GitHub Copilot app modernization FAQ

We recognize that the migration process is always complex and intertwined, with different layers of app ecosystems. At this time, we're limiting the migration scope to Java backend apps. We support projects that are built with Maven or Gradle. For information about key product capabilities, see the GitHub Copilot app modernization overview.

We currently have no plans to open source GitHub Copilot app modernization.

GitHub Copilot app modernization is available to Pro, Pro+, Business, or Enterprise plan.

GitHub Copilot app modernization is a feature of GitHub Copilot, and shares the same subscription billing model as GitHub Copilot. App modernization tasks consume premium requests, with each subscription plan offering a monthly allowance of premium requests. Exceeding the plan limit requires a plan upgrade or extra purchase of premium requests.

Currently, GitHub Copilot app modernization is focused on assisting with Java and .NET applications. However, we're actively collecting requirements and feedback from customers regarding the need to support other languages.

No. GitHub Copilot app modernization uses GitHub Copilot in the same way you use it to modify code, which doesn't retain code snippets beyond the immediate session. We don't collect, transmit, or store your custom tasks either.

Telemetry metrics are collected and analyzed to track feature usage and effectiveness.

For more information, see the Microsoft Privacy Statement.

We tested GitHub Copilot app modernization on hundreds of open-source repositories to ensure build, consistency, and unit tests pass after the modernization process. We also worked extensively with customers during the Technical Preview phase. Input from users is used to improve the product experience. You can submit feedback using this link.

Although GitHub Copilot app modernization focuses on upgrading Java runtimes, it also optimizes upgrades for the following frameworks:

• Spring Boot up to version 3.5.
• Java EE - Javax to Jakarta EE, up to Jakarta EE 10.
• Legacy Spring Framework up to version 6.2+.
• JUnit.
• Various third-party dependencies.

For more information, see Customize the Java project upgrade plan.

We currently support the following Java Development Kit (JDK) versions:

• JDK 8
• JDK 11
• JDK 17
• JDK 21

The minimum required JDK version for a project is JDK 8, and you can upgrade the project to use any version up to JDK 21.

Currently, only the following project types are supported:

• Maven projects (including Maven Wrapper)
• Gradle projects (Gradle Wrapper only, version 5+)

Kotlin DSL-based Gradle projects aren't supported.

Currently, the extension has the following functional limitations:

• The extension exclusively supports Java upgrades and doesn't cater to other programming languages.
• It works only with Java projects built using Maven and Gradle.
• Only Git repositories are supported. Other version control systems aren't compatible.
• The extension can't guarantee that the changes it proposes are optimal or considered best practices.

We recommend using the following best practices with this tool:

• Run the extension only on projects that meet the specified characteristics as previously described.
• Complete thorough code reviews before merging extension output into production branches.
• Run all tests and complete the usual QA checks associated with your change management process as appropriate.

You can use the AppCAT CLI to scan multiple projects at the same time by using the -bulk flag. However, we recommend that you only modernize one project or app at a time. You can create your own migration task based on code changes from one project and apply them to other projects, reducing repetitive work.

As a general rule of thumb, newer models outperform previous models. For coding tasks, we recommend Claud Sonnet models for better accuracy. However to reduce cost, consider starting your exploration from models with a lower multiplier.

For detailed model specifications, see the GitHub Copilot documentation.

To ensure successful Java runtime and framework upgrades, the following information is required:

• The Project type. The project must be a Git-based Java project buildable with Maven or Gradle.
• The target Java version - the JDK version you want to upgrade to - for example, Java 21.
• The source and target JDK paths - the paths to the installed JDKs for the current and target versions.
• The Maven/Gradle setup - paths to the Maven/Gradle build tools. For Gradle, only Gradle wrappers are supported.

GitHub Copilot app modernization uses the MCP server to enhance code transformation capabilities. After you install the Visual Studio Code extension, the MCP server is registered and starts automatically.

If you notice a special refresh button in the bottom-right corner of the GitHub Copilot Chat panel, it might indicate that tool updates are available. Select the button to automatically load the latest versions of the tools.

The GitHub Copilot app modernization MCP server also maintains logs. To troubleshoot, check the log files located at: %USERPROFILE%/.ghcp-appmod-java/logs

Sometimes, GitHub Copilot app modernization requires explicit confirmation before proceeding. You can type yes or continue in the chat to enable the agent to move forward with the code modifications.

To ensure safer operations, the GitHub Copilot agent repeatedly asks for user confirmation. As a workaround, you can select the dropdown arrow next to the Continue button and then select Always Allow, or update your Visual Studio Code setting chat.tools.autoApprove to true to automatically approve all tools. We also recommend configuring chat.agent.maxRequests to 128 to reduce the number of steps that require confirmation to continue.

To ensure that the extension works correctly within Visual Studio Code, network connectivity must be stable and allow access to GitHub Copilot services. In restricted environments, you might need to configure proxy or firewall rules accordingly. If you encounter errors like "Language Model Unavailable" in the chat window, see the official troubleshooting guide Managing GitHub Copilot access to your enterprise's network.

GitHub Copilot might block certain code generations for files that commonly resemble public code, such as pom.xml. To prevent Copilot from blocking these changes, you must allow suggestions matching public code. For instructions, see Enabling or disabling suggestions matching public code.

To manage the settings for GitHub Copilot in your organization, see Enabling Copilot features in your organization.

GitHub Copilot app modernization uses the MCP server to provide specialized migration functionalities. When you select Refresh, it establishes a connection with this server and updates the available tools in the chat agent. This action is only necessary in the following cases:

• When you open a Java project for migration for the first time.
• When you upgrade the extension to a newer version.

GitHub Copilot app modernization is powered by AI, so occasional errors might occur. Always review the output carefully before use. You can also retry the regeneration process to see alternative code suggestions.

Predefined tasks are in the following location: %USERPROFILE%.vscode\extensions\microsoft.migrate-java-to-azure-0.1.0\rag

Custom tasks are in the following location: %USERPROFILE%.azure\migrate-copilot\custom-rule

The agent always includes explanations for its code changes in the chat window. However, these details might be collapsed in the UI. You can expand the response in the chat to see the full rationale and step-by-step reasoning.