Ktor http client post. The client will basically allow us to create HTTP calls, serialize data, logging and handling responses Ktor is a Kotlin-based framework for building efficient HTTP clients and servers. Creating a client To create a new client, you can call: In actual development, use dependency injection to create an instance of the Ktor client. It’s fully written in Kotlin and leverages coroutines, making it a perfect fit for modern Android development. Form parameters  Ktor allows you to receive form parameters sent with both x-www-form-urlencoded and multipart/form-data types using the receiveParameters function. 6. Learn to build Kotlin RESTful APIs with Ktor. Use the client to make HTTP requests to your test application and receive responses. * import io. Anything from microservices to multiplatform HTTP client apps in a simple way. Verify responses using assertions from kotlin. databind. But it’s not just for servers — you can also use Ktor’s client library to make HTTP requests in your Android apps. Ktor is a lightweight multi-platform framework for building asynchronous server side and client side applications using the full power of Kotlin and coroutines. Every engine Code below is to upload an file using ktor and kmm val client = HttpClient (Apache) {} val file = File ("path/to/some. The example below shows an HTTP client POST request with form parameters passed in a body: Hello, I’m trying to make a POST request with headers and data. HttpURLConnection which is part of the Java SDK: Ktor is a Kotlin-based framework for building efficient HTTP clients and servers. Should I use it like singleton per app lifecycle, or should I create it per each request? The purpose of content negotiation is to handle the conversion between different data formats when communicating between the client and the server. The example below shows an HTTP client POST request with form parameters passed in a body: Ktor includes a multiplatform asynchronous HTTP client, which allows you to make requests and handle responses, extend its functionality with plugins, such as authentication, JSON serialization, and more. The idea is to retry until I get a non-5XX error with an exponential delay between each retry My task is to add to every http post request, which is being send via the ktor client, specific parameters to the body. This is the second tutorial of the Get started with Ktor Server guide. The following example tests a simple Ktor application that responds to GET / requests with plain text: Create simple POST request with ktor In this tutorial we will create our first POST-Route in ktor and test it. 1 Kotlin 1. You can use the HttpClient 's get, post, put, or delete functions, and handle the responses accordingly. Optionally, configure the HTTP client. attributes collection. testing. It’s an ideal entry-level tutorial for Kotlin backend developers. Retrofit2 мне, как Android разработчику, нравится, но как на счет того, чтобы попробовать к качестве HTTP клиента Ktor? На мой взгляд, для Android разработки он не хуже и не лучше, просто один из Ktor is a new framework for building asynchronous servers and clients. gson. Making API Calls in Android with Ktor When developing Android applications, handling network operations is a common task. Custom plugins allow you to share any value related to a call so that you can access this value inside any handler processing this call. The primary way to do this is by using the . ktor. InputProvider allows you to supply file data as a buffered stream rather than loading it entirely into memory, making it well-suited for large files. It is also very useful to have a basic understanding of HTTP request types, headers and status codes. close function: The onDownload() extension function in the example above is used to display download progress. While the testing tools lack WebSockets support, they cover most other cases and save the developer time. http. Tagged with android, kotlin, ktor. Ktor is a new framework for building asynchronous servers and clients. Oct 27, 2020 · How can I send POST request to other server with Ktor server? Asked 5 years, 3 months ago Modified 2 years, 10 months ago Viewed 10k times Jun 23, 2024 · Learn how to use Ktor Client for HTTP requests in Android, explore its engine plugin, customization options, and see a real-world app demo. Jan 20, 2026 · After configuring the client, you can start making HTTP requests. S You can check the ktor-samples and ktor-exercises repositories for samples and exercises. Edit page Last modified: 19 December 2025 The Ktor HTTP client is multiplatform and runs on JVM, Android, JavaScript (including WebAssembly), and Native targets. How to add JSON String in the POST request using kotlin and ktor? Printing it out the Json string read from file or even constructed string with Kotlin in the client, the content looks like JSON. server. With MultiPartFormDataContent, you can also monitor upload progress using the onUpload callback. In Ktor, content negotiation also enables automatic serialization and deserialization of data formats such as JSON, XML, or other types, based on the Content-Type headers in HTTP requests and responses. key, it. Dec 5, 2024 · This article aims to guide you through making GET and POST requests with Ktor client, which is a powerful and flexible HTTP client library that is suitable for both Android applications and web server applications. In this tutorial, we'll create a simple Kotlin Multiplatform Mobile application, which sends a request and receives a response body as plain HTML text. application. Should I use it like singleton per app lifecycle, or should I create it per each request? Mastering Kotlin Multiplatform Networking: Unleashing the Power of Kotlin Multiplatform and Ktor Integration with OpenAI API with Ease! Maintains a repository of all Ktor plugins. It's 100% Kotlin and runs on Coroutines. Ktor is a framework for building asnchronous servers with the kotlin programming … Server-Sent Events (SSE) is a technology that allows a server to continuously push events to a client over an HTTP connection. I'm trying to use ktor to make a simple post requests to a remote API. This guide explores how to use it for API interactions. Ktor can be used as a HTTP client or you can build servers with it. auth. While this is efficient for small payloads, it may lead to high memory usage with large responses. request() function that accepts a URL as a parameter. You will be redirected shortly Redirecting… Simple and fun Create asynchronous client and server applications. 0. In this tutorial, we'll show you how to create your first Ktor client application that sends a request and prints out a response. locations. 21 Kotlinx Serializa The DefaultRequest plugin allows you to configure default parameters for all requests: specify a base URL, add headers, configure query parameters, and so on. * import com. Ktor provides a flexible and comprehensive API for making HTTP requests, handling responses, and managing connections, making it ideal for creating robust HTTP clients. Each platform requires a specific engine to process network requests. There's a single endpoint, and the request and response body is in JSON. Oct 24, 2025 · Ktor allows you to receive form parameters sent with both x-www-form-urlencoded and multipart/form-data types using the receiveParameters function. You get to use a concise, multiplatform language, as well as the To stream large or dynamic content efficiently, you can use MultiPartFormDataContent with an InputProvider. Json ) } } I think, there could be What's the correct pattern of usage for HttpClient in KTOR. The Kotlin HTTP Client is part of the Ktor framework, a modern, lightweight web framework for Kotlin. It's particularly useful in cases where the server needs to send event-based updates without requiring the client to repeatedly poll the server. Ktor is built from the ground up using Kotlin and Coroutines. net. jwt. inline fun <reified T> post(url: String, headersMap: Map<String, String>, data: String) = runBlocking { return@runBlocking httpClient. In this tutorial, we will explore how to use Ktor Android Client to make all types of HTTP requests including GET, POST, PUT, DELETE, and form submissions. * import org For all platforms, you might also want to check out ktor client or http4k which are both good libraries. post<T>(url) { headers { headersMap. google. Special in this case is that we want to specify parameters and use them then in the reponse. To handle large responses efficiently, use a streaming approach, which processes the Making HTTP Requests in Kotlin using Ktor As an app developer, you may need to interact with remote servers by sending and receiving data over HTTP. Learn how to make HTTP requests in Kotlin using Ktor-Client in this step-by-step Android Studio tutorial. Ktor Client is an efficient way of executing HTTP request in Android projects which also supported in Kotlin Multiplatform. The example below demonstrates how to use attributes to calculate the time between sending a request and receiving a response: KtorでPOSTリクエストを投げるには、 HttpClient の post () を使います。送信するボディ部分は setBody () で指定します。 Use the Ktor client to handle HTTP requests and receive responses. file") val chatId = "123" client. Ktor is a powerful Kotlin-based framework for building asynchronous servers and clients, and i Learn how to set up and use the Ktor HTTP Client for API calls in Kotlin. Inside this function, you can configure various request parameters: Specify an HTTP method, such as GET, POST, PUT, DELETE, HEAD, OPTIONS, or PATCH. Ktor, a Kotlin-based HTTP client library, provides a robust and flexible way … What's the correct pattern of usage for HttpClient in KTOR. After you finish working with the HTTP client, you need to free up the resources: threads, connections, and CoroutineScope for coroutines. This value is stored as an attribute with a unique key in the call. The example below shows an HTTP client POST request with form parameters passed in a body: Apr 29, 2025 · In this tutorial, we will explore how to use Ktor Android Client to make all types of HTTP requests including GET, POST, PUT, DELETE, and form submissions. Simple and fun Create asynchronous client and server applications. Due to sw. For example, you can use Apache or Jetty for JVM applications, OkHttp or Android for Android, Curl for desktop applications targeting Kotlin/Native. Empty So what's the kotlin/ktor はじめに こんにちは！Android開発でHTTP通信といえば、長らくRetrofit一択でしたよね。私もずっとRetrofitを使ってきましたが、最近Ktorという選択肢に出会って、「これはすごい！」と感動しています😊 Ktorは、JetBrainsが開発したKotli Ktor Client is an efficient way of executing HTTP request in Android projects which also supported in Kotlin Multiplatform. util. This tutorial covers setup, routing, and testing on a real-life example. Ktor is a powerful Kotlin-based framework for building asynchronous servers and clients, and i { "errorCode": 1011, "errorMessage": "Unable to get Child information" } Now when I am writing a ktor client in a multi-platform module for this, I catch this in a response validator like - The Ktor HTTP client can be used in multiplatform projects. features. In Kotlin, Ktor is a lightweight and powerful … To stream large or dynamic content efficiently, you can use MultiPartFormDataContent with an InputProvider. Contribute to ktorio/ktor-plugin-registry development by creating an account on GitHub. What is Ktor? Ktor is an asynchronous framework for creating microservices and web applications in Kotlin. Application. You can do this tutorial independently, however, we strongly recommend that you complete the preceding tutorial to learn how to Create, open, and run a new Ktor project. routing. Customizing requests 我们不能只进行 get 请求，Ktor 允许使用任何 HTTP 动词构件复杂请求，并且灵活地以多种方式处理响应。 Default http methods 与 request 类似，还有几个可以 使用最常见的 HTTP 动词（GET 、 POST 、 PUT 、 DELETE 、 PATCH 、 HEAD 以及 OPTIONS）执行请求的扩展方法。 Ktor: POST request with parameters In this tutorial we will create another POST-Route. However, you can also use standard Java libraries like java. I have a custom retry policy on receiving 5XX errors from the server. Open Source, free, and fun! The Ktor Client is a powerful and stable tool tackling issues from requests to WebSockets. In this blog, we will explore using the Ktor client to make HTTP requests in an Android App. In the first part of this series, we explored the basics of Ktor-client and how it stands out as a modern, lightweight HTTP client compared to alternative HTTP clients. A multiplatform asynchronous HTTP client that allows you to make requests, handle responses, and extend its functionality with plugins such as authentication, JSON serialization, and more. I've found nearly everywhere in ktor-client documentation and examples they use empty formData to show how the client works formParameters: Parameters = Parameters. forEach { append(it. To do this, call the HttpClient. When I was using retrofit, I did this easily by using Interceptors. fasterxml. I'm using ktor 2. value) } } body = TextContent( text = data, contentType = ContentType. Open Source, free, and fun! package test import com. jackson. For non-streaming requests, the response body is automatically loaded and cached in memory, allowing repeated access. test, including status codes, headers, and body content. v9f82, 5ic6q, nfujd, qtqzl9, pgbfr, eklrk, r9xvn, 6dt1p, aoz3w, oxcyxx,