What I'm doing wrong ?

[ignatandrei]

I was impressed with the generator and I want to add to my collection

https://ignatandrei.github.io/RSCG_Examples/v2/docs/List-of-RSCG

However, when I try to make a demo, I see that the files are generated for API, but I do not see in swagger the functions

builder.Services.AddErrorOrEndpoints();
//code
app.MapErrorOrEndpoints();

Attached the source for your convenience

src.zip

[ANcpLua]

I will have a look into this in a hour or two. Excited to help!
PS: 3.4.0 has 7000 difs so your issue might already be fixed just have to get it fully checked first.

[ANcpLua]

Hi @ignatandrei! Thanks for the kind words and for reporting this — your demo helped us identify the root cause.

Root Cause

The generated wrapper method returned Task which matches ASP.NET Core's RequestDelegate signature (Func<HttpContext, Task>). When MapGet sees a RequestDelegate, it bypasses RequestDelegateFactory entirely — so endpoints worked at runtime but were completely invisible to OpenAPI/Swagger.

Fix (v3.5.0)

The wrapper now returns Task<Results<Ok<T>, ...>> with an explicit (Delegate) cast, forcing the Delegate overload. This makes all endpoints visible to any OpenAPI document generator.

Tier 1 — Zero code changes (just update the package)

dotnet add package ErrorOrX.Generators --version 3.5.0

Your existing code works as-is:

builder.Services.AddOpenApi();
builder.Services.AddErrorOrEndpoints();
app.MapErrorOrEndpoints();

This gives you:

• All endpoints visible in Swagger
• Typed response schemas (200 with your type, 400/404/500 with ProblemDetails)
• Request body schemas for POST/PUT/PATCH

Tier 2 — Enhanced OpenAPI (optional)

Replace AddOpenApi() with the generated AddErrorOrOpenApi():

builder.Services.AddErrorOrOpenApi();    // instead of AddOpenApi()
builder.Services.AddErrorOrEndpoints();
app.MapErrorOrEndpoints();

This additionally gives you:

• Route/query/header parameters with typed schemas (e.g., Guid → string/uuid)
• XML doc summaries as operation descriptions
• <param> tags as parameter descriptions
• Type descriptions from XML docs on your models

Looking forward to seeing ErrorOrX in your RSCG collection!

[ANcpLua]

as opus said

What was happening

The generated wrapper Invoke_EpN(HttpContext ctx) returned Task — which is exactly the signature of RequestDelegate. So when ASP.NET Core saw MapGet("/path", Invoke_Ep1), it picked the RequestDelegate overload instead of the Delegate
overload.

The RequestDelegate path skips RequestDelegateFactory completely, which is the thing that builds OpenAPI metadata. Endpoints worked fine at runtime but were invisible to Swagger.

Fix:

1. Changed the wrapper return type from Task to Task<Results<Ok<T>, ...>> — this gives RequestDelegateFactory a typed return to inspect for OpenAPI metadata.

2. Added (Delegate) cast to all MapGet/MapPost calls — because Task<T> inherits from Task, the wrapper still matched RequestDelegate without an explicit cast. (Delegate)Invoke_Ep1 forces the right overload.

3. Always emit explicit ProducesResponseTypeMetadata — safety net. Even if RDF behavior changes in future ASP.NET Core versions, the response metadata is always there.

   modified: samples/ErrorOrX.Sample/Program.cs
   modified: src/ErrorOrX.Generators/CLAUDE.md
   modified: src/ErrorOrX.Generators/Core/ErrorOrEndpointGenerator.Emitter.cs
   modified: src/ErrorOrX.Generators/Emitters/EndpointMetadataEmitter.cs
   modified: src/ErrorOrX.Generators/Emitters/GroupEmitter.cs
   modified: src/ErrorOrX.Generators/Models/EndpointModels.cs
   modified: src/ErrorOrX.Generators/OpenApiTransformerGenerator.cs
   modified: src/ErrorOrX.Generators/TypeResolution/ResultsUnionTypeBuilder.cs

[ANcpLua]

I was impressed with the generator and I want to add to my collection

https://ignatandrei.github.io/RSCG_Examples/v2/docs/List-of-RSCG

However, when I try to make a demo, I see that the files are generated for API, but I do not see in swagger the functions

builder.Services.AddErrorOrEndpoints();
//code
app.MapErrorOrEndpoints();

Attached the source for your convenience

src.zip

dotnet add package ErrorOrX.Generators --version 3.5.0

and let me know if it works; any feature/addition are welcome <3

[ignatandrei]

I updated to 3.5.0 . It shows in swagger , thanks!

However, now it appeared a new problem : does not recognize the parameters .

Do you want me to open a new issue ? ( However, if I put AddErrorOrOpenApi instead of AddOpenApi , it works!)