Swagger different classes in different namespaces with same name don't work

Question

I got (more than) two Api POST endpoints. Each one needs a json as parameter. But when I use the same class name Payload in two endpoint argument classes, Swagger does not work. When I change one of it e.g. from Payload to Payload1 than it works. Of course I set the right namespaces into the wrapper classes so it finds it Payload. But I would love to use the same name "Payload" each time. How can I use the same class name Payload? I can keep the json name "Payload" at both cases and just set different names for the property ("Payload1", "Payload2"). It works. But would be nice to have same property names too.,

Endpoint A

[HttpPost()]

public async Task PostPerson([FromBody]JsonWrapperA jsonWrapperA)

namespace myProject.A
{
    public class JsonWrapperA
    {
        [JsonProperty("name", Required = Required.AllowNull)]
        public string Name { get; set; }

        [JsonProperty("payload", Required = Required.AllowNull)]
        public Payload Payload { get; set; }
    }

    public class Payload
    {
        [JsonProperty("value", Required = Required.AllowNull)]
        public double Value { get; set; }
    }
}

Endpoint B

[HttpPost()]

public async Task PostCompagn([FromBody]JsonWrapperB jsonWrapperB)

namespace myProject.B
{
    public class JsonWrapperB
    {
        [JsonProperty("compagny", Required = Required.AllowNull)]
        public string Compagny { get; set; }

        [JsonProperty("payload", Required = Required.AllowNull)]
        public Payload Payload { get; set; }
    }

    public class Payload
    {
        [JsonProperty("age", Required = Required.AllowNull)]
        public double Age{ get; set; }
    }
}

Answer 1

By default swagger will attempt to build its Schema Ids for objects that are return types or parameter types for your APIs endpoints, and it will display these objects in the "Models" section of the documentation. It will build these schema Ids based on the class names of the objects.

When you try to have two or more classes named the same, even though they are in different namespaces, then you will get the conflicting schemaIds error:

InvalidOperationException: Conflicting schemaIds: Identical schemaIds detected for types NamespaceOne.MyClass and NamespaceTwo.MyClass. See config settings - "CustomSchemaIds" for a workaround

This means Swagger needs to be configured to change the way it generates its SchemaIds. You can simply tell swagger to use an objects fully qualified name which will include namespaces in the schemaIds. You can do this in your Startup.cs file in the ConfigureServices method like this:

//add using statement for Swagger in Startup.cs
using Swashbuckle.AspNetCore.Swagger;

...

public void ConfigureServices(IServiceCollection services)
{
    services.AddSwaggerGen(config =>
    {
        //some swagger configuration code.

        //use fully qualified object names
        config.CustomSchemaIds(x => x.FullName);
    }
}