# Codex in JetBrains IDEs Source: https://www.youtube.com/watch?v=1XkVsE9-ZK4 Recap page: https://rapidrecap.app/video/1XkVsE9-ZK4 Generated: 2026-01-22T18:39:57.612+00:00 --- ## Quick Overview JetBrains has integrated OpenAI's Codex AI into its IDEs, allowing developers to use AI assistance for coding tasks like debugging, feature implementation, and localizing applications, demonstrated by successfully adding Spanish localization to the multiplatform KotlinConf App. **Key Points:** - Codex is now integrated directly within JetBrains IDEs (IntelliJ IDEA, Rider, WebStorm, PyCharm) for AI-assisted coding, requiring a ChatGPT subscription or API key for activation. - The demonstration uses the KotlinConf App, a Kotlin Multiplatform project, to showcase Codex's ability to assist with debugging and feature implementation across mobile, web, and desktop targets. - Codex successfully analyzed a build failure error related to missing SVG implementation for iOS, investigated relevant files (like Svg.ios.kt and build.gradle.kts), and suggested/applied a fix by adding an iOS actual for SVG. - The AI agent was prompted to add Spanish localization to the KotlinConf App, following a detailed set of requirements including platform-specific logic, resource setup, and adding a visible locale badge. - The agent performed extensive research across multiple project files (e.g., Platform.kt, strings.xml, BaseScreens.kt) in parallel with the developer's work, demonstrating efficient context awareness. - After applying changes, the agent successfully compiled the project for iOS Simulator (Arm64) and verified that the app launched with Spanish localization displayed on the home screen. - The Agent mode within Codex allows the AI to edit and run commands directly in the IDE, requiring user approval for potentially sensitive actions like running shell commands. ![Screenshot at 0:10: The title slide appears, announcing "Codex in JetBrains IDEs" and showing icons for IntelliJ \(IJ\), Rider \(RD\), WebStorm \(WS\), and PyCharm \(PC\).](https://ss.rapidrecap.app/screens/1XkVsE9-ZK4/00-00-10.jpg) **Context:** This video features two presenters from JetBrains demonstrating the integration of OpenAI's Codex AI within various JetBrains Integrated Development Environments (IDEs) such as IntelliJ IDEA, Rider, WebStorm, and PyCharm. The core concept being showcased is how developers can leverage this AI tool for complex, context-aware coding assistance, debugging build issues, and implementing new features directly within their development environment using either a subscription or API key. ## Detailed Analysis The video announces the integration of OpenAI's Codex into JetBrains IDEs, which supports IntelliJ IDEA, Rider, WebStorm, and PyCharm. Activation requires a ChatGPT subscription or API key. The presenters demonstrate Codex's capabilities using the KotlinConf App, a Kotlin Multiplatform project. Initially, they show Codex successfully debugging a build failure on the iOS target related to a missing SVG implementation; Codex analyzed the error, read related files like Svg.ios.kt, and provided a fix by adding an iOS actual implementation for SVG, which resolved the build issue. Next, they task the AI Agent (which requires user approval for running commands) with adding Spanish localization based on a detailed checklist, including updating shared strings, creating platform-specific logic for locale detection (using expect/actual), and implementing a visible locale badge on the Settings screen. The agent researched relevant files like strings.xml and Platform.kt, then applied numerous changes across shared and platform-specific modules. Upon re-running the build, the iOS simulator successfully launched with the operating system locale set to Spanish, verifying the feature's success. The presenters emphasize that the AI works concurrently and contextually within the IDE, requiring user approval for command execution in Agent mode, making complex, multi-file tasks manageable. ### Codex Integration Announcement - Codex is now available in JetBrains IDEs (IJ, RD, WS, PC) - Requires ChatGPT subscription or API key for activation - Demonstrated using the KotlinConf App, a Kotlin Multiplatform project. ### Debugging Build Failures - Codex successfully diagnosed and fixed an iOS build error caused by a missing SVG implementation in shared code - AI read Svg.ios.kt and build files to propose and implement a native iOS actual for SVG. ### Feature Implementation (Localization) - The Agent mode was tasked with adding Spanish localization based on a multi-point requirement list - Requirements included platform-specific locale detection, UI badge implementation, and string resource management. ### AI Research and Execution - Codex performed parallel research across multiple files (e.g., Platform.kt, strings.xml, BaseScreens.kt) to understand context - It executed Gradle commands to verify compilation for Android and iOS targets. ### Verification and Results - After code changes, the iOS simulator successfully launched with the system locale set to Spanish, confirming localization worked across platforms - The agent's actions were reviewed, showing file modifications across shared and platform-specific modules. ![Screenshot at 0:10: The title slide appears, announcing "Codex in JetBrains IDEs" and showing icons for IntelliJ \(IJ\), Rider \(RD\), WebStorm \(WS\), and PyCharm \(PC\).](https://ss.rapidrecap.app/screens/1XkVsE9-ZK4/00-00-10.jpg) ![Screenshot at 0:38: The project's README is displayed, showing screenshots of the KotlinConf App running on mobile and a map layout, while the AI Chat panel shows Codex describing the project.](https://ss.rapidrecap.app/screens/1XkVsE9-ZK4/00-00-38.jpg) ![Screenshot at 0:52: The IDE environment shows the project structure on the left, the video feed in the center, and the AI Chat panel on the right, where Codex is showing the build failure error message.](https://ss.rapidrecap.app/screens/1XkVsE9-ZK4/00-00-52.jpg) ![Screenshot at 2:22: The build output window shows a detailed error message: "FAILURE: Build failed with an exception" related to compiling for iOS Simulator Arm64.](https://ss.rapidrecap.app/screens/1XkVsE9-ZK4/00-02-22.jpg) ![Screenshot at 7:12: The AI Chat panel displays the list of files changed by the Agent, including updates to BaseScreens.kt, SettingsScreen.kt, ConferenceService.kt, and strings.xml, confirming the localization changes were implemented.](https://ss.rapidrecap.app/screens/1XkVsE9-ZK4/00-07-12.jpg)