How can I define a .NET 6 Minimal Web API route that includes a colon?

Question

I've created a .NET 6 Minimal Web API that needs to support a particularly formatted URL. The URL that needs to be accepted is similar to /sensor/sensor:123/measurement

The following is the relevant Program.cs.

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.MapGet("/sensor/sensor:{sensorId}/measurement", (int sensorId) =>
{
    return Results.Ok();
});

app.Run();

However, when I run this and check the generated Swagger UI I see the GET URL listed as /sensor/sensor}/measurement. Trying it out properly shows the sensorId as a path parameter, but actually entering data and executing via this interface results in a 404.

If I modify it to the following, I can get it to run, and it allows me to pass the colon in the request, but I would prefer if the colon was part of the route definition, since it a) should be and b) requires extra parsing logic.

app.MapGet("/sensor/sensor{sensorId}/measurement", (string sensorId) =>
{
    return Results.Ok();
});

Is there a way to allow/escape colons in .NET 6 Minimal Web APIs so they can be part of the defined route?

Answer 1

In ASP.NET Core, : is a special character in the route if between {}. But a bug in Swashbuckle that interpret : outside {} like it's inside.

https://github.com/domaindrivendev/Swashbuckle.AspNetCore/pull/2310

That is fixed in the version 6.2.4. But actually, the ASP.NET Core API template add Swashbuckle at version 6.2.3 with the bug.

We need to update manually the NuGet package Swashbuckle.