Undo AI

Undo gives AI agents the runtime context they need to investigate complex problems and answer questions about what your program actually did. The agent replays an Undo recording, a deterministic recording of runtime execution, through Undo’s time travel debugging capabilities. As a result, the AI agent sees not just the source code, but the values the program produced, the paths it actually took, and the order in which things happened.

Two ways to use it

You can use Undo from your AI agent or in UDB.

• From your AI agent: configure your AI agent (such as Claude Code, Codex, Cursor, GitHub Copilot in Visual Studio Code, etc.) to use the MCP server shipped with the Undo Suite. The agent decides on its own when to investigate an Undo recording and what tools to use.

• In UDB: load a recording or start a program in UDB as usual and use the ai command to ask questions inline. UDB starts Claude Code under the hood and shows you the answer in the same session.

The How it works page describes the underlying mechanism and lists the kinds of investigation Undo can help with.

Your data and your IP stay with you

When you use Undo from your AI agent, all traffic stays between your machine and the LLM provider that your AI agent is already configured to use. Undo’s servers are not in the loop (except for the existing usage statistics), so anything you would already share with your AI agent, and only that, is what is shared.

Requirements

The AI features of Undo require:

• A modern AI agent capable of acting as an MCP client (for example Claude Code, Codex, Cursor, GitHub Copilot in Visual Studio Code, etc.). You also need access to a sufficiently capable model through that AI agent, since the quality of the analysis depends heavily on the underlying model; we have seen good results with current-generation models such as Claude Sonnet 4.5+, Claude Opus 4.5+, or GPT 5.3+.

• An Undo Suite installation on a Linux machine that has the source code and debug symbols for the program being investigated.

• An Undo license that has the AI features enabled.

Warning

AI features are not enabled in every license. If the ai command in UDB or the undo mcp server reports that AI is disabled, contact support@undo.io to upgrade your license.

If AI is not available for your license, you can still use the simpler explain add-on from the Undo add-ons repository, which covers a subset of the use cases without requiring an AI-enabled license.