Claude Code Ultraplan: What It Is, How It Works, and When to Use It

Anthropic shipped a feature called Ultraplan for Claude Code in early April, and it solves a specific problem: planning complex tasks in a terminal is awkward. You get scrollback, you get a wall of text, and your only real option is to accept, reject, or type a follow-up.

Ultraplan does something different. It moves the planning phase off your machine entirely, hands the task to a cloud container running Opus 4.6, and gives you a proper browser UI to review, comment on, and approve the plan before a single line of code changes.

What Ultraplan Actually Does

When you run /ultraplan migrate the auth service from sessions to JWTs, Claude Code spins up a remote session in Anthropic’s cloud infrastructure. That session gets access to a snapshot of your GitHub repository, dedicated compute, and up to 30 minutes of thinking time. Your local terminal stays free the entire time. You’re not blocked waiting for output.

When the plan is ready, a link appears in your terminal. Open it in a browser and you get four sections: a Context summary of what Claude understood about the project, a Shape of the Change overview with a high-level diagram, a list of files to create or modify, and Detailed Steps with code snippets and diffs for each proposed change.

The review UI is meaningfully better than reading terminal output. You can leave inline comments on specific passages, use emoji reactions to flag sections you want revised, and navigate a structured sidebar to jump between parts of the plan. If something’s wrong, you ask for a revision and Claude revises. When you’re satisfied, you pick what happens next.

The Two Execution Options

Once you approve a plan, you can either execute it in the cloud or pull it back to your local environment.

Cloud execution runs the implementation in the same web session, so when it’s done you get a diff view and a button to open a pull request. No local environment involved.

The second option, which Anthropic calls “teleport back to terminal,” returns the approved plan to your local Claude Code session for execution there. This is the right path when you need access to local tooling, internal dependencies, or things that don’t live in a public GitHub repository.

Requirements and Limitations

Ultraplan requires Claude Code v2.1.91 or later and a Pro or Max subscription. The feature is currently in research preview, so Anthropic may change behavior as it collects feedback.

The most significant constraint is GitHub only. If your repository is on GitLab, Bitbucket, or hosted internally without a public GitHub remote, Ultraplan won’t work. Local-only repositories are also out. This matters for teams with private infrastructure or organizations that don’t use GitHub for their main codebase.

The 30-minute thinking window is generous compared to what you’d typically get from a local plan command, but it also means Ultraplan is not the right tool for quick tasks. Running it on something simple wastes cloud compute and adds latency for no reason. The feature is designed for complex, high-stakes work where getting the plan right before touching any files is worth the overhead.

When to Use It vs. Local Plan Mode

Local plan mode (/plan) is still the right tool for daily tasks. It’s fast, doesn’t require GitHub, and works offline. For anything you’d treat as a routine refactor or a feature you’ve done a dozen times before, local planning is faster and gets you moving sooner.

Ultraplan’s value shows up on work where you’d want a senior review before starting: a large migration, a system redesign, a change that touches many files across multiple services. The browser review interface and revision workflow make it easier to catch a bad plan early, before hours of implementation work are built on a shaky foundation.

The third use case is parallelism. Because planning runs in the cloud without blocking your terminal, you can kick off an Ultraplan session and keep working locally on something else. When the plan lands, you review it and decide whether to proceed.

How It Shipped

Ultraplan was first referenced in leaked Claude Code source code in late March 2026, along with several other features that appeared in the npm source map. It entered early preview in Week 15 (April 6-10) and is documented in Claude Code’s official docs.

The feature requires a connected GitHub account and at least a Pro subscription. If you’re on Claude Code today and haven’t seen it, check your version with claude --version and update if you’re below 2.1.91.

Sources: Claude Code Docs, Better Stack, DevOps.com, The Decoder