Kotlin and ChatGPT: Creating an AI Assistant for Code

Kotlin Meets AI: Why Kotlin Developers Are Already Using ChatGPT

The world of development is changing before our eyes. Just yesterday we feared that neural networks would replace programmers, and today we actively use them as super-assistants. And if you write in Kotlin, you have a unique advantage: this language is perfect for creating fast, modern, and secure applications that can communicate with ChatGPT.

In this article, we will break down how to use ChatGPT in Kotlin development — not as a theoretical concept, but as a working tool. You will learn how to integrate the OpenAI API into your project, process neural network responses, and build useful features based on them. No fluff, with real code examples.

Where Kotlin and AI Meet in Practice

Kotlin is not just Android. It's backend on Ktor, microservices on Spring Boot, data science, and even multiplatform applications. By adding ChatGPT API to this, you get the ability to:

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• Automatically generate code documentation
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• Create chatbots with natural language
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• Analyze user input and classify it
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• Build "smart" search over a knowledge base
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• Check code for errors and suggest fixes
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And all this — in your native Kotlin. No Python, no unnecessary dependencies. Just Ktor, ktor-client, and a bit of prompt magic.

Preparing the Project: Minimal Setup for Working with ChatGPT

To start, we need an HTTP client. In the Kotlin world, the best choice is Ktor Client. It is lightweight, asynchronous, and perfect for working with REST APIs.

Add the dependencies to build.gradle.kts:

dependencies {\n    implementation("io.ktor:ktor-client-core:2.3.7")\n    implementation("io.ktor:ktor-client-cio:2.3.7")\n    implementation("io.ktor:ktor-client-content-negotiation:2.3.7")\n    implementation("io.ktor:ktor-serialization-kotlinx-json:2.3.7")\n    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.6.2")\n}

Now let's create a simple class for communicating with OpenAI. It will send requests to the ChatGPT API and return the response in a convenient format.

Writing Code: First Request to ChatGPT in Kotlin

Let's start with the data model. We will use Kotlin Serialization for working with JSON.

@Serializable\ndata class ChatMessage(\n    val role: String,\n    val content: String\n)\n\n@Serializable\ndata class ChatRequest(\n    val model: String = "gpt-3.5-turbo",\n    val messages: List<ChatMessage>,\n    val temperature: Double = 0.7\n)\n\n@Serializable\ndata class ChatResponse(\n    val choices: List<Choice>\n)\n\n@Serializable\ndata class Choice(\n    val message: ChatMessage\n)

Now let's write a function that sends a message to ChatGPT and returns the response:

class OpenAIClient(private val apiKey: String) {\n    private val client = HttpClient(CIO) {\n        install(ContentNegotiation) {\n            json(Json {\n                ignoreUnknownKeys = true\n            })\n        }\n    }\n\n    suspend fun ask(prompt: String): String {\n        val request = ChatRequest(\n            messages = listOf(\n                ChatMessage("user", prompt)\n            )\n        )\n\n        val response: ChatResponse = client.post("https://api.openai.com/v1/chat/completions") {\n            header("Authorization", "Bearer $apiKey")\n            contentType(ContentType.Application.Json)\n            setBody(request)\n        }.body()\n\n        return response.choices.first().message.content\n    }\n}

Note: we use a suspend function — this means the call does not block the thread. Perfect