Generate Typed API Client from OpenAPI

Generate a fully typed HTTP client from an OpenAPI/Swagger specification.

For .NET (NSwag)

dotnet tool install -g NSwag.ConsoleCore
nswag openapi2csclient /input:swagger.json /output:ApiClient.cs /namespace:MyApp.ApiClients /className:SourcingApiClient /generateClientInterfaces:true /injectHttpClient:true

Register in DI:

builder.Services.AddHttpClient<ISourcingApiClient, SourcingApiClient>(client =>
    client.BaseAddress = new Uri(config["ApiBaseUrl"]));

For TypeScript (openapi-typescript + openapi-fetch)

npm install openapi-typescript openapi-fetch
npx openapi-typescript ./openapi.yaml -o ./src/api/schema.d.ts

Usage:

import createClient from "openapi-fetch";
import type { paths } from "./api/schema";
const client = createClient<paths>({ baseUrl: "http://localhost:5000" });
const { data } = await client.GET("/api/candidates/{id}", { params: { path: { id: "c-001" } } });

For .NET (Microsoft Kiota)

dotnet tool install -g Microsoft.OpenApi.Kiota
kiota generate -l CSharp -d openapi.yaml -c SourcingClient -n MyApp.ApiClients -o ./Generated

Arguments

• <openapi-url-or-path>: URL or path to OpenAPI spec
• --lang=<typescript|csharp>: Target language (default: csharp)