CODEWITHSUNDEEP
c#asp.net-coreswaggerswashbuckle
John Livermore
John Livermore

Reputation: 31313

ASP.NET Core - Swashbuckle not creating swagger.json file

I am having trouble getting the Swashbuckle.AspNetCore (1.0.0) package to generate any output. I read the swagger.json file should be written to '~/swagger/docs/v1'. However, I am not getting any output.

I started with a brand new ASP.NET Core API project. I should mention this is ASP.NET Core 2. The API works, and I am able to retrieve values from the values controller just fine.

My startup class has the configuration exactly as described in this article (Swashbuckle.AspNetCore on GitHub).

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc();

        services.AddSwaggerGen(c =>
        {
            c.SwaggerDoc("v1", new Info { Title = "My API", Version = "v1" });
        });
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();

            // Enable middleware to serve generated Swagger as a JSON endpoint.
            app.UseSwagger();
            app.UseSwaggerUI(c =>
            {
                c.SwaggerEndpoint("/swagger/v1/swagger.json", "MyAPI V1");
            });
        }
        else
        {
            app.UseExceptionHandler();
        }

        app.UseStatusCodePages();
        app.UseMvc();

        //throw new Exception();
    }
}

You can see the NuGet references...

enter image description here

Again, this is all the default template, but I include the ValuesController for reference...

[Route("api/[controller]")]
public class ValuesController : Controller
{
    // GET api/values
    [HttpGet]
    public IEnumerable<string> Get()
    {
        return new string[] { "value1", "value2" };
    }

    // GET api/values/5
    [HttpGet("{id}")]
    public string Get(int id)
    {
        return "value";
    }

    // POST api/values
    [HttpPost]
    public void Post([FromBody]string value)
    {
    }

    // PUT api/values/5
    [HttpPut("{id}")]
    public void Put(int id, [FromBody]string value)
    {
    }

    // DELETE api/values/5
    [HttpDelete("{id}")]
    public void Delete(int id)
    {
    }
}

Upvotes: 118

Views: 221802

Answers (30)

armin sadeghi
armin sadeghi

Reputation: 59

maybe you have duplicate route in one api!

Upvotes: 1

Abdelwahid Oubaalla
Abdelwahid Oubaalla

Reputation: 865

To get the json api file, I ve used @mysAdresse:port/swagger/docs/v1

Upvotes: 0

mihirjoshi
mihirjoshi

Reputation: 12201

In my case, multiple endpoints inside my controller have the same HttpPost attribute name. You can either change one of them or remove it entirely.

[HttpPost("Post")]
[Route("someroute")]
public async Task<IActionResult> Method1([FromBody] Request request)
{
 // Some body
 return Ok(JsonConvert.SerializeObject(citations));
}

// Rename this "Post" or remove it
[HttpPost("Post")]
[Route("otherroute")]
public async Task<IActionResult> Method2([FromBody] Request request)
{
 // Some body
 return Ok(JsonConvert.SerializeObject(citations));
}

Upvotes: 0

Byron Gavras
Byron Gavras

Reputation: 990

Be aware that in Visual Studio 2022 and .NetCore 6 if you create a new ASP.NET Core Web App, Program.cs has the oposite check for Development environment.

instead of

if (app.Environment.IsDevelopment())
{
   app.UseSwagger();
   app.UseSwaggerUI();
}

you will find

if (!app.Environment.IsDevelopment())
{
     app.UseExceptionHandler("/Home/Error");
}
// You shoukd add swagger calls here 
app.UseSwagger();
app.UseSwaggerUI();

If you create a new project by selecting the template ASP.NET Core Web API and check "Enable OpenAPI support" you will have different Program.cs with preinstalled swagger package and related code.

This took some time for me to find, hope to help someone.

Upvotes: 7

Mohammad Barbast
Mohammad Barbast

Reputation: 2049

You must conform to 2 rules:

  1. Decorate all actions with explicit Http Verbs like[HttpGet("xxx")], [HttpPost("xxx")], ... instead of [Route("xxx")].
  2. Decorate public methods in controllers with [NonAction] Attribute.

Note that http://localhost:XXXX/swagger/ page requests for http://localhost:XXXX/swagger/v1/swagger.json file, but an Exception will occur from Swagger if you wouldn't conform above rules.

Upvotes: 28

Sajeeb Chandan Saha
Sajeeb Chandan Saha

Reputation: 865

Please use the following convention for simple API docs.

In ConfigureServices method

        services.AddSwaggerGen(c =>
        {
            c.SwaggerDoc("v1", new OpenApiInfo { Title = "My Test API", Version = "1.0.0.0" });
            c.OperationFilter<SwaggerAuthorizationOperationFilter>();
            c.AddSecurityDefinition("Bearer", new OpenApiSecurityScheme()
            {
                Description = "Enter the request header in the following box to add Jwt To grant authorization Token: Bearer Token",
                Name = "Authorization",
                In = ParameterLocation.Header,
                Type = SecuritySchemeType.ApiKey,
                BearerFormat = "JWT",
                Scheme = "Bearer"
            });
            //c.SchemaFilter<SwaggerExcludeSchemaFilter>();
            c.AddSecurityRequirement(new OpenApiSecurityRequirement
                {
                {
                    new OpenApiSecurityScheme
                    {
                        Reference = new OpenApiReference {
                            Type = ReferenceType.SecurityScheme,
                            Id = "Bearer"
                        }
                    },
                    new string[] { }
                }
                });
        });

In Configure method

        app.UseSwagger();
        app.UseSwaggerUI(c =>
            {
                c.DefaultModelExpandDepth(2);
                c.DefaultModelsExpandDepth(-1);
                c.DisplayOperationId();
                c.DisplayRequestDuration();
                c.EnableDeepLinking();
                c.EnableFilter();
                c.ShowExtensions();
                c.EnableValidator();
            });

        // Enable middleware to serve swagger-ui (HTML, JS, CSS, etc.),
        // specifying the Swagger JSON endpoint.
        app.UseSwaggerUI(c =>
        {
            c.SwaggerEndpoint("/swagger/v1/swagger.json", "My Test API");
            c.RoutePrefix = "";
            c.DocumentTitle = "My Test API Docs";                
        });

Please note following 2 lines form those 2 methods sequentially.

c.SwaggerDoc("v1", new OpenApiInfo { Title = "My Test API", Version = "1.0.0.0" });

c.SwaggerEndpoint("/swagger/v1/swagger.json", "My Test API");

So whatever you put instead of v1 that should be matched.

Upvotes: 0

Aaron Herchmer
Aaron Herchmer

Reputation: 381

I was running into a similar, but not exactly the same issue with swagger. Hopefully this helps someone else.

I was using a custom document title and was not changing the folder path in the SwaggerEndPoint to match the document title. If you leave the endpoint pointing to swagger/v1/swagger.json it won't find the json file in the swagger UI.

Example:

services.AddSwaggerGen(swagger =>
{
    swagger.SwaggerDoc("AppAdministration", new Info { Title = "App Administration API", Version = "v1.0" });
            
});


app.UseSwaggerUI(c =>
{
    c.SwaggerEndpoint("/swagger/AppAdministration/swagger.json", "App Administration");
});

Upvotes: 38

Ram
Ram

Reputation: 16804

If you have any issues in your controller to map to an unique URL you get this error.

The best way to find the cause of issue is exclude all controllers from project. Then try running the app by enabling one controller or one or more methods in a controller at a time to find the controllers/ controller method(S) which have an issue. Or you could get smart and do a binary search logic to find the disable enable multiple controller/methods to find the faulty ones.

Some of the causes is

  1. Having public methods in controller without HTTP method attributes

  2. Having multiple methods with same Http attributes which could map to same api call if you are not using "[action]" based mapping

  3. If you are using versioning make sure you have the method in all the controller versions (if using inheritance even though you use from base)

Upvotes: 8

Vu Re Vu
Vu Re Vu

Reputation: 41

I'd a similar issue, my Swagger documentation broke after I was adding async version of APIs to existing ones. I played around the Swagger DLL's by installing / Reinstalling, finally commenting newly added APIs, and it worked. Then I added different signature in attributes, and bingo!, It worked.

In your case, you are having two API with matching signatures

[HttpGet]
public IEnumerable<string> Get()
{
  return new string[] { "value1", "value2" };
}

// GET api/values/5
[HttpGet("{id}")]
public string Get(int id)
{`enter code here`
  return "value";
}

Try providing different names in attributes like
[HttpGet("List")]
public IEnumerable<string> Get()
{
 return new string[] { "value1", "value2" };
}

// GET api/values/5
[HttpGet("ListById/{id}")]
public string Get(int id)
{
  return "value";
}

This should solve the issue.

Upvotes: 1

Sheriff
Sheriff

Reputation: 868

You might forgetting to include.. StartUp.cs/Configure()

app.UseSwagger();

Check if you forgot to include, you error must be remove.

Upvotes: 1

kostas.kapasakis
kostas.kapasakis

Reputation: 1142

After watching the answers and checking the recommendations, I end up having no clue what was going wrong.

I literally tried everything. So if you end up in the same situation, understand that the issue might be something else, completely irrelevant from swagger.

In my case was a OData exception.

Here's the procedure:

1) Navigate to the localhost:xxxx/swagger
2) Open Developer tools
3) Click on the error shown in the console and you will see the inner exception that is causing the issue.

Upvotes: 17

Grace Streaming
Grace Streaming

Reputation: 1

// Enable middleware to serve generated Swagger as a JSON endpoint.

app.UseSwagger(c =>
{
    c.SerializeAsV2 = true;
});

// Enable middleware to serve swagger-ui (HTML, JS, CSS, etc.),
// specifying the Swagger JSON endpoint.
app.UseSwaggerUI(c =>
{
    c.SwaggerEndpoint("/swagger/v1/swagger.json", "API Name");
});

Upvotes: 0

Abdullah Hashim
Abdullah Hashim

Reputation: 89

You actually just need to fix the swagger url by removing the starting backslash just like this :

c.SwaggerEndpoint("swagger/v1/swagger.json", "MyAPI V1");

instead of :

c.SwaggerEndpoint("/swagger/v1/swagger.json", "MyAPI V1");

Upvotes: 6

Richard Asenjo
Richard Asenjo

Reputation: 101

I don't know if this is useful for someone, but in my case the problem was that the name had different casing.

V1 in the service configuration - V capital letter
v1 in Settings -- v lower case

The only thing I did was to use the same casing and it worked.

version name with capital V

Upvotes: 10

Amirhossein Yari
Amirhossein Yari

Reputation: 2316

In my case, I've had forgotten to set public access modifier for methods!

Upvotes: 0

Ali
Ali

Reputation: 1200

i had the same Error , but due to different issue ,i was using a 3rd party library which cause this issue, and i did not need to have this library in my exposure ,so i used the below solution that is posted here .

Create somewhere class ApiExplorerIgnores with following content

public class ApiExplorerIgnores : IActionModelConvention
{
    public void Apply(ActionModel action)
    {
        if (action.Controller.ControllerName.Equals("ImportExport"))
            action.ApiExplorer.IsVisible = false;
    }
}

Add following code to method ConfigureServices in Startup.cs

services.AddMvc(c => c.Conventions.Add(new ApiExplorerIgnores()))

this will get read of all methods in that controller ,you can also use a specific level ,like method name or so ,also you can remove one Method only and so one ,

Upvotes: 0

Mohammed A. Fadil
Mohammed A. Fadil

Reputation: 9377

Adding a relative path worked for me:

app.UseSwaggerUI(c =>
{
    c.SwaggerEndpoint("../swagger/v1/swagger.json", "My App");
});

Upvotes: 5

Esmaeel Motaghi
Esmaeel Motaghi

Reputation: 31

According to Microsoft: To serve the Swagger UI at the app's root (http://localhost:/), set the RoutePrefix property to an empty string:

app.UseSwaggerUI(c =>
{
c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");
c.RoutePrefix = string.Empty;
});

Upvotes: 0

2b77bee6-5445-4c77-b1eb-4df3e5
2b77bee6-5445-4c77-b1eb-4df3e5

Reputation: 967

I am moving my comment to an answer since it appears to be helpful.

To avoid issues with IIS aliases, remove /swagger/ from the URL path. It should look like this: 

app.UseSwaggerUI(c => { c.SwaggerEndpoint("v1/swagger.json", "API name"); });

Upvotes: 16

Tiago B
Tiago B

Reputation: 2065

I believe you missed these two lines on your Configure:

if (env.IsDevelopment())
{
    app.UseDeveloperExceptionPage();

    // Enable middleware to serve generated Swagger as a JSON endpoint.
    app.UseSwagger();
    app.UseSwaggerUI(c =>
    {
        c.SwaggerEndpoint("v1/swagger.json", "MyAPI V1");
    });
}

To access Swagger UI, the URL should be: http://localhost:XXXX/swagger/

The json can be found at the top of Swagger UI:

enter image description here

Upvotes: 73

Christopher Thomas
Christopher Thomas

Reputation: 372

I had a silly issue, I had a capital v in the AddSwaggerGen method and a lowercase v in c.SwaggerEndpoint.

It appears to be case sensitive.

Upvotes: 0

Malcolm Swaine
Malcolm Swaine

Reputation: 2258

Same problem - easy fix for me.

To find the underlying problem I navigated to the actual swagger.json file which gave me the real error

/swagger/v1/swagger.json

The actual error displayed from this Url was

NotSupportedException: Ambiguous HTTP method for action  ... Actions require an explicit HttpMethod binding for Swagger/OpenAPI 3.0

The point being

Actions require an explicit HttpMethod

I then decorated my controller methods with [HttpGet]

[Route("GetFlatRows")]
 [HttpGet]
 public IActionResult GetFlatRows()
 {

Problem solved

Upvotes: 2

Pratheek S
Pratheek S

Reputation: 21

Answer:

If using directories or application  with IIS or a reverse proxy,<br/> set the Swagger endpoint to a relative path using the ./ prefix. For example,<br/> ./swagger/v1/swagger.json. Using /swagger/v1/swagger.json instructs the app to<br/>look for the JSON file at the true root of the URL (plus the route prefix, if used). For example, use http://localhost:<br/><br/><port>/<route_prefix>/swagger/v1/swagger.json instead of http://localhost:<br/><port>/<virtual_directory>/<route_prefix>/swagger/v1/swagger.json.<br/>
if (env.IsDevelopment())
{
    app.UseDeveloperExceptionPage();

    // Enable middleware to serve generated Swagger as a JSON endpoint.
    app.UseSwagger();
    app.UseSwaggerUI(c =>
    {
//c.SwaggerEndpoint("/swagger/v1/swagger.json", "MyAPI V1");
//Add dot in front of swagger path so that it takes relative path in server
c.SwaggerEndpoint("./swagger/v1/swagger.json", "MyAPI V1");
    });
}

[Detail description of the swagger integration to web api core 3.0][1]


  [1]: https://learn.microsoft.com/en-us/aspnet/core/tutorials/getting-started-with-swashbuckle?view=aspnetcore-3.1&tabs=visual-studio

Upvotes: 0

Mehmet Recep Yildiz
Mehmet Recep Yildiz

Reputation: 2127

You should install the following packages into your project.

5.0.0-rc4 version of Swashbuckle is the minimum. Otherwise, it won't work.

As of now, directly installing it from Nuget, installs the old versions which won't work for Core 3.

I inserted the following lines into .csproj project file like that:

<PackageReference Include="Microsoft.OpenApi" Version="1.1.4" />
<PackageReference Include="Swashbuckle.AspNetCore.Swagger" Version="5.0.0-rc4" />
<PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen" Version="5.0.0-rc4" />
<PackageReference Include="Swashbuckle.AspNetCore.SwaggerUi" Version="5.0.0-rc4" />

After that, Rebuild installs the newer versions. If not, you can use restore too.

In the Startup.cs, you should configure Swashbuckle like that:

 // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllers();

            // Register the Swagger generator, defining 1 or more Swagger documents
            services.AddSwaggerGen(c =>
            {
                c.SwaggerDoc("v1", new OpenApiInfo { Title = "My API", Version = "v1" });
            });

        services.AddMvc();
    }

  

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseHttpsRedirection();

        // Enable middleware to serve generated Swagger as a JSON endpoint.
        app.UseSwagger();

        // Enable middleware to serve swagger-ui (HTML, JS, CSS, etc.),
        // specifying the Swagger JSON endpoint.
        app.UseSwaggerUI(c =>
        {
            c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");
            //c.RoutePrefix = String.Empty;
        });

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
        });
    }

Just go to the "https://localhost:5001/swagger/index.html" and you'll see the Swagger UI. (5001 is my local port, you should change it with yours)

It took a little time for me to figure it out.

I hope it will help others :)

Upvotes: 0

Sachin Mishra
Sachin Mishra

Reputation: 1183

I had the same problem. I was using swagger like below mentioned pattern i.e. "../swagger/v1/swagger.json" because I am using IIS Express.Later than I change it to "/swagger/v1/swagger.json"and clean,rebuild the solution worked for me.

Swagger Enable UI

Upvotes: 1

Random Person
Random Person

Reputation: 49

In my case problem was in method type, should be HttpPOST but there was HttpGET Once I changed that, everything starts work.

https://c2n.me/44p7lRd.png

Upvotes: 0

pvma
pvma

Reputation: 433

I was able to fix and understand my issue when I tried to go to the swagger.json URL location:

https://localhost:XXXXX/swagger/v1/swagger.json

The page will show the error and reason why it is not found.

In my case, I saw that there was a misconfigured XML definition of one of my methods based on the error it returned:

NotSupportedException: HTTP method "GET" & path "api/Values/{id}" overloaded by actions - ...
...
...

Upvotes: 0

UniCoder
UniCoder

Reputation: 3233

Try to follow these steps, easy and clean.

  1. Check your console are you getting any error like "Ambiguous HTTP method for action. Actions require an explicit HttpMethod binding for Swagger 2.0."
  2. If YES: Reason for this error: Swagger expects

each endpoint should have the method (get/post/put/delete)

. Solution:

Revisit your each and every controller and make sure you have added expected method.

(or you can just see in console error which controller causing ambiguity)

  1. If NO. Please let us know your issue and solution if you have found any.

Upvotes: 2

Cassio Tavares
Cassio Tavares

Reputation: 65

I had this problem when I used a inner class in Post parameters

[HttpPost]
public async Task Post([FromBody] Foo value)
{
}

Where Foo is

public class Foo
{
    public IEnumerable<Bar> Bars {get;set;}

    public class Bar
    {
    }
}

Upvotes: 2

TomFp
TomFp

Reputation: 567

I was getting this Swagger error when I created Version 2 of my api using version headers instead of url versioning. The workaround was to add [Obsolete] attributes to the Version 1 methods then use SwaggerGeneratorOptions to ignore the obsolete api methods in Startup -> ConfigureServices method.

services.AddSwaggerGen(c =>
{
    c.SwaggerGeneratorOptions.IgnoreObsoleteActions = true;
    c.SwaggerDoc("v2", new Info { Title = "My API", Version = "v2" });
});

Upvotes: 1

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