Installing the CodeGym Plugin for CLion

1. How to find and install the CodeGym plugin

If CLion were a smartphone, plugins would be the apps that make it truly useful. Plugins extend the IDE functionality: they add support for new tools, service integrations, themes, and smart code analyzers.

The CodeGym plugin is a special extension designed so you can solve course tasks right in CLion. Imagine: no copying code back and forth, no constant switching between the browser and your local IDE — everything works in one window! The plugin lets you:

• Receive C++ tasks directly in your project;
• Submit solutions for checking with one click;
• See results immediately: accepted, error, hint;
• And, of course, be less distracted by the browser.

2. Installing and activating the CodeGym plugin

To work with the plugin you need CLion 2025.3 (or newer) and plugin version 251.1.18+. You can download the CodeGym plugin directly from the JetBrains internal marketplace.

1. Go to the "Settings" section: on Windows/Linux it's File -> Settings, on macOS — CLion -> Settings.... If you don't see the settings section, open any project or click the gear on the welcome screen.
2. In the window that appears, select Plugins in the side menu and open the Marketplace tab. In the search box type codegym.

3. Select the plugin, click the Install button and accept the "Third-Party Plugins Notice".

4. Restart IDE so the plugin integrates into CLion.

5. After restarting you will see a slightly changed interface and a Sign in button on the top horizontal toolbar.

   Clicking it will open a sign-in window where you need to enter your secret key. You can find the key in “Settings” → “Security & Sign-in” on the site.

   After logging in the learning project will be downloaded automatically and a CMake profile will be prepared for building tasks. Please do not change these build settings manually so the auto-checking works correctly.

   Trust and Open... — this is the standard security feature in CLion. The IDE asks whether you trust the code in this project. For CodeGym projects you can safely click "Trust Project".

6. To open a new task, click the Tasks tab on the left vertical panel, then select a task card and in the popup click Open:

   You will see a window with two tabs. Solution — your .cpp file for writing code, and Condition — the task statement text.

   Write your solution and click the Check button (the green check).

Congratulations! The plugin is installed, the workspace is ready — you can start solving C++ tasks.

Yellow warning panel

If upon opening a new task you see a yellow warning panel at the top saying "This file does not belong to any project target", don't worry. Your code is fine.

Let's break down why this message appears and how our IDE works under the hood.

1. Why does this message appear and what does it affect?

The C++ language has a strict build system. When a new task file appears on your computer, the IDE sees it, but by default considers it "detached" from the main project. Since the environment doesn't know exactly how to compile this file, it temporarily switches to a resource-saving mode and disables its "smart" features for it: code autocompletion, deep syntax highlighting, and static error analysis (Clang-Tidy).

2. What is the core of the conflict?

It is important to understand: this is not a plugin error or a platform error. It's about the difference in architectural approaches. We gradually load hundreds of new tasks via the plugin, and for us, each task is a separate, independent micro-project.

However, CLion perceives our entire shared folder as one large monolithic project. When the plugin downloads a new file, the IDE simply doesn't understand how this new part should integrate into the overall mechanism and waits for your instructions. This is the standard behavior of professional tools.

3. How to restore autocompletion?

You won't have to configure the environment manually every time. CLion has an excellent automatic recognition mechanism. As soon as you run the code once (press the Run button), the IDE will independently form the run configuration.

Immediately after that, autocompletion, highlighting, and code checking will instantly start working for all your files.

4. How to remove visual noise?

If this banner simply annoys you, you can hide it. Click on the settings icon directly on the yellow panel itself and select "Disable notification banner".

Site — plugin task synchronization

The task list and their statuses are updated automatically: every five minutes or after a successful submission of any task for checking.

So if you solved a task on the website via the browser, it will also be marked as solved in the plugin. If you need to force-update statuses right now, click your avatar (top-right in the CLion interface), and in the dropdown choose Synchronize tasks:

Beginner mode in the plugin

This is a simplified interface version for those who have little experience with complex IDEs. It hides some advanced CLion features so you don't get overloaded with extra information. To disable this mode (when you feel confident), click your avatar and uncheck the menu item: Settings -> Beginner mode.

How to hide the plugin navigation panel in PRO mode

If you are an experienced developer and want to see more code on the screen, click Settings (⚙️) in the plugin menu and uncheck the item "Show navigation panel of the plugin".

4. Must-have plugins for CLion

The JetBrains ecosystem is famous for its plugins. Although CLion "out of the box" provides everything necessary for C++, there are several universal extensions that greatly simplify life and learning.

1. Key Promoter X

A real virtual hotkey coach! Key Promoter X watches how you work in CLion. If you reach for the mouse to press some button (for example, Run or Build), the plugin helpfully shows a notification: "You could have done this in a millisecond by pressing Shift+F10". Install it — and in a month your hands will fly across the keyboard without the mouse.

2. Rainbow Brackets (Rainbow brackets)

In C++ you'll have a huge number of curly {}, round (), and angle <> brackets (especially when you get to templates). It's very easy to get confused. The Rainbow Brackets plugin colors each bracket pair in a unique color. It visually breaks the "wall of code" into understandable logical blocks and saves a lot of time when looking for a forgotten closing bracket.

3. Material Theme UI

Want your IDE to look stylish, personalized, and modern? Material Theme UI is the most popular interface customization plugin across the JetBrains IDE lineup. It replaces the default CLion appearance with beautiful Material Design-style themes, changes system icons, makes the project folder pop, and adds nice accents. It doesn't affect C++ code, but makes your study hours much more pleasant visually.