JasperFx · jeremydmiller · Oct 15, 2025 · Oct 15, 2025
diff --git a/docs/guide/durability/marten/event-sourcing.md b/docs/guide/durability/marten/event-sourcing.md
@@ -914,16 +914,114 @@ own rules about value type identifiers](https://martendb.io/documents/identity.h
 
 For a message handler, let's start with this example identifier type and aggregate from the Wolverine tests:
 
-snippet: sample_strong_typed_identifier_with_aggregate
+<!-- snippet: sample_strong_typed_identifier_with_aggregate -->
+<a id='snippet-sample_strong_typed_identifier_with_aggregate'></a>
+```cs
+[StronglyTypedId(Template.Guid)]
+public readonly partial struct LetterId;
+
+public class StrongLetterAggregate
+{
+    public StrongLetterAggregate()
+    {
+    }
+
+    public LetterId Id { get; set; }
+
+    public int ACount { get; set; }
+    public int BCount { get; set; }
+    public int CCount { get; set; }
+    public int DCount { get; set; }
+
+    public void Apply(AEvent _) => ACount++;
+    public void Apply(BEvent _) => BCount++;
+    public void Apply(CEvent _) => CCount++;
+    public void Apply(DEvent _) => DCount++;
+}
+```
+<sup><a href='https://github.com/JasperFx/wolverine/blob/main/src/Persistence/MartenTests/AggregateHandlerWorkflow/strong_named_identifiers.cs#L185-L209' title='Snippet source file'>snippet source</a> | <a href='#snippet-sample_strong_typed_identifier_with_aggregate' title='Start of snippet'>anchor</a></sup>
+<!-- endSnippet -->
 
 And now let's use that identifier type in message handlers:
 
-snippet: sample_using_strong_typed_identifier_with_aggregate_handler_workflow
+<!-- snippet: sample_using_strong_typed_identifier_with_aggregate_handler_workflow -->
+<a id='snippet-sample_using_strong_typed_identifier_with_aggregate_handler_workflow'></a>
+```cs
+public record IncrementStrongA(LetterId Id);
+
+public record AddFrom(LetterId Id1, LetterId Id2);
+
+public record IncrementBOnBoth(LetterId Id1, LetterId Id2);
+
+public record FetchCounts(LetterId Id);
+
+public static class StrongLetterHandler
+{
+    public static StrongLetterAggregate Handle(FetchCounts counts,
+        [ReadAggregate] StrongLetterAggregate aggregate) => aggregate;
+
+    public static AEvent Handle(IncrementStrongA command, [WriteAggregate] StrongLetterAggregate aggregate)
+    {
+        return new();
+    }
+
+    public static void Handle(
+        IncrementBOnBoth command,
+        [WriteAggregate(nameof(IncrementBOnBoth.Id1))] IEventStream<StrongLetterAggregate> stream1,
+        [WriteAggregate(nameof(IncrementBOnBoth.Id2))] IEventStream<StrongLetterAggregate> stream2
+    )
+    {
+        stream1.AppendOne(new BEvent());
+        stream2.AppendOne(new BEvent());
+    }
+
+    public static IEnumerable<object> Handle(
+        AddFrom command,
+        [WriteAggregate(nameof(AddFrom.Id1))] StrongLetterAggregate _,
+        [ReadAggregate(nameof(AddFrom.Id2))] StrongLetterAggregate readOnly)
+    {
+        for (int i = 0; i < readOnly.ACount; i++)
+        {
+            yield return new AEvent();
+        }
+
+        for (int i = 0; i < readOnly.BCount; i++)
+        {
+            yield return new BEvent();
+        }
+
+        for (int i = 0; i < readOnly.CCount; i++)
+        {
+            yield return new CEvent();
+        }
+
+        for (int i = 0; i < readOnly.DCount; i++)
+        {
+            yield return new DEvent();
+        }
+    }
+}
+```
+<sup><a href='https://github.com/JasperFx/wolverine/blob/main/src/Persistence/MartenTests/AggregateHandlerWorkflow/strong_named_identifiers.cs#L124-L181' title='Snippet source file'>snippet source</a> | <a href='#snippet-sample_using_strong_typed_identifier_with_aggregate_handler_workflow' title='Start of snippet'>anchor</a></sup>
+<!-- endSnippet -->
 
 And also in some of the equivalent Wolverine.HTTP endpoints:
 
-snippet: sample_using_strong_typed_id_as_route_argument
+<!-- snippet: sample_using_strong_typed_id_as_route_argument -->
+<a id='snippet-sample_using_strong_typed_id_as_route_argument'></a>
+```cs
+[WolverineGet("/sti/aggregate/longhand/{id}")]
+public static ValueTask<StrongLetterAggregate> Handle2(LetterId id, IDocumentSession session) =>
+    session.Events.FetchLatest<StrongLetterAggregate>(id.Value);
+
+// This is an equivalent to the endpoint above 
+[WolverineGet("/sti/aggregate/{id}")]
+public static StrongLetterAggregate Handle(
+    [ReadAggregate] StrongLetterAggregate aggregate) => aggregate;
+```
+<sup><a href='https://github.com/JasperFx/wolverine/blob/main/src/Http/WolverineWebApi/Marten/StrongTypedIdentifiers.cs#L11-L22' title='Snippet source file'>snippet source</a> | <a href='#snippet-sample_using_strong_typed_id_as_route_argument' title='Start of snippet'>anchor</a></sup>
+<!-- endSnippet -->
 
 
 tools do this for you, and value types generated by these tools are
-legal route argument variables for Wolverine.HTTP now. 
+legal route argument variables for Wolverine.HTTP now. 
diff --git a/docs/guide/http/fluentvalidation.md b/docs/guide/http/fluentvalidation.md
@@ -82,3 +82,46 @@ public class ValidatedQuery
 ```
 <sup><a href='https://github.com/JasperFx/wolverine/blob/main/src/Http/WolverineWebApi/FormEndpoints.cs#L201-L228' title='Snippet source file'>snippet source</a> | <a href='#snippet-sample_using_fluent_validation_with_asparameters' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
+
+## QueryString Binding <Badge type="tip" text="5.0" />
+
+Wolverine.HTTP can apply the Fluent Validation middleware to complex types that are bound by the `[FromQuery]` behavior:
+
+<!-- snippet: sample_CreateCustomer_endpoint_with_validation -->
+<a id='snippet-sample_createcustomer_endpoint_with_validation'></a>
+```cs
+public record CreateCustomer
+(
+    string FirstName,
+    string LastName,
+    string PostalCode
+)
+{
+    public class CreateCustomerValidator : AbstractValidator<CreateCustomer>
+    {
+        public CreateCustomerValidator()
+        {
+            RuleFor(x => x.FirstName).NotNull();
+            RuleFor(x => x.LastName).NotNull();
+            RuleFor(x => x.PostalCode).NotNull();
+        }
+    }
+}
+
+public static class CreateCustomerEndpoint
+{
+    [WolverinePost("/validate/customer")]
+    public static string Post(CreateCustomer customer)
+    {
+        return "Got a new customer";
+    }
+
+    [WolverinePost("/validate/customer2")]
+    public static string Post2([FromQuery] CreateCustomer customer)
+    {
+        return "Got a new customer";
+    }
+}
+```
+<sup><a href='https://github.com/JasperFx/wolverine/blob/main/src/Http/WolverineWebApi/Validation/CreateCustomerEndpoint.cs#L8-L43' title='Snippet source file'>snippet source</a> | <a href='#snippet-sample_createcustomer_endpoint_with_validation' title='Start of snippet'>anchor</a></sup>
+<!-- endSnippet -->
diff --git a/docs/introduction/from-mediatr.md b/docs/introduction/from-mediatr.md
@@ -186,9 +186,15 @@ public static class CreateCustomerEndpoint
     {
         return "Got a new customer";
     }
+
+    [WolverinePost("/validate/customer2")]
+    public static string Post2([FromQuery] CreateCustomer customer)
+    {
+        return "Got a new customer";
+    }
 }
 ```
-<sup><a href='https://github.com/JasperFx/wolverine/blob/main/src/Http/WolverineWebApi/Validation/CreateCustomerEndpoint.cs#L7-L36' title='Snippet source file'>snippet source</a> | <a href='#snippet-sample_createcustomer_endpoint_with_validation' title='Start of snippet'>anchor</a></sup>
+<sup><a href='https://github.com/JasperFx/wolverine/blob/main/src/Http/WolverineWebApi/Validation/CreateCustomerEndpoint.cs#L8-L43' title='Snippet source file'>snippet source</a> | <a href='#snippet-sample_createcustomer_endpoint_with_validation' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 In the application bootstrapping, I've added this option:

diff --git a/src/Http/Wolverine.Http.FluentValidation/Internals/HttpChainFluentValidationPolicy.cs b/src/Http/Wolverine.Http.FluentValidation/Internals/HttpChainFluentValidationPolicy.cs
@@ -12,15 +12,18 @@ internal class HttpChainFluentValidationPolicy : IHttpPolicy
 {
     public void Apply(IReadOnlyList<HttpChain> chains, GenerationRules rules, IServiceContainer container)
     {
-        foreach (var chain in chains.Where(x => x.HasRequestType))
+        foreach (var chain in chains)
         {
             Apply(chain, container);
         }
     }
 
     public void Apply(HttpChain chain, IServiceContainer container)
     {
-        var validatorInterface = typeof(IValidator<>).MakeGenericType(chain.RequestType!);
+        var validatedType = chain.HasRequestType ? chain.RequestType : chain.ComplexQueryStringType;
+        if (validatedType == null) return;
+
+        var validatorInterface = typeof(IValidator<>).MakeGenericType(validatedType);
 
         var registered = container.RegistrationsFor(validatorInterface);
 
@@ -30,27 +33,27 @@ public void Apply(HttpChain chain, IServiceContainer container)
 
             var method =
                 typeof(FluentValidationHttpExecutor).GetMethod(nameof(FluentValidationHttpExecutor.ExecuteOne))!
-                    .MakeGenericMethod(chain.RequestType);
+                    .MakeGenericMethod(validatedType);
 
             var methodCall = new MethodCall(typeof(FluentValidationHttpExecutor), method)
             {
                 CommentText = "Execute FluentValidation validators"
             };
 
             var maybeResult = new MaybeEndWithResultFrame(methodCall.ReturnVariable!);
-            chain.Middleware.InsertRange(0, new Frame[]{methodCall,maybeResult});
+            chain.Middleware.InsertRange(0, [methodCall, maybeResult]);
         }
         else if (registered.Count() > 1)
         {
             chain.Metadata.ProducesValidationProblem(400);
 
             var method =
                 typeof(FluentValidationHttpExecutor).GetMethod(nameof(FluentValidationHttpExecutor.ExecuteMany))!
-                    .MakeGenericMethod(chain.RequestType);
+                    .MakeGenericMethod(validatedType);
 
             var methodCall = new MethodCall(typeof(FluentValidationHttpExecutor), method);
             var maybeResult = new MaybeEndWithResultFrame(methodCall.ReturnVariable!);
-            chain.Middleware.InsertRange(0, new Frame[]{methodCall,maybeResult});
+            chain.Middleware.InsertRange(0, [methodCall, maybeResult]);
         }
     }
 }
diff --git a/src/Http/Wolverine.Http.Tests/fluent_validation_middleware.cs b/src/Http/Wolverine.Http.Tests/fluent_validation_middleware.cs
@@ -58,6 +58,41 @@ public async Task one_validator_sad_path()
         // in the request
         var problems = results.ReadAsJson<HttpValidationProblemDetails>();
     }
+
+    [Fact]
+    public async Task one_validator_happy_path_on_complex_query_string_argument()
+    {
+        // Succeeds w/ a 200
+        var result = await Scenario(x =>
+        {
+            x.Post.Url("/validate/customer2")
+                .QueryString(nameof(CreateCustomer.FirstName), "Creed")
+                .QueryString(nameof(CreateCustomer.LastName), "Humphrey")
+                .QueryString(nameof(CreateCustomer.PostalCode), "11111") ;
+            x.ContentTypeShouldBe("text/plain");
+        });
+    }
+
+    [Fact]
+    public async Task one_validator_sad_path_on_complex_query_string_argument()
+    {
+        var createCustomer = new CreateCustomer(null, "Humphrey", "11111");
+
+        var results = await Scenario(x =>
+        {
+            x.Post.Url("/validate/customer2")
+                .QueryString(nameof(CreateCustomer.FirstName), "Creed")
+                //.QueryString(nameof(CreateCustomer.LastName), "Humphrey")
+                .QueryString(nameof(CreateCustomer.PostalCode), "11111") ;
+            x.ContentTypeShouldBe("application/problem+json");
+            x.StatusCodeShouldBe(400);
+        });
+
+        // Just proving that we have HttpValidationProblemDetails content
+        // in the request
+        var problems = results.ReadAsJson<HttpValidationProblemDetails>();
+    }
+
     [Fact]
     public async Task one_validator_sad_path_in_different_assembly()
     {

diff --git a/...ttp/WolverineWebApi/Internal/Generated/WolverineHandlers/DELETE_validate_user_compound.cs b/...ttp/WolverineWebApi/Internal/Generated/WolverineHandlers/DELETE_validate_user_compound.cs
@@ -14,14 +14,14 @@ namespace Internal.Generated.WolverineHandlers
     public sealed class DELETE_validate_user_compound : Wolverine.Http.HttpHandler
     {
         private readonly Wolverine.Http.WolverineHttpOptions _wolverineHttpOptions;
-        private readonly Wolverine.Http.FluentValidation.IProblemDetailSource<WolverineWebApi.Validation.BlockUser> _problemDetailSource;
         private readonly FluentValidation.IValidator<WolverineWebApi.Validation.BlockUser> _validator;
+        private readonly Wolverine.Http.FluentValidation.IProblemDetailSource<WolverineWebApi.Validation.BlockUser> _problemDetailSource;
 
-        public DELETE_validate_user_compound(Wolverine.Http.WolverineHttpOptions wolverineHttpOptions, Wolverine.Http.FluentValidation.IProblemDetailSource<WolverineWebApi.Validation.BlockUser> problemDetailSource, FluentValidation.IValidator<WolverineWebApi.Validation.BlockUser> validator) : base(wolverineHttpOptions)
+        public DELETE_validate_user_compound(Wolverine.Http.WolverineHttpOptions wolverineHttpOptions, FluentValidation.IValidator<WolverineWebApi.Validation.BlockUser> validator, Wolverine.Http.FluentValidation.IProblemDetailSource<WolverineWebApi.Validation.BlockUser> problemDetailSource) : base(wolverineHttpOptions)
         {
             _wolverineHttpOptions = wolverineHttpOptions;
-            _problemDetailSource = problemDetailSource;
             _validator = validator;
+            _problemDetailSource = problemDetailSource;
         }
 
 

diff --git a/src/Http/WolverineWebApi/Internal/Generated/WolverineHandlers/POST_validate_customer.cs b/src/Http/WolverineWebApi/Internal/Generated/WolverineHandlers/POST_validate_customer.cs
@@ -14,14 +14,14 @@ namespace Internal.Generated.WolverineHandlers
     public sealed class POST_validate_customer : Wolverine.Http.HttpHandler
     {
         private readonly Wolverine.Http.WolverineHttpOptions _wolverineHttpOptions;
-        private readonly Wolverine.Http.FluentValidation.IProblemDetailSource<WolverineWebApi.Validation.CreateCustomer> _problemDetailSource;
         private readonly FluentValidation.IValidator<WolverineWebApi.Validation.CreateCustomer> _validator;
+        private readonly Wolverine.Http.FluentValidation.IProblemDetailSource<WolverineWebApi.Validation.CreateCustomer> _problemDetailSource;
 
-        public POST_validate_customer(Wolverine.Http.WolverineHttpOptions wolverineHttpOptions, Wolverine.Http.FluentValidation.IProblemDetailSource<WolverineWebApi.Validation.CreateCustomer> problemDetailSource, FluentValidation.IValidator<WolverineWebApi.Validation.CreateCustomer> validator) : base(wolverineHttpOptions)
+        public POST_validate_customer(Wolverine.Http.WolverineHttpOptions wolverineHttpOptions, FluentValidation.IValidator<WolverineWebApi.Validation.CreateCustomer> validator, Wolverine.Http.FluentValidation.IProblemDetailSource<WolverineWebApi.Validation.CreateCustomer> problemDetailSource) : base(wolverineHttpOptions)
         {
             _wolverineHttpOptions = wolverineHttpOptions;
-            _problemDetailSource = problemDetailSource;
             _validator = validator;
+            _problemDetailSource = problemDetailSource;
         }
 
 

diff --git a/src/Http/WolverineWebApi/Internal/Generated/WolverineHandlers/POST_validate_user.cs b/src/Http/WolverineWebApi/Internal/Generated/WolverineHandlers/POST_validate_user.cs
@@ -14,14 +14,14 @@ namespace Internal.Generated.WolverineHandlers
     public sealed class POST_validate_user : Wolverine.Http.HttpHandler
     {
         private readonly Wolverine.Http.WolverineHttpOptions _wolverineHttpOptions;
-        private readonly System.Collections.Generic.IEnumerable<FluentValidation.IValidator<WolverineWebApi.Validation.CreateUser>> _validatorIEnumerable;
         private readonly Wolverine.Http.FluentValidation.IProblemDetailSource<WolverineWebApi.Validation.CreateUser> _problemDetailSource;
+        private readonly System.Collections.Generic.IEnumerable<FluentValidation.IValidator<WolverineWebApi.Validation.CreateUser>> _validatorIEnumerable;
 
-        public POST_validate_user(Wolverine.Http.WolverineHttpOptions wolverineHttpOptions, System.Collections.Generic.IEnumerable<FluentValidation.IValidator<WolverineWebApi.Validation.CreateUser>> validatorIEnumerable, Wolverine.Http.FluentValidation.IProblemDetailSource<WolverineWebApi.Validation.CreateUser> problemDetailSource) : base(wolverineHttpOptions)
+        public POST_validate_user(Wolverine.Http.WolverineHttpOptions wolverineHttpOptions, Wolverine.Http.FluentValidation.IProblemDetailSource<WolverineWebApi.Validation.CreateUser> problemDetailSource, System.Collections.Generic.IEnumerable<FluentValidation.IValidator<WolverineWebApi.Validation.CreateUser>> validatorIEnumerable) : base(wolverineHttpOptions)
         {
             _wolverineHttpOptions = wolverineHttpOptions;
-            _validatorIEnumerable = validatorIEnumerable;
             _problemDetailSource = problemDetailSource;
+            _validatorIEnumerable = validatorIEnumerable;
         }
 
 

diff --git a/src/Http/WolverineWebApi/Validation/CreateCustomerEndpoint.cs b/src/Http/WolverineWebApi/Validation/CreateCustomerEndpoint.cs
@@ -1,5 +1,6 @@
 using System.Diagnostics;
 using FluentValidation;
+using Microsoft.AspNetCore.Mvc;
 using Wolverine.Http;
 
 namespace WolverineWebApi.Validation;
@@ -31,6 +32,12 @@ public static string Post(CreateCustomer customer)
     {
         return "Got a new customer";
     }
+
+    [WolverinePost("/validate/customer2")]
+    public static string Post2([FromQuery] CreateCustomer customer)
+    {
+        return "Got a new customer";
+    }
 }
 
 #endregion