ServiceStack Plugin API provides a declarative way to enable modular functionality in ServiceStack:

Plugin API

public interface IPlugin
    void Register(IAppHost appHost);

Custom Logic before Plugins are loaded

If your plugin also implements IPreInitPlugin it will get run before any plugins are registered:

public interface IPreInitPlugin
    void BeforePluginsLoaded(IAppHost appHost);

Custom Logic after Plugins are loaded

If your plugin implements IPostInitPlugin it will get run after all plugins are registered:

public interface IPostInitPlugin
    void AfterPluginsLoaded(IAppHost appHost);

Custom Logic after AppHost is initialized

If your plugin implements IAfterInitAppHost it will get run after the AppHost has finished initializing:

public interface IAfterInitAppHost
    void AfterInit(IAppHost appHost);

Disabling Plugins via Feature Enum Flags

All built-in Plugins are Registered and available via base.Plugins before your Configure() script is run so you have a chance to modify the behaviour or remove un-used plugins which is exactly what the short-hand:

SetConfig(new HostConfig { 
    EnableFeatures = Feature.All.Remove(Feature.Csv)

Which under the covers just does:

if ((Feature.Csv & config.EnableFeatures) != Feature.Csv)
    Plugins.RemoveAll(x => x is CsvFormat);

Which you now also have an opportunity to also do in your AppHost Configure() start-up script yourself - if you want to remove or customize any pre-loaded plugins.

Configuring Plugins

The ConfigurePlugin API lets us avoid time-coupling between plugin registrations by letting us configure plugins before they've been added by registering a lazy callback invoked just before a plugin is registered.

As it's resilient against ordering, it's the recommended way to configure any plugin it doesn't register, here's some usage examples:

// App's can use to change logo API Explorer uses
appHost.ConfigurePlugin<UiFeature>(feature => {
    feature.Info.BrandIcon.Uri = "";

// OpenApiFeature uses to add the /swagger-ui link to /metadata page
    feature => feature.AddPluginLink(swaggerUrl, "Swagger UI"));

// GrpcFeature uses to add a link to gRPC .proto APIs on /metadata page
    feature => feature.AddPluginLink("types/proto", "gRPC .proto APIs"));

ConfigurePlugin is invoked just before a plugin is registered, there's also PostConfigurePlugin to configure a plugin just after it's registered and AfterPluginLoaded invoked after any of its IPostInitPlugin callbacks have completed.

Resolving Plugins

You can easily use LINQ to fetch any specific plugin:

var htmlFormat = base.Plugins.First(x => x is HtmlFormat) as HtmlFormat;

Which is also what the this.GetPlugin<T>() convenience extension method does:

var htmlFormat = base.GetPlugin<HtmlFormat>();

To resolve a required plugin it's recommended to use AssertPlugin instead which will throw if a required plugin was not registered:

var htmlFormat = base.AssertPlugin<HtmlFormat>();

List of Plugins added by Default

A list of all of the plugins available on ServiceStack and how to add them:

Auto-registered plugins

These plugins below are already added by default, you can remove or customize them using the methods described above.

Metadata Feature

Provides ServiceStack's auto-generated metadata pages.

var feature = Plugins.FirstOrDefault(x => x is MetadataFeature); 
Plugins.RemoveAll(x => x is MetadataFeature); 

Predefined Routes

Provides ServiceStack's pre-defined routes used in the built-in C# Service Clients.

var feature = Plugins.FirstOrDefault(x => x is PredefinedRoutesFeature); 
Plugins.RemoveAll(x => x is PredefinedRoutesFeature); 

Native Types

Enables ServiceStack's Add ServiceStack Reference support allowing API Consumers to download API DTOs generated in their preferred programming language.

var feature = Plugins.FirstOrDefault(x => x is NativeTypesFeature); 
Plugins.RemoveAll(x => x is NativeTypesFeature); 

Request Info

Provides ServiceStack's Request Info feature useful for debugging requests. Just add ?debug=requestinfo in your /pathinfo and ServiceStack will return a dump of all the HTTP Request parameters to help with with debugging interoperability issues. The RequestInfoFeature is only enabled for Debug builds.

var feature = Plugins.FirstOrDefault(x => x is RequestInfoFeature); 
Plugins.RemoveAll(x => x is RequestInfoFeature); 


Enabling ServiceStack's SVG Support.

var feature = Plugins.FirstOrDefault(x => x is SvgFeature); 
Plugins.RemoveAll(x => x is SvgFeature); 

CSV Format

Registers the CSV Serializers to enable ServiceStack's CSV Format.

var feature = Plugins.FirstOrDefault(x => x is CsvFormat); 
Plugins.RemoveAll(x => x is CsvFormat); 


By default the CSV Format tries serialize the Response object directly into CSV which is only ideal if your responses return List<Poco>. If however you mark your Response DTO with the [Csv(CsvBehavior.FirstEnumerable)] attribute the CSV Format instead will only serialize the first IEnumerable<T> it finds on your Response DTO e.g. if you had a List<Poco> Results property it will only serialize this list in the tabular CSV Format which is typically the behaviour you want.

JSON Lines Format

Registers the JsonlSerializer to enable ServiceStack's JSON Lines Format.

var feature = Plugins.FirstOrDefault(x => x is JsonlFormat); 
Plugins.RemoveAll(x => x is JsonlFormat); 


The JSON Lines format follows CSV Format's behavior for serializing IEnumerable POCOs.

Html Format

Providing ServiceStack's Html Format.

var feature = Plugins.FirstOrDefault(x => x is HtmlFormat); 
Plugins.RemoveAll(x => x is HtmlFormat); 


Enables the validation feature to enable ServiceStack's Fluent Validation and Declarative validators support.

var feature = Plugins.FirstOrDefault(x => x is ValidationFeature); 
Plugins.RemoveAll(x => x is ValidationFeature); 

HTTP Caching

Enables HTTP Caching support

var feature = Plugins.FirstOrDefault(x => x is HttpCacheFeature); 
Plugins.RemoveAll(x => x is HttpCacheFeature); 

Available Plugins

The rest of ServiceStack's plugins are not enabled by default by can easily be added on adhoc basis, as and when needed.

Auto Query

AutoQuery enables instant querying support on RDBMS tables behind clean self-describing APIs by enhancing the ideal API the developer would naturally write and completing their implementation for them! This is essentially the philosophy behind AutoQuery which utilizes conventions to automate creation of intent-based self-descriptive APIs that are able to specify configurable conventions and leverage extensibility options to maximize the utility of AutoQuery services.

Plugins.Add(new AutoQueryFeature { MaxLimit = 100 });


Requires ServiceStack.Server

Server Events

Server Events enables server push notifications to create real-time responsive web apps with its support for Server Sent Events. It offers a number of different API's for sending notifications to select users at different levels of granularity, letting you interact and modify live-running web apps.

Plugins.Add(new ServerEventsFeature());


The Postman Rest Client is a very popular and easy to use HTTP Request composer that makes it easy to call web services, similar to Fiddler's Composer. It also provides as an alternative for auto-generating API documentation to ServiceStack's Open API support that makes it easier to call existing services but does require users to install the Postman Rest Client.

Plugins.Add(new PostmanFeature());
Plugins.Add(new CorsFeature());

Open API support

Swagger support an optional add-on available in the ServiceStack.Api.OpenApi NuGet package.

After installing the NuGet package enable the Swagger with:

Plugins.Add(new OpenApiFeature());

Now you can enjoy your shiny new Swagger UI at: http://yoursite/swagger-ui/index.html

Annotating your services

You can further document your services in the Swagger UI with the new [Api] and [ApiMember] annotation attributes, e,g: Here's an example of a fully documented service:

[Api("Service Description")]
[Route("/swagger/{Name}", "GET", Summary = @"GET Summary", Notes = "GET Notes")]
[Route("/swagger/{Name}", "POST", Summary = @"POST Summary", Notes = "POST Notes")]
public class MyRequestDto
    [ApiMember(Name="Name", Description = "Name Description", 
               ParameterType = "path", DataType = "string", IsRequired = true)]
    public string Name { get; set; }

Razor Format

Provides ServiceStack's primary HTML story with support for the MVC Razor view engine.

Plugins.Add(new RazorFormat()); 

It's an optional .NET 4.0 plugin that is available in the ServiceStack.Razor NuGet package.


The Authentication Feature enables the Authentication and Authorization support in ServiceStack. It makes available the AuthService at the default route at /auth/{provider}, registers AssignRoles and UnAssignRoles services (at /assignroles and /unassignroles default routes) and auto-enables Session support if it's not added already.

An example AuthFeature registration (taken from the SocialBootstrapApi project):

Plugins.Add(new AuthFeature(
    () => new CustomUserSession(), //Use your own typed Custom UserSession type
    new IAuthProvider[] {
        new CredentialsAuthProvider(),         //HTML Form post of UserName/Password
        new TwitterAuthProvider(appSettings),  //Sign-in with Twitter
        new FacebookAuthProvider(appSettings), //Sign-in with Facebook
        new BasicAuthProvider(),               //Sign-in with Basic Auth

This registers and provides your ServiceStack host a myriad of different Authentication options as described above.

Session support

If you're not using the AuthFeature above and you still want Session support you need to enable it explicitly with:

Plugins.Add(new SessionFeature());

This will add a Request Filter to instruct any HTTP client calling a ServiceStack web service to create a Temporary (ss-id) and Permanent (ss-pid) cookie if not already done so.


Related to Authentication is Registration which enables the Registration Service at the default route /register which lets new Users to be registered and validated with the Credentials and Basic AuthProviders.

Plugins.Add(new RegistrationFeature());

See the SocialBootstrapApi project for a working example of Registration and Authentication.

MessagePack format

To add fast binary MessagePack support to ServiceStack install the ServiceStack.MsgPack NuGet package and register the plugin with:

Plugins.Add(new MsgPackFormat());

ProtoBuf format

To enable ProtoBuf support install the ServiceStack.ProtoBuf NuGet package and register the plugin with:

Plugins.Add(new ProtoBufFormat());

Proxy Feature

The ProxyFeature plugin is an application-level proxy that can be used to transparently proxy HTTP Requests through to downstream servers whose behavior can be customized with custom C# hooks to control how requests are proxied.

Plugins.Add(new ProxyFeature(
    matchingRequests: req => req.PathInfo.StartsWith("/sales"),
    resolveUrl:req => "" + req.RawUrl.Replace("/sales", "/")))

Request Logger

Add an In-Memory IRequestLogger and service with the default route at /requestlogs which maintains a live log of the most recent requests (and their responses). Supports multiple config options incl. Rolling-size capacity, error and session tracking, hidden request bodies for sensitive services, etc.

Plugins.Add(new RequestLogsFeature());

The IRequestLogger is a great way to introspect and analyze your service requests in real-time, e.g:

Live Screenshot

It supports multiple queryString filters and switches so you filter out related requests for better analysis and debuggability:

Request Logs Usage

The RequestLogsService is just a simple C# service under-the-hood but is a good example of how a little bit of code can provide a lot of value in ServiceStack's by leveraging its generic, built-in features.

Encrypted Messaging

The Encrypted Messaging feature enables a secure channel for all Services to offer protection to clients who can now easily send and receive encrypted messages over unsecured HTTP by registering the EncryptedMessagesFeature plugin:

Plugins.Add(new EncryptedMessagesFeature {
    PrivateKeyXml = ServerRsaPrivateKeyXml

Where PrivateKeyXml is the Servers RSA Private Key Serialized as XML. See the Encrypted Messaging docs for more info.

Razor Markdown Format

This provides ServiceStack's Razor Markdown Format and also enables ServiceStack to serve static .md or .markdown files in either plain text, rendered as HTML (partial), or rendered in HTML inside a static _Layout.shtml HTML template.

Plugins.Add(new MarkdownFormat()); 

Cancellable Requests

The Cancellable Requests Feature makes it easy to design long-running Services that are cancellable with an external Web Service Request. To enable this feature, register the CancellableRequestsFeature plugin:

Plugins.Add(new CancellableRequestsFeature());

Web Sudo

A common UX in some websites is to add an extra layer of protection for super protected functionality by getting users to re-confirm their password verifying it's still them using the website, common in places like confirming a financial transaction.

WebSudo is a new feature similar in spirit requiring users to re-authenticate when accessing Services annotated with the [WebSudoRequired] attribute. To make use of WebSudo, first register the plugin:

Plugins.Add(new WebSudoFeature());

Your Custom AuthUserSession would need to either inherit WebSudoAuthUserSession or implement IWebSudoAuthSession, e.g:

public class CustomUserSession : WebSudoAuthUserSession {}

Then tell ServiceStack to use your CustomUserSession by registering it with the AuthFeature, e.g:

Plugins.Add(new AuthFeature(() => new CustomUserSession(), ...);

You can then apply WebSudo behavior to existing services by annotating them with [WebSudoRequired]:

public class RequiresWebSudoService : Service
    public object Any(RequiresWebSudo request)
        return request;

Once enabled this will throw a 402 Web Sudo Required HTTP Error the first time the service is called:

var requiresWebSudo = new RequiresWebSudo { Name = "test" };
    client.Send<RequiresWebSudoResponse>(requiresWebSudo); //throws
catch (WebServiceException)
    client.Send(authRequest); //re-authenticate
    var response = client.Send(requiresWebSudo); //success!

Re-authenticating afterwards will allow access to the WebSudo service.

Community Plugins


If you need to implement a Webhooks solution for your Services check out ServiceStack.Webhooks. ServiceStack.Webhooks is a well documented solution for raising and managing application-level "events" raised by your services:

The ServiceStack.Webhooks plugin is versatile and supports persisting event subscriptions in multiple back-end data stores including: Memory, Cache Clients, Azure Table Storage as well as every major RDBMS that supported by OrmLite.

Getting Started

Install ServiceStack.Webhooks from NuGet:

<PackageReference Include="ServiceStack.Webhooks" Version="8.*" />

Register the WebhookFeature plugin in your AppHost:

public override void Configure(Container container)
    // Add ValidationFeature and AuthFeature plugins first
    Plugins.Add(new WebhookFeature());

Then configure the plugin to suit your needs.

Community Resources