Response Generators

IdentityServer’s endpoints follow a pattern of abstraction in which a response generator uses a validated input model to produce a response model. The response model is a type that represents the data that will be returned from the endpoint. The response model is then wrapped in a result model, which is a type that facilitates serialization by an implementation of IHttpResponseWriter.

Customization of protocol endpoint responses is possible in both the response generators and response writers. Response generator customization is appropriate when you want to change the “business logic” of an endpoint and is typically accomplished by overriding virtual methods in the default response generator. Response writer customization is appropriate when you want to change the serialization, encoding, or headers of the HTTP response and is accomplished by registering a custom implementation of the IHttpResponseWriter.

Available Response Generators

Interface	Default Implementation	Endpoint
IAuthorizeInteractionResponseGenerator	AuthorizeInteractionResponseGenerator	Authorize
IAuthorizeResponseGenerator	AuthorizeResponseGenerator	Authorize
ITokenResponseGenerator	TokenResponseGenerator	Token
IDiscoveryResponseGenerator	DiscoveryResponseGenerator	Discovery
IIntrospectionResponseGenerator	IntrospectionResponseGenerator	Introspection
ITokenRevocationResponseGenerator	TokenRevocationResponseGenerator	Revocation
IUserInfoResponseGenerator	UserInfoResponseGenerator	UserInfo
IDeviceAuthorizationResponseGenerator	DeviceAuthorizationResponseGenerator	Device Authorization
IBackchannelAuthenticationResponseGenerator	BackchannelAuthenticationResponseGenerator	CIBA
IPushedAuthorizationResponseGenerator	PushedAuthorizationResponseGenerator	Pushed Authorization

Customization Pattern

To customize a response generator, inherit from the default implementation and override its virtual methods:

public class CustomTokenResponseGenerator : TokenResponseGenerator
{
    public CustomTokenResponseGenerator(
        ITokenService tokenService,
        IRefreshTokenService refreshTokenService,
        IScopeParser scopeParser,
        IResourceStore resources,
        IClientStore clients,
        ILogger<TokenResponseGenerator> logger)
        : base(tokenService, refreshTokenService, scopeParser, resources, clients, logger)
    {
    }

    protected override async Task<TokenResponse> ProcessAuthorizationCodeRequestAsync(
        TokenRequestValidationResult request, CancellationToken ct)
    {
        var response = await base.ProcessAuthorizationCodeRequestAsync(request, ct);
        // Add custom response parameters
        response.Custom["custom_field"] = "custom_value";
        return response;
    }
}

Register your custom implementation:

builder.Services.AddTransient<ITokenResponseGenerator, CustomTokenResponseGenerator>();