MCP-Reborn

MCP-Reborn is a Java-based MCP tool designed to assist in creating and researching modded clients for Minecraft. It builds upon MCPConfig and ForgeGradle to decompile Minecraft, expose its code, and allow you to modify and repackage a modded client. The typical workflow is to import the project into an IDE using Gradle, run the setup task to generate decompiled sources, then modify code as needed and use the runclient task to test changes in a Minecraft client. After you’re satisfied, you can build a new JAR that corresponds to a modded version and integrate it with a Minecraft installation via the standard version JSON and JAR replacement steps described in the repository’s guidance. The tool is version-aware, with compatibility notes indicating required Java Development Kit (JDK) versions per Minecraft range.

Key tools you’ll interact with include:

• Gradle tasks such as setup and runclient to generate and test a decompiled client.
• The generated decompiled source in the project’s src directory for modification.
• The build task to produce a runnable modded JAR and the process to integrate it into a Minecraft version folder for launcher use.
• Documentation and project structure within the IDE to navigate decompiled Minecraft code and custom changes.

Prerequisites:

• Java Development Kit (JDK) matching the Minecraft version range you plan to modify (e.g., JDK 16 for 1.17+, JDK 17 for 1.18+, JDK 21 for 1.21+).
• Gradle (usually managed by the project scripts).
• A compatible development environment (e.g., IntelliJ IDEA).

Installation steps:

1. Clone the MCP-Reborn repository: git clone https://github.com/Hexeption/MCP-Reborn.git cd MCP-Reborn

2. Ensure you have a compatible JDK installed for your target Minecraft version. Set JAVA_HOME accordingly.

3. Import the project into your IDE as a Gradle project, or use the command line to build/setup: ./gradlew setup // This will generate the decompiled source in the src directory.

4. Open the Gradle tasks panel and locate the mcp setup task. Run it to generate the decompiled sources that you can modify.

5. Modify the source code as desired within the src folder.

6. To test changes, run the Gradle task: ./gradlew runclient // This compiles and launches a Minecraft client based on your current changes.

7. Once you are satisfied with your changes, generate a runnable JAR: ./gradlew build // The new JAR will appear in build/libs/.

8. Follow the repository’s instructions to integrate the new JAR with a Minecraft version folder (copy assets, data, pack files as needed, adjust the version JSON, and place the new JAR in the version folder).

9. Launch Minecraft and select the custom version you created to test your modded client.

Notes:

• The exact steps may vary slightly depending on the target Minecraft version and your IDE. Always consult the README for version-specific notes and any environment variable requirements.

Tips and common issues:

• Never publish code generated or modified with MCP-Reborn; the repository explicitly warns that generated code cannot be published.
• Ensure you are using the correct JDK version for your target Minecraft version to avoid compilation or runtime issues.
• If the Gradle setup task fails, verify that your environment has adequate permissions and that your JAVA_HOME points to a valid JDK installation.
• When modifying the launcher integration, keep a backup of the original version folder to avoid corruption of your Minecraft installation.
• If you encounter issues running the client, re-run the setup task to regenerate sources, then rebuild to ensure changes are correctly compiled and linked.
• The build process produces a JAR that must be placed in the corresponding Minecraft version folder along with the required assets and data folders.
• Refer to the project’s Gradle tasks and the images linked in the README for UI guidance during setup in your IDE.