Universal.CodeGeneration.CSharp 1.6.1

Universal.CodeGeneration.CSharp

Generates strongly typed C# HTTP clients, models, and URI builders from OpenAPI documents and route definitions.

HTTP clients

Parse an OpenAPI document, select the generated language and client shape, then generate one file or a file set:

var specification = HttpServiceClientGenerator.ApiSpecification.FromOpenApi(openApiJson);
var generator = new HttpServiceClientGenerator(
    "MyApi.Client",
    "MyApiClient",
    new HttpServiceClientGenerator.Options
    {
        ClientStyle = HttpServiceClientGenerator.ClientStyle.TagGroups,
        LanguageVersion = HttpServiceClientGenerator.CSharpLanguageVersion.Latest,
        ModelPropertyStyle = HttpServiceClientGenerator.ModelPropertyStyle.Auto,
        OutputType = HttpServiceClientGenerator.OutputType.MultipleFiles,
        TargetFramework = "net10.0"
    });

generator.GenerateFiles(specification, "Generated", deleteStaleFiles: true);

Client styles:

• HierarchicalResources exposes operations through the URL resource tree.
• FlatBuilders exposes one builder for each path.
• Simple places operations directly on the client.
• TagGroups groups operations by their primary OpenAPI tag.

Generation options control the base client, JSON serializer, nullable annotations, DTO property style, target framework, default headers, constructor shape, namespace layout, and output layout.

Generated clients can include authentication and header helpers, transport and serialization hooks, raw request methods, response envelopes, cancellation, and partial types. Built-in client bases accept an injected HttpClient and take ownership of it, enabling handler configuration, IHttpClientFactory, automatic decompression, proxies, certificates, and test transports. Put handwritten behavior in separate partial-class files or source transforms so regeneration can replace the generated directory safely.

URI builders

UriBuilderGenerator generates flat or fluent URI builders from route definitions. UriBuilderGenerator.ApiRoutes can derive routes from OpenAPI JSON.

var routes = UriBuilderGenerator.ApiRoutes.FromOpenApiJson(openApiJson);
var generator = new UriBuilderGenerator(
    "MyApi.Routes",
    "ApiRoutes",
    new UriBuilderGenerator.Options { UseFluentGeneration = true });

var source = generator.Generate(routes);

Initializer expressions

ToInitializerString converts supported values and object graphs to C# initializer expressions.