Training
Module
Build a web API with minimal API, ASP.NET Core, and .NET - Training
Learn how to build a web API by using .NET. You'll also learn how to set up different routes to handle both reading and writing.
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In this tutorial, you build a sample command line interface (CLI) app that calls a REST API that doesn't require authentication.
A command line tool is required. We recommend:
Run the following command in the directory you want to create a new project.
dotnet new console -o KiotaPostsCLI
cd KiotaPostsCLI
dotnet new gitignore
In case you're adding a Kiota client to an existing project, the following configuration is required:
Before you can compile and run the generated API client, you need to make sure the generated source files are part of a project with the required dependencies. Your project must have a reference to the bundle package and the cli-commons package. For more information about Kiota dependencies, see the dependencies documentation.
For this tutorial, use the default implementations.
Run the following commands to get the required dependencies.
dotnet add package Microsoft.Kiota.Bundle
dotnet add package Microsoft.Kiota.Cli.Commons --prerelease
Kiota generates API clients from OpenAPI documents. Create a file named posts-api.yml and add the following.
openapi: '3.0.2'
info:
title: JSONPlaceholder
version: '1.0'
servers:
- url: https://jsonplaceholder.typicode.com/
components:
schemas:
post:
type: object
properties:
userId:
type: integer
id:
type: integer
title:
type: string
body:
type: string
parameters:
post-id:
name: post-id
in: path
description: 'key: id of post'
required: true
style: simple
schema:
type: integer
paths:
/posts:
get:
description: Get posts
parameters:
- name: userId
in: query
description: Filter results by user ID
required: false
style: form
schema:
type: integer
maxItems: 1
- name: title
in: query
description: Filter results by title
required: false
style: form
schema:
type: string
maxItems: 1
responses:
'200':
description: OK
content:
application/json:
schema:
type: array
items:
$ref: '#/components/schemas/post'
post:
description: 'Create post'
requestBody:
required: true
content:
application/json:
schema:
$ref: '#/components/schemas/post'
responses:
'201':
description: Created
content:
application/json:
schema:
$ref: '#/components/schemas/post'
/posts/{post-id}:
get:
description: 'Get post by ID'
parameters:
- $ref: '#/components/parameters/post-id'
responses:
'200':
description: OK
content:
application/json:
schema:
$ref: '#/components/schemas/post'
patch:
description: 'Update post'
requestBody:
required: true
content:
application/json:
schema:
$ref: '#/components/schemas/post'
parameters:
- $ref: '#/components/parameters/post-id'
responses:
'200':
description: OK
content:
application/json:
schema:
$ref: '#/components/schemas/post'
delete:
description: 'Delete post'
parameters:
- $ref: '#/components/parameters/post-id'
responses:
'200':
description: OK
This file is a minimal OpenAPI description that describes how to call the /posts
endpoint in the JSONPlaceholder REST API.
You can then use the Kiota command line tool to generate the API client classes.
kiota generate -l CLI -c PostsClient -n KiotaPostsCLI.Client -d ./posts-api.yml -o ./src/Client
Tip
Add --exclude-backward-compatible
if you want to reduce the size of the generated client and are not concerned about
potentially source breaking changes with future versions of Kiota when updating the client.
The final step is to update the Program.cs file that was generated as part of the console application, replacing its contents with the following code.
using System.CommandLine.Builder;
using System.CommandLine.Parsing;
using KiotaPostsCLI.Client;
using Microsoft.Kiota.Abstractions;
using Microsoft.Kiota.Abstractions.Authentication;
using Microsoft.Kiota.Cli.Commons.Extensions;
using Microsoft.Kiota.Http.HttpClientLibrary;
using Microsoft.Kiota.Serialization.Form;
using Microsoft.Kiota.Serialization.Json;
using Microsoft.Kiota.Serialization.Text;
var rootCommand = new PostsClient().BuildRootCommand();
rootCommand.Description = "Kiota Posts CLI";
var builder = new CommandLineBuilder(rootCommand)
.UseDefaults()
.UseRequestAdapter(context =>
{
var authProvider = new AnonymousAuthenticationProvider();
var adapter = new HttpClientRequestAdapter(authProvider);
adapter.BaseUrl = "https://jsonplaceholder.typicode.com";
// Register default serializers
ApiClientBuilder.RegisterDefaultSerializer<JsonSerializationWriterFactory>();
ApiClientBuilder.RegisterDefaultSerializer<TextSerializationWriterFactory>();
ApiClientBuilder.RegisterDefaultSerializer<FormSerializationWriterFactory>();
// Register default deserializers
ApiClientBuilder.RegisterDefaultDeserializer<JsonParseNodeFactory>();
ApiClientBuilder.RegisterDefaultDeserializer<TextParseNodeFactory>();
ApiClientBuilder.RegisterDefaultDeserializer<FormParseNodeFactory>();
return adapter;
}).RegisterCommonServices();
return await builder.Build().InvokeAsync(args);
Note
The JSONPlaceholder REST API doesn't require any authentication, so this sample uses the AnonymousAuthenticationProvider. For APIs that require authentication, use an applicable authentication provider.
To invoke the CLI app, run the following commands in your project directory.
dotnet run -- posts list
dotnet run -- posts get --post-id 5
dotnet run -- posts create --body '{ "userId": 42, "title": "Testing Kiota-generated API client", "body": "Hello world!" }'
dotnet run -- posts patch --post-id 5 --body '{ "title": "Updated title" }'
dotnet run -- posts delete --post-id 5
Training
Module
Build a web API with minimal API, ASP.NET Core, and .NET - Training
Learn how to build a web API by using .NET. You'll also learn how to set up different routes to handle both reading and writing.