Add SystemTextJsonMatchers (#1447)

* SystemTextJsonMatcher * , * . * new projectx * Update test/WireMock.Net.Tests/Pact/PactTests.cs Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update test/WireMock.Net.Tests/WebSockets/WebSocketIntegrationTests.cs Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update src/WireMock.Net/WireMock.Net.csproj Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update src/WireMock.Net.Minimal/Properties/AssemblyInfo.cs Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * . * more tests * . * . * x * ... * . * fix tests * 0.11.0 * . * delete jsonutils.cs * s * fix findings * Apply suggestions from code review Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com> * Potential fix for pull request finding 'Missing Dispose call on local IDisposable' Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com> * JsonConverter 0.12.0 * -- tools --------- Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com>
2026-05-30 10:30:45 +02:00 · 2026-05-29 20:19:51 +02:00
parent fed1c87663
commit 36b0a93a6c
68 changed files with 4202 additions and 976 deletions
@@ -31,19 +31,19 @@ public partial class WireMockAssertions
    }

    [CustomAssertion]
-    public AndConstraint<WireMockAssertions> WithBodyAsJson(object body, string because = "", params object[] becauseArgs)
+    public AndConstraint<WireMockAssertions> WithBodyAsJson(object body, IJsonMatcher? jsonMatcher = null, string because = "", params object[] becauseArgs)
    {
-        return WithBodyAsJson(new JsonMatcher(body), because, becauseArgs);
+        return WithBodyAsJson(jsonMatcher ?? new JsonMatcher(body), because, becauseArgs);
    }

    [CustomAssertion]
-    public AndConstraint<WireMockAssertions> WithBodyAsJson(string body, string because = "", params object[] becauseArgs)
+    public AndConstraint<WireMockAssertions> WithBodyAsJson(string body, IJsonMatcher? jsonMatcher = null, string because = "", params object[] becauseArgs)
    {
-        return WithBodyAsJson(new JsonMatcher(body), because, becauseArgs);
+        return WithBodyAsJson(jsonMatcher ?? new JsonMatcher(body), because, becauseArgs);
    }

    [CustomAssertion]
-    public AndConstraint<WireMockAssertions> WithBodyAsJson(IObjectMatcher matcher, string because = "", params object[] becauseArgs)
+    public AndConstraint<WireMockAssertions> WithBodyAsJson(IJsonMatcher matcher, string because = "", params object[] becauseArgs)
    {
        var (filter, condition) = BuildFilterAndCondition(r => r.BodyAsJson, matcher);

@@ -126,15 +126,44 @@ public partial class WireMockAssertions

    private static string? FormatBody(object? body)
    {
-        return body switch
+        if (body == null)
        {
-            null => null,
-            string str => str,
-            AnyOf<string, StringPattern>[] stringPatterns => FormatBodies(stringPatterns.Select(p => p.GetPattern())),
-            byte[] bytes => $"byte[{bytes.Length}] {{...}}",
-            JToken jToken => jToken.ToString(Formatting.None),
-            _ => JToken.FromObject(body).ToString(Formatting.None)
-        };
+            return null;
+        }
+
+        if (body is string str)
+        {
+            return str;
+        }
+
+        if (body is AnyOf<string, StringPattern>[] stringPatterns)
+        {
+            return FormatBodies(stringPatterns.Select(p => p.GetPattern()));
+        }
+
+        if (body is byte[] bytes)
+        {
+            return $"byte[{bytes.Length}] {{...}}";
+        }
+
+        if (body is JToken jToken)
+        {
+            return jToken.ToString(Formatting.None);
+        }
+
+        // System.IO.FileNotFoundException : Could not load file or assembly 'System.Text.Json, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
+        var typeName = body.GetType().FullName;
+        if (typeName == "System.Text.Json.JsonElement")
+        {
+            return ((dynamic)body).GetRawText();
+        }
+
+        if (typeName == "System.Text.Json.JsonDocument")
+        {
+            return ((dynamic)body).RootElement.GetRawText();
+        }
+
+        return JToken.FromObject(body).ToString(Formatting.None);
    }

    private static string? FormatBodies(IEnumerable<object?> bodies)
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <Description>WireMock.Net.Routing extends WireMock.Net with modern, minimal-API-style routing for .NET</Description>
        <Authors>Gennadii Saltyshchak</Authors>
@@ -25,7 +25,7 @@
    </PropertyGroup>

    <ItemGroup>
-      <PackageReference Include="JsonConverter.Abstractions" Version="0.9.0" />
+      <PackageReference Include="JsonConverter.Abstractions" Version="0.12.0" />
    </ItemGroup>

    <ItemGroup>
@@ -31,19 +31,19 @@ public partial class WireMockAssertions
    }

    [CustomAssertion]
-    public AndConstraint<WireMockAssertions> WithBodyAsJson(object body, string because = "", params object[] becauseArgs)
+    public AndConstraint<WireMockAssertions> WithBodyAsJson(object body, IJsonMatcher? jsonMatcher = null, string because = "", params object[] becauseArgs)
    {
-        return WithBodyAsJson(new JsonMatcher(body), because, becauseArgs);
+        return WithBodyAsJson(jsonMatcher ?? new JsonMatcher(body), because, becauseArgs);
    }

    [CustomAssertion]
-    public AndConstraint<WireMockAssertions> WithBodyAsJson(string body, string because = "", params object[] becauseArgs)
+    public AndConstraint<WireMockAssertions> WithBodyAsJson(string body, IJsonMatcher? jsonMatcher = null, string because = "", params object[] becauseArgs)
    {
-        return WithBodyAsJson(new JsonMatcher(body), because, becauseArgs);
+        return WithBodyAsJson(jsonMatcher ?? new JsonMatcher(body), because, becauseArgs);
    }

    [CustomAssertion]
-    public AndConstraint<WireMockAssertions> WithBodyAsJson(IObjectMatcher matcher, string because = "", params object[] becauseArgs)
+    public AndConstraint<WireMockAssertions> WithBodyAsJson(IJsonMatcher matcher, string because = "", params object[] becauseArgs)
    {
        var (filter, condition) = BuildFilterAndCondition(r => r.BodyAsJson, matcher);

@@ -126,15 +126,44 @@ public partial class WireMockAssertions

    private static string? FormatBody(object? body)
    {
-        return body switch
+        if (body == null)
        {
-            null => null,
-            string str => str,
-            AnyOf<string, StringPattern>[] stringPatterns => FormatBodies(stringPatterns.Select(p => p.GetPattern())),
-            byte[] bytes => $"byte[{bytes.Length}] {{...}}",
-            JToken jToken => jToken.ToString(Formatting.None),
-            _ => JToken.FromObject(body).ToString(Formatting.None)
-        };
+            return null;
+        }
+
+        if (body is string str)
+        {
+            return str;
+        }
+
+        if (body is AnyOf<string, StringPattern>[] stringPatterns)
+        {
+            return FormatBodies(stringPatterns.Select(p => p.GetPattern()));
+        }
+
+        if (body is byte[] bytes)
+        {
+            return $"byte[{bytes.Length}] {{...}}";
+        }
+
+        if (body is JToken jToken)
+        {
+            return jToken.ToString(Formatting.None);
+        }
+
+        // System.IO.FileNotFoundException : Could not load file or assembly 'System.Text.Json, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
+        var typeName = body.GetType().FullName;
+        if (typeName == "System.Text.Json.JsonElement")
+        {
+            return ((dynamic)body).GetRawText();
+        }
+
+        if (typeName == "System.Text.Json.JsonDocument")
+        {
+            return ((dynamic)body).RootElement.GetRawText();
+        }
+
+        return JToken.FromObject(body).ToString(Formatting.None);
    }

    private static string? FormatBodies(IEnumerable<object?> bodies)
@@ -0,0 +1,184 @@
+// Copyright © WireMock.Net
+
+using System.Text.Json;
+using System.Text.Json.Nodes;
+using AnyOfTypes;
+using Json.Path;
+using Stef.Validation;
+using WireMock.Extensions;
+using WireMock.Models;
+using WireMock.Util;
+
+namespace WireMock.Matchers;
+
+/// <summary>
+/// SystemTextJsonPathMatcher - behaves the same as JsonPathMatcher but uses System.Text.Json and Json.Path instead of Newtonsoft.Json.
+/// </summary>
+/// <seealso cref="ISystemTextJsonPathMatcher" />
+public class SystemTextJsonPathMatcher : ISystemTextJsonPathMatcher
+{
+    private readonly AnyOf<string, StringPattern>[] _patterns;
+
+    /// <inheritdoc />
+    public MatchBehaviour MatchBehaviour { get; }
+
+    /// <inheritdoc />
+    public object Value { get; }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SystemTextJsonPathMatcher"/> class.
+    /// </summary>
+    /// <param name="patterns">The patterns.</param>
+    public SystemTextJsonPathMatcher(params string[] patterns)
+        : this(MatchBehaviour.AcceptOnMatch, MatchOperator.Or, patterns.ToAnyOfPatterns())
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SystemTextJsonPathMatcher"/> class.
+    /// </summary>
+    /// <param name="patterns">The patterns.</param>
+    public SystemTextJsonPathMatcher(params AnyOf<string, StringPattern>[] patterns)
+        : this(MatchBehaviour.AcceptOnMatch, MatchOperator.Or, patterns)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SystemTextJsonPathMatcher"/> class.
+    /// </summary>
+    /// <param name="matchBehaviour">The match behaviour.</param>
+    /// <param name="matchOperator">The <see cref="Matchers.MatchOperator"/> to use. (default = "Or")</param>
+    /// <param name="patterns">The patterns.</param>
+    public SystemTextJsonPathMatcher(
+        MatchBehaviour matchBehaviour,
+        MatchOperator matchOperator = MatchOperator.Or,
+        params AnyOf<string, StringPattern>[] patterns)
+    {
+        _patterns = Guard.NotNull(patterns);
+        MatchBehaviour = matchBehaviour;
+        MatchOperator = matchOperator;
+        Value = patterns;
+    }
+
+    /// <inheritdoc />
+    public MatchResult IsMatch(string? input)
+    {
+        var score = MatchScores.Mismatch;
+        Exception? exception = null;
+
+        if (!string.IsNullOrWhiteSpace(input))
+        {
+            try
+            {
+                var node = JsonNode.Parse(input!);
+                score = IsMatchInternal(node);
+            }
+            catch (Exception ex)
+            {
+                exception = ex;
+            }
+        }
+
+        return MatchResult.From(Name, MatchBehaviourHelper.Convert(MatchBehaviour, score), exception);
+    }
+
+    /// <inheritdoc />
+    public MatchResult IsMatch(object? input)
+    {
+        var score = MatchScores.Mismatch;
+        Exception? exception = null;
+
+        // When input is null or byte[], return Mismatch.
+        if (input != null && input is not byte[])
+        {
+            try
+            {
+                JsonNode? node = input switch
+                {
+                    JsonNode jsonNode => jsonNode,
+                    string str => JsonNode.Parse(str),
+                    _ => JsonNode.Parse(JsonSerializer.Serialize(input))
+                };
+
+                score = IsMatchInternal(node);
+            }
+            catch (Exception ex)
+            {
+                exception = ex;
+            }
+        }
+
+        return MatchResult.From(Name, MatchBehaviourHelper.Convert(MatchBehaviour, score), exception);
+    }
+
+    /// <inheritdoc />
+    public AnyOf<string, StringPattern>[] GetPatterns()
+    {
+        return _patterns;
+    }
+
+    /// <inheritdoc />
+    public MatchOperator MatchOperator { get; }
+
+    /// <inheritdoc />
+    public string Name => nameof(SystemTextJsonPathMatcher);
+
+    /// <inheritdoc />
+    public string GetCSharpCodeArguments()
+    {
+        return $"new {Name}" +
+               $"(" +
+               $"{MatchBehaviour.GetFullyQualifiedEnumValue()}, " +
+               $"{MatchOperator.GetFullyQualifiedEnumValue()}, " +
+               $"{MappingConverterUtils.ToCSharpCodeArguments(_patterns)}" +
+               $")";
+    }
+
+    private double IsMatchInternal(JsonNode? node)
+    {
+        // JsonPath.Net requires the node to be inside an object or array for filter expressions.
+        // Similar to JsonPathMatcher's ConvertJTokenToJArrayIfNeeded, wrap a plain object in an array
+        // when it's an object with a single non-array child property.
+        var evaluationNode = WrapIfNeeded(node);
+
+        var values = _patterns
+            .Select(pattern =>
+            {
+                var path = JsonPath.Parse(pattern.GetPattern());
+                var result = path.Evaluate(evaluationNode);
+                return result.Matches is { Count: > 0 };
+            })
+            .ToArray();
+
+        return MatchScores.ToScore(values, MatchOperator);
+    }
+
+    // Mirrors JsonPathMatcher.ConvertJTokenToJArrayIfNeeded:
+    // If the node is an object with exactly one property whose value is not already an array,
+    // wrap that value in an array so that filter expressions (e.g. [?(@.x == y)]) can match.
+    private static JsonNode? WrapIfNeeded(JsonNode? node)
+    {
+        if (node is not JsonObject obj)
+        {
+            return node;
+        }
+
+        var properties = obj.ToList();
+        if (properties.Count != 1)
+        {
+            return node;
+        }
+
+        var single = properties[0];
+        if (single.Value is JsonArray)
+        {
+            return node;
+        }
+
+        var clonedValue = JsonNode.Parse(single.Value?.ToJsonString() ?? "null");
+        return new JsonObject
+        {
+            [single.Key] = new JsonArray(clonedValue)
+        };
+    }
+}
@@ -0,0 +1,5 @@
+// Copyright © WireMock.Net
+
+using System.Runtime.CompilerServices;
+
+[assembly: InternalsVisibleTo("WireMock.Net.Tests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100e138ec44d93acac565953052636eb8d5e7e9f27ddb030590055cd1a0ab2069a5623f1f77ca907d78e0b37066ca0f6d63da7eecc3fcb65b76aa8ebeccf7ebe1d11264b8404cd9b1cbbf2c83f566e033b3e54129f6ef28daffff776ba7aebbc53c0d635ebad8f45f78eb3f7e0459023c218f003416e080f96a1a3c5ffeb56bee9e")]
@@ -0,0 +1,41 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <Description>A SystemTextJsonPathMatcher which can be used to match WireMock.Net Requests using JsonPath.Net.</Description>
+        <AssemblyTitle>WireMock.Net.Matchers.SystemTextJsonPath</AssemblyTitle>
+        <Authors>Stef Heyenrath</Authors>
+        <TargetFrameworks>netstandard2.0;net8.0</TargetFrameworks>
+        <GenerateDocumentationFile>true</GenerateDocumentationFile>
+        <PackageTags>wiremock;matchers;matcher;jsonpath;systemtextjson</PackageTags>
+        <RootNamespace>WireMock</RootNamespace>
+        <PackageId>WireMock.Net.Matchers.SystemTextJsonPath</PackageId>
+        <ProjectGuid>{A1B2C3D4-E5F6-7890-ABCD-EF1234567890}</ProjectGuid>
+        <PublishRepositoryUrl>true</PublishRepositoryUrl>
+        <AllowedOutputExtensionsInPackageBuildOutputFolder>$(AllowedOutputExtensionsInPackageBuildOutputFolder);.pdb</AllowedOutputExtensionsInPackageBuildOutputFolder>
+        <EmbedUntrackedSources>true</EmbedUntrackedSources>
+        <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+        <GenerateBindingRedirectsOutputType>true</GenerateBindingRedirectsOutputType>
+        <SignAssembly>true</SignAssembly>
+        <AssemblyOriginatorKeyFile>../WireMock.Net/WireMock.Net.snk</AssemblyOriginatorKeyFile>
+        <!--<DelaySign>true</DelaySign>-->
+        <PublicSign Condition=" '$(OS)' != 'Windows_NT' ">true</PublicSign>
+        <PackageLicenseExpression>MIT</PackageLicenseExpression>
+    </PropertyGroup>
+
+    <PropertyGroup Condition="'$(Configuration)' == 'Debug - Sonar'">
+        <CodeAnalysisRuleSet>../WireMock.Net/WireMock.Net.ruleset</CodeAnalysisRuleSet>
+    </PropertyGroup>
+
+    <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
+        <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\WireMock.Net.Shared\WireMock.Net.Shared.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+        <PackageReference Include="JsonPath.Net" Version="3.0.2" />
+    </ItemGroup>
+
+</Project>
@@ -1,7 +1,8 @@
 // Copyright © WireMock.Net

-using System;
-using System.Collections.Generic;
+using JsonConverter.Abstractions;
+using JsonConverter.Newtonsoft.Json;
+using Newtonsoft.Json;
 using WireMock.Matchers.Helpers;
 using WireMock.Models.Mime;
 using WireMock.Util;
@@ -15,6 +16,8 @@ public class MimePartMatcher : IMimePartMatcher
 {
    private readonly IList<(string Name, Func<IMimePartData, MatchResult> func)> _matcherFunctions;

+    private readonly IJsonConverter _jsonConverter;
+
    /// <inheritdoc />
    public string Name => nameof(MimePartMatcher);

@@ -41,7 +44,8 @@ public class MimePartMatcher : IMimePartMatcher
        IStringMatcher? contentTypeMatcher,
        IStringMatcher? contentDispositionMatcher,
        IStringMatcher? contentTransferEncodingMatcher,
-        IMatcher? contentMatcher
+        IMatcher? contentMatcher,
+        IJsonConverter? jsonConverter = null
    )
    {
        MatchBehaviour = matchBehaviour;
@@ -49,6 +53,7 @@ public class MimePartMatcher : IMimePartMatcher
        ContentDispositionMatcher = contentDispositionMatcher;
        ContentTransferEncodingMatcher = contentTransferEncodingMatcher;
        ContentMatcher = contentMatcher;
+        _jsonConverter = jsonConverter ?? new NewtonsoftJsonConverter();

        _matcherFunctions = [];
        if (ContentTypeMatcher != null)
@@ -107,7 +112,8 @@ public class MimePartMatcher : IMimePartMatcher
            ContentType = GetContentTypeAsString(mimePart.ContentType),
            DeserializeJson = true,
            ContentEncoding = null, // mimePart.ContentType?.CharsetEncoding.ToString(),
-            DecompressGZipAndDeflate = true
+            DecompressGZipAndDeflate = true,
+            DefaultJsonConverter = _jsonConverter
        };

        var bodyData = BodyParser.ParseAsync(bodyParserSettings).ConfigureAwait(false).GetAwaiter().GetResult();
@@ -1,8 +1,7 @@
 // Copyright © WireMock.Net

-using System.Linq;
 using System.Net;
-using System.Net.Http;
+using JsonConverter.Abstractions;
 using WireMock.Util;

 namespace WireMock.Http;
@@ -15,7 +14,8 @@ internal static class HttpResponseMessageHelper
        Uri originalUri,
        bool deserializeJson,
        bool decompressGzipAndDeflate,
-        bool deserializeFormUrlEncoded)
+        bool deserializeFormUrlEncoded,
+        IJsonConverter jsonConverter)
    {
        var responseMessage = new ResponseMessage { StatusCode = (int)httpResponseMessage.StatusCode };

@@ -45,7 +45,8 @@ internal static class HttpResponseMessageHelper
                    DeserializeJson = deserializeJson,
                    ContentEncoding = contentEncodingHeader?.FirstOrDefault(),
                    DecompressGZipAndDeflate = decompressGzipAndDeflate,
-                    DeserializeFormUrlEncoded = deserializeFormUrlEncoded
+                    DeserializeFormUrlEncoded = deserializeFormUrlEncoded,
+                    DefaultJsonConverter = jsonConverter
                };
                responseMessage.BodyData = await BodyParser.ParseAsync(bodyParserSettings).ConfigureAwait(false);
            }
@@ -1,6 +1,5 @@
 // Copyright © WireMock.Net

-using System.Linq;
 using Newtonsoft.Json.Linq;
 using WireMock.Util;

@@ -0,0 +1,173 @@
+// Copyright © WireMock.Net
+
+using System.Text.Json;
+using WireMock.Util;
+
+namespace WireMock.Matchers;
+
+/// <summary>
+/// Generic AbstractSystemTextJsonPartialMatcher - uses System.Text.Json instead of Newtonsoft.Json.
+/// </summary>
+public abstract class AbstractSystemTextJsonPartialMatcher : SystemTextJsonMatcher
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="AbstractSystemTextJsonPartialMatcher"/> class.
+    /// </summary>
+    protected AbstractSystemTextJsonPartialMatcher(string value, bool ignoreCase = false, bool regex = false)
+        : base(value, ignoreCase, regex)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="AbstractSystemTextJsonPartialMatcher"/> class.
+    /// </summary>
+    protected AbstractSystemTextJsonPartialMatcher(object value, bool ignoreCase = false, bool regex = false)
+        : base(value, ignoreCase, regex)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="AbstractSystemTextJsonPartialMatcher"/> class.
+    /// </summary>
+    protected AbstractSystemTextJsonPartialMatcher(MatchBehaviour matchBehaviour, object value, bool ignoreCase = false, bool regex = false)
+        : base(matchBehaviour, value, ignoreCase, regex)
+    {
+    }
+
+    /// <inheritdoc />
+    protected override bool IsMatch(JsonElement value, JsonElement? input)
+    {
+        if (input == null)
+        {
+            return false;
+        }
+
+        var inputElement = input.Value;
+
+        // Regex on a string value
+        if (Regex && value.ValueKind == JsonValueKind.String)
+        {
+            var valueAsString = value.GetString()!;
+            var inputAsString = GetStringValue(inputElement);
+
+            var (valid, result) = RegexUtils.MatchRegex(valueAsString, inputAsString);
+            if (valid)
+            {
+                return result;
+            }
+        }
+
+        // Guid comparison: both strings, both parseable as Guid
+        if (value.ValueKind == JsonValueKind.String && inputElement.ValueKind == JsonValueKind.String)
+        {
+            var valueStr = value.GetString()!;
+            var inputStr = inputElement.GetString()!;
+            if (Guid.TryParse(valueStr, out var vg) && Guid.TryParse(inputStr, out var ig))
+            {
+                return IsMatch(vg.ToString(), ig.ToString());
+            }
+        }
+
+        // Type mismatch (after regex/guid checks)
+        if (value.ValueKind != inputElement.ValueKind)
+        {
+            return false;
+        }
+
+        switch (value.ValueKind)
+        {
+            case JsonValueKind.Object:
+            {
+                var nestedValues = value.EnumerateObject().ToArray();
+                if (nestedValues.Length == 0)
+                {
+                    return true;
+                }
+
+                return nestedValues.All(pair =>
+                {
+                    var selected = SelectElement(inputElement, pair.Name);
+                    return selected != null && IsMatch(pair.Value, selected.Value);
+                });
+            }
+
+            case JsonValueKind.Array:
+            {
+                var valuesArray = value.EnumerateArray().ToArray();
+                if (valuesArray.Length == 0)
+                {
+                    return true;
+                }
+
+                var tokenArray = inputElement.EnumerateArray().ToArray();
+                if (tokenArray.Length == 0)
+                {
+                    return false;
+                }
+
+                return valuesArray.All(subFilter => tokenArray.Any(subToken => IsMatch(subFilter, subToken)));
+            }
+
+            default:
+                return IsMatch(GetStringValue(value), GetStringValue(inputElement));
+        }
+    }
+
+    /// <summary>
+    /// Check if two strings are a match (matching can be done exact or wildcard).
+    /// </summary>
+    protected abstract bool IsMatch(string value, string input);
+
+    /// <summary>
+    /// Selects a <see cref="JsonElement"/> from an object using a key that may be a plain property name,
+    /// a dotted path (e.g. "a.b.c") or bracket notation (e.g. "['name.with.dot']"),
+    /// mirroring Newtonsoft's <c>SelectToken</c> + direct indexer fallback.
+    /// </summary>
+    private static JsonElement? SelectElement(JsonElement input, string key)
+    {
+        if (input.ValueKind != JsonValueKind.Object)
+        {
+            return null;
+        }
+
+        // Direct property access (also handles keys containing colons or dots that are literal property names)
+        if (input.TryGetProperty(key, out var direct))
+        {
+            return direct;
+        }
+
+        // Bracket notation: ['property.name.with.dots']
+        if (key.StartsWith("['") && key.EndsWith("']"))
+        {
+            var propertyName = key.Substring(2, key.Length - 4);
+            return input.TryGetProperty(propertyName, out var bracketValue) ? bracketValue : null;
+        }
+
+        // Dotted path: a.b.c
+        if (key.Contains('.'))
+        {
+            var parts = key.Split('.');
+            var current = input;
+            foreach (var part in parts)
+            {
+                if (current.ValueKind != JsonValueKind.Object || !current.TryGetProperty(part, out var next))
+                {
+                    return null;
+                }
+
+                current = next;
+            }
+
+            return current;
+        }
+
+        return null;
+    }
+
+    private static string GetStringValue(JsonElement element)
+    {
+        return element.ValueKind == JsonValueKind.String
+            ? element.GetString()!
+            : element.GetRawText();
+    }
+}
@@ -1,6 +1,5 @@
 // Copyright © WireMock.Net

-using System.Linq;
 using AnyOfTypes;
 using Newtonsoft.Json.Linq;
 using Stef.Validation;
@@ -13,9 +12,8 @@ namespace WireMock.Matchers;
 /// <summary>
 /// JsonPathMatcher
 /// </summary>
-/// <seealso cref="IStringMatcher" />
-/// <seealso cref="IObjectMatcher" />
-public class JsonPathMatcher : IStringMatcher, IObjectMatcher
+/// <seealso cref="IJsonPathMatcher" />
+public class JsonPathMatcher : IJsonPathMatcher
 {
    private readonly AnyOf<string, StringPattern>[] _patterns;

@@ -1,11 +1,12 @@
 // Copyright © WireMock.Net

-using System.Linq;
+using System.Collections;
+using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 using Stef.Validation;
 using WireMock.Extensions;
+using WireMock.Serialization;
 using WireMock.Util;
-using JsonUtils = WireMock.Util.JsonUtils;

 namespace WireMock.Matchers;

@@ -69,7 +70,7 @@ public class JsonMatcher : IJsonMatcher
        Regex = regex;

        Value = value;
-        _valueAsJToken = JsonUtils.ConvertValueToJToken(value);
+        _valueAsJToken = ConvertValueToJToken(value);
    }

    /// <inheritdoc />
@@ -83,7 +84,7 @@ public class JsonMatcher : IJsonMatcher
        {
            try
            {
-                var inputAsJToken = JsonUtils.ConvertValueToJToken(input);
+                var inputAsJToken = ConvertValueToJToken(input);

                var match = IsMatch(RenameJToken(_valueAsJToken), RenameJToken(inputAsJToken));
                score = MatchScores.ToScore(match);
@@ -103,7 +104,7 @@ public class JsonMatcher : IJsonMatcher
        return $"new {Name}" +
               $"(" +
               $"{MatchBehaviour.GetFullyQualifiedEnumValue()}, " +
-               $"{CSharpFormatter.ConvertToAnonymousObjectDefinition(Value, 3)}, " + 
+               $"{CSharpFormatter.ConvertToAnonymousObjectDefinition(Value, 3)}, " +
               $"{CSharpFormatter.ToCSharpBooleanLiteral(IgnoreCase)}, " +
               $"{CSharpFormatter.ToCSharpBooleanLiteral(Regex)}" +
               $")";
@@ -241,6 +242,18 @@ public class JsonMatcher : IJsonMatcher
        return new JObject(renamedProperties);
    }

+    private static JToken ConvertValueToJToken(object value)
+    {
+        // Check if JToken, string, IEnumerable or object
+        return value switch
+        {
+            JToken tokenValue => tokenValue,
+            string stringValue => JsonConvert.DeserializeObject<JToken>(stringValue, JsonSerializationConstants.JsonDeserializerSettingsWithDateParsingNone)!,
+            IEnumerable enumerableValue => JArray.FromObject(enumerableValue),
+            _ => JObject.FromObject(value),
+        };
+    }
+
    private static string? ToUpper(string? input)
    {
        return input?.ToUpperInvariant();
@@ -1,6 +1,5 @@
 // Copyright © WireMock.Net

-using System.Linq;
 using Stef.Validation;
 using WireMock.Matchers.Helpers;
 using WireMock.Util;
@@ -0,0 +1,282 @@
+// Copyright © WireMock.Net
+
+using System.Collections;
+using System.Text.Json;
+using Stef.Validation;
+using WireMock.Extensions;
+using WireMock.Util;
+
+namespace WireMock.Matchers;
+
+/// <summary>
+/// SystemTextJsonMatcher - behaves the same as <see cref="JsonMatcher"/> but uses System.Text.Json instead of Newtonsoft.Json.
+/// </summary>
+public class SystemTextJsonMatcher : IJsonMatcher
+{
+    private static readonly JsonSerializerOptions DefaultSerializerOptions = new()
+    {
+        PropertyNameCaseInsensitive = false
+    };
+
+    /// <inheritdoc />
+    public virtual string Name => nameof(SystemTextJsonMatcher);
+
+    /// <inheritdoc />
+    public object Value { get; }
+
+    /// <inheritdoc />
+    public MatchBehaviour MatchBehaviour { get; }
+
+    /// <inheritdoc cref="IIgnoreCaseMatcher.IgnoreCase"/>
+    public bool IgnoreCase { get; }
+
+    /// <summary>
+    /// Support Regex
+    /// </summary>
+    public bool Regex { get; }
+
+    private readonly JsonElement _valueAsJsonElement;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SystemTextJsonMatcher"/> class.
+    /// </summary>
+    /// <param name="value">The string value to check for equality.</param>
+    /// <param name="ignoreCase">Ignore the case from the PropertyName and PropertyValue (string only).</param>
+    /// <param name="regex">Support Regex.</param>
+    public SystemTextJsonMatcher(string value, bool ignoreCase = false, bool regex = false)
+        : this(MatchBehaviour.AcceptOnMatch, value, ignoreCase, regex)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SystemTextJsonMatcher"/> class.
+    /// </summary>
+    /// <param name="value">The object value to check for equality.</param>
+    /// <param name="ignoreCase">Ignore the case from the PropertyName and PropertyValue (string only).</param>
+    /// <param name="regex">Support Regex.</param>
+    public SystemTextJsonMatcher(object value, bool ignoreCase = false, bool regex = false)
+        : this(MatchBehaviour.AcceptOnMatch, value, ignoreCase, regex)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SystemTextJsonMatcher"/> class.
+    /// </summary>
+    /// <param name="matchBehaviour">The match behaviour.</param>
+    /// <param name="value">The value to check for equality.</param>
+    /// <param name="ignoreCase">Ignore the case from the PropertyName and PropertyValue (string only).</param>
+    /// <param name="regex">Support Regex.</param>
+    public SystemTextJsonMatcher(MatchBehaviour matchBehaviour, object value, bool ignoreCase = false, bool regex = false)
+    {
+        Guard.NotNull(value);
+
+        MatchBehaviour = matchBehaviour;
+        IgnoreCase = ignoreCase;
+        Regex = regex;
+
+        Value = value;
+        _valueAsJsonElement = ConvertToJsonElement(value);
+    }
+
+    /// <inheritdoc />
+    public MatchResult IsMatch(object? input)
+    {
+        var score = MatchScores.Mismatch;
+        Exception? error = null;
+
+        // When input is null or byte[], return Mismatch.
+        if (input != null && input is not byte[])
+        {
+            try
+            {
+                var inputAsJsonElement = ConvertToJsonElement(input);
+
+                var match = IsMatch(NormalizeElement(_valueAsJsonElement), NormalizeElement(inputAsJsonElement));
+                score = MatchScores.ToScore(match);
+            }
+            catch (Exception ex)
+            {
+                error = ex;
+            }
+        }
+
+        return MatchResult.From(Name, MatchBehaviourHelper.Convert(MatchBehaviour, score), error);
+    }
+
+    /// <inheritdoc />
+    public virtual string GetCSharpCodeArguments()
+    {
+        return $"new {Name}" +
+               $"(" +
+               $"{MatchBehaviour.GetFullyQualifiedEnumValue()}, " +
+               $"{CSharpFormatter.ConvertToAnonymousObjectDefinition(Value, 3)}, " +
+               $"{CSharpFormatter.ToCSharpBooleanLiteral(IgnoreCase)}, " +
+               $"{CSharpFormatter.ToCSharpBooleanLiteral(Regex)}" +
+               $")";
+    }
+
+    /// <summary>
+    /// Compares the input against the matcher value
+    /// </summary>
+    protected virtual bool IsMatch(JsonElement value, JsonElement? input)
+    {
+        if (input == null)
+        {
+            return false;
+        }
+
+        var inputElement = input.Value;
+
+        // If using Regex and the value is a string, use the MatchRegex method.
+        if (Regex && value.ValueKind == JsonValueKind.String)
+        {
+            var valueAsString = value.GetString()!;
+            var inputAsString = inputElement.ValueKind == JsonValueKind.String
+                ? inputElement.GetString()!
+                : inputElement.GetRawText();
+
+            var (valid, result) = RegexUtils.MatchRegex(valueAsString, inputAsString);
+            if (valid)
+            {
+                return result;
+            }
+        }
+
+        // If the value is a Guid (string) and input is a string, or vice versa, compare as strings.
+        if (value.ValueKind == JsonValueKind.String && inputElement.ValueKind == JsonValueKind.String)
+        {
+            var valueStr = value.GetString()!;
+            var inputStr = inputElement.GetString()!;
+
+            if (Guid.TryParse(valueStr, out var valueGuid) && Guid.TryParse(inputStr, out var inputGuid))
+            {
+                return valueGuid == inputGuid;
+            }
+        }
+
+        switch (value.ValueKind)
+        {
+            case JsonValueKind.Object:
+                {
+                    if (inputElement.ValueKind != JsonValueKind.Object)
+                    {
+                        return false;
+                    }
+
+                    var valueProperties = value.EnumerateObject().ToDictionary(p => p.Name, p => p.Value);
+                    var inputProperties = inputElement.EnumerateObject().ToDictionary(p => p.Name, p => p.Value);
+
+                    if (valueProperties.Count != inputProperties.Count)
+                    {
+                        return false;
+                    }
+
+                    foreach (var pair in valueProperties)
+                    {
+                        if (!inputProperties.TryGetValue(pair.Key, out var inputPropValue))
+                        {
+                            return false;
+                        }
+
+                        if (!IsMatch(pair.Value, inputPropValue))
+                        {
+                            return false;
+                        }
+                    }
+
+                    return true;
+                }
+
+            case JsonValueKind.Array:
+                {
+                    if (inputElement.ValueKind != JsonValueKind.Array)
+                    {
+                        return false;
+                    }
+
+                    var valueArray = value.EnumerateArray().ToArray();
+                    var inputArray = inputElement.EnumerateArray().ToArray();
+
+                    if (valueArray.Length != inputArray.Length)
+                    {
+                        return false;
+                    }
+
+                    return !valueArray.Where((valueToken, index) => !IsMatch(valueToken, inputArray[index])).Any();
+                }
+
+            default:
+                return value.GetRawText() == inputElement.GetRawText();
+        }
+    }
+
+    private JsonElement NormalizeElement(JsonElement element)
+    {
+        if (!IgnoreCase)
+        {
+            return element;
+        }
+
+        var normalized = NormalizeValue(element);
+        return ConvertToJsonElement(normalized);
+    }
+
+    private object NormalizeValue(JsonElement element)
+    {
+        switch (element.ValueKind)
+        {
+            case JsonValueKind.Object:
+                {
+                    var dict = new Dictionary<string, object?>();
+                    foreach (var prop in element.EnumerateObject())
+                    {
+                        var normalizedKey = prop.Name.ToUpperInvariant();
+                        dict[normalizedKey] = NormalizeValue(prop.Value);
+                    }
+
+                    return dict;
+                }
+
+            case JsonValueKind.Array:
+                {
+                    if (Regex)
+                    {
+                        return element.EnumerateArray().Select(e => (object)e.GetRawText()).ToArray();
+                    }
+
+                    return element.EnumerateArray().Select(NormalizeValue).ToArray();
+                }
+
+            case JsonValueKind.String:
+                {
+                    var str = element.GetString()!;
+                    return Regex ? str : str.ToUpperInvariant();
+                }
+
+            default:
+                return element.GetRawText();
+        }
+    }
+
+    private static JsonElement ConvertToJsonElement(object value)
+    {
+        switch (value)
+        {
+            case JsonElement jsonElement:
+                return jsonElement;
+
+            case JsonDocument jsonDocument:
+                return jsonDocument.RootElement;
+
+            case string stringValue:
+                return JsonDocument.Parse(stringValue).RootElement;
+
+            case IEnumerable enumerableValue when value is not string:
+                return JsonSerializer.SerializeToElement(enumerableValue, DefaultSerializerOptions);
+
+            default:
+                var json = JsonSerializer.Serialize(value, DefaultSerializerOptions);
+                return JsonDocument.Parse(json).RootElement;
+        }
+    }
+}
@@ -0,0 +1,52 @@
+// Copyright © WireMock.Net
+
+using WireMock.Extensions;
+using WireMock.Util;
+
+namespace WireMock.Matchers;
+
+/// <summary>
+/// SystemTextJsonPartialMatcher - uses System.Text.Json instead of Newtonsoft.Json.
+/// </summary>
+public class SystemTextJsonPartialMatcher : AbstractSystemTextJsonPartialMatcher
+{
+    /// <inheritdoc />
+    public override string Name => nameof(SystemTextJsonPartialMatcher);
+
+    /// <inheritdoc />
+    public SystemTextJsonPartialMatcher(string value, bool ignoreCase = false, bool regex = false)
+        : base(value, ignoreCase, regex)
+    {
+    }
+
+    /// <inheritdoc />
+    public SystemTextJsonPartialMatcher(object value, bool ignoreCase = false, bool regex = false)
+        : base(value, ignoreCase, regex)
+    {
+    }
+
+    /// <inheritdoc />
+    public SystemTextJsonPartialMatcher(MatchBehaviour matchBehaviour, object value, bool ignoreCase = false, bool regex = false)
+        : base(matchBehaviour, value, ignoreCase, regex)
+    {
+    }
+
+    /// <inheritdoc />
+    protected override bool IsMatch(string value, string input)
+    {
+        var exactStringMatcher = new ExactMatcher(MatchBehaviour.AcceptOnMatch, IgnoreCase, MatchOperator.Or, value);
+        return exactStringMatcher.IsMatch(input).IsPerfect();
+    }
+
+    /// <inheritdoc />
+    public override string GetCSharpCodeArguments()
+    {
+        return $"new {Name}" +
+               $"(" +
+               $"{MatchBehaviour.GetFullyQualifiedEnumValue()}, " +
+               $"{CSharpFormatter.ConvertToAnonymousObjectDefinition(Value, 3)}, " +
+               $"{CSharpFormatter.ToCSharpBooleanLiteral(IgnoreCase)}, " +
+               $"{CSharpFormatter.ToCSharpBooleanLiteral(Regex)}" +
+               $")";
+    }
+}
@@ -0,0 +1,52 @@
+// Copyright © WireMock.Net
+
+using WireMock.Extensions;
+using WireMock.Util;
+
+namespace WireMock.Matchers;
+
+/// <summary>
+/// SystemTextJsonPartialWildcardMatcher - uses System.Text.Json instead of Newtonsoft.Json.
+/// </summary>
+public class SystemTextJsonPartialWildcardMatcher : AbstractSystemTextJsonPartialMatcher
+{
+    /// <inheritdoc />
+    public override string Name => nameof(SystemTextJsonPartialWildcardMatcher);
+
+    /// <inheritdoc />
+    public SystemTextJsonPartialWildcardMatcher(string value, bool ignoreCase = false, bool regex = false)
+        : base(value, ignoreCase, regex)
+    {
+    }
+
+    /// <inheritdoc />
+    public SystemTextJsonPartialWildcardMatcher(object value, bool ignoreCase = false, bool regex = false)
+        : base(value, ignoreCase, regex)
+    {
+    }
+
+    /// <inheritdoc />
+    public SystemTextJsonPartialWildcardMatcher(MatchBehaviour matchBehaviour, object value, bool ignoreCase = false, bool regex = false)
+        : base(matchBehaviour, value, ignoreCase, regex)
+    {
+    }
+
+    /// <inheritdoc />
+    protected override bool IsMatch(string value, string input)
+    {
+        var wildcardStringMatcher = new WildcardMatcher(MatchBehaviour.AcceptOnMatch, value, IgnoreCase);
+        return wildcardStringMatcher.IsMatch(input).IsPerfect();
+    }
+
+    /// <inheritdoc />
+    public override string GetCSharpCodeArguments()
+    {
+        return $"new {Name}" +
+               $"(" +
+               $"{MatchBehaviour.GetFullyQualifiedEnumValue()}, " +
+               $"{CSharpFormatter.ConvertToAnonymousObjectDefinition(Value, 3)}, " +
+               $"{CSharpFormatter.ToCSharpBooleanLiteral(IgnoreCase)}, " +
+               $"{CSharpFormatter.ToCSharpBooleanLiteral(Regex)}" +
+               $")";
+    }
+}
@@ -53,7 +53,8 @@ internal class OwinRequestMapper : IOwinRequestMapper
                ContentType = request.ContentType,
                DeserializeJson = !options.DisableJsonBodyParsing.GetValueOrDefault(false),
                ContentEncoding = contentEncodingHeader?.FirstOrDefault(),
-                DecompressGZipAndDeflate = !options.DisableRequestBodyDecompressing.GetValueOrDefault(false)
+                DecompressGZipAndDeflate = !options.DisableRequestBodyDecompressing.GetValueOrDefault(false),
+                DefaultJsonConverter = options.DefaultJsonSerializer
            };

            body = await BodyParser.ParseAsync(bodyParserSettings).ConfigureAwait(false);
@@ -1,7 +1,6 @@
 // Copyright © WireMock.Net

 using System.Diagnostics;
-using System.Linq;
 using WireMock.Logging;
 using WireMock.Owin.ActivityTracing;
 using WireMock.Serialization;
@@ -42,7 +41,7 @@ internal class WireMockMiddlewareLogger(
            if (_options.SaveUnmatchedRequests == true && match?.RequestMatchResult is not { IsPerfectMatch: true })
            {
                var filename = $"{logEntry.Guid}.LogEntry.json";
-                _options.FileSystemHandler?.WriteUnmatchedRequest(filename, JsonUtils.Serialize(logEntry));
+                _options.FileSystemHandler?.WriteUnmatchedRequest(filename, _options.DefaultJsonSerializer.Serialize(logEntry));
            }
        }
        catch
@@ -7,4 +7,4 @@ using System.Runtime.CompilerServices;
 [assembly: InternalsVisibleTo("WireMock.Net.Tests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100e138ec44d93acac565953052636eb8d5e7e9f27ddb030590055cd1a0ab2069a5623f1f77ca907d78e0b37066ca0f6d63da7eecc3fcb65b76aa8ebeccf7ebe1d11264b8404cd9b1cbbf2c83f566e033b3e54129f6ef28daffff776ba7aebbc53c0d635ebad8f45f78eb3f7e0459023c218f003416e080f96a1a3c5ffeb56bee9e")]

 // Needed for Moq in the UnitTest project
-[assembly: InternalsVisibleTo("DynamicProxyGenAssembly2, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c547cac37abd99c8db225ef2f6c8a3602f3b3606cc9891605d02baa56104f4cfc0734aa39b93bf7852f7d9266654753cc297e7d2edfe0bac1cdcf9f717241550e0a7b191195b7667bb4f64bcb8e2121380fd1d9d46ad2d92d2d15605093924cceaf74c4861eff62abf69b9291ed0a340e113be11e6a7d3113e92484cf7045cc7")] 
+[assembly: InternalsVisibleTo("DynamicProxyGenAssembly2, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c547cac37abd99c8db225ef2f6c8a3602f3b3606cc9891605d02baa56104f4cfc0734aa39b93bf7852f7d9266654753cc297e7d2edfe0bac1cdcf9f717241550e0a7b191195b7667bb4f64bcb8e2121380fd1d9d46ad2d92d2d15605093924cceaf74c4861eff62abf69b9291ed0a340e113be11e6a7d3113e92484cf7045cc7")]
@@ -48,7 +48,8 @@ internal class ProxyHelper(WireMockServerSettings settings)
            originalUri,
            deserializeJson,
            decompressGzipAndDeflate,
-            deserializeFormUrlEncoded
+            deserializeFormUrlEncoded,
+            _settings.DefaultJsonSerializer
        ).ConfigureAwait(false);

        IMapping? newMapping = null;
@@ -2,8 +2,10 @@

 using System.Text;
 using JsonConverter.Abstractions;
+using JsonConverter.Newtonsoft.Json;
 using Stef.Validation;
 using WireMock.Models;
+using WireMock.Serialization;
 using WireMock.Types;
 using WireMock.Util;

@@ -119,11 +121,13 @@ public partial class Response
    }

    /// <inheritdoc />
-    public IResponseBuilder WithBody(string body, string? destination = BodyDestinationFormat.SameAsSource, Encoding? encoding = null)
+    public IResponseBuilder WithBody(string body, string? destination = BodyDestinationFormat.SameAsSource, Encoding? encoding = null, IJsonConverter? jsonConverter = null, JsonConverterOptions? options = null)
    {
        Guard.NotNull(body);

        encoding ??= Encoding.UTF8;
+        jsonConverter ??= new NewtonsoftJsonConverter();
+        options ??= JsonSerializationConstants.JsonConverterOptionsWithDateParsingNone;

        ResponseMessage.BodyDestination = destination;
        ResponseMessage.BodyData = new BodyData
@@ -140,7 +144,7 @@ public partial class Response

            case BodyDestinationFormat.Json:
                ResponseMessage.BodyData.DetectedBodyType = BodyType.Json;
-                ResponseMessage.BodyData.BodyAsJson = JsonUtils.DeserializeObject(body);
+                ResponseMessage.BodyData.BodyAsJson = jsonConverter.Deserialize<object>(body, options);
                break;

            default:
@@ -197,7 +197,7 @@ public partial class Response : IResponseBuilder

        if (ProxyAndRecordSettings != null && _httpClientForProxy != null)
        {
-            string RemoveFirstOccurrence(string source, string find)
+            static string RemoveFirstOccurrence(string source, string find)
            {
                int place = source.IndexOf(find, StringComparison.OrdinalIgnoreCase);
                return place >= 0 ? source.Remove(place, find.Length) : source;
@@ -265,7 +265,7 @@ public partial class Response : IResponseBuilder
                    var decoded = await protoBufMatcher.DecodeAsync(requestMessage.BodyData?.BodyAsBytes).ConfigureAwait(false);
                    if (decoded != null)
                    {
-                        requestMessageImplementation.BodyAsJson = JsonUtils.ConvertValueToJToken(decoded);
+                        requestMessageImplementation.BodyAsJson = settings.DefaultJsonSerializer.ToJsonToken(decoded);
                    }
                }
            }
@@ -1,55 +1,31 @@
 // Copyright © WireMock.Net

 using JsonConverter.Abstractions;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Linq;
-#if NETSTANDARD2_0_OR_GREATER || NETCOREAPP3_1_OR_GREATER || NET6_0_OR_GREATER || NET461
-using System.Text.Json;
-#endif
+using JsonConverter.Abstractions.Models;

 namespace WireMock.Serialization;

 internal class MappingSerializer(IJsonConverter jsonConverter)
 {
-    private static readonly JsonConverterOptions JsonConverterOptions = new JsonConverterOptions
-    {
-        DateParseHandling = (int) DateParseHandling.None
-    };
-
    internal T[] DeserializeJsonToArray<T>(string value)
    {
-        // DeserializeObject
-        return DeserializeObjectToArray<T>(jsonConverter.Deserialize<object>(value, JsonConverterOptions)!);
+        switch (JsonTypeHelper.GetJsonType(value))
+        {
+            case JsonType.Array:
+                return jsonConverter.Deserialize<T[]>(value, JsonSerializationConstants.JsonConverterOptionsWithDateParsingNone)!;
+
+            case JsonType.Object:
+                var singleResult = jsonConverter.Deserialize<T>(value, JsonSerializationConstants.JsonConverterOptionsWithDateParsingNone);
+                return [singleResult!];
+
+            default:
+                throw new InvalidOperationException("Cannot deserialize the provided value to an array or object.");
+        }
    }

-    internal static T[] DeserializeObjectToArray<T>(object value)
+    internal T[] DeserializeObjectToArray<T>(object value)
    {
-        if (value is JArray jArray)
-        {
-            return jArray.ToObject<T[]>()!;
-        }
-
-        if (value is JObject jObject)
-        {
-            var singleResult = jObject.ToObject<T>();
-            return [singleResult!];
-        }
-
-#if NETSTANDARD2_0_OR_GREATER || NETCOREAPP3_1_OR_GREATER || NET6_0_OR_GREATER || NET461
-        if (value is JsonElement jElement)
-        {
-            if (jElement.ValueKind == JsonValueKind.Array)
-            {
-                return jElement.Deserialize<T[]>()!;
-            }
-
-            if (jElement.ValueKind == JsonValueKind.Object)
-            {
-                var singleResult = jElement.Deserialize<T>();
-                return [singleResult!];
-            }
-        }
-#endif
-        throw new InvalidOperationException("Cannot deserialize the provided value to an array or object.");
+        var json = jsonConverter.Serialize(value, JsonSerializationConstants.JsonConverterOptionsWithDateParsingNone);
+        return DeserializeJsonToArray<T>(json);
    }
 }
@@ -106,9 +106,29 @@ internal class MatcherMapper
                var valueForJsonPartialWildcardMatcher = matcherModel.Pattern ?? matcherModel.Patterns;
                return new JsonPartialWildcardMatcher(matchBehaviour, valueForJsonPartialWildcardMatcher!, ignoreCase, useRegex);

+            case nameof(SystemTextJsonMatcher):
+                var valueForSystemTextJsonMatcher = matcherModel.Pattern ?? matcherModel.Patterns;
+                return new SystemTextJsonMatcher(matchBehaviour, valueForSystemTextJsonMatcher!, ignoreCase, useRegex);
+
+            case nameof(SystemTextJsonPartialMatcher):
+                var valueForSystemTextJsonPartialMatcher = matcherModel.Pattern ?? matcherModel.Patterns;
+                return new SystemTextJsonPartialMatcher(matchBehaviour, valueForSystemTextJsonPartialMatcher!, ignoreCase, useRegex);
+
+            case nameof(SystemTextJsonPartialWildcardMatcher):
+                var valueForSystemTextJsonPartialWildcardMatcher = matcherModel.Pattern ?? matcherModel.Patterns;
+                return new SystemTextJsonPartialWildcardMatcher(matchBehaviour, valueForSystemTextJsonPartialWildcardMatcher!, ignoreCase, useRegex);
+
            case nameof(JsonPathMatcher):
                return new JsonPathMatcher(matchBehaviour, matchOperator, stringPatterns);

+            case "SystemTextJsonPathMatcher":
+                if (TypeLoader.TryLoadNewInstance<ISystemTextJsonPathMatcher>(out var systemTextJsonPathMatcher, matchBehaviour, matchOperator, stringPatterns))
+                {
+                    return systemTextJsonPathMatcher;
+                }
+
+                throw new InvalidOperationException("The 'SystemTextJsonPathMatcher' cannot be loaded. Please install the WireMock.Net.Matchers.SystemTextJsonPath package.");
+
            case nameof(JmesPathMatcher):
                return new JmesPathMatcher(matchBehaviour, matchOperator, stringPatterns);

@@ -171,6 +191,10 @@ internal class MatcherMapper
                model.Regex = jsonMatcher.Regex;
                break;

+            case SystemTextJsonMatcher stjMatcher:
+                model.Regex = stjMatcher.Regex;
+                break;
+
            case XPathMatcher xpathMatcher:
                model.XmlNamespaceMap = xpathMatcher.XmlNamespaceMap;
                break;
@@ -1,6 +1,8 @@
 // Copyright © WireMock.Net

 using System.Linq;
+using System.Text;
+using Newtonsoft.Json;
 using WireMock.Admin.Mappings;
 using WireMock.Extensions;
 using WireMock.Pact.Models.V2;
@@ -49,7 +51,7 @@ internal static class PactMapper
            pact.Interactions.Add(interaction);
        }

-        return (filename, JsonUtils.SerializeAsPactFile(pact));
+        return (filename, SerializeAsPactFile(pact));
    }

    private static PactRequest MapRequest(RequestModel request, string path)
@@ -152,7 +154,7 @@ internal static class PactMapper
    /// </summary>
    private static object? TryDeserializeJsonStringAsObject(string? value)
    {
-        return value != null ? JsonUtils.TryDeserializeObject<object?>(value) ?? value : null;
+        return value != null ? TryDeserializeObject<object?>(value) ?? value : null;
    }

    //private static string GetPatternAsStringFromMatchers(MatcherModel[]? matchers, string defaultValue)
@@ -164,4 +166,22 @@ internal static class PactMapper

    //    return defaultValue;
    //}
+
+    private static byte[] SerializeAsPactFile(object value)
+    {
+        var json = JsonConvert.SerializeObject(value, JsonSerializationConstants.JsonSerializerSettingsPact);
+        return Encoding.UTF8.GetBytes(json);
+    }
+
+    private static T? TryDeserializeObject<T>(string json)
+    {
+        try
+        {
+            return JsonConvert.DeserializeObject<T>(json);
+        }
+        catch
+        {
+            return default;
+        }
+    }
 }
@@ -1,7 +1,8 @@
 // Copyright © WireMock.Net

-using System.Linq;
+using System.Diagnostics.CodeAnalysis;
 using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
 using NJsonSchema;
 using NJsonSchema.Extensions;
 using NSwag;
@@ -281,7 +282,7 @@ internal static class SwaggerMapper
        if (matcher is { Name: nameof(JsonMatcher) })
        {
            var pattern = GetPatternAsStringFromMatcher(matcher);
-            if (JsonUtils.TryParseAsJObject(pattern, out var jObject))
+            if (TryParseAsJObject(pattern, out var jObject))
            {
                return jObject;
            }
@@ -292,6 +293,39 @@ internal static class SwaggerMapper
        return null;
    }

+    private static bool IsJson(string? value)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+        {
+            return false;
+        }
+
+        value = value!.Trim();
+
+        return (value.StartsWith("{") && value.EndsWith("}")) || (value.StartsWith("[") && value.EndsWith("]"));
+    }
+
+    private static bool TryParseAsJObject(string? strInput, [NotNullWhen(true)] out JObject? value)
+    {
+        value = null;
+
+        if (!IsJson(strInput))
+        {
+            return false;
+        }
+
+        try
+        {
+            // Try to convert this string into a JObject
+            value = JObject.Parse(strInput!);
+            return true;
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
    private static string GetContentType(RequestModel request)
    {
        var contentType = request.Headers?.FirstOrDefault(h => h.Name == "Content-Type");
@@ -346,7 +346,7 @@ public partial class WireMockServer
            }

            o.CorsPolicyOptions = corsPolicyOptions;
-            o.ClientCertificateMode = (Microsoft.AspNetCore.Server.Kestrel.Https.ClientCertificateMode) _settings.ClientCertificateMode;
+            o.ClientCertificateMode = (Microsoft.AspNetCore.Server.Kestrel.Https.ClientCertificateMode)_settings.ClientCertificateMode;
            o.AcceptAnyClientCertificate = _settings.AcceptAnyClientCertificate;
        });

@@ -883,6 +883,18 @@ public partial class WireMockServer
        };
    }

+    private T[] DeserializeRequestMessageToArray<T>(IRequestMessage requestMessage)
+    {
+        if (requestMessage.BodyData?.DetectedBodyType == BodyType.Json && requestMessage.BodyData.BodyAsJson != null)
+        {
+            var bodyAsJson = requestMessage.BodyData.BodyAsJson!;
+
+            return _mappingSerializer.DeserializeObjectToArray<T>(bodyAsJson);
+        }
+
+        throw new NotSupportedException();
+    }
+
    private static Encoding? ToEncoding(EncodingModel? encodingModel)
    {
        return encodingModel != null ? Encoding.GetEncoding(encodingModel.CodePage) : null;
@@ -902,28 +914,16 @@ public partial class WireMockServer
        };
    }

-    private static T[] DeserializeRequestMessageToArray<T>(IRequestMessage requestMessage)
-    {
-        if (requestMessage.BodyData?.DetectedBodyType == BodyType.Json && requestMessage.BodyData.BodyAsJson != null)
-        {
-            var bodyAsJson = requestMessage.BodyData.BodyAsJson!;
-
-            return MappingSerializer.DeserializeObjectToArray<T>(bodyAsJson);
-        }
-
-        throw new NotSupportedException();
-    }
-
-    private static T DeserializeObject<T>(IRequestMessage requestMessage)
+    private T DeserializeObject<T>(IRequestMessage requestMessage)
    {
        switch (requestMessage.BodyData?.DetectedBodyType)
        {
-            case BodyType.String:
-            case BodyType.FormUrlEncoded:
-                return JsonUtils.DeserializeObject<T>(requestMessage.BodyData.BodyAsString!);
+            case BodyType.String when requestMessage.BodyData?.BodyAsString != null:
+            case BodyType.FormUrlEncoded when requestMessage.BodyData?.BodyAsString != null:
+                return _settings.DefaultJsonSerializer.Deserialize<T>(requestMessage.BodyData.BodyAsString)!;

            case BodyType.Json when requestMessage.BodyData?.BodyAsJson != null:
-                return ((JObject)requestMessage.BodyData.BodyAsJson).ToObject<T>()!;
+                return _settings.DefaultJsonSerializer.ParseJsonToken<T>(requestMessage.BodyData.BodyAsJson)!;

            default:
                throw new NotSupportedException();
@@ -1,6 +1,5 @@
 // Copyright © WireMock.Net

-using System.Linq;
 using Stef.Validation;
 using WireMock.Admin.Mappings;
 using WireMock.Matchers;
@@ -153,7 +152,7 @@ public partial class WireMockServer
            }
            else
            {
-                var clientIPModel = JsonUtils.ParseJTokenToObject<ClientIPModel>(requestModel.ClientIP);
+                var clientIPModel = _settings.DefaultJsonSerializer.ParseJsonToken<ClientIPModel>(requestModel.ClientIP);
                if (clientIPModel.Matchers != null)
                {
                    requestBuilder = requestBuilder.WithPath(clientIPModel.Matchers.Select(_matcherMapper.Map).OfType<IStringMatcher>().ToArray());
@@ -169,7 +168,7 @@ public partial class WireMockServer
            }
            else
            {
-                var pathModel = JsonUtils.ParseJTokenToObject<PathModel>(requestModel.Path);
+                var pathModel = _settings.DefaultJsonSerializer.ParseJsonToken<PathModel>(requestModel.Path);
                if (pathModel.Matchers != null)
                {
                    var matchOperator = StringUtils.ParseMatchOperator(pathModel.MatchOperator);
@@ -185,7 +184,7 @@ public partial class WireMockServer
            }
            else
            {
-                var urlModel = JsonUtils.ParseJTokenToObject<UrlModel>(requestModel.Url);
+                var urlModel = _settings.DefaultJsonSerializer.ParseJsonToken<UrlModel>(requestModel.Url);
                if (urlModel.Matchers != null)
                {
                    var matchOperator = StringUtils.ParseMatchOperator(urlModel.MatchOperator);
@@ -273,7 +272,7 @@ public partial class WireMockServer
        return requestBuilder;
    }

-    private static IResponseBuilder InitResponseBuilder(ResponseModel responseModel)
+    private IResponseBuilder InitResponseBuilder(ResponseModel responseModel)
    {
        var responseBuilder = Response.Create();

@@ -338,7 +337,7 @@ public partial class WireMockServer
                }
                else
                {
-                    var headers = JsonUtils.ParseJTokenToObject<string[]>(entry.Value);
+                    var headers = _settings.DefaultJsonSerializer.ParseJsonToken<string[]>(entry.Value);
                    responseBuilder.WithHeader(entry.Key, headers);
                }
            }
@@ -364,7 +363,7 @@ public partial class WireMockServer
                }
                else
                {
-                    var headers = JsonUtils.ParseJTokenToObject<string[]>(entry.Value);
+                    var headers = _settings.DefaultJsonSerializer.ParseJsonToken<string[]>(entry.Value);
                    responseBuilder.WithTrailingHeader(entry.Key, headers);
                }
            }
@@ -3,12 +3,14 @@
 using System.Collections;
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
-using System.Linq;
 using JetBrains.Annotations;
+using JsonConverter.Newtonsoft.Json;
+using JsonConverter.System.Text.Json;
 using Stef.Validation;
 using WireMock.Constants;
 using WireMock.Logging;
 using WireMock.Models;
+using WireMock.Transformers;
 using WireMock.Types;
 using WireMock.Util;

@@ -57,11 +59,9 @@ public static class WireMockServerSettingsParser
            DisableRequestBodyDecompressing = parser.GetBoolValue(nameof(WireMockServerSettings.DisableRequestBodyDecompressing)),
            DisableDeserializeFormUrlEncoded = parser.GetBoolValue(nameof(WireMockServerSettings.DisableDeserializeFormUrlEncoded)),
            DoNotSaveDynamicResponseInLogEntry = parser.GetBoolValue(nameof(WireMockServerSettings.DoNotSaveDynamicResponseInLogEntry)),
-            GraphQLSchemas = parser.GetObjectValueFromJson<Dictionary<string, GraphQLSchemaDetails>>(nameof(settings.GraphQLSchemas)),
            HandleRequestsSynchronously = parser.GetBoolValue(nameof(WireMockServerSettings.HandleRequestsSynchronously)),
            HostingScheme = parser.GetEnumValue<HostingScheme>(nameof(WireMockServerSettings.HostingScheme)),
            MaxRequestLogCount = parser.GetIntValue(nameof(WireMockServerSettings.MaxRequestLogCount)),
-            ProtoDefinitions = parser.GetObjectValueFromJson<Dictionary<string, string[]>>(nameof(settings.ProtoDefinitions)),
            QueryParameterMultipleValueSupport = parser.GetEnumValue<QueryParameterMultipleValueSupport>(nameof(WireMockServerSettings.QueryParameterMultipleValueSupport)),
            ReadStaticMappings = parser.GetBoolValue(nameof(WireMockServerSettings.ReadStaticMappings)),
            RequestLogExpirationDuration = parser.GetIntValue(nameof(WireMockServerSettings.RequestLogExpirationDuration)),
@@ -80,6 +80,7 @@ public static class WireMockServerSettingsParser
        settings.AcceptAnyClientCertificate = parser.GetBoolValue(nameof(WireMockServerSettings.AcceptAnyClientCertificate));
 #endif

+        ParseJsonSerializerSettings(settings, parser);
        ParseLoggerSettings(settings, logger, parser);
        ParsePortSettings(settings, parser);
        ParseProxyAndRecordSettings(settings, parser);
@@ -88,6 +89,9 @@ public static class WireMockServerSettingsParser
        ParseActivityTracingSettings(settings, parser);
        ParseWebSocketSettings(settings, parser);

+        settings.GraphQLSchemas = parser.GetObjectValueFromJson<Dictionary<string, GraphQLSchemaDetails>>(nameof(settings.GraphQLSchemas), settings.DefaultJsonSerializer);
+        settings.ProtoDefinitions = parser.GetObjectValueFromJson<Dictionary<string, string[]>>(nameof(settings.ProtoDefinitions), settings.DefaultJsonSerializer);
+
        return true;
    }

@@ -259,4 +263,21 @@ public static class WireMockServerSettingsParser
            };
        }
    }
+
+    private static void ParseJsonSerializerSettings(WireMockServerSettings settings, SimpleSettingsParser parser)
+    {
+        var defaultJsonSerializer = parser.GetStringValue(nameof(WireMockServerSettings.DefaultJsonSerializer));
+        settings.DefaultJsonSerializer = defaultJsonSerializer switch
+        {
+            nameof(SystemTextJsonConverter) => new SystemTextJsonConverter(),
+            _ => new NewtonsoftJsonConverter(),
+        };
+
+        var defaultJsonBodyTransformer = parser.GetStringValue(nameof(WireMockServerSettings.DefaultJsonBodyTransformer));
+        settings.DefaultJsonBodyTransformer = defaultJsonBodyTransformer switch
+        {
+            nameof(SystemTextJsonBodyTransformer) => new SystemTextJsonBodyTransformer(settings),
+            _ => new NewtonsoftJsonBodyTransformer(settings),
+        };
+    }
 }
@@ -1,6 +1,7 @@
 // Copyright © WireMock.Net

 using HandlebarsDotNet;
+using WireMock.Transformers;

 namespace WireMock.Transformers.Handlebars;

@@ -1,14 +0,0 @@
-// Copyright © WireMock.Net
-
-using WireMock.Handlers;
-
-namespace WireMock.Transformers;
-
-internal interface ITransformerContext
-{
-    IFileSystemHandler FileSystemHandler { get; }
-
-    string ParseAndRender(string text, object model);
-
-    object? ParseAndEvaluate(string text, object model);
-}
@@ -1,10 +1,5 @@
 // Copyright © WireMock.Net

-using System.Collections;
-using System.Linq;
-using HandlebarsDotNet.Helpers.Models;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Linq;
 using Stef.Validation;
 using WireMock.Settings;
 using WireMock.Types;
@@ -14,17 +9,13 @@ namespace WireMock.Transformers;

 internal class Transformer : ITransformer
 {
-    private readonly JsonSerializer _jsonSerializer;
+    private readonly IJsonBodyTransformer _jsonBodyTransformer;
    private readonly ITransformerContextFactory _factory;

    public Transformer(WireMockServerSettings settings, ITransformerContextFactory factory)
    {
        _factory = Guard.NotNull(factory);
-
-        _jsonSerializer = new JsonSerializer
-        {
-            Culture = Guard.NotNull(settings).Culture
-        };
+        _jsonBodyTransformer = Guard.NotNull(settings).DefaultJsonBodyTransformer;
    }

    public IBodyData? TransformBody(
@@ -121,13 +112,17 @@ internal class Transformer : ITransformer
        });
    }

-    private IBodyData? TransformBodyData(ITransformerContext transformerContext, ReplaceNodeOptions options, TransformModel model, IBodyData original, bool useTransformerForBodyAsFile)
+    private BodyData? TransformBodyData(ITransformerContext transformerContext, ReplaceNodeOptions options, TransformModel model, IBodyData original, bool useTransformerForBodyAsFile)
    {
        switch (original.DetectedBodyType)
        {
            case BodyType.Json:
            case BodyType.ProtoBuf:
-                return TransformBodyAsJson(transformerContext, options, model, original);
+                return _jsonBodyTransformer.TransformBodyAsJson(
+                    transformerContext,
+                    options,
+                    model,
+                    original);

            case BodyType.File:
                return TransformBodyAsFile(transformerContext, model, original, useTransformerForBodyAsFile);
@@ -159,185 +154,7 @@ internal class Transformer : ITransformer
        return newHeaders;
    }

-    private IBodyData TransformBodyAsJson(ITransformerContext transformerContext, ReplaceNodeOptions options, object model, IBodyData original)
-    {
-        JToken? jToken = null;
-        switch (original.BodyAsJson)
-        {
-            case JObject bodyAsJObject:
-                jToken = bodyAsJObject.DeepClone();
-                WalkNode(transformerContext, options, jToken, model);
-                break;
-
-            case JArray bodyAsJArray:
-                jToken = bodyAsJArray.DeepClone();
-                WalkNode(transformerContext, options, jToken, model);
-                break;
-
-            case var bodyAsEnumerable when bodyAsEnumerable is IEnumerable and not string:
-                jToken = JArray.FromObject(bodyAsEnumerable, _jsonSerializer);
-                WalkNode(transformerContext, options, jToken, model);
-                break;
-
-            case string bodyAsString:
-                jToken = ReplaceSingleNode(transformerContext, options, bodyAsString, model);
-                break;
-
-            case not null:
-                jToken = JObject.FromObject(original.BodyAsJson, _jsonSerializer);
-                WalkNode(transformerContext, options, jToken, model);
-                break;
-        }
-
-        return new BodyData
-        {
-            Encoding = original.Encoding,
-            DetectedBodyType = original.DetectedBodyType,
-            DetectedBodyTypeFromContentType = original.DetectedBodyTypeFromContentType,
-            ProtoDefinition = original.ProtoDefinition,
-            ProtoBufMessageType = original.ProtoBufMessageType,
-            BodyAsJson = jToken
-        };
-    }
-
-    private JToken ReplaceSingleNode(ITransformerContext transformerContext, ReplaceNodeOptions options, string stringValue, object model)
-    {
-        var transformedString = transformerContext.ParseAndRender(stringValue, model);
-
-        if (!string.Equals(stringValue, transformedString))
-        {
-            const string property = "_";
-            JObject dummy = JObject.Parse($"{{ \"{property}\": null }}");
-            if (dummy[property] == null)
-            {
-                // TODO: check if just returning null is fine
-                return string.Empty;
-            }
-
-            JToken node = dummy[property]!;
-
-            ReplaceNodeValue(options, node, transformedString);
-
-            return dummy[property]!;
-        }
-
-        return stringValue;
-    }
-
-    private void WalkNode(ITransformerContext transformerContext, ReplaceNodeOptions options, JToken node, object model)
-    {
-        switch (node.Type)
-        {
-            case JTokenType.Object:
-                // In case of Object, loop all children. Do a ToArray() to avoid `Collection was modified` exceptions.
-                foreach (var child in node.Children<JProperty>().ToArray())
-                {
-                    WalkNode(transformerContext, options, child.Value, model);
-                }
-                break;
-
-            case JTokenType.Array:
-                // In case of Array, loop all items. Do a ToArray() to avoid `Collection was modified` exceptions.
-                foreach (var child in node.Children().ToArray())
-                {
-                    WalkNode(transformerContext, options, child, model);
-                }
-                break;
-
-            case JTokenType.String:
-                // In case of string, try to transform the value.
-                var stringValue = node.Value<string>();
-                if (string.IsNullOrEmpty(stringValue))
-                {
-                    return;
-                }
-
-                var transformed = transformerContext.ParseAndEvaluate(stringValue!, model);
-                if (!Equals(stringValue, transformed))
-                {
-                    ReplaceNodeValue(options, node, transformed);
-                }
-                break;
-        }
-    }
-
-    // ReSharper disable once UnusedParameter.Local
-    private void ReplaceNodeValue(ReplaceNodeOptions options, JToken node, object? transformedValue)
-    {
-        switch (transformedValue)
-        {
-            case JValue jValue:
-                node.Replace(jValue);
-                return;
-
-            case string transformedString:
-                var (isConvertedFromString, convertedValueFromString) = TryConvert(options, transformedString);
-                if (isConvertedFromString)
-                {
-                    node.Replace(JToken.FromObject(convertedValueFromString, _jsonSerializer));
-                }
-                else
-                {
-                    node.Replace(ParseAsJObject(transformedString));
-                }
-                break;
-
-            case WireMockList<string> strings:
-                switch (strings.Count)
-                {
-                    case 1:
-                        node.Replace(ParseAsJObject(strings[0]));
-                        return;
-
-                    case > 1:
-                        node.Replace(JToken.FromObject(strings.ToArray(), _jsonSerializer));
-                        return;
-                }
-                break;
-
-            case { }:
-                var (isConverted, convertedValue) = TryConvert(options, transformedValue);
-                if (isConverted)
-                {
-                    node.Replace(JToken.FromObject(convertedValue, _jsonSerializer));
-                }
-                return;
-
-            default: // It's null, skip it. Maybe remove it ?
-                return;
-        }
-    }
-
-    private static JToken ParseAsJObject(string stringValue)
-    {
-        return JsonUtils.TryParseAsJObject(stringValue, out var parsedAsjObject) ? parsedAsjObject : stringValue;
-    }
-
-    private static (bool IsConverted, object ConvertedValue) TryConvert(ReplaceNodeOptions options, object value)
-    {
-        var valueAsString = value as string;
-
-        if (options == ReplaceNodeOptions.Evaluate)
-        {
-            if (valueAsString != null && WrappedString.TryDecode(valueAsString, out var decoded))
-            {
-                return (true, decoded);
-            }
-
-            return (false, value);
-        }
-
-        if (valueAsString != null)
-        {
-            return WrappedString.TryDecode(valueAsString, out var decoded) ?
-                (true, decoded) :
-                StringUtils.TryConvertToKnownType(valueAsString);
-        }
-
-        return (false, value);
-    }
-
-    private static IBodyData TransformBodyAsString(ITransformerContext transformerContext, object model, IBodyData original)
+    private static BodyData TransformBodyAsString(ITransformerContext transformerContext, object model, IBodyData original)
    {
        return new BodyData
        {
@@ -348,7 +165,7 @@ internal class Transformer : ITransformer
        };
    }

-    private static IBodyData TransformBodyAsFile(ITransformerContext transformerContext, object model, IBodyData original, bool useTransformerForBodyAsFile)
+    private static BodyData TransformBodyAsFile(ITransformerContext transformerContext, object model, IBodyData original, bool useTransformerForBodyAsFile)
    {
        var transformedBodyAsFilename = transformerContext.ParseAndRender(original.BodyAsFile!, model);

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <Description>Minimal version from the lightweight Http Mocking Server for .NET</Description>
        <AssemblyTitle>WireMock.Net.Minimal</AssemblyTitle>
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <Description>Some extensions for NUnit</Description>
        <AssemblyTitle>WireMock.Net.NUnit</AssemblyTitle>
@@ -25,7 +25,7 @@
    </PropertyGroup>

    <ItemGroup>
-        <PackageReference Include="JsonConverter.Newtonsoft.Json" Version="0.9.0" />
+        <PackageReference Include="JsonConverter.Newtonsoft.Json" Version="0.12.0" />
        <PackageReference Include="NUnit" Version="4.4.0" />
        <PackageReference Include="Stef.Validation" Version="0.2.0" />
    </ItemGroup>
@@ -32,15 +32,15 @@ public partial class WireMockAdminApiAssertions
    }

    [CustomAssertion]
-    public AndConstraint<WireMockAdminApiAssertions> WithBodyAsJson(object body, string because = "", params object[] becauseArgs)
+    public AndConstraint<WireMockAdminApiAssertions> WithBodyAsJson(object body, IJsonMatcher? jsonMatcher = null, string because = "", params object[] becauseArgs)
    {
-        return WithBodyAsJson(new JsonMatcher(body), because, becauseArgs);
+        return WithBodyAsJson(jsonMatcher ?? new JsonMatcher(body), because, becauseArgs);
    }

    [CustomAssertion]
-    public AndConstraint<WireMockAdminApiAssertions> WithBodyAsJson(string body, string because = "", params object[] becauseArgs)
+    public AndConstraint<WireMockAdminApiAssertions> WithBodyAsJson(string body, IJsonMatcher? jsonMatcher = null, string because = "", params object[] becauseArgs)
    {
-        return WithBodyAsJson(new JsonMatcher(body), because, becauseArgs);
+        return WithBodyAsJson(jsonMatcher ?? new JsonMatcher(body), because, becauseArgs);
    }

    [CustomAssertion]
@@ -127,15 +127,44 @@ public partial class WireMockAdminApiAssertions

    private static string? FormatBody(object? body)
    {
-        return body switch
+        if (body == null)
        {
-            null => null,
-            string str => str,
-            AnyOf<string, StringPattern>[] stringPatterns => FormatBodies(stringPatterns.Select(p => p.GetPattern())),
-            byte[] bytes => $"byte[{bytes.Length}] {{...}}",
-            JToken jToken => jToken.ToString(Formatting.None),
-            _ => JToken.FromObject(body).ToString(Formatting.None)
-        };
+            return null;
+        }
+
+        if (body is string str)
+        {
+            return str;
+        }
+
+        if (body is AnyOf<string, StringPattern>[] stringPatterns)
+        {
+            return FormatBodies(stringPatterns.Select(p => p.GetPattern()));
+        }
+
+        if (body is byte[] bytes)
+        {
+            return $"byte[{bytes.Length}] {{...}}";
+        }
+
+        if (body is JToken jToken)
+        {
+            return jToken.ToString(Formatting.None);
+        }
+
+        // System.IO.FileNotFoundException : Could not load file or assembly 'System.Text.Json, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
+        var typeName = body.GetType().FullName;
+        if (typeName == "System.Text.Json.JsonElement")
+        {
+            return ((dynamic)body).GetRawText();
+        }
+
+        if (typeName == "System.Text.Json.JsonDocument")
+        {
+            return ((dynamic)body).RootElement.GetRawText();
+        }
+
+        return JToken.FromObject(body).ToString(Formatting.None);
    }

    private static string? FormatBodies(IEnumerable<object?> bodies)
@@ -33,7 +33,7 @@
    </PropertyGroup>

    <ItemGroup>
-        <PackageReference Include="JsonConverter.Newtonsoft.Json" Version="0.9.0" />
+        <PackageReference Include="JsonConverter.Newtonsoft.Json" Version="0.12.0" />
        <PackageReference Include="RestEase" Version="1.6.4" />
        <PackageReference Include="Stef.Validation" Version="0.2.0" />
    </ItemGroup>
@@ -0,0 +1,11 @@
+// Copyright © WireMock.Net
+
+namespace WireMock.Matchers;
+
+/// <summary>
+/// IJsonPathMatcher
+/// <seealso cref="IStringMatcher"/> and <seealso cref="IObjectMatcher"/>.
+/// </summary>
+public interface IJsonPathMatcher : IStringMatcher, IObjectMatcher
+{
+}
@@ -0,0 +1,11 @@
+// Copyright © WireMock.Net
+
+namespace WireMock.Matchers;
+
+/// <summary>
+/// ISystemTextJsonPathMatcher
+/// <seealso cref="IJsonPathMatcher"/>.
+/// </summary>
+public interface ISystemTextJsonPathMatcher : IJsonPathMatcher
+{
+}
@@ -7,9 +7,10 @@ using System.Runtime.CompilerServices;
 [assembly: InternalsVisibleTo("WireMock.Net.GraphQL, PublicKey=0024000004800000940000000602000000240000525341310004000001000100e138ec44d93acac565953052636eb8d5e7e9f27ddb030590055cd1a0ab2069a5623f1f77ca907d78e0b37066ca0f6d63da7eecc3fcb65b76aa8ebeccf7ebe1d11264b8404cd9b1cbbf2c83f566e033b3e54129f6ef28daffff776ba7aebbc53c0d635ebad8f45f78eb3f7e0459023c218f003416e080f96a1a3c5ffeb56bee9e")]
 [assembly: InternalsVisibleTo("WireMock.Net.ProtoBuf, PublicKey=0024000004800000940000000602000000240000525341310004000001000100e138ec44d93acac565953052636eb8d5e7e9f27ddb030590055cd1a0ab2069a5623f1f77ca907d78e0b37066ca0f6d63da7eecc3fcb65b76aa8ebeccf7ebe1d11264b8404cd9b1cbbf2c83f566e033b3e54129f6ef28daffff776ba7aebbc53c0d635ebad8f45f78eb3f7e0459023c218f003416e080f96a1a3c5ffeb56bee9e")]
 [assembly: InternalsVisibleTo("WireMock.Net.Matchers.CSharpCode, PublicKey=0024000004800000940000000602000000240000525341310004000001000100e138ec44d93acac565953052636eb8d5e7e9f27ddb030590055cd1a0ab2069a5623f1f77ca907d78e0b37066ca0f6d63da7eecc3fcb65b76aa8ebeccf7ebe1d11264b8404cd9b1cbbf2c83f566e033b3e54129f6ef28daffff776ba7aebbc53c0d635ebad8f45f78eb3f7e0459023c218f003416e080f96a1a3c5ffeb56bee9e")]
+[assembly: InternalsVisibleTo("WireMock.Net.Matchers.SystemTextJsonPath, PublicKey=0024000004800000940000000602000000240000525341310004000001000100e138ec44d93acac565953052636eb8d5e7e9f27ddb030590055cd1a0ab2069a5623f1f77ca907d78e0b37066ca0f6d63da7eecc3fcb65b76aa8ebeccf7ebe1d11264b8404cd9b1cbbf2c83f566e033b3e54129f6ef28daffff776ba7aebbc53c0d635ebad8f45f78eb3f7e0459023c218f003416e080f96a1a3c5ffeb56bee9e")]
 [assembly: InternalsVisibleTo("WireMock.Net.OpenTelemetry, PublicKey=0024000004800000940000000602000000240000525341310004000001000100e138ec44d93acac565953052636eb8d5e7e9f27ddb030590055cd1a0ab2069a5623f1f77ca907d78e0b37066ca0f6d63da7eecc3fcb65b76aa8ebeccf7ebe1d11264b8404cd9b1cbbf2c83f566e033b3e54129f6ef28daffff776ba7aebbc53c0d635ebad8f45f78eb3f7e0459023c218f003416e080f96a1a3c5ffeb56bee9e")]
 // [assembly: InternalsVisibleTo("WireMock.Net.StandAlone, PublicKey=0024000004800000940000000602000000240000525341310004000001000100e138ec44d93acac565953052636eb8d5e7e9f27ddb030590055cd1a0ab2069a5623f1f77ca907d78e0b37066ca0f6d63da7eecc3fcb65b76aa8ebeccf7ebe1d11264b8404cd9b1cbbf2c83f566e033b3e54129f6ef28daffff776ba7aebbc53c0d635ebad8f45f78eb3f7e0459023c218f003416e080f96a1a3c5ffeb56bee9e")]
 [assembly: InternalsVisibleTo("WireMock.Net.Tests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100e138ec44d93acac565953052636eb8d5e7e9f27ddb030590055cd1a0ab2069a5623f1f77ca907d78e0b37066ca0f6d63da7eecc3fcb65b76aa8ebeccf7ebe1d11264b8404cd9b1cbbf2c83f566e033b3e54129f6ef28daffff776ba7aebbc53c0d635ebad8f45f78eb3f7e0459023c218f003416e080f96a1a3c5ffeb56bee9e")]

 // Needed for Moq in the UnitTest project
-[assembly: InternalsVisibleTo("DynamicProxyGenAssembly2, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c547cac37abd99c8db225ef2f6c8a3602f3b3606cc9891605d02baa56104f4cfc0734aa39b93bf7852f7d9266654753cc297e7d2edfe0bac1cdcf9f717241550e0a7b191195b7667bb4f64bcb8e2121380fd1d9d46ad2d92d2d15605093924cceaf74c4861eff62abf69b9291ed0a340e113be11e6a7d3113e92484cf7045cc7")] 
+[assembly: InternalsVisibleTo("DynamicProxyGenAssembly2, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c547cac37abd99c8db225ef2f6c8a3602f3b3606cc9891605d02baa56104f4cfc0734aa39b93bf7852f7d9266654753cc297e7d2edfe0bac1cdcf9f717241550e0a7b191195b7667bb4f64bcb8e2121380fd1d9d46ad2d92d2d15605093924cceaf74c4861eff62abf69b9291ed0a340e113be11e6a7d3113e92484cf7045cc7")]
@@ -1,8 +1,6 @@
 // Copyright © WireMock.Net

-using System;
 using System.Text;
-using System.Threading.Tasks;
 using JsonConverter.Abstractions;
 using WireMock.Models;

@@ -19,8 +17,10 @@ public interface IBodyResponseBuilder : IFaultResponseBuilder
    /// <param name="body">The body.</param>
    /// <param name="destination">The Body Destination format (SameAsSource, String or Bytes).</param>
    /// <param name="encoding">The body encoding.</param>
+    /// <param name="jsonConverter">The JSON converter.</param>
+    /// <param name="options">The JSON converter options.</param>
    /// <returns>A <see cref="IResponseBuilder"/>.</returns>
-    IResponseBuilder WithBody(string body, string? destination = BodyDestinationFormat.SameAsSource, Encoding? encoding = null);
+    IResponseBuilder WithBody(string body, string? destination = BodyDestinationFormat.SameAsSource, Encoding? encoding = null, IJsonConverter? jsonConverter = null, JsonConverterOptions? options = null);

    /// <summary>
    /// WithBody : Create a ... response based on a callback function.
@@ -14,16 +14,16 @@ internal static class JsonSerializationConstants
        IgnoreNullValues = true
    };

-    //internal static readonly JsonSerializerSettings JsonSerializerSettingsDefault = new()
-    //{
-    //    Formatting = Formatting.Indented,
-    //    NullValueHandling = NullValueHandling.Ignore
-    //};
-
-    internal static readonly JsonSerializerSettings JsonSerializerSettingsIncludeNullValues = new()
+    internal static readonly JsonConverterOptions JsonConverterOptionsIncludeNullValues = new()
    {
-        Formatting = Formatting.Indented,
-        NullValueHandling = NullValueHandling.Include
+        WriteIndented = true,
+        IgnoreNullValues = false
+    };
+
+    internal static readonly JsonConverterOptions JsonConverterOptionsWithDateParsingNone = new()
+    {
+        WriteIndented = true,
+        DateParseHandling = 0
    };

    internal static readonly JsonSerializerSettings JsonDeserializerSettingsWithDateParsingNone = new()
@@ -1,6 +1,7 @@
 // Copyright © WireMock.Net

 using System.Collections;
+using JsonConverter.Abstractions;
 using WireMock.Extensions;
 using WireMock.Util;

@@ -191,9 +192,9 @@ internal class SimpleSettingsParser
        return GetValue(name, values => values.FirstOrDefault());
    }

-    public T? GetObjectValueFromJson<T>(string name)
+    public T? GetObjectValueFromJson<T>(string name, IJsonConverter jsonConverter)
    {
        var value = GetValue(name, values => values.FirstOrDefault());
-        return string.IsNullOrWhiteSpace(value) ? default : JsonUtils.DeserializeObject<T>(value!);
+        return string.IsNullOrWhiteSpace(value) ? default : jsonConverter.Deserialize<T>(value!);
    }
 }
@@ -14,6 +14,7 @@ using WireMock.Logging;
 using WireMock.Matchers;
 using WireMock.Models;
 using WireMock.RegularExpressions;
+using WireMock.Transformers;
 using WireMock.Types;

 namespace WireMock.Settings;
@@ -362,11 +363,31 @@ public class WireMockServerSettings
    /// Default is <see cref="NewtonsoftJsonConverter"/>.
    /// </remarks>
    [PublicAPI]
-    public IJsonConverter DefaultJsonSerializer { get; set; } = new NewtonsoftJsonConverter();
+    public IJsonConverter DefaultJsonSerializer { get; set; }
+
+    /// <summary>
+    /// Gets or sets the default JSON body transformer used for template-based JSON body transformations.
+    /// </summary>
+    /// <remarks>
+    /// Set this property to provide a custom implementation for transforming JSON and ProtoBuf body content.
+    /// Default is <see cref="NewtonsoftJsonBodyTransformer"/>.
+    /// </remarks>
+    [PublicAPI]
+    [JsonIgnore]
+    public IJsonBodyTransformer DefaultJsonBodyTransformer { get; set; }

    /// <summary>
    /// WebSocket settings.
    /// </summary>
    [PublicAPI]
    public WebSocketSettings? WebSocketSettings { get; set; }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="WireMockServerSettings"/> class.
+    /// </summary>
+    public WireMockServerSettings()
+    {
+        DefaultJsonSerializer = new NewtonsoftJsonConverter();
+        DefaultJsonBodyTransformer = new NewtonsoftJsonBodyTransformer(this);
+    }
 }
@@ -0,0 +1,28 @@
+// Copyright © WireMock.Net
+
+using JetBrains.Annotations;
+using WireMock.Types;
+using WireMock.Util;
+
+namespace WireMock.Transformers;
+
+/// <summary>
+/// Defines the contract for transforming JSON-like body data using a transformer context.
+/// </summary>
+[PublicAPI]
+public interface IJsonBodyTransformer
+{
+    /// <summary>
+    /// Transforms the JSON body using the provided transformer context and model.
+    /// </summary>
+    /// <param name="transformerContext">The transformer context used to render and evaluate template values.</param>
+    /// <param name="options">The JSON node replacement behavior to apply during transformation.</param>
+    /// <param name="model">The model used when rendering or evaluating template values.</param>
+    /// <param name="original">The original body data to transform.</param>
+    /// <returns>The transformed JSON body data.</returns>
+    BodyData TransformBodyAsJson(
+        ITransformerContext transformerContext,
+        ReplaceNodeOptions options,
+        object model,
+        IBodyData original);
+}
@@ -0,0 +1,34 @@
+// Copyright © WireMock.Net
+
+using JetBrains.Annotations;
+using WireMock.Handlers;
+
+namespace WireMock.Transformers;
+
+/// <summary>
+/// Defines the transformer context used to render and evaluate templates during response transformation.
+/// </summary>
+[PublicAPI]
+public interface ITransformerContext
+{
+    /// <summary>
+    /// Gets the file system handler used by the current transformer context.
+    /// </summary>
+    IFileSystemHandler FileSystemHandler { get; }
+
+    /// <summary>
+    /// Renders the specified template text using the supplied model.
+    /// </summary>
+    /// <param name="text">The template text to render.</param>
+    /// <param name="model">The model used during rendering.</param>
+    /// <returns>The rendered text.</returns>
+    string ParseAndRender(string text, object model);
+
+    /// <summary>
+    /// Evaluates the specified template text using the supplied model.
+    /// </summary>
+    /// <param name="text">The template text to evaluate.</param>
+    /// <param name="model">The model used during evaluation.</param>
+    /// <returns>The evaluated value.</returns>
+    object? ParseAndEvaluate(string text, object model);
+}
@@ -0,0 +1,271 @@
+// Copyright © WireMock.Net
+
+using System.Collections;
+using HandlebarsDotNet.Helpers.Models;
+using JetBrains.Annotations;
+using JsonConverter.Newtonsoft.Json;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using WireMock.Settings;
+using WireMock.Types;
+using WireMock.Util;
+
+namespace WireMock.Transformers;
+
+/// <summary>
+/// Default JSON body transformer implementation based on Newtonsoft.Json.
+/// </summary>
+/// <remarks>
+/// Initializes a new instance of the <see cref="NewtonsoftJsonBodyTransformer"/> class.
+/// </remarks>
+/// <param name="settings">The server settings used to configure JSON transformation behavior.</param>
+[PublicAPI]
+public class NewtonsoftJsonBodyTransformer(WireMockServerSettings settings) : IJsonBodyTransformer
+{
+    private static readonly NewtonsoftJsonConverter _jsonConverter = new();
+
+    /// <inheritdoc />
+    public BodyData TransformBodyAsJson(
+        ITransformerContext transformerContext,
+        ReplaceNodeOptions options,
+        object model,
+        IBodyData original)
+    {
+        var jsonSerializer = new JsonSerializer
+        {
+            Culture = settings.Culture
+        };
+
+        JToken? jToken = null;
+        switch (original.BodyAsJson)
+        {
+            case JObject bodyAsJObject:
+                jToken = bodyAsJObject.DeepClone();
+                WalkNode(transformerContext, jsonSerializer, options, jToken, model);
+                break;
+
+            case JArray bodyAsJArray:
+                jToken = bodyAsJArray.DeepClone();
+                WalkNode(transformerContext, jsonSerializer, options, jToken, model);
+                break;
+
+            case var bodyAsEnumerable when bodyAsEnumerable is IEnumerable and not string:
+                jToken = JArray.FromObject(bodyAsEnumerable, jsonSerializer);
+                WalkNode(transformerContext, jsonSerializer, options, jToken, model);
+                break;
+
+            case string bodyAsString:
+                jToken = ReplaceSingleNode(transformerContext, jsonSerializer, options, bodyAsString, model);
+                break;
+
+            case not null:
+                jToken = JObject.FromObject(original.BodyAsJson, jsonSerializer);
+                WalkNode(transformerContext, jsonSerializer, options, jToken, model);
+                break;
+        }
+
+        return new BodyData
+        {
+            Encoding = original.Encoding,
+            DetectedBodyType = original.DetectedBodyType,
+            DetectedBodyTypeFromContentType = original.DetectedBodyTypeFromContentType,
+            ProtoDefinition = original.ProtoDefinition,
+            ProtoBufMessageType = original.ProtoBufMessageType,
+            BodyAsJson = jToken
+        };
+    }
+
+    private JToken ParseAsJObject(string stringValue)
+    {
+        if (_jsonConverter.IsValidJson(stringValue))
+        {
+            try
+            {
+                // Try to convert this string into a JObject
+                return JObject.Parse(stringValue!);
+            }
+            catch
+            {
+                settings.Logger.Warn("Failed to parse string ''{0}'' as JSON. Returning the original string value.", stringValue);
+            }
+        }
+
+        return stringValue;
+    }
+
+    private JToken ReplaceSingleNode(ITransformerContext transformerContext, JsonSerializer jsonSerializer, ReplaceNodeOptions options, string stringValue, object model)
+    {
+        var transformedString = transformerContext.ParseAndRender(stringValue, model);
+
+        if (!string.Equals(stringValue, transformedString))
+        {
+            const string property = "_";
+            JObject dummy = JObject.Parse($"{{ \"{property}\": null }}");
+            if (dummy[property] == null)
+            {
+                return string.Empty;
+            }
+
+            JToken node = dummy[property]!;
+
+            ReplaceNodeValue(jsonSerializer, options, node, transformedString);
+
+            return dummy[property]!;
+        }
+
+        return stringValue;
+    }
+
+    private void WalkNode(ITransformerContext transformerContext, JsonSerializer jsonSerializer, ReplaceNodeOptions options, JToken node, object model)
+    {
+        switch (node.Type)
+        {
+            case JTokenType.Object:
+                foreach (var child in node.Children<JProperty>().ToArray())
+                {
+                    WalkNode(transformerContext, jsonSerializer, options, child.Value, model);
+                }
+                break;
+
+            case JTokenType.Array:
+                foreach (var child in node.Children().ToArray())
+                {
+                    WalkNode(transformerContext, jsonSerializer, options, child, model);
+                }
+                break;
+
+            case JTokenType.String:
+                var stringValue = node.Value<string>();
+                if (string.IsNullOrEmpty(stringValue))
+                {
+                    return;
+                }
+
+                var transformed = transformerContext.ParseAndEvaluate(stringValue!, model);
+                if (!Equals(stringValue, transformed))
+                {
+                    ReplaceNodeValue(jsonSerializer, options, node, transformed);
+                }
+                break;
+        }
+    }
+
+    private void ReplaceNodeValue(JsonSerializer jsonSerializer, ReplaceNodeOptions options, JToken node, object? transformedValue)
+    {
+        switch (transformedValue)
+        {
+            case JValue jValue:
+                node.Replace(jValue);
+                return;
+
+            case string transformedString:
+                var (isConvertedFromString, convertedValueFromString) = TryConvert(options, transformedString);
+                if (isConvertedFromString)
+                {
+                    node.Replace(JToken.FromObject(convertedValueFromString, jsonSerializer));
+                }
+                else
+                {
+                    node.Replace(ParseAsJObject(transformedString));
+                }
+                break;
+
+            case WireMockList<string> strings:
+                switch (strings.Count)
+                {
+                    case 1:
+                        node.Replace(ParseAsJObject(strings[0]));
+                        return;
+
+                    case > 1:
+                        node.Replace(JToken.FromObject(strings.ToArray(), jsonSerializer));
+                        return;
+                }
+                break;
+
+            case { }:
+                var (isConverted, convertedValue) = TryConvert(options, transformedValue);
+                if (isConverted)
+                {
+                    node.Replace(JToken.FromObject(convertedValue, jsonSerializer));
+                }
+                return;
+
+            default:
+                return;
+        }
+    }
+
+    private static (bool IsConverted, object ConvertedValue) TryConvert(ReplaceNodeOptions options, object value)
+    {
+        var valueAsString = value as string;
+
+        if (options == ReplaceNodeOptions.Evaluate)
+        {
+            if (valueAsString != null && WrappedString.TryDecode(valueAsString, out var decoded))
+            {
+                return (true, decoded);
+            }
+
+            return (false, value);
+        }
+
+        if (valueAsString != null)
+        {
+            return WrappedString.TryDecode(valueAsString, out var decoded)
+                ? (true, decoded)
+                : TryConvertToKnownType(valueAsString);
+        }
+
+        return (false, value);
+    }
+
+    internal static (bool IsConverted, object ConvertedValue) TryConvertToKnownType(string value)
+    {
+        if (bool.TryParse(value, out var boolResult))
+        {
+            return (true, boolResult);
+        }
+
+        if (int.TryParse(value, out var intResult))
+        {
+            return (true, intResult);
+        }
+
+        if (long.TryParse(value, out var longResult))
+        {
+            return (true, longResult);
+        }
+
+        if (double.TryParse(value, out var doubleResult))
+        {
+            return (true, doubleResult);
+        }
+
+        if (Guid.TryParseExact(value, "D", out var guidResult))
+        {
+            return (true, guidResult);
+        }
+
+        if (TimeSpan.TryParse(value, out var timeSpanResult))
+        {
+            return (true, timeSpanResult);
+        }
+
+        if (DateTime.TryParse(value, out var dateTimeResult))
+        {
+            return (true, dateTimeResult);
+        }
+
+        if ((value.StartsWith("ftp://", StringComparison.OrdinalIgnoreCase) ||
+            value.StartsWith("ftps://", StringComparison.OrdinalIgnoreCase) ||
+            value.StartsWith("http://", StringComparison.OrdinalIgnoreCase) ||
+            value.StartsWith("https://", StringComparison.OrdinalIgnoreCase)) &&
+            Uri.TryCreate(value, UriKind.RelativeOrAbsolute, out var uriResult))
+        {
+            return (true, uriResult);
+        }
+
+        return (false, value);
+    }
+}
@@ -0,0 +1,208 @@
+// Copyright © WireMock.Net
+
+using System.Collections;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+using HandlebarsDotNet.Helpers.Models;
+using JetBrains.Annotations;
+using JsonConverter.System.Text.Json;
+using WireMock.Settings;
+using WireMock.Types;
+using WireMock.Util;
+
+namespace WireMock.Transformers;
+
+/// <summary>
+/// JSON body transformer implementation based on System.Text.Json.
+/// </summary>
+[PublicAPI]
+public class SystemTextJsonBodyTransformer(WireMockServerSettings settings) : IJsonBodyTransformer
+{
+    private static readonly SystemTextJsonConverter _jsonConverter = new();
+
+    /// <inheritdoc />
+    public BodyData TransformBodyAsJson(
+        ITransformerContext transformerContext,
+        ReplaceNodeOptions options,
+        object model,
+        IBodyData original)
+    {
+        JsonNode? jsonNode = null;
+        switch (original.BodyAsJson)
+        {
+            case JsonObject bodyAsJsonObject:
+                jsonNode = CloneNode(bodyAsJsonObject);
+                jsonNode = WalkNode(transformerContext, options, jsonNode, model);
+                break;
+
+            case JsonArray bodyAsJsonArray:
+                jsonNode = CloneNode(bodyAsJsonArray);
+                jsonNode = WalkNode(transformerContext, options, jsonNode, model);
+                break;
+
+            case var bodyAsEnumerable when bodyAsEnumerable is IEnumerable and not string:
+                jsonNode = JsonSerializer.SerializeToNode(bodyAsEnumerable);
+                if (jsonNode != null)
+                {
+                    jsonNode = WalkNode(transformerContext, options, jsonNode, model);
+                }
+                break;
+
+            case string bodyAsString:
+                jsonNode = ReplaceSingleNode(transformerContext, options, bodyAsString, model);
+                break;
+
+            case not null:
+                jsonNode = JsonSerializer.SerializeToNode(original.BodyAsJson);
+                if (jsonNode != null)
+                {
+                    jsonNode = WalkNode(transformerContext, options, jsonNode, model);
+                }
+                break;
+        }
+
+        return new BodyData
+        {
+            Encoding = original.Encoding,
+            DetectedBodyType = original.DetectedBodyType,
+            DetectedBodyTypeFromContentType = original.DetectedBodyTypeFromContentType,
+            ProtoDefinition = original.ProtoDefinition,
+            ProtoBufMessageType = original.ProtoBufMessageType,
+            BodyAsJson = jsonNode
+        };
+    }
+
+    private JsonNode ParseAsJsonObject(string stringValue)
+    {
+        if (_jsonConverter.IsValidJson(stringValue))
+        {
+            try
+            {
+                var parsed = JsonNode.Parse(stringValue);
+                if (parsed is JsonObject)
+                {
+                    return parsed;
+                }
+            }
+            catch
+            {
+                settings.Logger.Warn("Failed to parse string ''{0}'' as JSON. Returning the original string value.", stringValue);
+            }
+        }
+
+        return JsonValue.Create(stringValue)!;
+    }
+
+    private JsonNode? ReplaceSingleNode(ITransformerContext transformerContext, ReplaceNodeOptions options, string stringValue, object model)
+    {
+        var transformedString = transformerContext.ParseAndRender(stringValue, model);
+
+        if (!string.Equals(stringValue, transformedString))
+        {
+            return ReplaceNodeValue(options, transformedString);
+        }
+
+        return JsonValue.Create(stringValue);
+    }
+
+    private JsonNode? WalkNode(ITransformerContext transformerContext, ReplaceNodeOptions options, JsonNode? node, object model)
+    {
+        switch (node)
+        {
+            case JsonObject jsonObject:
+                foreach (var property in jsonObject.ToArray())
+                {
+                    jsonObject[property.Key] = WalkNode(transformerContext, options, property.Value, model);
+                }
+                return jsonObject;
+
+            case JsonArray jsonArray:
+                for (var i = 0; i < jsonArray.Count; i++)
+                {
+                    jsonArray[i] = WalkNode(transformerContext, options, jsonArray[i], model);
+                }
+                return jsonArray;
+
+            case JsonValue jsonValue when jsonValue.TryGetValue<string>(out var stringValue):
+                if (string.IsNullOrEmpty(stringValue))
+                {
+                    return jsonValue;
+                }
+
+                var transformed = transformerContext.ParseAndEvaluate(stringValue!, model);
+                return !Equals(stringValue, transformed) ? ReplaceNodeValue(options, transformed) ?? jsonValue : jsonValue;
+
+            default:
+                return node;
+        }
+    }
+
+    private JsonNode? ReplaceNodeValue(ReplaceNodeOptions options, object? transformedValue)
+    {
+        switch (transformedValue)
+        {
+            case JsonNode jsonNode:
+                return CloneNode(jsonNode);
+
+            case string transformedString:
+                var (isConvertedFromString, convertedValueFromString) = TryConvert(options, transformedString);
+                return isConvertedFromString
+                    ? JsonSerializer.SerializeToNode(convertedValueFromString)
+                    : ParseAsJsonObject(transformedString);
+
+            case WireMockList<string> strings:
+                switch (strings.Count)
+                {
+                    case 1:
+                        return ParseAsJsonObject(strings[0]);
+
+                    case > 1:
+                        return JsonSerializer.SerializeToNode(strings.ToArray());
+                }
+                break;
+
+            case { }:
+                var (isConverted, convertedValue) = TryConvert(options, transformedValue);
+                if (isConverted)
+                {
+                    return JsonSerializer.SerializeToNode(convertedValue);
+                }
+                break;
+        }
+
+        return null;
+    }
+
+    private static JsonNode? CloneNode(JsonNode? node)
+    {
+#if NET8_0_OR_GREATER
+        return node?.DeepClone();
+#else
+        return node == null ? null : JsonNode.Parse(node.ToJsonString());
+#endif
+    }
+
+    private static (bool IsConverted, object ConvertedValue) TryConvert(ReplaceNodeOptions options, object value)
+    {
+        var valueAsString = value as string;
+
+        if (options == ReplaceNodeOptions.Evaluate)
+        {
+            if (valueAsString != null && WrappedString.TryDecode(valueAsString, out var decoded))
+            {
+                return (true, decoded);
+            }
+
+            return (false, value);
+        }
+
+        if (valueAsString != null)
+        {
+            return WrappedString.TryDecode(valueAsString, out var decoded)
+                ? (true, decoded)
+                : NewtonsoftJsonBodyTransformer.TryConvertToKnownType(valueAsString);
+        }
+
+        return (false, value);
+    }
+}
@@ -1,6 +1,5 @@
 // Copyright © WireMock.Net

-using System.Linq;
 using System.Net.Http.Headers;
 using System.Text;
 using Stef.Validation;
@@ -129,11 +128,11 @@ internal static class BodyParser
    {
        Guard.NotNull(settings);

-        var bodyWithContentEncoding = await ReadBytesAsync(settings.Stream, settings.ContentEncoding, settings.DecompressGZipAndDeflate).ConfigureAwait(false);
+        var (ContentType, Bytes) = await ReadBytesAsync(settings.Stream, settings.ContentEncoding, settings.DecompressGZipAndDeflate).ConfigureAwait(false);
        var data = new BodyData
        {
-            BodyAsBytes = bodyWithContentEncoding.Bytes,
-            DetectedCompression = bodyWithContentEncoding.ContentType,
+            BodyAsBytes = Bytes,
+            DetectedCompression = ContentType,
            DetectedBodyType = BodyType.Bytes,
            DetectedBodyTypeFromContentType = DetectBodyTypeFromContentType(settings.ContentType)
        };
@@ -169,17 +168,17 @@ internal static class BodyParser
                data.DetectedBodyType = BodyType.FormUrlEncoded;
            }

-            // If string is not null or empty, try to deserialize the string to a JObject
-            if (settings.DeserializeJson && JsonUtils.IsJson(data.BodyAsString))
+            // If string is not null or empty, try to deserialize the string
+            if (settings.DeserializeJson && settings.DefaultJsonConverter.IsValidJson(data.BodyAsString))
            {
                try
                {
-                    data.BodyAsJson = JsonUtils.DeserializeObject(data.BodyAsString);
+                    data.BodyAsJson = settings.DefaultJsonConverter.Deserialize<object>(data.BodyAsString);
                    data.DetectedBodyType = BodyType.Json;
                }
                catch
                {
-                    // JsonConvert failed, just ignore.
+                    // JsonConverter failed, just ignore.
                }
            }
        }
@@ -202,7 +201,7 @@ internal static class BodyParser
        return (null, data);
    }

-    public static bool IsProbablyText(byte[] data)
+    private static bool IsProbablyText(byte[] data)
    {
        if (data.Length == 0)
        {
@@ -1,6 +1,7 @@
 // Copyright © WireMock.Net

-using System.IO;
+using JsonConverter.Abstractions;
+using JsonConverter.Newtonsoft.Json;

 namespace WireMock.Util;

@@ -35,4 +36,13 @@ internal class BodyParserSettings
    /// Try to deserialize the body as FormUrlEncoded.
    /// </summary>
    public bool DeserializeFormUrlEncoded { get; set; } = true;
+
+    /// <summary>
+    /// Gets or sets the default JSON converter used for deserialization.
+    /// </summary>
+    /// <remarks>
+    /// Set this property to customize how objects are serialized to and deserialized from JSON during mapping.
+    /// Default is <see cref="NewtonsoftJsonConverter"/>.
+    /// </remarks>
+    public IJsonConverter DefaultJsonConverter { get; set; } = new NewtonsoftJsonConverter();
 }
@@ -1,137 +0,0 @@
-// Copyright © WireMock.Net
-
-using System;
-using System.Collections;
-using System.Diagnostics.CodeAnalysis;
-using System.Text;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Linq;
-using WireMock.Serialization;
-
-namespace WireMock.Util;
-
-internal static class JsonUtils
-{
-    public static bool IsJson(string? value)
-    {
-        if (string.IsNullOrWhiteSpace(value))
-        {
-            return false;
-        }
-
-        value = value!.Trim();
-
-        return (value.StartsWith("{") && value.EndsWith("}")) || (value.StartsWith("[") && value.EndsWith("]"));
-    }
-
-    public static bool TryParseAsJObject(string? strInput, [NotNullWhen(true)] out JObject? value)
-    {
-        value = null;
-
-        if (!IsJson(strInput))
-        {
-            return false;
-        }
-
-        try
-        {
-            // Try to convert this string into a JToken
-            value = JObject.Parse(strInput!);
-            return true;
-        }
-        catch
-        {
-            return false;
-        }
-    }
-
-    public static string Serialize(object value)
-    {
-        return JsonConvert.SerializeObject(value, JsonSerializationConstants.JsonSerializerSettingsIncludeNullValues);
-    }
-
-    public static byte[] SerializeAsPactFile(object value)
-    {
-        var json = JsonConvert.SerializeObject(value, JsonSerializationConstants.JsonSerializerSettingsPact);
-        return Encoding.UTF8.GetBytes(json);
-    }
-
-    /// <summary>
-    /// Load a Newtonsoft.Json.Linq.JObject from a string that contains JSON.
-    /// Using : DateParseHandling = DateParseHandling.None
-    /// </summary>
-    /// <param name="json">A System.String that contains JSON.</param>
-    /// <returns>A Newtonsoft.Json.Linq.JToken populated from the string that contains JSON.</returns>
-    public static JToken Parse(string json)
-    {
-        return JsonConvert.DeserializeObject<JToken>(json, JsonSerializationConstants.JsonDeserializerSettingsWithDateParsingNone)!;
-    }
-
-    /// <summary>
-    /// Deserializes the JSON to a .NET object.
-    /// Using : DateParseHandling = DateParseHandling.None
-    /// </summary>
-    /// <param name="json">A System.String that contains JSON.</param>
-    /// <returns>The deserialized object from the JSON string.</returns>
-    public static object DeserializeObject(string json)
-    {
-        return JsonConvert.DeserializeObject(json, JsonSerializationConstants.JsonDeserializerSettingsWithDateParsingNone)!;
-    }
-
-    /// <summary>
-    /// Deserializes the JSON to the specified .NET type.
-    /// Using : DateParseHandling = DateParseHandling.None
-    /// </summary>
-    /// <param name="json">A System.String that contains JSON.</param>
-    /// <returns>The deserialized object from the JSON string.</returns>
-    public static T DeserializeObject<T>(string json)
-    {
-        return JsonConvert.DeserializeObject<T>(json, JsonSerializationConstants.JsonDeserializerSettingsWithDateParsingNone)!;
-    }
-
-    public static T? TryDeserializeObject<T>(string json)
-    {
-        try
-        {
-            return JsonConvert.DeserializeObject<T>(json);
-        }
-        catch
-        {
-            return default;
-        }
-    }
-
-    public static T ParseJTokenToObject<T>(object? value)
-    {
-        if (value != null && value.GetType() == typeof(T))
-        {
-            return (T)value;
-        }
-
-        return value switch
-        {
-            JToken tokenValue => tokenValue.ToObject<T>()!,
-
-            _ => throw new NotSupportedException($"Unable to convert value to {typeof(T)}.")
-        };
-    }
-
-    public static JToken ConvertValueToJToken(object value)
-    {
-        // Check if JToken, string, IEnumerable or object
-        switch (value)
-        {
-            case JToken tokenValue:
-                return tokenValue;
-
-            case string stringValue:
-                return Parse(stringValue);
-
-            case IEnumerable enumerableValue:
-                return JArray.FromObject(enumerableValue);
-
-            default:
-                return JObject.FromObject(value);
-        }
-    }
-}
@@ -3,7 +3,6 @@
 using System.Collections.Concurrent;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
 using System.Reflection;
 using Stef.Validation;

@@ -30,7 +30,8 @@
        <PackageReference Include="Stef.Validation" Version="0.2.0" />
        <PackageReference Include="AnyOf" Version="0.5.0.1" />
        <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="8.0.2" />
-        <PackageReference Include="JsonConverter.Newtonsoft.Json" Version="0.9.0" />
+        <PackageReference Include="JsonConverter.Newtonsoft.Json" Version="0.12.0" />
+        <PackageReference Include="JsonConverter.System.Text.Json" Version="0.12.0" />
    </ItemGroup>

    <ItemGroup>
@@ -34,5 +34,6 @@
        <ProjectReference Include="../WireMock.Net.GraphQL/WireMock.Net.GraphQL.csproj" />
        <ProjectReference Include="../WireMock.Net.ProtoBuf/WireMock.Net.ProtoBuf.csproj" />
        <ProjectReference Include="../WireMock.Net.OpenTelemetry/WireMock.Net.OpenTelemetry.csproj" />
+        <ProjectReference Include="../WireMock.Net.Matchers.SystemTextJsonPath/WireMock.Net.Matchers.SystemTextJsonPath.csproj" />
    </ItemGroup>
 </Project>