buff)
                 result += t.ToString("X2");
             return result;
+#endif
         }
 
         /// <summary>
@@ -439,6 +443,16 @@ namespace CryptoExchange.Net.Authentication
             return DateTimeConverter.ConvertToMilliseconds(GetTimestamp(apiClient)).Value.ToString(CultureInfo.InvariantCulture);
         }
 
+        /// <summary>
+        /// Get millisecond timestamp as a long including the time sync offset from the api client
+        /// </summary>
+        /// <param name="apiClient"></param>
+        /// <returns></returns>
+        protected long GetMillisecondTimestampLong(RestApiClient apiClient)
+        {
+            return DateTimeConverter.ConvertToMilliseconds(GetTimestamp(apiClient)).Value;
+        }
+
         /// <summary>
         /// Return the serialized request body
         /// </summary>

CryptoExchange.Net/Caching/MemoryCache.cs

@@ -26,7 +26,7 @@ namespace CryptoExchange.Net.Caching
         /// <returns>Cached value if it was in cache</returns>
         public object? Get(string key, TimeSpan maxAge)
         {
-            _cache.TryGetValue(key, out CacheItem value);
+            _cache.TryGetValue(key, out CacheItem? value);
             if (value == null)
                 return null;
 

CryptoExchange.Net/Clients/BaseApiClient.cs

@@ -93,6 +93,17 @@ namespace CryptoExchange.Net.Clients
                 AuthenticationProvider = CreateAuthenticationProvider(credentials.Copy());
         }
 
+        /// <inheritdoc />
+        public virtual void SetOptions<T>(UpdateOptions<T> options) where T : ApiCredentials
+        {
+            ClientOptions.Proxy = options.Proxy;
+            ClientOptions.RequestTimeout = options.RequestTimeout ?? ClientOptions.RequestTimeout;
+
+            ApiOptions.ApiCredentials = options.ApiCredentials ?? ClientOptions.ApiCredentials;
+            if (options.ApiCredentials != null)
+                AuthenticationProvider = CreateAuthenticationProvider(options.ApiCredentials.Copy());
+        }
+
         /// <summary>
         /// Dispose
         /// </summary>

CryptoExchange.Net/Clients/BaseClient.cs

@@ -15,7 +15,7 @@ namespace CryptoExchange.Net.Clients
         /// <summary>
         /// Version of the CryptoExchange.Net base library
         /// </summary>
-        public Version CryptoExchangeLibVersion { get; } = typeof(BaseClient).Assembly.GetName().Version;
+        public Version CryptoExchangeLibVersion { get; } = typeof(BaseClient).Assembly.GetName().Version!;
 
         /// <summary>
         /// Version of the client implementation
@@ -27,7 +27,7 @@ namespace CryptoExchange.Net.Clients
                lock(_versionLock)
                 {
                     if (_exchangeVersion == null)
-                        _exchangeVersion = GetType().Assembly.GetName().Version;
+                        _exchangeVersion = GetType().Assembly.GetName().Version!;
 
                     return _exchangeVersion;
                 }

CryptoExchange.Net/Clients/RestApiClient.cs

@@ -154,6 +154,7 @@ namespace CryptoExchange.Net.Clients
         /// <param name="cancellationToken">Cancellation token</param>
         /// <param name="additionalHeaders">Additional headers for this request</param>
         /// <param name="weight">Override the request weight for this request definition, for example when the weight depends on the parameters</param>
+        /// <param name="weightSingleLimiter">Specify the weight to apply to the individual rate limit guard for this request</param>
         /// <returns></returns>
         protected virtual Task<WebCallResult<T>> SendAsync<T>(
             string baseAddress,
@@ -161,7 +162,8 @@ namespace CryptoExchange.Net.Clients
             ParameterCollection? parameters,
             CancellationToken cancellationToken,
             Dictionary<string, string>? additionalHeaders = null,
-            int? weight = null) where T : class
+            int? weight = null,
+            int? weightSingleLimiter = null)
         {
             var parameterPosition = definition.ParameterPosition ?? ParameterPositions[definition.Method];
             return SendAsync<T>(
@@ -171,7 +173,8 @@ namespace CryptoExchange.Net.Clients
                 parameterPosition == HttpMethodParameterPosition.InBody ? parameters : null,
                 cancellationToken,
                 additionalHeaders,
-                weight);
+                weight,
+                weightSingleLimiter);
         }
 
         /// <summary>
@@ -185,6 +188,7 @@ namespace CryptoExchange.Net.Clients
         /// <param name="cancellationToken">Cancellation token</param>
         /// <param name="additionalHeaders">Additional headers for this request</param>
         /// <param name="weight">Override the request weight for this request definition, for example when the weight depends on the parameters</param>
+        /// <param name="weightSingleLimiter">Specify the weight to apply to the individual rate limit guard for this request</param>
         /// <returns></returns>
         protected virtual async Task<WebCallResult<T>> SendAsync<T>(
             string baseAddress,
@@ -193,7 +197,8 @@ namespace CryptoExchange.Net.Clients
             ParameterCollection? bodyParameters,
             CancellationToken cancellationToken,
             Dictionary<string, string>? additionalHeaders = null,
-            int? weight = null) where T : class
+            int? weight = null,
+            int? weightSingleLimiter = null)
         {
             string? cacheKey = null;
             if (ShouldCache(definition))
@@ -217,7 +222,7 @@ namespace CryptoExchange.Net.Clients
                 currentTry++;
                 var requestId = ExchangeHelpers.NextId();
 
-                var prepareResult = await PrepareAsync(requestId, baseAddress, definition, cancellationToken, additionalHeaders, weight).ConfigureAwait(false);
+                var prepareResult = await PrepareAsync(requestId, baseAddress, definition, cancellationToken, additionalHeaders, weight, weightSingleLimiter).ConfigureAwait(false);
                 if (!prepareResult)
                     return new WebCallResult<T>(prepareResult.Error!);
 
@@ -258,6 +263,7 @@ namespace CryptoExchange.Net.Clients
         /// <param name="cancellationToken">Cancellation token</param>
         /// <param name="additionalHeaders">Additional headers for this request</param>
         /// <param name="weight">Override the request weight for this request</param>
+        /// <param name="weightSingleLimiter">Specify the weight to apply to the individual rate limit guard for this request</param>
         /// <returns></returns>
         /// <exception cref="Exception"></exception>
         protected virtual async Task<CallResult> PrepareAsync(
@@ -266,10 +272,9 @@ namespace CryptoExchange.Net.Clients
             RequestDefinition definition,
             CancellationToken cancellationToken,
             Dictionary<string, string>? additionalHeaders = null,
-            int? weight = null)
+            int? weight = null,
+            int? weightSingleLimiter = null)
         {
-            var requestWeight = weight ?? definition.Weight;
-
             // Time sync
             if (definition.Authenticated)
             {
@@ -295,6 +300,7 @@ namespace CryptoExchange.Net.Clients
             }            
 
             // Rate limiting
+            var requestWeight = weight ?? definition.Weight;
             if (requestWeight != 0)
             {
                 if (definition.RateLimitGate == null)
@@ -316,7 +322,8 @@ namespace CryptoExchange.Net.Clients
 
                 if (ClientOptions.RateLimiterEnabled)
                 {
-                    var limitResult = await definition.RateLimitGate.ProcessSingleAsync(_logger, requestId, definition.LimitGuard, RateLimitItemType.Request, definition, baseAddress, AuthenticationProvider?._credentials.Key, ClientOptions.RateLimitingBehaviour, cancellationToken).ConfigureAwait(false);
+                    var singleRequestWeight = weightSingleLimiter ?? 1;
+                    var limitResult = await definition.RateLimitGate.ProcessSingleAsync(_logger, requestId, definition.LimitGuard, RateLimitItemType.Request, definition, baseAddress, AuthenticationProvider?._credentials.Key, singleRequestWeight, ClientOptions.RateLimitingBehaviour, cancellationToken).ConfigureAwait(false);
                     if (!limitResult)
                         return new CallResult(limitResult.Error!);
                 }
@@ -617,7 +624,7 @@ namespace CryptoExchange.Net.Clients
                 paramString = $" with request body '{request.Content}'";
 
             var headers = request.GetHeaders();
-            if (headers.Any())
+            if (headers.Count != 0)
                 paramString += " with headers " + string.Join(", ", headers.Select(h => h.Key + $"=[{string.Join(",", h.Value)}]"));
 
             TotalRequestsMade++;
@@ -693,10 +700,21 @@ namespace CryptoExchange.Net.Clients
                 }
 
                 // Json response received
-                var parsedError = TryParseError(accessor);
+                var parsedError = TryParseError(response.ResponseHeaders, accessor);
                 if (parsedError != null)
+                {
+                    if (parsedError is ServerRateLimitError rateError)
+                    {
+                        if (rateError.RetryAfter != null && gate != null && ClientOptions.RateLimiterEnabled)
+                        {
+                            _logger.RestApiRateLimitPauseUntil(request.RequestId, rateError.RetryAfter.Value);
+                            await gate.SetRetryAfterGuardAsync(rateError.RetryAfter.Value).ConfigureAwait(false);
+                        }
+                    }
+
                     // Success status code, but TryParseError determined it was an error response
                     return new WebCallResult<T>(response.StatusCode, response.ResponseHeaders, sw.Elapsed, responseLength, OutputOriginalData ? accessor.GetOriginalString() : null, request.RequestId, request.Uri.ToString(), request.Content, request.Method, request.GetHeaders(), ResultDataSource.Server, default, parsedError);
+                }
 
                 var deserializeResult = accessor.Deserialize<T>();
                 return new WebCallResult<T>(response.StatusCode, response.ResponseHeaders, sw.Elapsed, responseLength, OutputOriginalData ? accessor.GetOriginalString() : null, request.RequestId, request.Uri.ToString(), request.Content, request.Method, request.GetHeaders(), ResultDataSource.Server, deserializeResult.Data, deserializeResult.Error);
@@ -730,12 +748,13 @@ namespace CryptoExchange.Net.Clients
 
         /// <summary>
         /// Can be used to parse an error even though response status indicates success. Some apis always return 200 OK, even though there is an error.
-        /// When setting manualParseError to true this method will be called for each response to be able to check if the response is an error or not.
+        /// This method will be called for each response to be able to check if the response is an error or not.
         /// If the response is an error this method should return the parsed error, else it should return null
         /// </summary>
         /// <param name="accessor">Data accessor</param>
+        /// <param name="responseHeaders">The response headers</param>
         /// <returns>Null if not an error, Error otherwise</returns>
-        protected virtual ServerError? TryParseError(IMessageAccessor accessor) => null;
+        protected virtual Error? TryParseError(IEnumerable<KeyValuePair<string, IEnumerable<string>>> responseHeaders, IMessageAccessor accessor) => null;
 
         /// <summary>
         /// Can be used to indicate that a request should be retried. Defaults to false. Make sure to retry a max number of times (based on the the tries parameter) or the request will retry forever.
@@ -752,7 +771,7 @@ namespace CryptoExchange.Net.Clients
                 // Only retry once
                 return false;
 
-            if ((int?)callResult.ResponseStatusCode == 429 
+            if (callResult.Error is ServerRateLimitError
                 && ClientOptions.RateLimiterEnabled
                 && ClientOptions.RateLimitingBehaviour != RateLimitingBehaviour.Fail
                 && gate != null)
@@ -807,7 +826,7 @@ namespace CryptoExchange.Net.Clients
             if (parameterPosition == HttpMethodParameterPosition.InUri)
             {
                 foreach (var parameter in parameters)
-                    uri = uri.AddQueryParmeter(parameter.Key, parameter.Value.ToString());
+                    uri = uri.AddQueryParmeter(parameter.Key, parameter.Value.ToString()!);
             }
 
             var headers = new Dictionary<string, string>();
@@ -889,8 +908,8 @@ namespace CryptoExchange.Net.Clients
             {
                 // Write the parameters as json in the body
                 string stringData;
-                if (parameters.Count == 1 && parameters.ContainsKey(Constants.BodyPlaceHolderKey))
-                    stringData = CreateSerializer().Serialize(parameters[Constants.BodyPlaceHolderKey]);
+                if (parameters.Count == 1 && parameters.TryGetValue(Constants.BodyPlaceHolderKey, out object? value))
+                    stringData = CreateSerializer().Serialize(value);
                 else
                     stringData = CreateSerializer().Serialize(parameters);
                 request.SetContent(stringData, contentType);
@@ -961,6 +980,14 @@ namespace CryptoExchange.Net.Clients
         /// <returns>Server time</returns>
         protected virtual Task<WebCallResult<DateTime>> GetServerTimestampAsync() => throw new NotImplementedException();
 
+        /// <inheritdoc />
+        public override void SetOptions<T>(UpdateOptions<T> options)
+        {
+            base.SetOptions(options);
+
+            RequestFactory.UpdateSettings(options.Proxy, options.RequestTimeout ?? ClientOptions.RequestTimeout);
+        }
+
         internal async Task<WebCallResult<bool>> SyncTimeAsync()
         {
             var timeSyncParams = GetTimeSyncInfo();

CryptoExchange.Net/Clients/SocketApiClient.cs

@@ -158,7 +158,7 @@ namespace CryptoExchange.Net.Clients
         /// <param name="interval"></param>
         /// <param name="queryDelegate"></param>
         /// <param name="callback"></param>
-        protected virtual void RegisterPeriodicQuery(string identifier, TimeSpan interval, Func<SocketConnection, Query> queryDelegate, Action<CallResult>? callback)
+        protected virtual void RegisterPeriodicQuery(string identifier, TimeSpan interval, Func<SocketConnection, Query> queryDelegate, Action<SocketConnection, CallResult>? callback)
         {
             PeriodicTaskRegistrations.Add(new PeriodicTaskRegistration
             {
@@ -422,9 +422,10 @@ namespace CryptoExchange.Net.Clients
                     result.Error!.Message = "Authentication failed: " + result.Error.Message;
                     return new CallResult(result.Error)!;
                 }
+
+                _logger.Authenticated(socket.SocketId);
             }
 
-            _logger.Authenticated(socket.SocketId);
             socket.Authenticated = true;
             return new CallResult(null);
         }
@@ -710,6 +711,25 @@ namespace CryptoExchange.Net.Clients
             return new CallResult(null);
         }
 
+        /// <inheritdoc />
+        public override void SetOptions<T>(UpdateOptions<T> options)
+        {
+            var previousProxyIsSet = ClientOptions.Proxy != null;
+            base.SetOptions(options);
+
+            if ((!previousProxyIsSet && options.Proxy == null)
+                || !socketConnections.Any())
+            {
+                return;
+            }
+
+            _logger.LogInformation("Reconnecting websockets to apply proxy");
+
+            // Update proxy, also triggers reconnect
+            foreach (var connection in socketConnections)
+                _ = connection.Value.UpdateProxy(options.Proxy);
+        }
+
         /// <summary>
         /// Log the current state of connections and subscriptions
         /// </summary>

CryptoExchange.Net/Converters/JsonNet/ArrayConverter.cs

@@ -36,7 +36,7 @@ namespace CryptoExchange.Net.Converters.JsonNet
 
             var result = Activator.CreateInstance(objectType);
             var arr = JArray.Load(reader);
-            return ParseObject(arr, result, objectType);
+            return ParseObject(arr, result!, objectType);
         }
 
         private static object ParseObject(JArray arr, object result, Type objectType)
@@ -58,25 +58,25 @@ namespace CryptoExchange.Net.Converters.JsonNet
                     var count = 0;
                     if (innerArray.Count == 0)
                     {
-                        var arrayResult = (IList)Activator.CreateInstance(property.PropertyType, new [] { 0 });
+                        var arrayResult = (IList)Activator.CreateInstance(property.PropertyType, new [] { 0 })!;
                         property.SetValue(result, arrayResult);
                     }
                     else if (innerArray[0].Type == JTokenType.Array)
                     {
-                        var arrayResult = (IList)Activator.CreateInstance(property.PropertyType, new [] { innerArray.Count });
+                        var arrayResult = (IList)Activator.CreateInstance(property.PropertyType, new [] { innerArray.Count })!;
                         foreach (var obj in innerArray)
                         {
                             var innerObj = Activator.CreateInstance(objType!);
-                            arrayResult[count] = ParseObject((JArray)obj, innerObj, objType!);
+                            arrayResult[count] = ParseObject((JArray)obj, innerObj!, objType!);
                             count++;
                         }
                         property.SetValue(result, arrayResult);
                     }
                     else
                     {
-                        var arrayResult = (IList)Activator.CreateInstance(property.PropertyType, new [] { 1 });
+                        var arrayResult = (IList)Activator.CreateInstance(property.PropertyType, new [] { 1 })!;
                         var innerObj = Activator.CreateInstance(objType!);
-                        arrayResult[0] = ParseObject(innerArray, innerObj, objType!);
+                        arrayResult[0] = ParseObject(innerArray, innerObj!, objType!);
                         property.SetValue(result, arrayResult);
                     }
                     continue;
@@ -88,7 +88,7 @@ namespace CryptoExchange.Net.Converters.JsonNet
                 object? value;
                 if (converterAttribute != null)
                 {
-                    value = arr[attribute.Index].ToObject(property.PropertyType, new JsonSerializer {Converters = {(JsonConverter) Activator.CreateInstance(converterAttribute.ConverterType)}});
+                    value = arr[attribute.Index].ToObject(property.PropertyType, new JsonSerializer {Converters = {(JsonConverter) Activator.CreateInstance(converterAttribute.ConverterType)!}});
                 }
                 else if (conversionAttribute != null)
                 {
@@ -120,7 +120,7 @@ namespace CryptoExchange.Net.Converters.JsonNet
                     }
                     else if ((property.PropertyType == typeof(decimal)
                      || property.PropertyType == typeof(decimal?))
-                     && (value != null && value.ToString().IndexOf("e", StringComparison.OrdinalIgnoreCase) >= 0))
+                     && (value != null && value.ToString()!.IndexOf("e", StringComparison.OrdinalIgnoreCase) >= 0))
                     {
                         var v = value.ToString();
                         if (decimal.TryParse(v, NumberStyles.Float, CultureInfo.InvariantCulture, out var dec))
@@ -164,7 +164,7 @@ namespace CryptoExchange.Net.Converters.JsonNet
                 last = arrayProp.Index;
                 var converterAttribute = GetCustomAttribute<JsonConverterAttribute>(prop);
                 if (converterAttribute != null)
-                    writer.WriteRawValue(JsonConvert.SerializeObject(prop.GetValue(value), (JsonConverter)Activator.CreateInstance(converterAttribute.ConverterType)));
+                    writer.WriteRawValue(JsonConvert.SerializeObject(prop.GetValue(value), (JsonConverter)Activator.CreateInstance(converterAttribute.ConverterType)!));
                 else if (!IsSimple(prop.PropertyType))
                     serializer.Serialize(writer, prop.GetValue(value));
                 else
@@ -187,9 +187,9 @@ namespace CryptoExchange.Net.Converters.JsonNet
         }
 
         private static T? GetCustomAttribute<T>(MemberInfo memberInfo) where T : Attribute =>
-            (T?)_attributeByMemberInfoAndTypeCache.GetOrAdd((memberInfo, typeof(T)), tuple => memberInfo.GetCustomAttribute(typeof(T)));
+            (T?)_attributeByMemberInfoAndTypeCache.GetOrAdd((memberInfo, typeof(T)), tuple => memberInfo.GetCustomAttribute(typeof(T))!);
 
         private static T? GetCustomAttribute<T>(Type type) where T : Attribute =>
-            (T?)_attributeByTypeAndTypeCache.GetOrAdd((type, typeof(T)), tuple => type.GetCustomAttribute(typeof(T)));
+            (T?)_attributeByTypeAndTypeCache.GetOrAdd((type, typeof(T)), tuple => type.GetCustomAttribute(typeof(T))!);
     }
 }

CryptoExchange.Net/Converters/JsonNet/BigDecimalConverter.cs

@@ -27,7 +27,7 @@ namespace CryptoExchange.Net.Converters.JsonNet
             {
                 try
                 {
-                    return decimal.Parse(reader.Value!.ToString(), NumberStyles.Float, CultureInfo.InvariantCulture);
+                    return decimal.Parse(reader.Value!.ToString()!, NumberStyles.Float, CultureInfo.InvariantCulture);
                 }
                 catch (OverflowException) 
                 {
@@ -40,7 +40,7 @@ namespace CryptoExchange.Net.Converters.JsonNet
             {
                 try
                 {
-                    var value = reader.Value!.ToString();
+                    var value = reader.Value!.ToString()!;
                     return decimal.Parse(value, NumberStyles.Float, CultureInfo.InvariantCulture);
                 }
                 catch (OverflowException)

CryptoExchange.Net/Converters/JsonNet/BoolConverter.cs

@@ -34,7 +34,7 @@ namespace CryptoExchange.Net.Converters.JsonNet
         /// </returns>
         public override object? ReadJson(JsonReader reader, Type objectType, object? existingValue, JsonSerializer serializer)
         {
-            var value = reader.Value?.ToString().ToLower().Trim();
+            var value = reader.Value?.ToString()!.ToLower().Trim();
             if (value == null || value == "")
             {
                 if (Nullable.GetUnderlyingType(objectType) != null)

CryptoExchange.Net/Converters/JsonNet/JsonNetMessageAccessor.cs

@@ -297,7 +297,7 @@ namespace CryptoExchange.Net.Converters.JsonNet
 
             // Try getting the underlying byte[] instead of the ToArray to prevent creating a copy
             using var stream = MemoryMarshal.TryGetArray(data, out var arraySegment)
-                ? new MemoryStream(arraySegment.Array, arraySegment.Offset, arraySegment.Count)
+                ? new MemoryStream(arraySegment.Array!, arraySegment.Offset, arraySegment.Count)
                 : new MemoryStream(data.ToArray());
             using var reader = new StreamReader(stream, Encoding.UTF8, false, Math.Max(2, data.Length), true);
             using var jsonTextReader = new JsonTextReader(reader);

CryptoExchange.Net/Converters/SystemTextJson/ArrayConverter.cs

@@ -23,7 +23,7 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
         public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
         {
             Type converterType = typeof(ArrayConverterInner<>).MakeGenericType(typeToConvert);
-            return (JsonConverter)Activator.CreateInstance(converterType);
+            return (JsonConverter)Activator.CreateInstance(converterType)!;
         }
 
         private class ArrayPropertyInfo
@@ -79,7 +79,7 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
                     JsonSerializerOptions? typeOptions = null;
                     if (prop.JsonConverterType != null)
                     {
-                        var converter = (JsonConverter)Activator.CreateInstance(prop.JsonConverterType);
+                        var converter = (JsonConverter)Activator.CreateInstance(prop.JsonConverterType)!;
                         typeOptions = new JsonSerializerOptions();
                         typeOptions.Converters.Clear();
                         typeOptions.Converters.Add(converter);
@@ -90,7 +90,7 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
                         if (prop.PropertyInfo.PropertyType == typeof(string))
                             writer.WriteStringValue(Convert.ToString(objValue, CultureInfo.InvariantCulture));
                         else
-                            writer.WriteRawValue(Convert.ToString(objValue, CultureInfo.InvariantCulture));
+                            writer.WriteRawValue(Convert.ToString(objValue, CultureInfo.InvariantCulture)!);
                     }
                     else
                     {
@@ -107,7 +107,7 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
                 if (reader.TokenType == JsonTokenType.Null)
                     return default;
 
-                var result = Activator.CreateInstance(typeToConvert);
+                var result = Activator.CreateInstance(typeToConvert)!;
                 return (T)ParseObject(ref reader, result, typeToConvert, options);
             }
 
@@ -177,7 +177,7 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
                         {
                             if (!_converterOptionsCache.TryGetValue(attribute.JsonConverterType, out var newOptions))
                             {
-                                var converter = (JsonConverter)Activator.CreateInstance(attribute.JsonConverterType);
+                                var converter = (JsonConverter)Activator.CreateInstance(attribute.JsonConverterType)!;
                                 newOptions = new JsonSerializerOptions
                                 {
                                     NumberHandling = SerializerOptions.WithConverters.NumberHandling,
@@ -209,7 +209,7 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
                         }
 
                         if (targetType.IsAssignableFrom(value?.GetType()))
-                            attribute.PropertyInfo.SetValue(result, value == null ? null : value);
+                            attribute.PropertyInfo.SetValue(result, value);
                         else
                             attribute.PropertyInfo.SetValue(result, value == null ? null : Convert.ChangeType(value, targetType, CultureInfo.InvariantCulture));
                     }

CryptoExchange.Net/Converters/SystemTextJson/BigDecimalConverter.cs

@@ -17,7 +17,7 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
             {
                 try
                 {
-                    return decimal.Parse(reader.GetString(), NumberStyles.Float, CultureInfo.InvariantCulture);
+                    return decimal.Parse(reader.GetString()!, NumberStyles.Float, CultureInfo.InvariantCulture);
                 }
                 catch(OverflowException)
                 {

CryptoExchange.Net/Converters/SystemTextJson/BoolConverter.cs

@@ -21,7 +21,7 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
         public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
         {
             Type converterType = typeof(BoolConverterInner<>).MakeGenericType(typeToConvert);
-            return (JsonConverter)Activator.CreateInstance(converterType);
+            return (JsonConverter)Activator.CreateInstance(converterType)!;
         }
 
         private class BoolConverterInner<T> : JsonConverter<T>

CryptoExchange.Net/Converters/SystemTextJson/DateTimeConverter.cs

@@ -27,7 +27,7 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
         public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
         {
             Type converterType = typeof(DateTimeConverterInner<>).MakeGenericType(typeToConvert);
-            return (JsonConverter)Activator.CreateInstance(converterType);
+            return (JsonConverter)Activator.CreateInstance(converterType)!;
         }
 
         private class DateTimeConverterInner<T> : JsonConverter<T>
@@ -74,7 +74,9 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
             public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions options)
             {
                 if (value == null)
+                {
                     writer.WriteNullValue();
+                }
                 else
                 {
                     var dtValue = (DateTime)(object)value;

CryptoExchange.Net/Converters/SystemTextJson/JsonConverterCtorAttribute.cs

@@ -24,7 +24,7 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
         /// <inheritdoc />
         public override JsonConverter CreateConverter(Type typeToConvert)
         {
-            return (JsonConverter)Activator.CreateInstance(_type, _parameters);
+            return (JsonConverter)Activator.CreateInstance(_type, _parameters)!;
         }
     }
 

CryptoExchange.Net/CryptoExchange.Net.csproj

@@ -1,14 +1,14 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;netstandard2.1;net9.0</TargetFrameworks>
   </PropertyGroup>
   <PropertyGroup>
     <PackageId>CryptoExchange.Net</PackageId>
     <Authors>JKorf</Authors>
     <Description>CryptoExchange.Net is a base library which is used to implement different cryptocurrency (exchange) API's. It provides a standardized way of implementing different API's, which results in a very similar experience for users of the API implementations.</Description>
-    <PackageVersion>8.4.5</PackageVersion>
-    <AssemblyVersion>8.4.5</AssemblyVersion>
-    <FileVersion>8.4.5</FileVersion>
+    <PackageVersion>8.7.0</PackageVersion>
+    <AssemblyVersion>8.7.0</AssemblyVersion>
+    <FileVersion>8.7.0</FileVersion>
     <PackageRequireLicenseAcceptance>false</PackageRequireLicenseAcceptance>
     <PackageTags>OKX;OKX.Net;Mexc;Mexc.Net;Kucoin;Kucoin.Net;Kraken;Kraken.Net;Huobi;Huobi.Net;CoinEx;CoinEx.Net;Bybit;Bybit.Net;Bitget;Bitget.Net;Bitfinex;Bitfinex.Net;Binance;Binance.Net;CryptoCurrency;CryptoCurrency Exchange</PackageTags>
     <RepositoryType>git</RepositoryType>

CryptoExchange.Net/ExchangeHelpers.cs

@@ -180,7 +180,7 @@ namespace CryptoExchange.Net
         {
             var randomChars = new char[length];
 
-#if NETSTANDARD2_1_OR_GREATER
+#if NETSTANDARD2_1_OR_GREATER || NET9_0_OR_GREATER
             for (int i = 0; i < length; i++)
                 randomChars[i] = _allowedRandomChars[RandomNumberGenerator.GetInt32(0, _allowedRandomChars.Length)];
 #else
@@ -261,6 +261,7 @@ namespace CryptoExchange.Net
             if (price != null)
             {
                 adjustedPrice = AdjustValueStep(0, decimal.MaxValue, symbol.PriceStep, RoundingType.Down, price.Value);
+                adjustedPrice = symbol.PriceSignificantFigures.HasValue ? RoundToSignificantDigits(adjustedPrice.Value, symbol.PriceSignificantFigures.Value, RoundingType.Closest) : adjustedPrice;
                 adjustedPrice = symbol.PriceDecimals.HasValue ? RoundDown(price.Value, symbol.PriceDecimals.Value) : adjustedPrice;
                 if (adjustedPrice != 0 && adjustedPrice * quantity < symbol.MinNotionalValue)
                 {

CryptoExchange.Net/ExtensionMethods.cs

@@ -67,7 +67,7 @@ namespace CryptoExchange.Net
             {
                 if (serializationType == ArrayParametersSerialization.Array)
                 {
-                    uriString += $"{string.Join("&", ((object[])(urlEncodeValues ? Uri.EscapeDataString(arrayEntry.Value.ToString()) : arrayEntry.Value)).Select(v => $"{arrayEntry.Key}[]={string.Format(CultureInfo.InvariantCulture, "{0}", v)}"))}&";
+                    uriString += $"{string.Join("&", ((object[])(urlEncodeValues ? Uri.EscapeDataString(arrayEntry.Value.ToString()!) : arrayEntry.Value)).Select(v => $"{arrayEntry.Key}[]={string.Format(CultureInfo.InvariantCulture, "{0}", v)}"))}&";
                 }
                 else if (serializationType == ArrayParametersSerialization.MultipleValues)
                 {
@@ -111,7 +111,7 @@ namespace CryptoExchange.Net
                     formData.Add(kvp.Key, string.Format(CultureInfo.InvariantCulture, "{0}", kvp.Value));
                 }
             }
-            return formData.ToString();
+            return formData.ToString()!;
         }
 
         /// <summary>
@@ -366,7 +366,7 @@ namespace CryptoExchange.Net
         {
             using var decompressedStream = new MemoryStream();
             using var dataStream = MemoryMarshal.TryGetArray(data, out var arraySegment)
-                ? new MemoryStream(arraySegment.Array, arraySegment.Offset, arraySegment.Count)
+                ? new MemoryStream(arraySegment.Array!, arraySegment.Offset, arraySegment.Count)
                 : new MemoryStream(data.ToArray());
             using var deflateStream = new GZipStream(new MemoryStream(data.ToArray()), CompressionMode.Decompress);
             deflateStream.CopyTo(decompressedStream);
@@ -435,6 +435,8 @@ namespace CryptoExchange.Net
                 services.AddTransient(x => (IWithdrawalRestClient)client(x)!);
             if (typeof(IWithdrawRestClient).IsAssignableFrom(typeof(T)))
                 services.AddTransient(x => (IWithdrawRestClient)client(x)!);
+            if (typeof(IFeeRestClient).IsAssignableFrom(typeof(T)))
+                services.AddTransient(x => (IFeeRestClient)client(x)!);
 
             if (typeof(ISpotOrderRestClient).IsAssignableFrom(typeof(T)))
                 services.AddTransient(x => (ISpotOrderRestClient)client(x)!);

CryptoExchange.Net/Interfaces/IBaseApiClient.cs

@@ -1,5 +1,6 @@
 using CryptoExchange.Net.Authentication;
 using CryptoExchange.Net.Objects;
+using CryptoExchange.Net.Objects.Options;
 using CryptoExchange.Net.SharedApis;
 using System;
 
@@ -31,5 +32,12 @@ namespace CryptoExchange.Net.Interfaces
         /// <typeparam name="T"></typeparam>
         /// <param name="credentials"></param>
         void SetApiCredentials<T>(T credentials) where T : ApiCredentials;
+
+        /// <summary>
+        /// Set new options. Note that when using a proxy this should be provided in the options even when already set before or it will be reset.
+        /// </summary>
+        /// <typeparam name="T">Api crentials type</typeparam>
+        /// <param name="options">Options to set</param>
+        void SetOptions<T>(UpdateOptions<T> options) where T : ApiCredentials;
     }
 }

CryptoExchange.Net/Interfaces/IRequestFactory.cs

@@ -24,6 +24,13 @@ namespace CryptoExchange.Net.Interfaces
         /// <param name="requestTimeout">Request timeout to use</param>
         /// <param name="httpClient">Optional shared http client instance</param>
         /// <param name="proxy">Optional proxy to use when no http client is provided</param>
-        void Configure(ApiProxy? proxy, TimeSpan requestTimeout, HttpClient? httpClient=null);
+        void Configure(ApiProxy? proxy, TimeSpan requestTimeout, HttpClient? httpClient = null);
+
+        /// <summary>
+        /// Update settings
+        /// </summary>
+        /// <param name="proxy">Proxy to use</param>
+        /// <param name="requestTimeout">Request timeout to use</param>
+        void UpdateSettings(ApiProxy? proxy, TimeSpan requestTimeout);
     }
 }

CryptoExchange.Net/Interfaces/IWebsocket.cs

@@ -93,5 +93,10 @@ namespace CryptoExchange.Net.Interfaces
         /// </summary>
         /// <returns></returns>
         Task CloseAsync();
+
+        /// <summary>
+        /// Update proxy setting
+        /// </summary>
+        void UpdateProxy(ApiProxy? proxy);
     }
 }

CryptoExchange.Net/Logging/Extensions/CryptoExchangeWebSocketClientLoggingExtension.cs

@@ -35,6 +35,7 @@ namespace CryptoExchange.Net.Logging.Extensions
         private static readonly Action<ILogger, int, TimeSpan?, Exception?> _startingTaskForNoDataReceivedCheck;
         private static readonly Action<ILogger, int, TimeSpan?, Exception?> _noDataReceiveTimoutReconnect;
         private static readonly Action<ILogger, int, string, string, Exception?> _socketProcessingStateChanged;
+        private static readonly Action<ILogger, int, Exception?> _socketPingTimeout;
 
         static CryptoExchangeWebSocketClientLoggingExtension()
         {
@@ -169,7 +170,7 @@ namespace CryptoExchange.Net.Logging.Extensions
                 "[Sckt {SocketId}] starting task checking for no data received for {Timeout}");
 
             _noDataReceiveTimoutReconnect = LoggerMessage.Define<int, TimeSpan?>(
-                LogLevel.Debug,
+                LogLevel.Warning,
                 new EventId(1027, "NoDataReceiveTimeoutReconnect"),
                 "[Sckt {SocketId}] no data received for {Timeout}, reconnecting socket");
 
@@ -180,9 +181,14 @@ namespace CryptoExchange.Net.Logging.Extensions
 
             _socketProcessingStateChanged = LoggerMessage.Define<int, string, string>(
                 LogLevel.Trace,
-                new EventId(1028, "SocketProcessingStateChanged"),
+                new EventId(1029, "SocketProcessingStateChanged"),
                 "[Sckt {Id}] processing state change: {PreviousState} -> {NewState}");
 
+            _socketPingTimeout = LoggerMessage.Define<int>(
+                LogLevel.Warning,
+                new EventId(1030, "SocketPingTimeout"),
+                "[Sckt {Id}] ping frame timeout; reconnecting socket");
+
         }
 
         public static void SocketConnecting(
@@ -358,5 +364,11 @@ namespace CryptoExchange.Net.Logging.Extensions
         {
             _socketProcessingStateChanged(logger, socketId, prevState, newState, null);
         }
+
+        public static void SocketPingTimeout(
+            this ILogger logger, int socketId)
+        {
+            _socketPingTimeout(logger, socketId, null);
+        }
     }
 }

CryptoExchange.Net/Logging/Extensions/SocketConnectionLoggingExtension.cs

@@ -183,7 +183,7 @@ namespace CryptoExchange.Net.Logging.Extensions
             _sendingData = LoggerMessage.Define<int, int, string>(
                 LogLevel.Trace,
                 new EventId(2028, "SendingData"),
-                "[Sckt {SocketId}] [Req {RequestId}] sending messsage: {Data}");
+                "[Sckt {SocketId}] [Req {RequestId}] sending message: {Data}");
 
             _receivedMessageNotMatchedToAnyListener = LoggerMessage.Define<int, string, string>(
                 LogLevel.Warning,

CryptoExchange.Net/Objects/ByteOrderComparer.cs

@@ -14,7 +14,7 @@ namespace CryptoExchange.Net.Objects
         /// <param name="x"></param>
         /// <param name="y"></param>
         /// <returns></returns>
-        public int Compare(byte[] x, byte[] y)
+        public int Compare(byte[]? x, byte[]? y)
         {
             // Shortcuts: If both are null, they are the same.
             if (x == null && y == null) return 0;

CryptoExchange.Net/Objects/Enums.cs

@@ -235,4 +235,18 @@
         Cache
     }
 
+    /// <summary>
+    /// Type of exchange
+    /// </summary>
+    public enum ExchangeType
+    {
+        /// <summary>
+        /// Centralized
+        /// </summary>
+        CEX,
+        /// <summary>
+        /// Decentralized
+        /// </summary>
+        DEX
+    }
 }

CryptoExchange.Net/Objects/Options/UpdateOptions.cs

@@ -0,0 +1,29 @@
+using CryptoExchange.Net.Authentication;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace CryptoExchange.Net.Objects.Options
+{
+    /// <summary>
+    /// Options to update
+    /// </summary>
+    public class UpdateOptions<T> where T : ApiCredentials
+    {
+        /// <summary>
+        /// Proxy setting. Note that if this is not provided any previously set proxy will be reset
+        /// </summary>
+        public ApiProxy? Proxy { get; set; }
+        /// <summary>
+        /// Api credentials
+        /// </summary>
+        public T? ApiCredentials { get; set; }
+        /// <summary>
+        /// Request timeout
+        /// </summary>
+        public TimeSpan? RequestTimeout { get; set; }
+    }
+
+    /// <inheritdoc />
+    public class UpdateOptions : UpdateOptions<ApiCredentials> { }
+}

CryptoExchange.Net/Objects/OrderedStringComparer.cs

@@ -13,7 +13,7 @@ namespace CryptoExchange.Net.Objects
         /// <param name="x"></param>
         /// <param name="y"></param>
         /// <returns></returns>
-        public int Compare(string x, string y)
+        public int Compare(string? x, string? y)
         {
             // Shortcuts: If both are null, they are the same.
             if (x == null && y == null) return 0;

CryptoExchange.Net/Objects/ParameterCollection.cs

@@ -156,7 +156,7 @@ namespace CryptoExchange.Net.Objects
         /// <param name="value"></param>
         public void AddSecondsString(string key, DateTime value)
         {
-            Add(key, DateTimeConverter.ConvertToSeconds(value).ToString());
+            Add(key, DateTimeConverter.ConvertToSeconds(value).ToString()!);
         }
 
         /// <summary>
@@ -167,7 +167,7 @@ namespace CryptoExchange.Net.Objects
         public void AddOptionalSecondsString(string key, DateTime? value)
         {
             if (value != null)
-                Add(key, DateTimeConverter.ConvertToSeconds(value).ToString());
+                Add(key, DateTimeConverter.ConvertToSeconds(value).ToString()!);
         }
 
         /// <summary>
@@ -187,7 +187,7 @@ namespace CryptoExchange.Net.Objects
         /// <param name="value"></param>
         public void AddEnumAsInt<T>(string key, T value)
         {
-            var stringVal = EnumConverter.GetString(value);
+            var stringVal = EnumConverter.GetString(value)!;
             Add(key, int.Parse(stringVal)!);
         }
 

CryptoExchange.Net/Objects/RequestDefinitionCache.cs

@@ -58,9 +58,38 @@ namespace CryptoExchange.Net.Objects
             HttpMethodParameterPosition? parameterPosition = null,
             ArrayParametersSerialization? arraySerialization = null,
             bool? preventCaching = null)
+            => GetOrCreate(method + path, method, path, rateLimitGate, weight, authenticated, limitGuard, requestBodyFormat, parameterPosition, arraySerialization, preventCaching);
+
+        /// <summary>
+        /// Get a definition if it is already in the cache or create a new definition and add it to the cache
+        /// </summary>
+        /// <param name="identifier">Request identifier</param>
+        /// <param name="method">The HttpMethod</param>
+        /// <param name="path">Endpoint path</param>
+        /// <param name="rateLimitGate">The rate limit gate</param>
+        /// <param name="limitGuard">The rate limit guard for this specific endpoint</param>
+        /// <param name="weight">Request weight</param>
+        /// <param name="authenticated">Endpoint is authenticated</param>
+        /// <param name="requestBodyFormat">Request body format</param>
+        /// <param name="parameterPosition">Parameter position</param>
+        /// <param name="arraySerialization">Array serialization type</param>
+        /// <param name="preventCaching">Prevent request caching</param>
+        /// <returns></returns>
+        public RequestDefinition GetOrCreate(
+            string identifier,
+            HttpMethod method,
+            string path,
+            IRateLimitGate? rateLimitGate,
+            int weight,
+            bool authenticated,
+            IRateLimitGuard? limitGuard = null,
+            RequestBodyFormat? requestBodyFormat = null,
+            HttpMethodParameterPosition? parameterPosition = null,
+            ArrayParametersSerialization? arraySerialization = null,
+            bool? preventCaching = null)
         {
 
-            if (!_definitions.TryGetValue(method + path, out var def))
+            if (!_definitions.TryGetValue(identifier, out var def))
             {
                 def = new RequestDefinition(path, method)
                 {
@@ -73,7 +102,7 @@ namespace CryptoExchange.Net.Objects
                     ParameterPosition = parameterPosition,
                     PreventCaching = preventCaching ?? false
                 };
-                _definitions.TryAdd(method + path, def);
+                _definitions.TryAdd(identifier, def);
             }
 
             return def;

CryptoExchange.Net/Objects/TimeSyncState.cs

@@ -82,12 +82,12 @@ namespace CryptoExchange.Net.Objects
             TimeSyncState.LastSyncTime = DateTime.UtcNow;
             if (offset.TotalMilliseconds > 0 && offset.TotalMilliseconds < 500)
             {
-                Logger.Log(LogLevel.Information, $"{TimeSyncState.ApiName} Time offset within limits, set offset to 0ms");
+                Logger.Log(LogLevel.Information, "{TimeSyncState.ApiName} Time offset within limits, set offset to 0ms", TimeSyncState.ApiName);
                 TimeSyncState.TimeOffset = TimeSpan.Zero;
             }
             else
             {
-                Logger.Log(LogLevel.Information, $"{TimeSyncState.ApiName} Time offset set to {Math.Round(offset.TotalMilliseconds)}ms");
+                Logger.Log(LogLevel.Information, "{TimeSyncState.ApiName} Time offset set to {Offset}ms", TimeSyncState.ApiName, Math.Round(offset.TotalMilliseconds));
                 TimeSyncState.TimeOffset = offset;
             }
         }

CryptoExchange.Net/OrderBook/SymbolOrderBook.cs

@@ -843,9 +843,9 @@ namespace CryptoExchange.Net.OrderBook
 
     internal class DescComparer<T> : IComparer<T>
     {
-        public int Compare(T x, T y)
+        public int Compare(T? x, T? y)
         {
-            return Comparer<T>.Default.Compare(y, x);
+            return Comparer<T>.Default.Compare(y!, x!);
         }
     }
 }

CryptoExchange.Net/RateLimiting/Guards/RateLimitGuard.cs

@@ -20,7 +20,7 @@ namespace CryptoExchange.Net.RateLimiting.Guards
         /// <summary>
         /// Apply guard per connection
         /// </summary>
-        public static Func<RequestDefinition, string, string?, string> PerConnection { get; } = new Func<RequestDefinition, string, string?, string>((def, host, key) => def.ConnectionId.ToString());
+        public static Func<RequestDefinition, string, string?, string> PerConnection { get; } = new Func<RequestDefinition, string, string?, string>((def, host, key) => def.ConnectionId.ToString()!);
         /// <summary>
         /// Apply guard per API key
         /// </summary>

CryptoExchange.Net/RateLimiting/Interfaces/IRateLimitGate.cs

@@ -68,8 +68,9 @@ namespace CryptoExchange.Net.RateLimiting.Interfaces
         /// <param name="baseAddress">The host address</param>
         /// <param name="apiKey">The API key</param>
         /// <param name="behaviour">Behaviour when rate limit is hit</param>
+        /// <param name="requestWeight">The weight to apply to the limit guard</param>
         /// <param name="ct">Cancelation token</param>
         /// <returns>Error if RateLimitingBehaviour is Fail and rate limit is hit</returns>
-        Task<CallResult> ProcessSingleAsync(ILogger logger, int itemId, IRateLimitGuard guard, RateLimitItemType type, RequestDefinition definition, string baseAddress, string? apiKey, RateLimitingBehaviour behaviour, CancellationToken ct);
+        Task<CallResult> ProcessSingleAsync(ILogger logger, int itemId, IRateLimitGuard guard, RateLimitItemType type, RequestDefinition definition, string baseAddress, string? apiKey, int requestWeight, RateLimitingBehaviour behaviour, CancellationToken ct);
     }
 }

CryptoExchange.Net/RateLimiting/RateLimitGate.cs

@@ -69,6 +69,7 @@ namespace CryptoExchange.Net.RateLimiting
             RequestDefinition definition, 
             string host,
             string? apiKey,
+             int requestWeight,
             RateLimitingBehaviour rateLimitingBehaviour,
             CancellationToken ct)
         {
@@ -77,7 +78,7 @@ namespace CryptoExchange.Net.RateLimiting
             _waitingCount++;
             try
             {
-                return await CheckGuardsAsync(new IRateLimitGuard[] { guard }, logger, itemId, type, definition, host, apiKey, 1, rateLimitingBehaviour, ct).ConfigureAwait(false);
+                return await CheckGuardsAsync(new IRateLimitGuard[] { guard }, logger, itemId, type, definition, host, apiKey, requestWeight, rateLimitingBehaviour, ct).ConfigureAwait(false);
             }
             catch (TaskCanceledException)
             {

CryptoExchange.Net/Requests/Request.cs

@@ -48,7 +48,7 @@ namespace CryptoExchange.Net.Requests
         }
 
         /// <inheritdoc />
-        public Uri Uri => _request.RequestUri;
+        public Uri Uri => _request.RequestUri!;
 
         /// <inheritdoc />
         public int RequestId { get; }

CryptoExchange.Net/Requests/RequestFactory.cs

@@ -17,28 +17,7 @@ namespace CryptoExchange.Net.Requests
         public void Configure(ApiProxy? proxy, TimeSpan requestTimeout, HttpClient? client = null)
         {
             if (client == null)
-            {
-                var handler = new HttpClientHandler();
-                try
-                {
-                    handler.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
-                }
-                catch (PlatformNotSupportedException) { }
-
-                if (proxy != null)
-                {
-                    handler.Proxy = new WebProxy
-                    {
-                        Address = new Uri($"{proxy.Host}:{proxy.Port}"),
-                        Credentials = proxy.Password == null ? null : new NetworkCredential(proxy.Login, proxy.Password)
-                    };
-                }
-
-                client = new HttpClient(handler)
-                {
-                    Timeout = requestTimeout
-                };
-            }
+                client = CreateClient(proxy, requestTimeout);
 
             _httpClient = client;
         }
@@ -51,5 +30,37 @@ namespace CryptoExchange.Net.Requests
 
             return new Request(new HttpRequestMessage(method, uri), _httpClient, requestId);
         }
+
+        /// <inheritdoc />
+        public void UpdateSettings(ApiProxy? proxy, TimeSpan requestTimeout)
+        {
+            _httpClient = CreateClient(proxy, requestTimeout);
+        }
+
+        private static HttpClient CreateClient(ApiProxy? proxy, TimeSpan requestTimeout)
+        {
+            var handler = new HttpClientHandler();
+            try
+            {
+                handler.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
+                handler.DefaultProxyCredentials = CredentialCache.DefaultCredentials;
+            }
+            catch (PlatformNotSupportedException) { }
+
+            if (proxy != null)
+            {
+                handler.Proxy = new WebProxy
+                {
+                    Address = new Uri($"{proxy.Host}:{proxy.Port}"),
+                    Credentials = proxy.Password == null ? null : new NetworkCredential(proxy.Login, proxy.Password)
+                };
+            }
+
+            var client = new HttpClient(handler)
+            {
+                Timeout = requestTimeout
+            };
+            return client;
+        }
     }
 }

CryptoExchange.Net/SharedApis/Models/Options/Endpoints/EndpointOptions.cs

@@ -60,8 +60,8 @@ namespace CryptoExchange.Net.SharedApis
                 }
                 else
                 {
-                    if (param.Names.All(x => ExchangeParameters.HasValue(exchangeParameters, exchange, x, param.ValueType) != true))
-                        return new ArgumentError($"One of exchange parameters `{string.Join(", ", param.Names)}` for exchange `{exchange}` should be provided. Example: {param.ExampleValue}");
+                    if (param.Names!.All(x => ExchangeParameters.HasValue(exchangeParameters, exchange, x, param.ValueType) != true))
+                        return new ArgumentError($"One of exchange parameters `{string.Join(", ", param.Names!)}` for exchange `{exchange}` should be provided. Example: {param.ExampleValue}");
                 }
             }
 
@@ -113,13 +113,13 @@ namespace CryptoExchange.Net.SharedApis
             {
                 if (!string.IsNullOrEmpty(param.Name))
                 {
-                    if (typeof(T).GetProperty(param.Name).GetValue(request, null) == null)
+                    if (typeof(T).GetProperty(param.Name)!.GetValue(request, null) == null)
                         return new ArgumentError($"Required optional parameter `{param.Name}` for exchange `{exchange}` is missing. Example: {param.ExampleValue}");
                 }
                 else
                 {
-                    if (param.Names.All(x => typeof(T).GetProperty(param.Name).GetValue(request, null) == null))
-                        return new ArgumentError($"One of optional parameters `{string.Join(", ", param.Names)}` for exchange `{exchange}` should be provided. Example: {param.ExampleValue}");
+                    if (param.Names!.All(x => typeof(T).GetProperty(param.Name!)!.GetValue(request, null) == null))
+                        return new ArgumentError($"One of optional parameters `{string.Join(", ", param.Names!)}` for exchange `{exchange}` should be provided. Example: {param.ExampleValue}");
                 }
 
             }

CryptoExchange.Net/SharedApis/Models/Options/Endpoints/GetOrderBookOptions.cs

@@ -64,7 +64,7 @@ namespace CryptoExchange.Net.SharedApis
         public override string ToString(string exchange)
         {
             var sb = new StringBuilder(base.ToString(exchange));
-            sb.AppendLine($"Supported limit values: [{(SupportedLimits == null ? string.Join(", ", SupportedLimits) : $"{MinLimit}..{MaxLimit}")}]");
+            sb.AppendLine($"Supported limit values: [{(SupportedLimits != null ? string.Join(", ", SupportedLimits) : $"{MinLimit}..{MaxLimit}")}]");
             return sb.ToString();
         }
     }

CryptoExchange.Net/SharedApis/Models/Options/ParameterDescription.cs

@@ -55,7 +55,7 @@ namespace CryptoExchange.Net.SharedApis
         {
             if (Name != null)
                 return $"[{ValueType.Name}] {Name}: {Description} | example: {ExampleValue}";
-            return $"[{ValueType.Name}] {string.Join(" / ", Names)}: {Description} | example: {ExampleValue}";
+            return $"[{ValueType.Name}] {string.Join(" / ", Names!)}: {Description} | example: {ExampleValue}";
         }
     }
 }

CryptoExchange.Net/SharedApis/ResponseModels/SharedSpotSymbol.cs

@@ -46,6 +46,10 @@
         /// </summary>
         public int? PriceDecimals { get; set; }
         /// <summary>
+        /// The max amount of significant figures to use for price. For example with value of 5 these values are valid: 0.00001, 0.12300, 123.53, 12345, but this is not: 12345.1
+        /// </summary>
+        public int? PriceSignificantFigures { get; set; }
+        /// <summary>
         /// Whether the symbol is currently available for trading
         /// </summary>
         public bool Trading { get; set; }

CryptoExchange.Net/Sockets/CryptoExchangeWebSocketClient.cs

@@ -155,6 +155,12 @@ namespace CryptoExchange.Net.Sockets
             _baseAddress = $"{Uri.Scheme}://{Uri.Host}";
         }
 
+        /// <inheritdoc />
+        public void UpdateProxy(ApiProxy? proxy)
+        {
+            Parameters.Proxy = proxy;
+        }
+
         /// <inheritdoc />
         public virtual async Task<CallResult> ConnectAsync()
         {
@@ -189,9 +195,12 @@ namespace CryptoExchange.Net.Sockets
                     socket.Options.SetBuffer(_receiveBufferSize, _sendBufferSize);
                 if (Parameters.Proxy != null)
                     SetProxy(socket, Parameters.Proxy);
-                #if NET6_0_OR_GREATER
+#if NET6_0_OR_GREATER
                 socket.Options.CollectHttpResponseDetails = true;
-                #endif
+#endif
+#if NET9_0_OR_GREATER
+                socket.Options.KeepAliveTimeout = TimeSpan.FromSeconds(10);
+#endif
             }
             catch (PlatformNotSupportedException)
             {
@@ -229,13 +238,13 @@ namespace CryptoExchange.Net.Sockets
 
                 if (e is WebSocketException we)
                 {
-                    #if (NET6_0_OR_GREATER)
+#if (NET6_0_OR_GREATER)
                     if (_socket.HttpStatusCode == HttpStatusCode.TooManyRequests)
                     {
                         await (OnConnectRateLimited?.Invoke() ?? Task.CompletedTask).ConfigureAwait(false);
                         return new CallResult(new ServerRateLimitError(we.Message));
                     }
-                    #else
+#else
                     // ClientWebSocket.HttpStatusCode is only available in .NET6+ https://learn.microsoft.com/en-us/dotnet/api/system.net.websockets.clientwebsocket.httpstatuscode?view=net-8.0
                     // Try to read 429 from the message instead
                     if (we.Message.Contains("429"))
@@ -243,7 +252,7 @@ namespace CryptoExchange.Net.Sockets
                         await (OnConnectRateLimited?.Invoke() ?? Task.CompletedTask).ConfigureAwait(false);
                         return new CallResult(new ServerRateLimitError(we.Message));
                     }
-                    #endif
+#endif
                 }
 
                 return new CallResult(new CantConnectError());
@@ -435,8 +444,8 @@ namespace CryptoExchange.Net.Sockets
                     {
                         // Wait until we receive close confirmation
                         await Task.Delay(10).ConfigureAwait(false);
-                        if (DateTime.UtcNow - startWait > TimeSpan.FromSeconds(5))
-                            break; // Wait for max 5 seconds, then just abort the connection
+                        if (DateTime.UtcNow - startWait > TimeSpan.FromSeconds(1))
+                            break; // Wait for max 1 second, then just abort the connection
                     }
                 }
             }
@@ -578,15 +587,27 @@ namespace CryptoExchange.Net.Sockets
                             lock (_receivedMessagesLock)
                                 _receivedMessages.Add(new ReceiveItem(DateTime.UtcNow, receiveResult.Count));
                         }
-                        catch (OperationCanceledException)
+                        catch (OperationCanceledException ex)
                         {
+                            if (ex.InnerException?.InnerException?.Message.Equals("The WebSocket didn't recieve a Pong frame in response to a Ping frame within the configured KeepAliveTimeout.") == true)
+                            {
+                                // Spefic case that the websocket connection got closed because of a ping frame timeout
+                                // Unfortunately doesn't seem to be a nicer way to catch
+                                _logger.SocketPingTimeout(Id);
+                            }
+
+                            if (_closeTask?.IsCompleted != false)
+                                _closeTask = CloseInternalAsync();
+
                             // canceled
                             break;
                         }
                         catch (Exception wse)
                         {
-                            // Connection closed unexpectedly
-                            await (OnError?.Invoke(wse) ?? Task.CompletedTask).ConfigureAwait(false);
+                            if (!_ctsSource.Token.IsCancellationRequested)
+                                // Connection closed unexpectedly
+                                await (OnError?.Invoke(wse) ?? Task.CompletedTask).ConfigureAwait(false);
+
                             if (_closeTask?.IsCompleted != false)
                                 _closeTask = CloseInternalAsync();
                             break;
@@ -598,14 +619,14 @@ namespace CryptoExchange.Net.Sockets
                             if (_socket.State == WebSocketState.CloseReceived)
                             {
                                 // Close received means it server initiated, we should send a confirmation and close the socket
-                                _logger.SocketReceivedCloseMessage(Id, receiveResult.CloseStatus.ToString(), receiveResult.CloseStatusDescription);
+                                _logger.SocketReceivedCloseMessage(Id, receiveResult.CloseStatus.ToString()!, receiveResult.CloseStatusDescription ?? string.Empty);
                                 if (_closeTask?.IsCompleted != false)
                                     _closeTask = CloseInternalAsync();
                             }
                             else
                             {
                                 // Means the socket is now closed and we were the one initiating it
-                                _logger.SocketReceivedCloseConfirmation(Id, receiveResult.CloseStatus.ToString(), receiveResult.CloseStatusDescription);
+                                _logger.SocketReceivedCloseConfirmation(Id, receiveResult.CloseStatus.ToString()!, receiveResult.CloseStatusDescription ?? string.Empty);
                             }
 
                             break;
@@ -620,7 +641,7 @@ namespace CryptoExchange.Net.Sockets
                             // Write the data to a memory stream to be reassembled later
                             if (multipartStream == null)
                                 multipartStream = new MemoryStream();
-                            multipartStream.Write(buffer.Array, buffer.Offset, receiveResult.Count);
+                            multipartStream.Write(buffer.Array!, buffer.Offset, receiveResult.Count);
                         }
                         else
                         {
@@ -634,7 +655,7 @@ namespace CryptoExchange.Net.Sockets
                             {
                                 // Received the end of a multipart message, write to memory stream for reassembling
                                 _logger.SocketReceivedPartialMessage(Id, receiveResult.Count);
-                                multipartStream!.Write(buffer.Array, buffer.Offset, receiveResult.Count);
+                                multipartStream!.Write(buffer.Array!, buffer.Offset, receiveResult.Count);
                             }
 
                             break;

CryptoExchange.Net/Sockets/PeriodicTaskRegistration.cs

@@ -23,6 +23,6 @@ namespace CryptoExchange.Net.Sockets
         /// <summary>
         /// Callback after query
         /// </summary>
-        public Action<CallResult>? Callback { get; set; }
+        public Action<SocketConnection, CallResult>? Callback { get; set; }
     }
 }

CryptoExchange.Net/Sockets/Query.cs

@@ -23,6 +23,11 @@ namespace CryptoExchange.Net.Sockets
         /// </summary>
         public bool Completed { get; set; }
 
+        /// <summary>
+        /// Timeout for the request
+        /// </summary>
+        public TimeSpan? RequestTimeout { get; set; }
+
         /// <summary>
         /// The number of required responses. Can be more than 1 when for example subscribing multiple symbols streams in a single request,
         /// and each symbol receives it's own confirmation response

CryptoExchange.Net/Sockets/SocketConnection.cs

@@ -11,6 +11,8 @@ using System.Diagnostics;
 using CryptoExchange.Net.Clients;
 using CryptoExchange.Net.Logging.Extensions;
 using System.Threading;
+using CryptoExchange.Net.Objects.Options;
+using CryptoExchange.Net.Authentication;
 
 namespace CryptoExchange.Net.Sockets
 {
@@ -396,7 +398,7 @@ namespace CryptoExchange.Net.Sockets
         /// <returns></returns>
         protected virtual Task HandleRequestRateLimitedAsync(int requestId)
         {
-            Query query;
+            Query? query;
             lock (_listenersLock)
             {
                 query = _listeners.OfType<Query>().FirstOrDefault(x => x.Id == requestId);
@@ -425,7 +427,7 @@ namespace CryptoExchange.Net.Sockets
         /// <param name="requestId">Id of the request sent</param>
         protected virtual Task HandleRequestSentAsync(int requestId)
         {
-            Query query;
+            Query? query;
             lock (_listenersLock)
             {
                 query = _listeners.OfType<Query>().FirstOrDefault(x => x.Id == requestId);
@@ -437,7 +439,7 @@ namespace CryptoExchange.Net.Sockets
                 return Task.CompletedTask;
             }
 
-            query.IsSend(ApiClient.ClientOptions.RequestTimeout);
+            query.IsSend(query.RequestTimeout ?? ApiClient.ClientOptions.RequestTimeout);
             return Task.CompletedTask;
         }
 
@@ -583,6 +585,16 @@ namespace CryptoExchange.Net.Sockets
         /// <returns></returns>
         public async Task TriggerReconnectAsync() => await _socket.ReconnectAsync().ConfigureAwait(false);
 
+        /// <summary>
+        /// Update the proxy setting and reconnect
+        /// </summary>
+        /// <param name="proxy">New proxy setting</param>
+        public async Task UpdateProxy(ApiProxy? proxy)
+        {
+            _socket.UpdateProxy(proxy);
+            await TriggerReconnectAsync().ConfigureAwait(false);
+        }
+
         /// <summary>
         /// Close the connection
         /// </summary>
@@ -988,7 +1000,7 @@ namespace CryptoExchange.Net.Sockets
         /// <param name="interval">How often</param>
         /// <param name="queryDelegate">Method returning the query to send</param>
         /// <param name="callback">The callback for processing the response</param>
-        public virtual void QueryPeriodic(string identifier, TimeSpan interval, Func<SocketConnection, Query> queryDelegate, Action<CallResult>? callback)
+        public virtual void QueryPeriodic(string identifier, TimeSpan interval, Func<SocketConnection, Query> queryDelegate, Action<SocketConnection, CallResult>? callback)
         {
             if (queryDelegate == null)
                 throw new ArgumentNullException(nameof(queryDelegate));
@@ -1020,7 +1032,7 @@ namespace CryptoExchange.Net.Sockets
                     try
                     {
                         var result = await SendAndWaitQueryAsync(query).ConfigureAwait(false);
-                        callback?.Invoke(result);
+                        callback?.Invoke(this, result);
                     }
                     catch (Exception ex)
                     {

CryptoExchange.Net/Testing/Comparers/JsonNetComparer.cs

@@ -378,7 +378,7 @@ namespace CryptoExchange.Net.Testing.Comparers
                 if (objectValue is bool boolVal && jsonValue.Value<bool>() != boolVal)
                     throw new Exception($"{method}: {property} not equal: {jsonValue.Value<bool>()} vs {(bool)objectValue}");
 
-                if (jsonValue.Value<bool>() != bool.Parse(objectValue.ToString()))
+                if (jsonValue.Value<bool>() != bool.Parse(objectValue.ToString()!))
                     throw new Exception($"{method}: {property} not equal: {jsonValue.Value<bool>()} vs {(bool)objectValue}");
             }
         }

CryptoExchange.Net/Testing/Comparers/SystemTextJsonComparer.cs

@@ -211,7 +211,7 @@ namespace CryptoExchange.Net.Testing.Comparers
 
                     if (dictProp.Value.Type == JTokenType.Object)
                     {
-                        CheckPropertyValue(method, dictProp.Value, dict[dictProp.Name]!, dict[dictProp.Name].GetType(), null, null, ignoreProperties);
+                        CheckPropertyValue(method, dictProp.Value, dict[dictProp.Name]!, dict[dictProp.Name]!.GetType(), null, null, ignoreProperties);
                     }
                     else
                     {

CryptoExchange.Net/Testing/EnumValueTraceListener.cs

@@ -5,8 +5,11 @@ namespace CryptoExchange.Net.Testing
 {
     internal class EnumValueTraceListener : TraceListener
     {
-        public override void Write(string message)
+        public override void Write(string? message)
         {
+            if (message == null)
+                return;
+
             if (message.Contains("Cannot map"))
                 throw new Exception("Enum value error: " + message);
 
@@ -14,8 +17,11 @@ namespace CryptoExchange.Net.Testing
                 throw new Exception("Enum null error: " + message);
         }
 
-        public override void WriteLine(string message)
+        public override void WriteLine(string? message)
         {
+            if (message == null)
+                return;
+
             if (message.Contains("Cannot map"))
                 throw new Exception("Enum value error: " + message);
 

CryptoExchange.Net/Testing/Implementations/TestRequestFactory.cs

@@ -25,5 +25,7 @@ namespace CryptoExchange.Net.Testing.Implementations
             _request.RequestId = requestId;
             return _request;
         }
+
+        public void UpdateSettings(ApiProxy? proxy, TimeSpan requestTimeout) {}
     }
 }

CryptoExchange.Net/Testing/Implementations/TestSocket.cs

@@ -92,5 +92,7 @@ namespace CryptoExchange.Net.Testing.Implementations
 
         public Task ReconnectAsync() => throw new NotImplementedException();
         public void Dispose() { }
+
+        public void UpdateProxy(ApiProxy? proxy) => throw new NotImplementedException();
     }
 }

CryptoExchange.Net/Testing/TestHelpers.cs

@@ -150,9 +150,9 @@ namespace CryptoExchange.Net.Testing
         /// </summary>
         /// <typeparam name="TClient"></typeparam>
         /// <exception cref="Exception"></exception>
-        public static void CheckForMissingRestInterfaces<TClient>()
+        public static void CheckForMissingRestInterfaces<TClient>(string[]? excludeInterfaces = null)
         {
-            CheckForMissingInterfaces(typeof(TClient), typeof(Task));
+            CheckForMissingInterfaces(typeof(TClient), typeof(Task), excludeInterfaces);
         }
 
         /// <summary>
@@ -160,28 +160,32 @@ namespace CryptoExchange.Net.Testing
         /// </summary>
         /// <typeparam name="TClient"></typeparam>
         /// <exception cref="Exception"></exception>
-        public static void CheckForMissingSocketInterfaces<TClient>()
+        public static void CheckForMissingSocketInterfaces<TClient>(string[]? excludeInterfaces = null)
         {
-            CheckForMissingInterfaces(typeof(TClient), typeof(Task<CallResult<UpdateSubscription>>));
+            CheckForMissingInterfaces(typeof(TClient), typeof(Task<CallResult<UpdateSubscription>>), excludeInterfaces);
         }
 
-        private static void CheckForMissingInterfaces(Type clientType, Type implementationTypes)
+        private static void CheckForMissingInterfaces(Type clientType, Type implementationTypes, string[]? excludeInterfaces = null)
         {
             var assembly = Assembly.GetAssembly(clientType);
             var interfaceType = clientType.GetInterface("I" + clientType.Name);
-            var clientInterfaces = assembly.GetTypes().Where(t => t.Name.StartsWith("I" + clientType.Name) && !t.Name.EndsWith("Shared"));
+            var clientInterfaces = assembly!.GetTypes()
+                .Where(t => t.Name.StartsWith("I" + clientType.Name)
+                        && !t.Name.EndsWith("Shared")
+                        && (excludeInterfaces?.Contains(t.Name) != true));
 
             foreach (var clientInterface in clientInterfaces)
             {
-                var implementations = assembly.GetTypes().Where(t => clientInterface.IsAssignableFrom(t) && t != clientInterface);
+                var implementations = assembly.GetTypes().Where(t => clientInterface.IsAssignableFrom(t) && !t.IsInterface && t != clientInterface);
                 foreach (var implementation in implementations)
                 {
                     int methods = 0;
                     foreach (var method in implementation.GetMethods().Where(m => implementationTypes.IsAssignableFrom(m.ReturnType)))
                     {
-                        var interfaceMethod = clientInterface.GetMethod(method.Name, method.GetParameters().Select(p => p.ParameterType).ToArray());
-                        if (interfaceMethod == null)
-                            throw new Exception($"Missing interface for method {method.Name} in {implementation.Name} implementing interface {clientInterface.Name}");
+                        var interfaceMethod = 
+                            clientInterface.GetMethod(method.Name, method.GetParameters().Select(p => p.ParameterType).ToArray())
+                            ?? clientInterface.GetInterfaces().Select(x => x.GetMethod(method.Name, method.GetParameters().Select(p => p.ParameterType).ToArray())).FirstOrDefault()
+                            ?? throw new Exception($"Missing interface for method {method.Name} in {implementation.Name} implementing interface {clientInterface.Name}");
                         methods++;
                     }
 

CryptoExchange.Net/Trackers/Trades/TradeTracker.cs

@@ -350,7 +350,8 @@ namespace CryptoExchange.Net.Trackers.Trades
                     _data.Add(item);
                 }
 
-                _firstTimestamp = _data.Min(v => v.Timestamp);
+                if (_data.Any())
+                    _firstTimestamp = _data.Min(v => v.Timestamp);
 
                 ApplyWindow(false);
             }

README.md

@@ -66,6 +66,33 @@ Make a one time donation in a crypto currency of your choice. If you prefer to d
 Alternatively, sponsor me on Github using [Github Sponsors](https://github.com/sponsors/JKorf). 
 
 ## Release notes
+* Version 8.7.0 - 21 Jan 2025
+    * Added GetMillisecondTimestampLong helper method to AuthenticationProvider
+    * Added PriceSignificationFigures to SharedSpotSymbol model
+
+* Version 8.6.1 - 09 Jan 2025
+    * Fixed websocket connection getting stuck after a ping frame timeout
+    * Removed websocket Error callback when exception is expected
+    * Removed unnecessary type restraints on RestApiClient.SendAsync methods
+
+* Version 8.6.0 - 07 Jan 2025
+    * Added support for passing weight to apply to an individual ratelimit guard
+    * Added IFeeRestClient to service registration
+    * Added response headers parameter to RestApiClient.TryParseError method
+    * Added check for ServerRateLimitError on RestApiClient.TryParseError response
+    * Added ExchangeType Enum
+    * Some small improvements
+
+* Version 8.5.0 - 23 Dec 2024
+    * Added SetOptions method to update client settings
+    * Added SocketConnection parameter to PeriodicQuery callback
+    * Added setting of DefaultProxyCredentials on HttpClient instance when client is not provided by DI
+    * Added support for overriding request timeout per request
+    * Added build target for net9.0
+    * Added setting of KeepAliveTimeout on websocket connections to improve dropped connection detection
+    * Changed max wait time for close handshake response from 5 seconds to 1 second
+    * Fixed exception in trade tracker when there is no data in the initial snapshot
+
 * Version 8.4.5 - 20 Dec 2024
     * Added EmptyArrayObjectConverter System.Text.Json JsonConverter
     * Added JsonSerializerOptions parameter to SystemTextJsonMessageAccessor constructor