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Claude Code quietly entered a new “ultra” prefix era. Ultraplan is now available in early preview: it takes a planning task from your terminal, runs it on Opus 4.6 in Anthropic’s Cloud Container Runtime for up to 30 minutes, and delivers a structured plan to a browser editor where you review, comment, and choose how to execute. Your terminal stays free the entire time.
Here is what builders need to know before switching it on.
What Ultraplan Actually Does
A normal Claude Code planning run happens locally in your terminal window. It uses whatever model is currently active, competes with your other terminal work for attention, and produces output inline. If you step away, the context is idle.
Ultraplan breaks that coupling. When you trigger it:
- Claude Code hands the task to the cloud. A remote session spins up in Anthropic’s Cloud Container Runtime using Opus 4.6. Your local terminal polls for status every 3 seconds, but it’s otherwise free.
- The remote session clones your repo from a point-in-time GitHub snapshot, reads the codebase, and generates a structured plan: steps, dependencies, expected tool calls, output shapes, and error-handling branches.
- The plan lands in a browser editor. You open it on
claude.ai/code, read the structured plan, add inline comments, flag concerns, ask for revisions, and approve or reject sections. - You choose where to execute. Locally in your terminal (full observability), remotely in Anthropic’s cloud (laptop can be off), or start a fresh local session with just the approved plan as context.
The planning session runs for up to 30 minutes. For most architecture and migration tasks, that’s generous. For the very largest monorepo-scale plans, it may not cover everything.
Three Plan Variants (You Don’t Choose)
Analysis of the Claude Code source reveals that Ultraplan runs three internally distinct variants, assigned dynamically — appearing to use A/B routing:
| Variant | What it produces |
|---|---|
| Simple Plan | Straightforward step-by-step breakdown, fast |
| Visual Plan | Steps plus diagrams for system relationships |
| Deep Plan | Uses subagents for multi-perspective analysis; slower, most thorough |
You don’t select the variant. If your task consistently gets Simple Plan and you believe it warrants Deep Plan, there is no flag to override this. This is a research preview tradeoff.
How to Enable and Trigger
Requirements:
- Claude Code v2.1.91 or later
- Claude Claude on the web account: Pro, Max, Team, or Enterprise
- Repository hosted on GitHub (GitLab and Bitbucket are not supported)
- Does not work on Amazon Bedrock, Google Cloud Vertex AI, or Microsoft Foundry deployments
Enable the preview:
claude ultraplan --enable-preview
Three trigger methods:
/ultraplan <your prompt>— explicit command, cleanest control- Include the word “ultraplan” anywhere in a normal prompt — Claude detects the intent
- At the end of a local plan, when Claude shows the approval dialog, choose “No, refine with Ultraplan on Claude Code on the web” — sends the draft to cloud for expansion
The Web Editor
Once the cloud session finishes, the plan appears in a structured browser editor at claude.ai/code. Key features:
- Inline comments — attach notes to specific steps
- Outline sidebar — jump between sections of long plans
- Revision requests — ask the plan to be rewritten before approving
- Approve or reject — gate execution on your explicit sign-off
This is the human-in-the-loop gate. For teams, the browser link is shareable — multiple engineers can review and comment asynchronously before anyone triggers execution.
After Approval: Three Execution Paths
| Path | What happens |
|---|---|
| Execute locally | Plan runs in your terminal with full Claude Code observability. Tool calls, file changes, and errors stream live. Your local environment and credentials are available. |
| Execute remotely | Plan runs in Anthropic’s cloud. You can close your laptop. Results surface in the browser interface. |
| Start fresh with plan | Opens a new local session using only the approved plan as context. Clears prior conversation. Best when the original planning context was long or noisy. |
Most builders will use execute locally for tasks touching local credentials, databases, or unpublished code. Remote execution makes sense for pure refactors on a clean main branch where the full codebase is on GitHub.
Hard Limitations
Point-in-time snapshot. The cloud session clones your repo at the moment you launch Ultraplan. Changes you make locally after launch are invisible to the planning session. If you are actively editing while the plan runs, you may get a plan that refers to code you’ve already changed.
GitHub only. No GitLab, no Bitbucket, no local-only repos. If your team uses anything else, Ultraplan is not available.
Remote Control conflict. Ultraplan and Claude Code’s Remote Control feature both use the claude.ai/code interface. They cannot run simultaneously. Launching Ultraplan disconnects any active Remote Control session.
No third-party provider support. Bedrock, Vertex AI, and Microsoft Foundry deployments cannot use Ultraplan. It requires direct Anthropic API access through the Claude on the web account.
30-minute cap. Generous for most tasks, but the largest multi-service migrations may exceed it. Deep Plan variant exacerbates this.
Ultraplan vs Ultrareview
Both carry the “ultra” prefix — both offload heavy compute to Anthropic’s cloud — but they serve different phases:
| Feature | Purpose | When to use |
|---|---|---|
| Ultraplan | Cloud-based planning: generates structured execution plan | Before implementation, when planning is the hard part |
| Ultrareview | Multi-agent code review: Security + Performance + Maintainability passes in parallel | After implementation, to find real bugs with independent verification |
They are complementary. A natural workflow: Ultraplan before a big refactor → implement locally → Ultrareview when done.
Builder Decision Table
| Situation | Use Ultraplan? |
|---|---|
| Migration affecting 20+ files across multiple services | Yes — planning is the hard part |
| Architectural decision with multiple valid approaches | Yes — Deep Plan may surface tradeoffs you’d miss |
| Team needs async plan review before execution | Yes — shareable browser link is the key feature |
| You want terminal free while planning runs in background | Yes — the primary value proposition |
| Quick 3-file refactor you already understand | No — local plan is faster |
| Repo on GitLab or Bitbucket | No — not supported |
| Bedrock / Vertex / Foundry deployment | No — not supported |
| Your local working tree has uncommitted changes that matter | No — cloud session won’t see them |
| Active Remote Control session | No — conflict; pick one |
Action Items
- Update Claude Code to v2.1.91+ before trying to enable the preview
- Confirm your Claude account tier — Pro, Max, Team, or Enterprise required (Free tier cannot use Ultraplan)
- Enable the preview:
claude ultraplan --enable-preview - Pick a real planning task — not a toy refactor. Ultraplan’s value is most visible on tasks where you’d normally spend 20-30 minutes mapping dependencies before writing a line of code
- Share the browser link with a teammate if your team reviews implementation plans before execution — the async review flow is the feature that Local Plan Mode cannot match
- Plan your repo snapshot timing — commit and push the state you want the cloud session to see before triggering Ultraplan
Ultraplan is in early preview, which means the plan variant routing is opaque, the 30-minute cap is fixed, and the GitHub-only constraint is unlikely to change soon. Within those boundaries, for any team doing large agentic refactors, it is worth enabling now.