Integrating DeepSeek AI Assistant into IntelliJ IDEA for Java Development

In early 2025, AI-powered coding assistants like DeepSeek have become essential tools for developers, and integrating DeepSeek into IntelliJ IDEA provides a seamless AI companion for Java programming.

Environment preparation : Ensure you are using IntelliJ IDEA 2023.x or newer and have Python 3.7+ installed and added to the system PATH. Install the CodeGPT plugin (a robust AI‑driven code assistant) from the JetBrains Marketplace.

Plugin installation : Open IDEA, go to Settings (Windows/Linux) or IntelliJ IDEA → Preferences (macOS), select Plugins , switch to the Marketplace tab, search for CodeGPT , and click Install . Restart IDEA after installation.

DeepSeek configuration : Visit https://www.deepseek.com/ , navigate to the API Open Platform, and create an API key. In IDEA, open the CodeGPT settings, locate the DeepSeek section, and paste the obtained API key.

IDEA integration steps :

In the CodeGPT settings, choose Custom OpenAI and set the chat endpoint to https://api.deepseek.com/chat/completions with the model deepseek-chat .

For the inference model, enable Enable code completions and Parse response as Chat Completions , select the FIM template DeepSeek Coder , set the same endpoint URL, and choose the model deepseek-reasoner .

After applying the settings, the DeepSeek assistant is ready for use.

Using DeepSeek :

To generate ideas or code, open the CodeGPT panel, select Custom OpenAI , and type your request (e.g., “Write a Java method that filters numbers and provide a test”).

For code completion, place the cursor after a partial statement and press Ctrl + Space (or your custom shortcut); DeepSeek will suggest the next code segment.

To explain code, select a snippet, right‑click, and choose CodeGPT to receive a detailed description.

For troubleshooting, select the code or describe the problem and choose CodeGPT: Ask Question to get targeted solutions.

Example Java code generated by DeepSeek:

public class TestNumberFilter {
    public static String filterNumbers(String input) {
        // Use regex to keep only digits
        return input.replaceAll("[^0-9]", "");
    }

    public static void main(String[] args) {
        String testInput2 = "SSFSDFS结论萨芬122432的噶大都是4无人区是14认识832safsss";
        String result = filterNumbers(testInput2);
        System.out.println("Filtered numbers: " + result); // Output: 122432447832
    }
}

DeepSeek also provides token‑usage statistics; you can view daily usage and cost details on the DeepSeek dashboard (e.g., https://api-docs.deepseek.com/zh-cn/ ).

By following these steps, you can fully integrate DeepSeek into IntelliJ IDEA, boost coding efficiency, and leverage AI assistance throughout your Java development workflow.