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Cambridge, UK – June 24, 2026 

Undo, the technology that gives developers the runtime context needed to solve the most challenging problems in the most complex codebases, today announced the release of its new AI capability. Undo AI makes coding agents more powerful by enabling them to find the root cause of even the most challenging and elusive bugs automatically.

It can take skilled engineers days, weeks, or sometimes even years to track down complex problems in large codebases, and AI coding agents alone are unequal to the task. The cause of these problems often lies in the precise details of what the program does at runtime, which source code analysis and logs cannot reveal. Until now, coding agents have been unable to see this detail – relying on static context from source code and documentation. As a result, AI agents fill the gap with a plausible guess and frequently hallucinate an answer that looks right but is not. The hardest problems – the intermittent failures and state-dependent bugs that live in complex, multithreaded, multiprocess systems – therefore remain unsolved, no matter how capable the model is.

With Undo AI, agents can now combine the static context (what the code says) with the dynamic, runtime context (what the program does). They have a deterministic recording of runtime execution that contains the information needed to solve problems with certainty. Undo records exactly what a program did as it ran: every variable, line of code, and instruction, so the agent can query that information to work out why something happened. Instead of guessing, or making up the cause of a problem, the agent reasons from what took place.

Undo AI enables engineering teams to:

• Identify the root cause of long-standing production bugs that have gone unsolved for months or years.
• Resolve failing tests quickly and automatically, so engineers can close the tickets and move on to work that drives more value.
• Track down the source of bad data flowing through systems with many interacting processes.
• Diagnose hard-to-reproduce issues such as intermittent failures, memory corruptions or concurrency issues in highly complex environments.
• Pinpoint the root cause of subtle issues by comparing a working and a broken recording, where the agent alone cannot find the problem.
• Automate bug triage, with agents able to execute an initial analysis of a recording – even if the developer isn’t online.

“AI agents don’t have an intelligence problem, they have a context problem,” said Greg Law, co-founder and CEO of Undo. “No matter how capable a model is, it can only reason about what it can see. When it cannot see what the program did at runtime, it’s left to guess, which is where hallucinations come from. We’ve spent years building deterministic recording technology that captures precisely what happened inside a running program. AI has now made that capability essential. With Undo AI, engineers can hand their agent that ground truth, so it can stop guessing and start reasoning about runtime behaviour the same way it can reason about static code.”

Undo AI plugs into any coding agent an engineering team already uses, including Claude Code, Codex, Cursor and GitHub Copilot in Visual Studio Code. Once the agent is connected to the Undo MCP server, it decides for itself when to investigate, when to capture a recording, and which tools to call. Each recording is deterministic, self-contained and portable, so a problem captured in development, test or production can be handed to the agent and replayed anywhere, behaving identically every time.

“As AI writes more of the code running in critical systems, someone still has to be accountable for it. However, you can’t be accountable for something you don’t understand,” continued Law. “Undo lets engineers see exactly what AI-generated code did and why, so they can put agents to work on solving their hardest problems with confidence rather than blindly trusting them. It makes Sonnet work like Opus, closes the gap between Opus 4.8 and Fable 5, and supercharges Mythos’ ability to analyze and understand code behavior. This means teams get to answers faster and stay firmly in control of how their software behaves.”

Undo AI is generally available today as part of the Undo Suite and works with any coding agent that supports MCP.

Teams can connect it to their existing agent or start a free trial.

About Undo

Undo makes AI coding agents effective on the software that matters most. By capturing a full recording of how a program executed and making that behaviour queryable, Undo lets agents automatically pinpoint the cause of failures that would otherwise defeat them and gives engineers the visibility to review and answer for the code their agents produce. The payoff is faster resolution of difficult issues, fewer outages, and code that stays maintainable even as agents generate more of it. Trusted by engineering teams at companies including AMD, AWS, Bloomberg, Palo Alto Networks, SAP, Cadence, Siemens EDA and Synopsys, Undo is headquartered in Cambridge, UK.